boiler istructional manual.pdf

OWNER:

JSW ENERGY（VIJAYANAGAR） LIMITED

OWNER CONSULTANT:

TATA CONSULTANCY ENGINEERS LIMITED

BTG PACKAGE FOR 2×300 MW Coal Based

Thermal Power Station at Toranagallu, Bellary

1015t/h SUBCRITICAL PRESSURE NATURAL CIRCULATION BOILER

产品说明书 INSTRUCTION FOR BOILER

DOCUMENT NO. 730-1-8601 Rev No. 0 CONTRACTOR: SHANGHAI ELECTRIC GROUP CO., LTD.

SUBCONTRACTOR: 上海锅炉厂有限公司

SHANGHAI BOILER WORKS, LTD

SHANGHAI BOILER WORKS,LTD.

1015t/h SUBCRITICAL PRESSURE

NATURAL CIRCULATION BOILER

BTG PACKAGE FOR 2 x 300 MW COAL BASED THERMAL POWER STATION AT TORANAGALLU ,

BELLARY

DOCUMENT NO.: 730-1-8601 Page 1 of 1

上海锅炉厂有限公司SHANGHAI BOILER WORKS,LTD.

DOCUMENT CONTROL SHEET

PROJECT ： BTG PACKAGE FOR 2×300MW COAL BASED THERMAL POWER STATION at TORANAGALLU BELLARY CLIENT ： JSW ENERGY（VIJAYANAGAR） LIMITED

DOCUMENT TITLE ：产品说明书 INSTRUCTION FOR BOILER DOCUMENT NO ： 730-1-8601 REV. NO. ： 0 ENDORSEMENTS

REV. NO. DATE DESCRIPTION

PREP. BY SIGN.（INITIAL）

REVW. BY SIGN.（INITIAL）

APPD . BY SIGN.（INITIAL）

Product Description 730-1-8601

1

产品说明书 INSTRUCTION FOR BOILER

产品型号 SG-1015/17.5-M730 MODEL OF PRODUCT

产品名称 1015t/h 亚临界压力自然循环锅炉 NAME OF PRODUCT 1015t/h SUBCRITICAL PRESSURE

NATURAL CIRCULATION BOILER 编号 730-1-8601 SERLES NO.

编制日期 PREPARED BY DATE 审核日期 2 0 0 8 . 1 1 . 0 4 CHECKED BY DATE 审定日期 REVIEWED BY DATE 批准日期 APPROVED BY DATE

上海锅炉厂有限公司

SHANGHAI BOILER WORKS, LTD.

2008 年 11 月


2

Content

Foreword .............................................................................................................................................4

1 Boiler Design Condition and Technical Data.................................................... 7

1.1 Design Parameters of Boiler......................................................................... 7

1.2 Fuel .............................................................................................................. 7

1.3 The Steam and Water Quality Standard................................................... 10

1.4 Environmental Condition .............................................................................11

1.5 Boiler Operating Condition ......................................................................... 12

1.6. PERFORMANCE DATA (design coal) ....................................................... 13

2 Boiler General Arrangement and System ...................................................... 21

2.1 General....................................................................................................... 21

2.2 Steam & Water System .............................................................................. 25

2.3 Burning System .......................................................................................... 35

2.4 Flue Gas and Air System............................................................................ 38

2.5 Bottom Ash System .................................................................................... 38

2.6 Attamperation System ................................................................................ 39

2.7 Sootblowing System................................................................................... 40

2.8 Pipeline System.......................................................................................... 42

2.9 Arrangement for Ports and Measuring Points............................................. 45

3 Main Pressure Parts ...................................................................................... 46

3.1 Drum and Drum Internals ........................................................................... 46

3.2 Waterwall.................................................................................................... 55

3.3 Economizer ................................................................................................ 58

3.4 Superheater................................................................................................ 60

3.5 Reheater (RH) ............................................................................................ 64

3.6 SH and RH Control & Protection Maintenance........................................... 66

3.7 Desuperheater............................................................................................ 68

4 Others ................................................................................................................................69

4.1Steel Structure ............................................................................................. 69


3

4.2 Sealing and Insulation ................................................................................ 70

4.3 Air preheater (APH) .................................................................................... 70

5 Boiler Hydro Test ........................................................................................... 71

5.1 The Pressure of Hydro Test ........................................................................ 71

5.2 Water Quality.............................................................................................. 71

5.3 Notices ....................................................................................................... 71

5.4 Water Volume of Boiler Pressure Parts ...................................................... 72


4

Foreword

1015t/h subcritical pressure boilers in India BTG PACKAGE For 2×300MW

COAL BASED THERMAL POWER STATION at TORANAGALLU is optimized

the design and manufactured by Shanghai Boiler Words Ltd.(SBWL). The

design and manufacture is on the basis of 300MW subcritical pressure natural

circulation boiler, following the principle of "Make excellent boiler, build famous

brand".

The close considerations in boiler design:

(1) High available rate，

(2) High thermal efficiency and lesser air-heater leakage，

(3) Better control and regulating performance, flexible and reliable

control, low steam temperature deviation as much as possible，

(4) Better flexibility with coal range, stable combustion within the regular

change of fuel, safe and reliable，

(5) Better part load stable combustion performance and better start-up

and peak load performance，

(6) Mature structure with increased universal parts and components.

This instruction gives a detailed introduction of boiler performance, general

arrangement, and other systems and main pressure parts. Except this,

installation instruction, operation instruction and related equipment instruction

are also offered. instruction list as follows:

序号 ITEM No.

编号 SERIES No. 名称 DESCRIPTION

1 730-1-8301 锅筒强度计算书汇总

DRUM STRENGTH CALCULATION SUMMARY

2 730-1-8302 集箱强度计算书汇总

HEADER STRENGTH CALCULATION SUMMARY

3 730-1-8401 安全阀整定压力及排放量汇总

SAFETY VALVE SET PRESS. & CAPACITY SUMMRY

4 730-1-8701 热力计算汇总

THERMAL CALCULATION SUMMARY

5 730-1-8702 管子金属壁温及强度计算汇总


5

序号 ITEM No.


TUBE & PIPING METAL TEMP. & STRENGTH CALCULATION SUMMARY

6 730-1-8703 汽水阻力计算汇总

STEAM & WATER PRESSURE DROP CALCULATION SUMMARY

7 730-1-8704 循环系统性能计算汇总

EVAPORATION CIRCULATION CALCULATION SUMMARY

8 730-1-8705 烟风系统阻力计算汇总

GAS & AIR PRESSURE DROP CALCULATION SUMMARY

9 730-1-8601 产品说明书

INSTRUCTION FOR BOILER

10 730-1-8602 锅炉使用说明书

INSTRUCTION FOR BOILER OPERATING

11 730-1-8603 钢结构说明书

INSTRUCTION FOR STEEL STRUCTURE

12 730-1-8604 锅炉保护限定值

PROTECTING LIMIT VALUE FOR BOILER

13 730-1-8607 炉墙与保温说明书

INSTRUCTION FOR INSULATING

14 730-1-8608 锅炉安装说明书

INSTRUCTION FOR BOILER ERECTION

15 680197-1-8661 煤粉燃烧设备说明书

INSTRUCTION FOR COAL FIRING EQUPMENT

16 730-1-8609 安全阀说明书

INSTRUCTION FOR SAFETY VALVE

17 730-1-8610 动力泄放阀说明书

INSTRUCTION FOR ERV

18 730-1-8611 调节阀说明书

INSTRUCTION FOR CONTROL VALVE

19 730-1-8612 截止阀、闸阀说明书

INSTRUCTION FOR SHUT OFF & GATE VALVE


6

序号 ITEM No.


20 730-1-8613 炉膛火焰电视说明书

INSTRUCTION FOR FURNACE FLAME TV MONITOR SYSTEM

21 730-1-8614 锅筒水位电视说明书

INSTRUCTION FOR DRUM WATER-LEVEL TV MONITOR SYSTEM

22 730-1-8615 水位表说明书

INSTRUCTION FOR WATER LEVEL GAUGE

23 730-1-8616 吹灰器本体说明书

INSTRUCTION FOR SOOTBLOWER

24 730-1-8617 吹灰管路系统说明书

INSTRUCTION FOR SOOTBLOWER PIPING SYSTEM

25 730-1-8618 烟温探针说明书

INSTRUCTION FOR TEMP. PROBE

26 770059-2-7201 预热器供应客户技术文件清单

DOCUMENT LIST OF AIR PREHEATER FOR CUSTOMER


7

1 Boiler Design Condition and Technical Data

The design coal and worst coal for the boiler are medium volatile bituminous

coal. The boiler is subcritical pressure, single reheat, natural circulation, single

furnace, balanced draft, tangential firing, corner arranged tilting burner, solid

slag extraction, open air arrangement, all steel structure, monitor roof and

direct fired pulverized coal system with middle speed mill .

1.1 Design Parameters of Boiler

Name Unit BMCR BECR

SH steam flow t/h 1015 913.6

Outlet pressure of SH MPa(g) 17.47 17.30

Outlet temperature of SH steam

oC 541 541

RH flow t/h 840.7 761.9

Inlet steam pressure of RH MPa(g) 3.72 3.37

Outlet steam pressure of RH MPa(g) 3.52 3.19

Inlet steam temperature of RH

oC 323 313

Outlet steam temperature of RH

oC 541 541

Water temperature at ECON inlet

oC 279 273

1.2 Fuel 1.2.1 Coal Quality Data

The coal quality analysis of design coal and worst coal


8

Sl.No Proximate Analysis

Design coal Worst Coal

1 Fixed Carbon % 54.82 41.59

2 Volatile Matter % 23.02 20.09

3 Moisture % 11.04 15.01 4 Ash % 11.12 23.31

5 Higher Heating Value Kcal/Kg

6300 5977(LHV)

5000 4679(LHV)

Ultimate Analysis

1 Carbon % 64.64 49.19

2 Hydrogen % 4.75 4.24

3 Sulphur % 0.30 0.46

4 Nitrogen % 2.24 1.39

5 Oxygen % 5.94 6.40

6 Moisture % 11.04 15.00

7 Ash % 11.12 23.32

8 Grindability index (HGI)

53 45

9 Initial Deformation TEMP. C

1180

10 Hemispherical TEMP.

1240 <1400

11 Fluid Deg. C 1290 <1400

12 Crucibie swelling index (FSI)

>1

13 Bulk Density 0.91


9

Ash characteristics %/Wt Design coal Worst coal

1 Silico 53.3 37.0

2 Alumina 35.3 45.8

3 Ferric Oxide 4.0 10.7

4 Calcium Oxide 2.2 1.69

5 Magnesium Oxide 0.50 0.44

6 Sodium Oxide 0.30 0.08

7 Potassium Oxide 0.50 0.29

8 Titanium Oxide 1.40 1.27

9 Phosphate pent Oxide 1.30 0.67

10 Sulphur Trioxide 0.40 0.94

11 Undetermined 1.1

Sieve Analysis +60 Mesh 02-0.4% +120 Mesh 2.5-6.5% +200 Mesh 8-11% -200 Mesh 80-90% Un-burnt % 4.0-18.0

1.2.2 Ignition and Combustion Supporting Oil

LDO ANALYSIS 1.0 LIGHT DIESEL OIL (LDO) ANALYSIS AS PER IS 1460, 1995 1.1 Viscosity at 40 Cst 2.5 to 15.7 1.2 Density at 15 kg/m3 920 1.3 Flash point, Min 66 1.4 Pour point, Max. 12 for Winter 21 for summer 1.5 Water content, Max. % vol. 0.25 1.6 Sediment, Max. % wt 0.05 1.7 Sulphur, Max. % wt 1.8 1.8 Ash content, Max. % wt 0.02 1.9 Gross calorific value (Approximate) Kcal/kg 9950

ANALYSIS OF HEAVY FUEL OIL (HFO)


10

Sl. No. Particulars Unit Furnace Oil

Grade MV2 (IS : 1593)

1. Flash point Deg. C min. 66 2. Viscosity @ 150C Maxi. Cst 180 3. Pour point 21 4. Ash content by weight % max. 01 5. Free Water content by volume % max. 1.0 6. Sediments by weight % max. 0.25 7. Total sulphur by weight % max. 4.0 8. Calcium PPM 30.5 9. Sodium PPM 10

10. Lead content PPM 0.2 11. Vanadium PPM 40.50 12. Carbon residence (Rams bottom) % wt 7.74 14. Approximate gross calorific value Kcal/kg 10,000

15.0 SP gravity at 15 Max. 0.933

1.3 The Steam and Water Quality Standard

1.3.1 The quality standard of feedwater To ensure steam quality, the boiler feedwater should be strictly controlled

according to the following quality standard.

Boiler feedwater quality should comply with quality standard.

(GB/T12145-1999 “Quality criterion of water and steam for thermal

generating unit and steam power equipment ”)

The quality of the feedwater in the operation should be higher than this

standard.

Rigidity ~0µmol/L

Conductivity ≤0.30 µS/cm

Oxygen ≤0.007mg/l

Iron ≤0.02mg/l

Cuprum ≤0.005mg/l

Hydrazine 0.01~0.05mg/l

PH value 9.0~9.5

Oil ＜0.3 mg/l


11

1.3.2 The Ensure Quality of Boiler Steam

The quality of boiler saturation steam and superheating steam should comply

with quality standard. (GB/T12145-1999 “Quality criterion of water and steam

for thermal generating unit and steam power equipment” )

1.4 Environmental Condition

1.4.1 Meteorological data

Annual average highest dry bulb temperature 32.9

Annual average lowest dry bulb temperature 22.2

Annual average highest wet bulb temperature 38.1

Annual average lowest wet bulb temperature 17.4

highest day average temperature 31.1

Lowest day average temperature 17.6

Ultimate highest temperature 40.8

Ultimate lowest temperature 14.6

Annual average rainfall 500mm

Highest relative humidity 73%

Lowest relative humidity 22%

Highest and lowest annual average humidity 73% 22%

Altitude 478.375m

Annual average wind speed 8.4km/hr

Annual average highest wind speed 14.8km/hr

Wind load

Calculations for wind effect shall be in accordance with

IS:875-1987(Part-3) taking into account the following:

a) Basic wind speed = 39 m/sec

b) Factor K1 = 1.07

c) Category of terrain = Category 2

d) K3 – as per IS 875

1.4.2 Earthquake The earthquake basic intensity at plant side, ZONE NO. II AS PER IS 893:2002.


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1.5 Boiler Operating Condition

a. Boiler supply a basic load, being capable of constant-sliding-constant

pressure operation. b. Boiler minimum stable load without oil support is 30%BMCR.

c. Boiler load continuous changing rates can reach following requirements

Constant pressure operation 5% BMCR/min

Sliding pressure operation 3% BMCR /min Load jump 10% BMCR /min

d. The time period required to start-up the unit shall not exceed the following

duration,

Cold start-up 6~8hours

Warm start-up 3~4hours

Hot start-up 1.5~2 hours

e. Boiler ignition, HEA-LDO-HFO-coal .

f. NOx emission at 100%TMCR with design coal is not higher than 650

mg/Nm3 .

g. It is ensured that steam temperature (SH,RH steam outlet temperature)

will reach design data within the load range from 60%BMCR to

100%BMCR. The temperature deviation is allowed to be +5/-10.

h. Furnace is normal operating at pressure -37.3Pa (-3.8mmH2O column).

Furnace water wall and buckstay are capable of withstanding transient

furnace pressure. The limit values show in following,

No. Item Unit value 1 Design furnace pressure Pa ±5230 2 Transient furnace pressure Pa ±8720 3 Furnace alarm pressure Pa ±996

+3240 4 Main fuel trip pressure Pa -2490


13

1.6. PERFORMANCE DATA (design coal)

序号项目单位 BMCR TMCR HPHO* 80%TMCR 60%TMCR 30%BMCR

ITEM NO. ITEM UNIT

CONSTANT PRESS. SLIDING PRESS.

1 主蒸气流量 t/h 1014.954 913.624 796.851 717.218 537.533 304.486

SH STEAM FLOW 2 过热汽出口压力 Mpa(g) 17.47 17.30 17.13 17.02 12.62 7.25

SH STEAM OUTLET PRESSURE 3 过热汽出口温度 oC 541 541 541 541 541 541

SH STEAM OUTLET TEMP. 4 再热蒸气流量 t/h 840.7 761.9 778.0 606.5 462.3 268.0

RH STEAM FLOW 5 再热器进口压力 Mpa(g) 3.72 3.37 3.51 2.67 2.02 1.14

RH STEAM INLET PRESSURE 6 再热器出口压力 Mpa(g) 3.52 3.19 3.32 2.53 1.91 1.08

RH STEAM OUTLET PRESSURE 7 再热器进口温度 oC 322.9 312.8 320.6 294.9 301.3 309.6

RH STEAM INLET TEMP. 8 再热器出口温度 oC 541 541 541 541 541 541

RH STEAM OUTLET TEMP. 9 给水压力 Mpa(g) 19.24 18.78 18.32 18.03 13.43 7.80

FEEDWATER PRESSURE 10 给水温度 oC 279 273 177 258 242 213

FEEDWATER TEMP.


14


ITEM NO. ITEM UNIT


11 减温水温度 oC 177 173 176 164 153 133

SPRAY WATER TEMP. 12 过热器喷水量（一级） t/h 8.10 22.50 83.90 37.90 32.40 19.00

SH SPRAY WATER FLOW（Primary)

13 过热器喷水量（二级） t/h 0 3 5 10 5 3

SH SPRAY WATER FLOW(Secondary) 14 再热器喷水量 t/h 0.0 0.0 0.0 0.0 0.0 0.0

RH SPRAY WATER FLOW 15 锅筒压力 Mpa(g) 18.84 18.43 17.99 17.73 13.17 7.57

DRUM PRESSURE 16 锅筒温度 oC 361.2 359.3 357.4 356.2 332.4 292.0

DRUM TEMPERATURE 17 排烟温度（修正前） oC 143.9 143.3 122.8 139.4 131.1 122.2

EXIT GAS TEMP. （UNCORRECT） 18 排烟温度（修正后） oC 138.3 136.7 118.3 133.9 124.4 112.8

EXIT GAS TEMP. （CORRECT）

19 高位热效率 % 88.79 88.82 89.75 88.65 88.97 88.78 HEAT EFFICIENCY (GCV)

20 燃料消耗量 t/h 112.0 103.0 105.7 84.4 65.4 39.4 FUEL CONSUMPTION

21 炉膛容积热负荷 103Kcal/h

m3 94.5 86.6 87.7 71.0 54.0 31.8


15


ITEM NO. ITEM UNIT


HEAT RELEASE RATE IN FURNACE VOLUME

22 炉膛断面热负荷 106Kcal/h

m2 4.21 3.86 3.91 3.17 2.41 1.42

HEAT RELEASE RATE IN FURNACE SECTION

23 燃烧器区热负荷 106Kcal/h

m2 1.30 1.19 1.21 0.98 0.74 0.44

HEAT RELEASE RATE IN BURNER AREA 24 净热输入 106Kcal/h 729.8 668.8 677.1 548.1 417.1 246.0 NET HEAT INPUT

25 燃烧器投运层数 \ 4 4 4 4 3 2 NUMBER OF NOZZLES IN SERVICE

26 过量空气系数 1.20 1.20 1.20 1.29 1.20 1.20 EXCESS AIR

墙式再热器进口蒸汽温度 oC 323 313 321 295 301 310 27

RH. WALL INLET STEAM TEMPERATURE

墙式再热器出口蒸汽温度 oC 383 378 381 369 381 402 28

RH. WALL OUTLET STEAM TEMPERATURE 29 分隔屏过热器进口蒸汽温度 oC 412 407 395 402 382 355

SH. DIV. PANEL INLET STEAM TEMPERATURE

30 分隔屏过热器出口蒸汽温度 oC 455 454 442 455 447 443 SH. DIV. PANEL OUTLET STEAM TEMPERATURE

31 后屏过热器进口蒸汽温度 oC 455 454 442 455 447 443


16


ITEM NO. ITEM UNIT


SH. PLATEN INLET STEAM TEMPERATURE

32 后屏过热器出口蒸汽温度 oC 509 512 508 521 523 537

SH. PLATEN OUTLET STEAM TEMPERATURE

33 屏式再热器进口蒸汽温度 oC 383 378 381 369 381 402 RH PLATEN INLET STEAM TEMPERATURE

34 屏式再热器出口蒸汽温度 oC 476 475 476 473 483 499

RH PLATENOUTLET STEAM TEMPERATURE

35 末级再热器进口蒸汽温度 oC 476 475 476 473 483 499 RH FINISH INLET STEAM TEMPERATURE

36 末级再热器出口蒸汽温度 oC 541 540 540 540 539 541 RH FINISH OUTLET STEAM TEMPERATURE

37 末级过热器进口蒸汽温度 oC 509 509 502 508 513 525 SH FINISH INLET STEAM TEMPERATURE

38 末级过热器出口蒸汽温度 oC 541 541 541 541 541 541 SH FINISH OUTLET STEAM TEMPERATURE

39 低过垂直部分进口蒸汽温度 oC 406 408 436 417 408 394 SHLT. PENDANT INLET TEMP.

40 低过垂直部分出口蒸汽温度 oC 416 419 452 430 423 412 SHLT. PENDANT OUTLET TEMP.

41 低过水平部分进口蒸汽温度 oC 364 363 364 362 342 309

SHLT. HORIZ INLET STEAM


17


ITEM NO. ITEM UNIT


TEMPERATURE

42 低过水平部分出口蒸汽温度 oC 406 408 436 417 408 394

SHLT HORIZ OUTLET STEAM TEMPERATURE

43 省煤器进口水温度 oC 279 273 177 258 242 213 ECONOMIZER INLET WATERTEMPERATURE

44 省煤器出口水温度 oC 303 298 237 289 273 246

ECONOMIZER OUTLET WATER TEMPERATURE

45 炉膛出口烟温 oC 1047 1031 1026 984 911 794 FORNANCE OULTET GAS TEMP.

46 分隔屏过热器进口烟气温度 oC 1326 1327 1313 1299 1243 1140 SH. DVI. PANEL INLET GAS TEMPERATURE

47 分隔屏过热器出口烟气温度 oC 1139 1127 1119 1082 1009 893

SH. DVI. PANEL OUTLET GAS TEMPERATURE

48 后屏过热器进口烟气温度 oC 1139 1127 1119 1082 1009 893 SH. PLATEN INLET GAS TEMPERATURE

49 后屏过热器出口烟气温度 oC 1047 1031 1026 984 911 794 SH. PLATEN OUTLET GAS TEMPERATURE

50 屏式再热器进口烟气温度 oC 1047 1031 1026 984 911 794 RH PLATEN INLET GAS TEMPERATURE

51 屏式再热器出口烟气温度 oC 934 917 914 873 801 693


18


ITEM NO. ITEM UNIT


RH PLATENOUTLET GAS TEMPERATURE

51 末级再热器进口烟气温度 oC 924 906 904 863 790 682 RH FINISH INLET GAS TEMPERATURE

52 末级再热器出口烟气温度 oC 842 826 824 788 723 634 RH FINISH OUTLET GAS TEMPERATURE

53 末级过热器进口烟气温度 oC 811 794 794 757 691 602 SH FINISH INLET GAS TEMPERATURE

54 末级过热器出口烟气温度 oC 742 727 727 698 644 578 SH FINISH OUTLET GAS TEMPERATURE

55 低过垂直部分进口烟气温度 oC 735 721 721 691 637 571 SHLT. PENDANT INLET TEMP.

56 低过垂直部分出口烟气温度 oC 698 684 688 660 607 542 SHLT. PENDANT OUTLET TEMP.

57 低过水平部分进口烟气温度 oC 669 655 656 630 576 508

SHLT. HORIZ INLET GAS TEMPERATURE 58 低过水平部分出口烟气温度 oC 430 424 431 418 387 345

SHLT HORIZ OUTLET GAS TEMPERATURE 59 省煤器进口烟气温度 oC 424 419 422 412 382 339 ECONOMIZER INLET GAS TEMPERATURE

60 省煤器出口烟气温度 oC 343 336 288 322 296 256 ECONOMIZER OUTLET GAS TEMPERATURE

61 预热器进口烟气温度 oC 343 336 288 322 296 256


19


ITEM NO. ITEM UNIT


AIR PREHEATER INLET GAS TEMP. 62 预热器出口烟气温度 oC 138 137 118 134 124 113 AIR PREHEATER OUTLET GAS TEMP.

63 进预热器一次空气流量 T/h 204534 191765 219862 149918 130203 105759 ENTERING PRIMARY AIR FLOW

64 进预热器二次空气流量 T/h 884440 798004 823741 690626 484364 273446 ENTERING SECONDARY AIR FLOW

65 进预热器烟气流量 T/h 1264996 1162941 1193027 1014780 736445 442171

ENTERING GAS FLOW

66 调温一次空气流量 T/h 111465 119466 91344 121128 83905 45798

PRIMARY BY-PASSED AIR FLOW

67 出预热器一次空气流量 T/h 135133 122818 152729 108640 89832 67203

LEAVING PRIMARY AIR FLOW

68 出预热器二次空气流量 T/h 872646 786664 811494 667492 462138 251674

LEAVING SECONDARY AIR FLOW

69 出预热器烟气流量 T/h 1346190 1243228 1272407 1079192 799042 502499

LEAVING GAS FLOW 70 预热器进口一次空气温度 oC 42.8 42.8 42.8 42.8 42.8 42.8 PRIMARY AIR INLET TEMP.

71 预热器进口二次空气温度 oC 37.8 37.8 37.8 37.8 37.8 37.8 SECONDARY AIR INLET TEMP.

72 预热器出口一次空气温度 oC 304.4 301.7 256.7 293.9 276.1 239.4


20


ITEM NO. ITEM UNIT


PRIMARY AIR OUTLET TEMP. 73 预热器出口二次空气温度 oC 312.8 308.3 262.8 298.9 278.9 240.6 SECONDARY AIR OUTLET TEMP.

Note: *HPHO means all high pressure heater out of service.

74 过热蒸汽阻力 kPa 1313 SUPERHEATER STEAM PRESSURE DROP

75 再热蒸汽阻力 kPa 184 REHEATER STEAM PRESSURE DROP

76 省煤器阻力 kPa 376 ECONOMIZER WATER PRESSURE DROP


21

2 Boiler General Arrangement and System

2.1 General

The boiler is a natural circulation subcritical pressure with single reheat, it is

semi outdoor arranged and has a single furnace of reverse u-form arrangement

and full pendant steel structure, dry bottom type water cooled, balance draft

furnace and is designed with tangential firing arrangement of burners and

direct fired pulverized coal system. For general arrangement drawing of boiler,

please refer to Figure 2.1. The furnace width is 14022mm，depth is 12350mm，the elevation of the top of

the boiler is 59500mm，the elevation of the centerline of the drum is 64000mm，

the elevation of the girder at the furnace crown is 69750 mm. The furnace

crown is a big hood of metal structure of full seal. The furnace is composed of

outside diameter 60mm and thickness 7mm membrane water wall, and the

angle of the dry bottom hopper is 55°. The floor seal is water seal structure and

the separating panel, superheater panel and platen, reheater platen are settled

at the upside of the furnace. Radiation reheater is arranged at front wall and

both side wall. The elevation of lower header of waterwall is 7340mm.

The convection pass with the depth of 6278 mm is composed of the roof by

pass superheater as the extended sidewall of furnace and extended sidewall of

back pass. There are also final reheater and final superheater arranged in it .

The depth of back pass is 10260 mm and low temperature superheater and

economizer arranged in it.

Positive pressure direct fired pulverization system is used for the boiler, with 6

HP863 medium speed coal pulverizers which is arranged in front of the boiler.

At the four corners of the burner, tangential firing (totally 6 layers) is arranged.

The center line elevation of the top burner nozzle is 28100 mm. The distance to

the bottom of the compartition shield is 17800mm. The center line elevation of

lowest burner nozzle is 20470mm. The distance to the corner of the cold ash bin

is 4519 mm. Each corner burner bellow is equipped with 4 layers of startup &

combustion supporting oil guns.

The steel structure of the boiler is a full steel frame connected with high strength


22

bolts. For the whole boiler, totally 17 layers of platforms are provided, including

7 rigid platforms. To facilitate the operation, local platforms are provided for

some places. Except for the deslagging bin device and the preheater, the whole

weight of the boiler is suspended on the roof steel frame.

For the steam temperature regulation of the superheater, mainly water spraying

desuperheater is used. Two stages of water spraying desuperheaters are

arranged in the superheater system. The first stage is arranged in the low

temperature superheater outlet pipe, and the second stage is on the outlet pipe

of the SH. Platen superheater.

The steam temperature of the reheater will be controlled by tilting burners and

excess air. One stage spray water attemperation in case of emergency

condition. The emergency spraying desuperheater, which is arranged in the

reheater inlet pipe.

This boiler is provided with a startup drainage bypass with capacity of 5%BMCR

at the lower header of the back pass.

The boiler is provided with an expansion center. During the operation, the whole

boiler expands with the expansion point as the origin. The expansion zero point

of the boiler in the vertical direction is set at the top of the roof enclosure. The

expansion points of the boiler in the depth and width directions are at the

furnace center and boiler center. In the furnace height direction, three layers of

guiding devices are provided to restrict the expansion direction of the boiler

heating surface and to transmit the horizontal load of the boiler.

The furnace and buckstays are provided with wire wound rigid beams around

them to bear the pressure in both positive and negative directions. 20 layers of

rigid beams are provided at the furnace part and 14 layers are at the back pass.

There is water seal flash board device at the bottom of furnace ash hopper.

56 wall-type sootblowers are arranged in the lower furnace and 44 long-

retractable sootblower are arranged at the upper furnace and in the convection

flue gas area. The air preheater is provided with 2 sootblowers altogether. All

the sootblowers are controlled with program during the operation.

The body of the boiler is provided with 10 spring safety valves, including 3

arranged on the boiler drum, 2 at the superheater outlet, 2 on the reheater inlet

pipe, and 3 on the reheater outlet pipe. To minimize the tripping times of the

safety valves, 2 dynamic relief valves are provided at the outlet of the


23

superheater.

Flue gas temperature detection probes are provided at both the left and right

sides of the furnace. During the startup, they can control the flue gas

temperature at the furnace outlet. Furnace flame TV are provided at both the left

and right sides of the furnace for observing the in-furnace combustion

conditions. The boiler is equipped with boiler drum level gauge and water level

gauge as well as the safety protection devices such as furnace safety &

supervision system (FSSS).


24

Fig. 2.1 Boiler general drawing


25

2.2 Steam & Water System 2.2.1 Feedwater and Water Circulation System The feedwater flows along the route at the right side of the boiler, and enters the

economizer inlet header after passing through the check valve and electric gate

valve. It then flows through the economizer tube bank , intermediate connection

header and suspension tube, and is collected in the economizer outlet header.

Then it is led from the economizer outlet header to the boiler drum through

three OD. 219mm boiler drum feedwater tubes.

To ensure the safe and reliable operation of the economizer during the boiler

startup, an economizer recirculation pipeline is provided between the boiler

drum and the economizer inlet header. There is an electric shutoff valve in the

pipeline. When certain feedwater quantity is established in the boiler, this valve

can be closed. The capacity of the recirculation pipeline is designed on the

basis of 5%BMCR

The steam & water circulation system includes boiler drum (ID.1743mm), 4

large-diameter downcomers (OD. 558.8mm), furnace waterwall tube are rifled

tube. The unboiled water coming from the economizer is injected into 4

large-diameter downcomer seats respectively in 4 routes from the feedwater

distribution tubes arranged along the length of the boiler drum. The feedwater is

mixed with the boiler water directly in the downcomers to avoid the contact of

the feedwater with the drum wall. This can improve the stress conditions of the

couplings and reduce the temperature difference between the internal/external

walls and upper/lower walls of the boiler furnace, which is favorable for boiler

startup and shutdown. A distributor is provided at the lower end of the 4

downcomers, and is connected with 96 waterwall connected tubes (80

OD.159mm and 16 OD.133mm). The connected tubes send the under-enthalpy

water into the lower headers surrounding the waterwall. The waterwall is

composed of 664 tubes with diameter of 60mm. According to the heating

conditions and geometric shapes, they are divided into 51 circulation cycles.

The waterwall tubes at the furnace corners are designed with chamfers to meet

the corner tangential burning conditions. In addition, to improve the heating

conditions of the corner waterwall circuits and to enhance the stability of the

circulation circuits of this part, the chamfer tubes are designed as the


26

water-cooling sleeves of the burner to protect the burner nozzle from being

damaged. The working fluid is heated continuously while flowing upwards along

the diaphragm waterwall, and a steam-water mixture is formed gradually. The

steam-water mixture is led into the drum through 106 steam-water lead-out

tubes (98 OD.159mm and 8 OD.133mm). In the boiler drum, the steam and

water are separated properly with the axial flow cyclone separator and vertical

bent plate. The separated water enters the downcomers again, and the dry

steam is led by the 18 (OD.159mm) connection tubes to the roof superheater

inlet header.

The lower headers surrounding the waterwall are provided with neighbor boiler

heating devices. Prior to the boiler ignition, the neighbor boiler heating steam

enters the waterwall lower headers in 4 routes to accelerate the boiler startup

speed.

To ensure the safety and reliability of the circulation system, due attention is

paid in the design to the abnormal work conditions that may occur during the

operation. The parameters of the circulation system and the structural

dimensions are selected under the principle of safety and reliability. For the

middle part of the front and side waterwalls and almost all the rear waterwalls,

internal thread tubes are used, improving greatly the safety margin for

prevention of diaphragm-state boiling. The circulation magnification is

reasonable, the circulation flow rate is relatively high, and the water circulation

is stable and reliable.

Due to the possibility of diaphragm-state boiling in the boiler chamber high-heat

load area of the evaporation tube under subcritical pressure, how to avoid

diaphragm-state boiling must be taken into consideration when the circulation

system is designed. The circulation system of the waterwall of this boiler is

designed reasonably. Even if smooth-tube waterwalls are used completely in

this boiler, the actual steam content (mass) in the max. heat load area can keep

a safety margin from the critical steam content. In this design, internal thread

tubes of sufficient height are used, further improving the critical steam content in

the max. heat load area. Therefore, no diaphragm-state boiling will occur under

any load of the boiler. For the process, refer to Fig. 2.2-1 “Feedwater & water

circulation system diagram”.


27

F22

F11

F2

F6

F1

F3

F4

F21

F30

F9

F8 F13

F14

F20

F19

F24

F23

F18

F17

F16

F5F10 F15

F12

F7

E.1

E.2

E.3

E.4E.5

E.6

E-7


28

E.1 Economizer inlet tube F.5 Front waterwall lead-in

pipes

F.16 Rear water wall lower

header

E.2 Economizer inlet

header

F.6 Front waterwall lower

header

F.17 Rear water wall

E.3 Economizer F.7 Front waterwall F.18 Furn. rear wall hanger

E.4 Economizer suspension

tube inlet header

F.8 Front waterwall upper

header

F.19 Furn. rear wall hanger

outlet header


tube

F.9 Front waterwall lead-out

pipes

F.20 Furn. rear wall hanger

header lead-out tube


tube outlet header

F.10 Left/right side waterwall

lead-in pipes

F.21 Furn. corner

E.7 Economizer outlet

connection tube

F.11 Left/right side waterwall

lower header

F.22 Furn. Rear arch water

wall

F.1 Drum F.12 Left/right side waterwall F.23 Furn. Rear arch water

wall outlet header

F.2 Downcomer seat F.13 Left/right side waterwall

upper header

F.24 Furn. Rear arch water

wall outlet header

lead-out pipe

F.3 Downcomer F.14 Left/right side waterwall

lead-out pipes

F.30 Connection tube from

steam drum to

downcomer

F.4 Downcomer distribution

header

F.15 Rear waterwall lead-in

pipes

Fig. 2.2-1 Feedwater & water circulation system diagram


29

2.2.2 SH Steam System The saturated steam led out from the top of boiler drum enters the roof inlet

header which is divided into two line. The steam of first line enters convection

pass sidewall at RH finish through the bypass tube. Then, it enters the rear

sidewall of back pass and continues into lower temperature SH inlet header

through rear wall of back pass. The steam of second line enters sidewall upper

header of back pass through front roof. The sidewall upper header of back pass

is joined with back roof header. Then it enters into sidewall lower header

through front sidewall of back pass. The steam of second line is divided into two

line (A and B) at sidewall lower header. Steam of one line A enters backpass

EXT. side wall at SH finish through connection pipe. In frontwall upper header of

back pass it is mixed with steam of one line B which pass through front wall of

backpass. The steam of second line continues into lower temperature SH inlet

header through rear roof and rear wall of back pass. Here it finally mixed with

the steam of first line. Then It flows through the lower temperature superheater

and to its outlet header. After that, the steam is led to Stage-I desuperheater

through the tee at the middle part of the header. After Stage-I desuperheater,

the steam is re-divided into two routes and flows to the DIV panel SH. inlet

header. It flows through the DIV panel SH. heating face tubes to the DIV panel

SH. outlet header. From the DIV panel SH. outlet header, the steam is led to the

SH. Platen inlet header in two routes. Then it enters the SH. Platen outlet

header through the SH. Platen heating face tube. Through the tee on the SH.

Platen outlet header, it converges into one route and flows into Stage-II

water-spraying desuperheater so that the steam is mixed sufficiently. Finally, it

enters the Final superheater and is heated to the required steam temperature. It

then flows through the Final superheater to the last superheater outlet header,

and then from the last superheater outlet header to the main steam pipe and to

the turbine high-pressure cylinder. For the process, refer to Figure 2.2-2

“Superheater system”.


30

Figure 2.2-2 Superheater system

S.21B

S.27

S.26

S.25

S.11

S.19

S.20A

S.21A

S.49

S.48

S.22A

S.23

S.32

S.5

S.16

S.15

S.13S.10 S.10

S.29

S.31S.30

S.6 S.6

S.7

S.24

S.12

S.18S.8

S.17

S.9

I

隔板

隔板

I-I

S.4

S.34

S.32

S.35

S.39S.38

S.40

S.33

S.48

S.44

S.46

S.14

S.42

S.31

S.30

S.28

S.41

S.52 S.47

S.46S.40 S.42

S.43

S.3

S.1

S.2

S.36 S.37

S.50 S.51

S.38

S.39

S.33

S.44 S.45I

∩

S.35

S.34

S.22B

S.20B


31

S.1 Steam drum outlet connection tube S.24 Low-temperature superheater inlet header

S.2 Roof inlet header S.25 Low-temperature superheater horizontal section lower tube bank

S.3 Front roof tube S.26 Low-temperature superheater horizontal section middle lower tube bank

S.4 Convection pass extension side wall at final reheater inlet connection tube

S.27 Low-temperature superheater horizontal section middle tube bundle

S.5 Roof outlet header S.28 Low-temperature superheater horizontal section upper tube bundle

S.6 Back pass side wall upper header left (right)

S.29 Low-temperature superheater horizontal section upper vertical tube bundle

S.7 Convection pass extension side wall at final reheater outlet connection tube

S.30 Low-temperature superheater outlet header

S.8 Back pass front side wall tube S.31 Stage-I desuperheater inlet pipe S.9 Back pass rear side wall tube S.32 Stage-I desuperheater S.10 Back pass left/right side wall lower

header S.33 Stage-I desuperheater outlet pipe

S.11 Back pass rearwall lower header S.34 DIV panel SH. inlet pipe S.12 Back pass rearwall lower tube S.35 DIV panel SH. inlet header S.13 Back pass frontwall lower header S.36 DIV panel SH. (front) S.14 Back pass frontwall lower tube S.37 DIV panel SH. (rear) S.15 Back pass frontwall upper tube S.38 DIV panel SH. outlet header S.16 Back pass frontwall upper header S.39 DIV panel SH. outlet pipe S.17 Rear roof tube S.40 SH. Platen inlet header S.18 Back pass rearwall upper tube S.41 SH. Platen reheater S.19 Back pass extension side wall at SH

finish inlet connection pipe S.42 SH. Platen outlet header

S.20A Final superheater extension side wall lower header

S.43 Stage-II desuperheater inlet pipe

S.20B Final reheater extension side wall lower header

S.44 Stage-II desuperheater

S.21A Final superheater extension side wall tube

S.45 Stage-II desuperheater outlet pipe

S.21B Final reheater extension side wall tube S.46 Final superheater inlet header S.22A Final superheater extension side wall

upper header S.47 Final superheater


32

S.22B Final reheater extension side wall upper header

S.48 Final superheater outlet header

S.23 Final superheater extension side wall outlet connection tube

S.49 Final superheater outlet pipe


33

2.2.3 RH Steam System The steam discharged from the turbine high-pressure cylinder is divided into

two routes through the tee before the reheater inlet. It enters the wall radiation

reheater inlet header and passes through the wall radiation reheater. Then it is

led out from the upper outlet header and to the platen reheater inlet header

through 4 connection tubes. After that, it passes through the platen reheater and

Final reheater in turn, and then is led out of the top of the Final reheater outlet

header to the reheater steam pipeline and enters the turbine medium-pressure

cylinder. For the process, refer to Fig. 2.2-3 “Reheater system”.

For the reheaters of all stages, large diameter pipes and tee connections are

used to improved the conditions for sufficient mixing. Accidental water-spraying

desuperheaters are arranged on the wall-type reheater inlet pipes. The left-right

crossing is realized through connection pipes between the screen reheater and

Final reheater. Desuperheater is mounted on the connection pipe to minimize

the reheated steam temperature deviation caused by the flue gas temperature

deviation between the left and right sides of the furnace.


34

II

II II

锅炉中心线

前墙

I-I

前墙

R.1

R.2 R.5

R.3

R.6

R.7

R.4

R.8

R.9

R.10

R.12

R.14

R.15

R.16

II-II

R.1 R.2

R.5

R.4

R.7 R.9 R.15

锅炉中心线

R.11 R.13

R.10 R.14

R.13

R.12c

R.11

R.11

R.12b

R.12a

R.1 Desuperheater R.10 Platen reheater R.2 Front-wall reheater inlet

header R.11 Platen reheater outlet

header R.3 Front-wall reheater R.12a Micro-spraying

desuperheater inlet pipeline

R.4 Front-wall reheater outlet header

R.12b Micro-spraying desuperheater

R.5 Side-wall reheater inlet header

R.12c Micro-spraying desuperheater outlet pipeline

R.6 Side-wall reheater R.13 Final reheater inlet header

R.7 Side-wall reheater outlet header

R.14 Final reheater

R.8 Platen reheater inlet connection pipeline

R.15 Final reheater outlet header

R.9 Platen reheater inlet header

R.16 Final reheater outlet pipeline

Fig. 2.2-3 “Reheater system”


35

2.2.4 Bypass System

Use 5%BMCR start-up bypass system as the method of controlling the pressure

and temperature of the superheated steam when the boiler start-up to shorten

the start-up time. 4 drain tubes are setted on the ring header that behind the boiler and below the

back pass, 2 setted on the downside header. Each drain tube has 2 DN50

electric check valve. Four ducts converged to one duct connecting to the

condenser, and the pressure reducer should be installed on it and the flow of

the ducts is designed according to 5% maximum continuous load and rigidity

design according to the rigidity design parameter of boiler.

For cold start-up, the drain valve totally opened when the temperature of the

medium in this system is the saturated temperature of 4.12 MPa . Increase the

superheated steam temperature by the method of increase the burning rate.

The drain valve should also be opened to drain the water in SH system. The

temperature of the superheated steam when start-up is controlled by furnace

burning rate, the pressure of the superheated steam is controlled by the drain

valve, and this valve should be shut off when the steam turbine is

synchronization.

2.3 Burning System

The milling system is positive pressure and direct-fired with 6 HP863 type

medium speed pulverizers and the burner is setted at four corner and firing at

tangential mode.

2.3.1 Pulverized Coal Duct

Pulverized coal pipes starts from pulverizing mill outlet until burner inlet, which

is equipped with abrasion proof. For every pulverizing mill, there are 4

pulverized coal pipes connecting with coal burners arranged at four corners at

the same level.

2.3.2 Burning Equipment

The burner is arranged at the four corners, i.e. corner tangential DC burner.


36

a. Adopting vertical rich-lean primary air nozzle.

When the coal powder flows through the burner inlet elbow, under the action

of the centrifugal force, most of the coal particles enter the coal powder

spraying tube closely along the external edge of the elbow. The partition

board in the coal powder spraying tube divides the primary air into two parts,

i.e. thick and thin parts. This can improve the coal powder concentration at

the outlet of the primary air nozzle. In the primary air nozzle, a V-shaped

bluff body is mounted so that the primary air can form a stable reflux zone in

front of the V-shaped bluff body. This can suck the high-temperature flue gas

and functions to stabilize the flame.

b. The burner nozzles at the four corners have their respective oscillation link

levers. They are driven by electric actuators through rocker devices and

main link levers. The primary air nozzle can oscillate upwards and

downwards for 20° respectively, while the secondary air nozzles for 30°. The

top manual secondary air nozzle can oscillate upwards for 30° and

downwards for 6°. During the boiler operation, the temperature of the

reheater can be adjusted through the oscillation of the burner. The control of

the burner nozzle oscillation can be connected to BMS system. If BMS

system is not used or the oscillation control steps out of the BMS temporarily,

to ensure the normal operation of the nozzle oscillation device, the nozzle

should be operated manually to oscillate upwards & downwards for 1 or 2

times at appropriate time every day and then resume to the original position.

c. The burner bellows are provided with 3 layers (totally 12 EA) of steam

atomization stable-burning HFO guns. The total output of the oil guns is

30%BMCR.

d. The burner bellows are provided with 1 layer (totally 4 EA) of mechanical

atomization ignition & warming-up oil guns. The total output of the LDO guns

is 10%BMCR.

e. Each oil gun is provided with a set of 20J high-energy igniter, which is

controlled with the forward/backward mechanism during the ignition.


37

f. To facilitate the field installation and to ensure the correct angle for the air

flow to be injected into the furnace, the burner and the water-cooling jacket

(burner area waterwall) should be assembled before being released from

the factory.

g. The burner housing is bolted to the water-cooling jacket. The 24

high-strength bolts at the center of the housing flange are used for

securing, while the other bolts are not tightened completely to allow

relative displacement between the housing and the waterwall and to

absorb the expansion difference between the housing and the waterwall

under various work conditions.

For the detailed instructions concerning the burning equipments, refer to

680197-1-8661 “Burning equipment instruction manual”.

2.3.3 Ignition Equipment

The burner is provided with 1 layer (4 EA) of forward/backward type air

atomization LDO guns used for boiler warming-up and pressure increasing,and

also provided with 3 layers (12 EA) of forward/backward type steam atomization

HFO guns used for ignition and burning stabilization. These oil guns can be

used to ignite and stabilize the burning of the adjacent coal powder nozzles.

The oil guns and forward/backward mechanisms are outsourced products. For

the detailed requirements for the installation, operation and maintenance of the

oil guns and forward/backward mechanisms, refer to the related documents

provided by the oil gun manufacturer. Output of the oil guns is 1.75t/h.

Boiler front oil system is composed of the pipelines, primary instruments,

valves, etc. It functions mainly to protect and supervise that the medium in the

front oil system works under the normal pressure, flow rate and temperature,

and to realize the requirements of FSSS and BMS (see Fig. 501730-E1-06 Rev.

B).


38

2.4 Flue Gas and Air System 2.4.1 Air System

The primary air is used to transport and dry the pulverized coal. It is pumped

from the atmosphere by fan to the primary chamber of the trisector air heater,

and then goes into the pulverizer through the primary air duct after it is heated.

Before goes into the air preheater, part of the cold air bypass the cold primary

air duct and is mixed with the hot air at the inlet of the pulverizer, which is used

as tempering air for the pulverizer.

The function of the secondary air is to strengthen the combustion and control

the quantity of NOx. The secondary air pumped by fan from the atmosphere to

the secondary chamber of air preheater, and then goes into the wind box

through the secondary air duct. SBWL design and supply the part of secondary

air from air preheater outlet until wind box.

2.4.2 Flue Gas System

The flue gas produced in the furnace flow from the back pass to the flue gas

chamber of the air preheater through the flue gas duct. The primary air and

secondary air is preheated in the air preheater by the residual heat of the flue

gas. The flue gas goes out of the preheater and discharged to the chimney by

the electrical precipitator and the induced-draft fan. Bargainor design and supply

the parts and components until 1 meter outside the last column (M5 Column) of

preheater outlet flue gas duct.

2.5 Bottom Ash System Mechanical deslagging is used for this boiler. The deslagging equipments are

supplied by the buyer. The scope of design and supply of the seller is to the

bottom sealing baffle device, which inserts into the upper-edge water sealing

slot of the slag hopper annularly. It functions to seal the bottom of the furnace

bottom.


39

2.6 Attamperation System 2.6.1 Superheated Steam Attamperation Except for the influence of the tilting of the burner nozzles, the temperature of

the superheated steam is mainly controled by water spray desuperheaters. This

boiler is arranged with two stages of water-spray desuperheaters. Stage-I

desuperheater is installed at the division panel superheater inlet piping to mainly

control steam temperature. Stage-II desuperheater is installed at the final

superheater inlet piping to regulate a small quantity of steam temperature. The

spraying water comes from the feedwater pump outlet piping, and is divided into

two routes at the water-spray header isolation valve, and then enters the

desuperheater through Stage-I and Stage-II water-spray pipelines respectively.

For the diagram of the water spray system, refer to Fig. 501730-E1-03

“Steam-water system diagram”. Electric gate valves (or electric shutoff valves)

and pneumatic regulation valves are arranged in the piping. The pneumatic

regulation valves are controlled by controlled panel. The electric cut-off valve

before the regulation valve is interlocked with the regulation valve. During the

operation of the boiler, normally the electric cut-off valve after the regulation

valve is opened, and is only closed for isolation when the regulation valve is

repaired in case of failure.

The Maximum design water spraying quantity of the Stage-I desuperheater is

103t/h, and that of the Stage-II desuperheater is 15t/h. The nozzles of the

desuperheaters are of perforated flute tube structure. The water spraying

quantity (calculated) of the various stages of desuperheaters under different

loads are as shown in the following table.

BMCR TMCR

80%

TMCR

60%

TMCR

30%

BMCR

High plus

tangential

Water-spraying volume of

Stage-I desuperheater t/h 8.10 22.50 37.90 32.40 19.00 83.90

Water-spraying volume of

Stage-II desuperheater t/h 0 3 10 5 3 5

Water spraying temperature 177 173 164 153 133 176


40

2.6.2 Reheat Steam Attemperation The reheated steam temperature is generally controlled by fuel nozzle tilts to

change the height of the flame center and subsequently the furnace outlet flue

gas temperature. The tilting angle of the nozzle is approximately ± 20º . As the

reheater is arranged in the furnace outlet high-temperature flue gas area, it is

quite sensitive to the temperature regulation of the tilting nozzles. When the

load is lower than a certain value, the temperature can be regulated by excess

air.

In addition, two accidental water-spraying desuperheaters are provided at the

reheater inlet. The nozzle is Monarch nozzle, which is used to control the steam

temperature at the reheater steam under accidental condition. The

desuperheaters are arranged in the wall radiant reheater inlet piping, with max.

design water spray capacity of 42t/h. The spraying water comes from the

feedwater pump middle tap, and is divided into two routes at the isolation valve.

Then it passes through the pneumatic regulation valve and electric shut-off

valve and enters the desuperheater. The regulation valve is controlled by

controlled panel. The isolation valve and the regulation valve are interlocked.

2.7 Sootblowing System The boiler is equipped with sootblowing system to keep the heating surface

clean and to achieve proper heat transfer effect. The whole sootblowing system

is divided into two parts, i.e. boiler body heating surface sootblowing and

preheater sootblowing. The boiler body part includes 56 boiler wall sootblowers

arranged in the lower furnace and 44 long retractable sootblowers arranged at

the upper furnace and the convection flue area. Each air preheater flue gas cold

end is provided with a retractable sootblower. The sootblowing steam is

connected from the platen superheater outlet header. Automatic drainage points

are provided in the pipeline. Process control is realized in the whole sootblowing

system of the boiler. Usually the system is designed considering that 2 long

retractable and 2 furnace sootblowers and 2 air preheaters are put into service

in the same time. One sootblower on each wall (side walls or front/rearwalls)

relative to the long retractable and furnace sootblowers is put into service in the

same time. It can also be set as per the requirements of the user. The design

and manufacture of the whole set of sootblowing equipments for this boiler

(including sootblower, pipeline and control equipment) is undertaken by


41

Shanghai Clyde Mechanical Co. Ltd. For the details, refer to 730-1-8616

“Sootblower body instruction manual” and 730-1-8617 “Sootblowing pipeline

system instruction manual.”

2.7.1 Sootblowing System The sootblowing steam is led out of the DIV panel SH. outlet header. After the

steam is subject to pressure reduction at the 2″ pneumatic diaphragm reduction

valve, the set value is 2.94MPa (30kgf/cm2) and the temperature is approx.

330. The optimal usage value depends on the various conditions after the

sootblower is put into service, and this pressure value is regulated by the user

according to the demand. A manual shut-off valve and an electric shut-off valve

are arranged on the pipeline before the pressure reduction valve for closing the

steam supply. A safety valve is arranged on the pipeline after the pressure

reduction valve to avoid over-pressure of the sootblowing steam. Pressure

measurement points are provided in the pipelines to monitor the outlet pressure

of the pressure reduction valves. All the sootblower pipelines are provided with

flow switches, and are connected with the program control. The set value of the

flow switch contact is the minimum cooling flow rate necessary for keeping the

sootblower.

To ensure the appropriate dryness of the sootblowing medium, the sootblowing

pipeline is provided with drainage system. The body sootblowing part has 4

drainage points, including 1 at the furnace sootblower and 3 at the long

retractable sootblower. Each drainage pipeline is provided with an electric

shut-off valve for temperature control and water drainage. The valve open/close

set value is 300. To ensure the thorough drainage, all the horizontal pipelines

should be sloped by at least 0.025m/m.

2.7.2 Air preheater Sootblowing System The air preheater sootblowing steam comes from the platen superheater outlet

header, with steam temperature of 510 and pressure of 18.1MPa (g). After the

pressure reduction at the 2” pneumatic diaphragm pressure reduction valve, the

steam pressure becomes 2.94MPa (30kgf/cm2) and the temperature is

approximately 330.


42

2.7.3 Main Design Parameters of the Sootblower

Item

Name Type

Steam temperature

()

Steam pressure

(g) (MPa)

Stroke

(mm)

Boiler wall

sootblower V04 ~315 ~2.45 255

Long retractable

sootblower PS-SL ~315 ~2.45 7000

Preheater

sootblower PS-AT ~330 ~2.45 970

2.7.4 Furnace flue gas temperature probes A retractable flue gas temperature probe is arranged at each side of the furnace

outlet. On the boiler startup stage, the flue gas temperature probe extends into

the furnace to monitor the furnace outlet flue gas temperature. The max.

measurement temperature of the probe is 600. When the flue gas

temperature arrives at 540, it will give an alarm and the probe retracts

automatically. At such time, the fuel quantity should be reduced to prevent the

wall-type reheater from being damaged due to excessive heat.

The flue gas temperature probe is of TS-O type with stroke of 4700mm. For the

details, refer to 730-1-8618 “Flue gas temperature probe instruction manual”.

2.8 Pipeline System 2.8.1 Drainage, Venting and Dosing Pipelines To ensure the safe and reliable operation of the boiler, drainage and venting

points are provided at the necessary positions on the pressure parts. For the

specific arrangement, refer to 820730-E1-01 “Venting & drainage pipelines” and

820730-E1-02 “Drainage pipelines”. The drainage pipelines below the four

downcomer distributors are connected in parallel with four routes of regular

blowdown pipelines. In addition, the economizer inlet header, roof inlet header

and back pass lower annular header are all provided with drainage pipelines. In

addition to the above normal drainage pipelines, the boiler is provided with an

emergency accidental drainage pipeline, which is led from the lower front side


43

of the boiler drum to the 12.6m platform in front of the boiler. The pipeline is

provided with two electric shut-off valves with inlet of DN100. When the boiler

drum level is above +180mm, open this valve, when the normal water level is

achieved, close this valve.

Prior to the boiler ignition, the drainage valves and venting valves of the

superheater and reheater systems must be opened to ensure the drainage of

the pipelines in the systems. When steam is generated in the pipelines after

drainage, close the venting valves in the superheated steam pipelines. The

drainage valve on the back pass lower header should be closed as soon as the

turbine is connected to the grid, and the reheater drainage valve and venting

valve must be closed before vacuum is established in the condenser.

The dosing pipe is provided on the boiler drum. To prevent from corrosion, the

pipes and valves are made of stainless steel materials.

2.8.2 Blowdown Piping This boiler is provided with continuous and regular blowdown lines. The boiler

blowdown is used to control the boiler water concentration and to remove the

sediment. The blowdown quantity and blowdown times depend on the operation

conditions of the boiler, such as water characteristics, water treatment nature,

boiler load, etc. Under normal conditions, the continuous blowdown can meet

the requirements. However, when excessive sediment forms due to high solid

content or poor feedwater treatment causing carryover, regular blowdown is

needed for the boiler through the regular blowdown pipeline.

The continuous blowdown pipeline is led out of the lower part of the boiler drum

end. Through the manual cut-off valve and regulation valve, it is led directly to

the blowdown box. The specification of the regulation valve is 1″, with max. flow

rate of 10.15t/h and pressure difference of 9.09MPa.

The drainage lines below the four downcomer distributors are connected in

parallel with four routes of regular blowdown lines. Each pipeline is provided

with a regular blowdown valve. In addition, each pipeline is connected in series

with a high pressure difference regulation valve to reduce the inlet/outlet

pressure difference of the regular blowdown valve, to improve the operation

conditions and to prolong the service life. The pressure difference of the high

pressure difference regulation valve is set at 10MPa. For the regulation, the flow

rate and pressure difference necessary for the operation can be regulated


44

through the hand wheel. Each pipeline is also connected in series with a

manual cut-off valve for isolating the regular blowdown valve for maintenance.

These four regular blowdown lines eventually converge to a OD.133mm small

header, which is equipped with a drainage valve. Prior to the blowdown,

drainage should be carried out to prevent from water hammer. The steam /

water quality during the boiler operation is normally guaranteed through

continuous blowdown means. Only in case of a new boiler or during the startup

after overhaul or when the continuous blowdown is not enough to ensure the

steam / water quality should the regular blowdown system be started. For the

regular blowdown system lines, it is necessary to design the hangers and

supports properly, which can meet the expansion displacement requirements

and the requirements that no vibration should occur when the regular blowdown

is started. If it suffer severe vibration during the blowdown, the cause should be

found immediately and should be resolved through improving the hangers and

supports.

2.8.3 Sampling Piping The boiler is provided with saturated steam sampling points, boiler water

sampling points, superheated steam sampling points and reheated steam

sampling points. The saturated steam sample is taken from the steam lead-out

tube from the boiler drum to the roof superheater inlet header. 6 points are

arranged evenly along the length of the boiler drum. The boiler water sample is

taken from the continuous blowdown tube. 1 steam sampling point is set at the

superheater inlet main steam pipeline, and 2 points at the reheater outlet steam

pipeline. Each sampling pipeline is arranged with two manual cut-off valves.

2.8.4 Safety Valve ,Venting Piping To ensure the safe operation of the boiler and to protect the pressure parts

against excessive pressure, the boiler is provided with 10 safety valves,

including 2 at the boiler drum, 2 at the superheater outlet main steam pipeline, 2

at the reheater inlet and 3 at the reheater outlet . In addition, to minimize the

tripping times of the safety valve at the superheater outlet and subsequently to

protect the safety valve, electric relief valve is arranged downstream the

superheater outlet . For the setting pressures and discharge quantities of the

safety valve and electric relief valve, refer to 730-1-8401 “Summary of safety

valve setting pressure and discharge quantity”.


45

Each safety valve or electric relief valve is provided with a venting tube, which

penetrates the large house roof starting from above the drainage dish on the

safety valve venting elbow. There are sufficient gaps between the venting tube

and the safety valve venting elbow and drainage dish to prevent the weight of

the venting tube from being transferred to the end of the valve venting tube. The

venting tubes of the boiler drum safety valve, reheater inlet/outlet safety valve,

superheater outlet safety valve and electric relief valve are provided with

silencers（first jump safety valve）.

2.9 Arrangement for Ports and Measuring Points 2.9.1 Arrangement for Ports The boiler is provided with holes for inspection, observation, sootblowing,

instrumentation measurement, TV pickup, temperature probe, boiler tube

leakage alarming device, etc. This is convenient for operation, maintenance and

commissioning. All the holes are arranged at proper positions on the boiler as

per the requirements. To prevent from flue gas leakage and to ensure the boiler

sealing, all the holes that need elbows should be provided with sealing boxes.

A 610mm×760mm water cooling door is arranged on each side of the waterwall

at the bottom of the furnace cold ash bin. During the operation, water circulates

in it for cooling to prevent from burning damage. The parameters of the cooling

water are as follows: inlet temperature 20, inlet pressure 0.29MPa, water

volume 0.91m3/h, outlet temperature 54. For 420mm×460mm maintenance

doors, the holes should be blocked with refractory materials during the boiler

operation to prevent the gas from damaging the maintenance doors. For the

details of the ports, refer to 502730-E1-10 “port arrangement drawing” and

751730-D1-01 “port sealing box arrangement drawing”.

2.9.2 Measuring Points for Steam-Water System The steam-water system measurement points include the measurement points

for working fluid temperature, pressure, flow rate and metal wall temperature,

and are used for recording, control and test. Measurement points for working

fluid temperature are provided at the economizer inlet/outlet pipelines,

downcomers, inlets/outlets of Stage-I & -II desuperheaters of the superheaters,

outlets of Final superheaters, inlets of reheater desuperheaters, inlets of


46

wall-type reheaters, inlets/outlets of screen-type reheaters, and outlets of Final

reheater outlets. The measurement points for working fluid pressure are

arranged at the economizer inlet, boiler drum, superheater outlet, reheater

inlet/outlet, etc. The measurement points for metal wall temperature are

classified under two types: one is for record and for control in the control room,

and the other is for local test. For the measurement points used for record and

control, the thermocouples are led directly to the control room; while for the

measurement points for local test, the thermocouples are connected to the

terminal boxes at the side of the roof large enclosure. (The thermocouples are

not in the scope of supply of SBWL.) For the detailed arrangement of the

measurement points, refer to 502730-E1-11 “Steam-water system measurement

point arrangement drawing”.

2.9.3 Measuring Points for Gas-Air System The measurement points for the gas-air system include those for furnace

pressure, flue gas temperature, pressure difference between furnace and

various air ducts, tail flue gas pressure & temperature, etc. Some of these

measurement points are needed for operation supervision, and some are for

regulation and alarming required by FSSS and BMS control. For the details,

refer to 502730-E1-12 “Gas-air system measurement point arrangement

drawing”.

3 Main Pressure Parts

3.1 Drum and Drum Internals

3.1.1 Drum The length of the straight section of the boiler drum is 19662mm, and the total

length (including heads) is ~22338mm. The internal diameter of the drum is

1743mm and the thickness is 192mm. It is composed of six (6) 3277mm long

cylindrical sections made of SA-299. The heads at the two ends of the drum are

spherical, with the material as same as that of the drum body.

Four large diameter downcomer seats made of SA-299 plates are welded to the

lower part of the boiler drum. 8 OD.133mm lead-in tube seats and 98

OD.159mm lead-out tube seats are arranged at the horizontal and vertical

positions of the boiler drum respectively. 3 feedwater lead-in tube seats are


47

arranged evenly at the lower part of the boiler drum. The drum body is also

provided with 2 economizer recycling tube seats, 1 accidental (emergency)

drainage tube seat and 1 dosing tube seat. At each end of the lower part of the

drum body, 1 downcomer connection tube is provided to eliminate the “dead

corner” at the end of the boiler drum. 9 pairs of internal/external wall

temperature measurement points are provided along the length of the boiler

drum, which are arranged in 3 sections, i.e. upper, middle and lower. They are

used for monitoring the boiler drum wall temperature difference during the

startup and shutdown of the boiler. The auxiliary steam tube seat is located at

the left end of the boiler drum. 3 safety valve tube seats are arranged at the

upper parts of the left and right heads respectively (1 at left and 2 at right). 7

groups of level monitoring tube seats (2 dual-color level gauges, 3

single-chamber level balance vessels and 2 electrode level gauges) are

arranged on the heads of the two sides respectively. The continuous drainage

tube seats are located below the two ends of the boiler drum, and are gathered

and then led out.

The total weight of the boiler drum (including internal parts) is 217.5 tons. Two

pairs of lifting lugs are welded at the upper part of the boiler drum for lifting of

the boiler drum.

The normal water level of the boiler drum is -50mm below its centerline.

The water level control protection limits are as follows:

Serial

No. Item Limits

1 Normal water level Steam Drum’s center-line

-50mm

Max. Normal water level +50mm： 2

Normal water level

range： Min. Normal water level -50mm

3 High water level alarm Normal water level +125mm

4 Low water level alarm Normal water level -200mm

5 High water level trip Normal water level +250mm

6 Low water level trip Normal water level -350mm


48

3.1.2 Drum Internals The boiler drum internal devices include axial-flow separator, corrugated dryer,

blowdown tube, dosing tube, accident drainage tube and feedwater distribution

tube. (See Fig. 3.1 “Boiler drum internal devices”.) The water feed mode of this

boiler is direct injection type, i.e. the feedwater is injected into the inlet end of

the downcomer directly. The purpose is to reduce the upper/lower and

internal/external wall temperature difference of the boiler drum during the

startup, sliding pressure operation and high plus tangential operation of the

boiler. Especially, it can prevent from the temperature difference thermal stress

of the downcomer tube seat under the above operation conditions, improving

the service life of the boiler drum.

The feedwater distribution tubes located at the bottom of the boiler drum have 4

feedwater injection tubes led from above the downcomer seats. The feedwater

enters the center of the downcomer through the injection tube, avoiding the

direct contact of the downcomer tube seat weld area and the feedwater and

eliminating the possibility of excessive temperature difference stress at the weld

area. Grid plates are provided at the inlet of the downcomer tube seat to avoid

eddy. This prevents the downcomer from bringing in large quantity of steam and

improves the water circulation safety.

In the boiler drum, 94 axial-flow cyclone separators and 112 wave-shaped

dryers are arranged. The steam-water mixture enters the cyclone separator

through the steam-water lead-in tube and flows in a rotational way from the top

to the bottom. The steam passes through the shutter at the upper part of the

separators, and then to the dryers at the top. The water drops fall along the

separator partition layers and the bottom of the dryers, and then enter the water

space of the boiler drum. The separated dry steam is led from the top of the

boiler drum to the superheater system through 18 OD.159mm steam guiding

tubes.

As a deal of axial flow cyclone separators and wave-shaped dryers are set in

the boiler drum, the data of the separators such as steam load values are quite

conservative (see the following table). Therefore, the quality of the steam can

be guaranteed effectively even when the load varies. The steam-water space of

the boiler drum is quite large. This is favorable for the stability of the water level.


49

Characteristics of axial-flow cyclone separators at 100% boiler load

Separator

size

Separator

quantity

Steam load of each

separator

Mean mixture load of each

separator

Φ254mm 94 10.80t/h 40.2t/h

If the boiler drum internals are assembled with the drum in the factory, the

cyclone separators and dryers should be removed before the pickling on site so

that they would not participate in the pickling. This is to prevent the scraps from

blocking the gaps and to protect the steel sheets from being corroded.


50

-+

Figure 3.1 Boiler drum internal devices


51

3.1.3 Water Level Test To calibrate the local level gauges and the remote level indicators, the drums of

all the large boilers (with design pressure ≥16.6MPa) are provided with water

level measurement sampling devices to establish a real water level during the

high-pressure operation.

1. Equipment The typical water level measurement sampling device is as shown in Fig. 3.2.

Normally only 4 couplings are used on the sampling cylinder to connect with the

test pipeline. All the other couplings are blocked with blind plates. Sufficient

high-pressure sampling coolers should be prepared so that at least two

connection tubes can be used for sampling and cooling in the same time. Each

sampling pipeline should be provided with a conductivity gauge (0.1 setting).

The conductivity value can be detected with portable instrument complete with

switch boxes or with multiple-point recorder.

Because the approximate conductivity is enough to differentiate the water and

steam in the boiler drum, no temperature compensation is needed. However, all

the sampling tubes should be cooled to approximately the same temperature for

the measurement.

The water level sampling barrel should not be arranged directly above the

large-diameter downcomer inlet as the water level in such area is liable to the

interference of vortex. Therefore, it is wrong and meaningless to measure the

water level in such affected area. The level measurement should be limited to

the position as shown in the figure. See 3.2 “Water level measurement sampling

device (typical arrangement) drawing”.

2. Test Requirements To obtain the maximum reliable documents, the test group and operators are

required to cooperate appropriately in the water level performance test. The

max. deviation of the boiler drum level appears at the full load. Therefore, it is

suggested that the test should be carried out under stable full-load work

conditions. Load variation in process of the test can cause some additional

factors and complicate the data processing. In addition, the water level must

vary evenly while observing the reaction of the various level indicators and the

relative position of the water level in the level sampling barrel. Sootblowing


52

should be avoided during the test as sootblowing can cause wrong water level.

It is absolutely necessary to supply sufficient quantity of cooling water during

the test. The normal necessity of each sampling cooler for cooling water is

0.5675m3/h (2.5 gallon/minute). As the test is carried out close to the boiler

drum, the water delivery head of the cooling water for the power plant must

meet the water level requirements.

As the conductivity is the foundation for differentiating the steam phase and

water phase, it is required that the boiler water should contain ideal electrolysis

concentration. If the power plant uses “volatile content” or “low solid” content to

control the boiler water, some sodium salt must be added into the boiler water to

generate conductivity of at least 30 µΩ.

3. Test Procedure (1) The connection tube should allow the sampling barrel to take samples from

the following four points:

a) 51mm below the normal water level

b) Normal water level

c) 51mm above the normal water level

d) 102mm above the normal water level

(2) The samples taken by the two probes on the sampling barrel should

condense in the same time, and the conductivity should be supervised. In the

beginning, the cooler should be connected with the points at the normal water

level and 51mm above the normal level. If such sampling probes are not

satisfactory, the cooler can be connected with one of the other two points.

(3) The water level in the boiler drum should decrease gradually until the

conductivity of steam at all the sampling points is shown (less than 5µΩ). Keep

it stable for 15 minutes and record the following data:

a) Conductivity of the various sampling points

b) Readout of the automatic level regulator

c) Readout of the remote water level indicator

d) Readout of the dual color level gauge

e) Readout of the electrical terminal level gauge

f) Time and load.

(4) Increase the water level by 13mm according to the automatic level regulator

and keep for 15 minutes. Repeat to record the data as described in Step (3).


53

(5) Repeat Step (4) until all the sampling points are immersed in the boiler water

(with conductivity >30µΩ).

If the test discloses that the real water level deviates greatly from the indicated

level, consider compensating the external level indicator or regulating the

pre-offset of the various level indicators.


54

Fig. 3.2 Water level measurement sampling device (typical arrangement)


55

3.2 Waterwall 3.2.1 Brief Introduction The boiler furnace is enclosed with a membrane wall, which is composed of 664

tubes with OD. 60mm, material of SA210-C and spacing of 76mm. The depth of the

furnace is 12350mm and the width is 14022mm. The whole waterwall system is

divided into 51 calculation circuits, i.e. 23 at the side walls, 12 at front wall and 16 at

rear wall. The four corners of the waterwall are large chamfers. The chamfer at the

lower part of the furnace is designed as burner water-cooling windbox, which leave

factory integrally assembled to the burner .

The front/rear waterwall forms a 55º angle with the horizontal level at the elevation of

15.951m, i.e. forming a furnace bottom. The front/rearwall of the furnace bottom

inclines downwards to the elevation of 7790mm to form a 1.4m-deep deslagging

opening, which is connected with the slag bin device as a flashboard water-sealing

structure. At the elevation of 42200mm, the rearwall forms a 2.591m-deep

diaphragm-type wall flame deflection corner, which is composed of tubes with

diameter of 70mm and spacing of 91.2mm. At this elevation, 28 OD.76mm,

SA213-T11 tubes penetrate evenly from the rearwall to form rearwall suspension

tube or suspension tube No. I to support the entire weight of the rearwall of the boiler

chamber. The flame deflection corner is at 30º angle to the horizontal direction, and

extends upwards and backwards. At the Final reheater, it extents to the front end of

the side wall to form the front bottom of the horizontal flue. Then, it extents upwards

vertically to form the rearwall tube bundle.

The fins of the waterwalls surrounding the boiler chamber are made of 16×6mm flat

carbon steel. The fins of the flame deflection diaphragm wall is made of 21.2×6mm

flat steel. They are connected with the tubes with submerged arc welding to form the

diaphragm wall. The whole waterwall is divided into 4 sections along the furnace

height direction, and is divided into 124 diaphragm screens (including 4 groups of

water-cooling jackets) before being released out of the factory. At the middle and

lower parts of the front and side waterwalls, sufficient quantity of internal thread

tubes are arranged. The rear waterwall, starting from the cold ash bin corner to the

flame deflection corner, is composed of almost all internal thread tubes.

3.2.2 Installation When waterwall is installed on site, the installation gaps among the various tube

screens should be controlled strictly to meet the requirements in the drawings.


56

Repair welding of the flat steel due to excessive fitting gaps is not allowed in order to

prevent from burning damage during the operation. When the bulk tubes at the 2#,3#

upper corners and the bulk tubes at the boiler bottom corners are installed on site,

the requirements in the drawings must be followed strictly so that the tubes in the

boiler could be at the same level. The spacing should be even, and the gaps should

be welded and sealed with flat steel or round steel to avoid leakage of flue gas or

ash during the operation. In the roof tube penetration area at the upper part of the

waterwall, all the gaps larger than 5mm must be welded and sealed with flat steel to

prevent the sealing devices and expansion joints from over-burning. When the upper

and lower tube screens are fitted, it is allowable to cut temporarily a section of flat

steel at the middle of the tube (without damaging the tube wall) to convenience the

fitting. After the fitting is completed, fill it up with round steel or flat steel and weld

them.

3.2.3 Operation 1) Encrust in pipe

Normally the heat transfer rate of furnace waterwall in design is very high, so only

good feedwater treatment can prevent encrust and copper and iron oxide deposition.

The insulation membrane made by deposed encrust on water side tube will increase

the tube surface temperature and may cause superheating in local tubes.

In high-pressure boiler, the iron oxide and copper oxide coming from feedwater may

cause internal corrosion at deposition zone, even tube destruction. Under this

condition, the water treatment of upstream steam drum system contains the control

of corrosion. Before putting into operation, the acid wash for the boiler circulation loop is good to

cleaning of boiler internals. After long time operation, it is necessary to acid wash the

boiler, especially when the feedwater can easily cause encrust or oxide deposition.

2) Blow-down

Boiler blow-down is a method to control the boiler water density (salt and alkaline)

and eliminate the deposition. The quantity of blow-down is decided by the working

condition online, such as water characteristics, water treatment characteristics, boiler

design and the evaporative rate. For most cases, the continuous blow-down system

can satisfy the requirements of controlling the boiler water density (salt and alkaline)


57

and eliminating the deposition.

However, in case that the quantity of deposition is very large while the feedwater

treatment is not very effective due to the high content of solid substance, the boiler

shall adopt the drainage of downcomer to achieve periodic blow-down.

3) Ash deposition (slagging)

The amount and speed of slag are largely decided by the fuel types. The furnace

waterwall cannot thoroughly avoid slagging, but it should keep “enough clean”(refers

to the note), and the proper use of sootblower devices can prevent severe local

slagging.

Note: at the early stage of operation, the steam temperature will be lower than the

design value. The reason is the excessive cleanness of furnace waterwall causes

the furnace heat absorption rate higher than normal condition. The period of set-up

“normal” slagging is called as “ageing”, and it is universal for the coal-fired units,

which use high ash content fuel, and some oil-fired units. The extension of “ageing”

is up to change of the characteristics of the fuel (characteristics of ash content).

At the stage of commercial operation, the furnace waterwall increasingly get fouling.

And this will cause the increase of furnace outlet flue gas temperature and steam

temperature, even exceeding the steam temperature control value. But the steam

temperature can be controlled within the operation range by furnace sootblowers.

4) Water quenching of floor tube

When directly contact with the comparatively cold water below the water-cooled

hopper bottom, the waterwall tube of boiler floor can produce fatigue failure.

Although the design of hopper and ash disposal system can meet with normal

operation code, abnormal working condition will still cause water quenching of

furnace waterwall. Therefore, the control to water level of water sealing of slag

disposal is of key importance.

3.2.4 Maintenance 1) Inspection

The routine inspection of furnace waterwall, steam drum and header are at every

boiling out, first time acid wash, routine acid wash and every unit trip period. During the inspection, open the steam drum manhole and dismantle the handhole

cap, then inspect the steam drum internals conditions and sampling inspect the

tubes, inspect the internal encrust to the tube section, after all the fouling is


58

diminished, use clean water to clean the headers, steam drum and pipes, and

inspect the blister outside the furnace tube, overburning corrosion and fissure (the

surrounding area of sootblower is easily eroded). For this purpose, the slag and ash

deposition in all the furnace tubes at fireside surface should be cleared.

The water-cooled hopper bottom should be inspected at the early stage of boiler

operation. The installment and operation of slag removal system, and any observed

conditions that may cause boiler floor water quenching (in normal or abnormal

working conditions) should be corrected.

All the inspections should be thoroughly proceeded in every detail, which shall be

performed by those personnel who have certain capabilities and are familiar with

boiler operation, maintenance, water treatment and so on. Every inspection record

should be filed in the same manual, so as to check all the corrected results to the

original condition. If the conditions of tube destruction or that may cause tube destruction is found, the

inspection to the tubes should be more thoroughly. If the sources of the conditions

are not clear or indefinite, then the inspection should include metallographic

examination to the tube section, chemistry analysis to the encrust, etc.

2) Tube repairing

The broken tube parts, which must be replaced because of severely destruction,

under most circumstances, can be easily replaced. After diminishing the heat

insulation material on furnace wall behind the destroyed parts of tubes, cut out the

tubes at enough height along the vertical direction of the broken tube parts, then

carefully cut out the fins on tubes both sides, (refers to the note) then take out the

tube section. Before welding with the new tube section and re-welding, good welding

groove preparation must be done.

Note: installing new tubes, the cut out of pins along the pipe lengthways should

extend to enough length near the tube vertical fracture, in order to allow thorough

welding along the tubes’ circumferences. The fins between the tubes must be

exchanged and sealed.

3.3 Economizer 3.3.1 General Description The functions of ECON are to preheat the feedwater before it comes into the steam

drum, and recycle part of heat in the exhaust gas to make the boiler more economic.


59

ECON is located below the low temperature superheater of back pass. ECON is

arranged in 2 banks. ECON adopts bare coil tubes with OD. 51mm, material of

SA210 C. There are 116 rows of coil tubes all together in ECON. Each row of them is

made up of 3 parallel coil sleeves, arranged in-line with horizontal spacing of 120mm

and vertical spacing of 102mm. ECON is hung by hanger plate and pipe clip, which

are hung to the bottoms of 3 ECON intermediate headers. They are hung in 3 rows.

And the weight of each row is undertaken by 56 hanger tubes at ECON intermediate

header. The outside diameter of the hanger tube there is 60mm, and material is

SA210- A1. The cooling medium inside the hanger tube is from ECON.

One DN300 check valve and one DN300 electric gate valve are set at the

economizer inlet pipeline. An economizer recycling tube is provided between the

furnace rear sewage bag and the economizer inlet pipeline.

In order to assure that the flue gas is evenly distributed in the back pass, baffle plate

are welded at both the rearwall enclosure tube of low temperature superheater inlet,

and the frontwall and rearwall enclosure tubes. The purpose is to avoid the forming

of flue gas passage, and local wear.

3.3.2 Operation At boiler’s star-up, 1 electric stop valves on ECON circulation piping must be open, in

order to provide enough water flow to ECON, and prevent ECON from gasification.

This valve can only be closed after a continuous water flow has been set up.

3.3.3 Maintenance a. At the time of unit trip and before operation, inspect the exterior of ECON. If

necessary, do the cleanings. As to the new unit, careful inspection to ECON is

needed. Pilling up and blocking of materials for assembling such as wood, heat

insulation material, welding electrode is very normal. The big sundries should be

eliminated by hand.,then water wash ECON.

b. Inspection hole should be tightened closely. And check the closeness of

Inspection hole at any time.

3) The usage times of sootblowers is up to the actual ash deposition in ECON. When

the first time of operation for ECON, the sootblowers should be used for every shift.

And the interval of sootblowing is decided by the changes of flue gas resistance

observed between the 2 neighboring sootblowings. In most cases, it is found that


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once a day for operation of ECON sootblower or even less is suitable.

3.4 Superheater 3.4.1 Introduction The superheaters are designed in radiation and convection type. All the

superheaters except for the low-temperature SH are arranged at the high flue gas

temperature area with in-line position. Large piping and tees are used for connection

so as to improve the mixing of steam.

The superheater consists of 5 parts: roof and side wall superheater of back pass and

convection pass, → low temperature superheater →division panel superheater

→platen superheater → final superheater.

1) Roof and side wall superheater of back pass and convection pass

The tube specification of roof and side wall superheater of back pass and

convection pass show in table below

.Item Size

mm qty.

spacing

mm material

Front roof Φ51×6 122 114 SA210-A1

Sidewall of

back pass Φ51×6 182 114 SA210-A1

Front wall of

back pass Φ45×6 92 152 SA210-A1

Rear roof Φ45×6 117 120 SA210-A1

Upper rear wall of

back pass Φ45×6 117 120 SA210-A1

Lower rear wall of

back pass Φ38×5.5 96 145 SA210-A1

Convection pass

EXT. side wall at

RH. finish

Φ45×6 72 94 SA210-A1

Back pass EXT. Φ51×6.5 60 102 SA210-A1


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sidewall at final

SH.

2). Low temperature SH

The low temperature SH is arranged above the ECON inside the back pass. There

are 116 assemblies with transverse spacing 120 mm, longitudinal spacing 102 mm.

Each tube assembly is made of four(4) parallel tubes of material OD.51mm,

thickness 7\6.5\6 mm, SA213-T22, SA213-T11, SA210-A1 . Specification show in

summary table 3.4.3.

The low temperature SH tubes are hung by the ECON suspendant tubes.

3). Division panel SH

Division panel SH is located at the upper furnace. There are 4 big assemblies

arranged in the furnace width with transverse spacing of 2565\ 2736\3420mm. Each

big assembly is composed of 6 small assembly. Each small assembly is composed

of 9 parallel tubes, with OD of 51mm. The bottoms material of No.1~3 tube is

SA213-T91, all the other is SA213-T11, T22. Specification show in summary table

3.4.3.

The fixing between tubes adopts sliding junction made of heat-resisting stainless

steel, which is composed of 1 protruding-shape junction and 2 concave-shape

junctions. These 3 junctions are directly welded onto the tube. Their function is to

connect tube one another, and to assure that each tube can freely expand in the

vertical direction. The junctions are arranged at 4 locations along the tube height of

division panel SH..

4). Platen SH

Platen SH is located behind the division panel SH. There are 23 assemblies in all.

Each assemblies is composed of 13 parallel tubes, the exterior tube size is

OD.60mm, while the other tubes size is OD.54mm. Their traverse spacing is 684mm.

longitudinal spacing is 63 mm. The bottom of the exterior tube and the bottom of

the interior tube is made of the material of stainless SA-213 TP347H，all the other

tubes SA213 -T22、T23、SA-213 T91. Specification show in summary table 3.4.3.

The fixing between the tubes of platen SH. is the same as that of the division panel

SH., adopting movable junctions. The junctions are arranged at 5 locations along the


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height direction of rear platen SH.. The traverse fixing between the platen SH.

assemblies adopt the locating tube of fluid cooled spacer tubes. The cooling steam is

educed in 2 line from the inlet pipe of backpass EXT. side wall at SH finish, one is

used for the traverse fixing of Platen SH, while the another one is used for the

traverse fixing of Platen RH.

5). Final SH

Final SH is arranged in the convection pass. There are 81 assemblies with

transverse spacing 171 mm, longitudinal spacing 102 mm. Each tube assembly is

made of four(4) parallel tubes of material OD.51mm, thickness 7\7.5mm, SA213-T23 .

Specification is in summary table 3.4.3

3.4.2 Operation For the operation instruction for whole boiler, please refer to “730-1-8602 , Boiler

Operation Instruction”. For the operation instruction of vent and draining valves,

please basically refer to following principle. (For the operation instruction of RH,

please refer to the section of RH).

Prior to ignition, draining valves on header and vent valves in the piping will be

opened in order to fully drain the bypass SH and main steam piping (specially after

hydro test). After draining, the vent valves in the piping will be closed immediately

when boiler generate steam. The draining valves on the header of back pass will be

closed when turbine is on line.

The draining valves and vent valves in the main steam piping are used for

exhausting the air during start-up, which will be opened before the turbine is

operated in low load. These valves can be used for throttle when the pressure of

steam drum increases. It ensures that the enough steam can flow through SH. The

vent valves on heater and piping will keep to be open before steam drum pressure

reach 172KPa(25Psig), which will be closed when the pressure of steam drum

reaches 172KPa. The draining valve which is close to turbine will coordinate with the

start-up vent valve during operation in order to provide more steam flow for draining

and for heating main steam piping prior to turbine rolling.Specification of SH. heating

surface is in summary table 3.4.3


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3.4.3 Specification of SH. Heating Surface

Item No. of

assemblies

No. of

elements

Transverse

spacing mm

Longitudinal

spacing mm Tube specification mm material

low temperature SH

Vertical section 1#~4# Φ51×7 SA213-T22

Upper section1#~4# Φ51×6.5 SA213-T11

Medium section1#~4# Φ51×6 SA213-T11

Lower section 1#~4#

116 4 120 102

Φ51×6 SA210-A1

Division panel SH

1# Φ51×6,Φ51×6.5 SA213-T91，SA213-T22

2#~3# Φ51×6,Φ51×6.5 SA213-T91，SA213-T22

4#~8# Φ51×6.0,Φ51×6.5,Φ51×7.0 SA213-T11，SA213-T22 9#

24 9 2736 60

Φ51×6.0,Φ51×6.5,Φ51×7.0 SA213-T11，SA213-T22 Platen SH

1# Φ60×7.5, Φ60×9 SA213-T23 SA213-T91，SA213-TP347

2#~3# Φ54×7, Φ54×7.5, Φ54×8 SA213-T23 SA213-T91 4#~6# Φ54×7,Φ51×7.5Φ54×8 SA213-T23 SA213-T22 7#~12# Φ54×7,Φ54×7.5 SA213-T23 SA213-T22

13#

20 13 684 63

Φ54×7,Φ54×8 SA213-T23 SA213-TP347 SA213-T22

Final SH

1#~4# 81 4 171 102

Φ51×7,Φ51×7.5 SA213-T23


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3.5 Reheater (RH)

3.5.1 Description

The temperature of RH steam is controled by burner nozzle tilting. RH is arranged at the

high flue gas temperature area, with in-line position.

RH is composed of radiation wall RH, platen RH and final RH. Each stage heating

surfaces of RH is connected to each other by big pipes and Tee junctions.

Radiation wall RH locate at the front wall and side wall of upper furnace. Radiation wall

RH covers a portion of waterwall. There are 204 tubes all in the front wall and 119 tubes

at each sidewall. These tubes are OD.54mm, thickness 5mm, material SA213-T22. The

radiation wall RH tubes are fixed to the waterwall by the connecting plate and tie rod.

The radiation wall RH and the waterwall can move comparatively, so as to avoid

expanding stress.

Platen RH is located above the arch nose, and behind the Platen SH. There are 30

assemblies in total with traverse spacing 456mm. Each assembly is composed of 14

parallel tubes. The tubes size OD.63mm, material A213-T22, T23 and SA213-T91. The

fixing between assemblies and longitudinal tubes of platen RH are the same as that of

the Platen SH.

Final RH is located inside the convection pass in front of final SH. There are 60

assemblies in total with traverse spacing 228 mm. Each assembly is composed of 7

parallel tubes. The tubes size OD.63mm, material SA213-T22 and SA213-T91. The

fixing between assemblies and longitudinal tubes of final RH are the same as that of the

final stage SH. Specification of RH. heating surface is in summary table 3.5.2


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3.5.2 Specification of RH. heating Surface：

Item No. of

assemblies

No. of

elements

Transverse

spacing mm

Longitudinal

spacing mm Tube specification mm material

Platen RH Φ63×4.0, Φ63×4.5 SA213-T22, T23 SA213-T91, TP304H

1# Φ63×4.0 SA213-T22, T23 SA213-T91, TP304H

2#~6# Φ63×4.0 SA213-T22 7#~12# Φ63×4.0 Φ63×5 SA213-T22

13#~14#

30 14 456 73

Φ63×4.0, Φ63×4.5 SA213-T22, T23 SA213-T91, TP304H

Final RH 1# Φ63×4.0, Φ63×4.5 SA213-T22 SA213-T91

2#~3# Φ63×4 SA213-T22 SA213-T91 4#~5# Φ63×6 SA213-T22

6# Φ63×4 SA213-T22 SA213-T91 7#

60 7 228 114

Φ63×4, Φ63×5.5 SA213-T22 SA213-T91 Radiant wall RH. 442 57 Φ54×5 SA213-T22


66

3.5.3 Operation Open all drain valves and vent valves before ignition, vent valve and drain valve

which leads to the atmosphere shall be closed before the condenser become

vacuum, drain valve which leads to condenser can be kept opened before the

turbine carrying low load.

3.6 SH and RH Control & Protection Maintenance 3.6.1 Control & Protection Necessary control and protection must be provided to SH and RH during

combustion, especially when the turbine has no need of steam, and its

protection is more important at start-up and shutdown stage. In the meanwhile,

there is no steam go through turbine, steam must go passing header，live steam

piping drainage and venting in order to assure enough flow in SH. During boiler

initial firing, RH drainage and venting provide residual moisture evaporation for

vertical RH piping.

This boiler utilize header drainage under back pass steam enclosure as handy

start-up bypass system，its capacity is 5%MCR，pressure is 4.14MPa. During

start-up，drain valve is full-open, and furnace combustion rate is increased so as

to improve and control the superheated steam temperature. During start-up,

superheated steam temperature is controlled by combustion rate within furnace,

superheated steam pressure is controlled by drain valve，close it after the

turbine synchronized, the drainage system directly goes to the condenser or

drain flash tank. The use of 5%MCR handy start-up bypass system shortens

start time and improves operating flexibility.

Piping strength and matching valves for bypass drainage system shall be

designed per full load design pressure.

safety valve is another control and protecting measure，and is essential. Safety

valves, which installed on SH main steam line, set-pressure is a little lower than

the one installed on steam drum, which assures adequate steam flow pass

through SH. The set-pressure of safety valve arranged at RH outlet piping is a

little lower than that of the safety valve arranged at RH inlet piping. Therefore,

this also assures enough flow passing RH.

PCV are installed on main steam line，its setting value is a little below the one


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for main steam line safety valve. PCV discharge amount is excluded from total

safety valve release, which required in boiler regulations, PCV discharge

amount is normally 10%MCR at least. And this PCV is accompanied with

isolation valve for overhaul.

During the whole process of start-up, the overheating of SH piping and RH

piping should be avoided. Especially in case that the turbine bypass is not used,

the furnace combustion rate should be controlled to maintain the flue gas

temperature at furnace outlet lower than 540, and to protect the wall-type RH.

Flue gas temperature probes are arranged at the panel bottom of the side wall

of upper furnace, so as to monitor the gas temperature at furnace outlet.

Thermocouples are installed on end tubes of roof SH and RH threading out roof,

during initial stage and normal operation, this can be used to supervising metal

tube wall temperature. Alarm temperature supervising set up on all levels of

heating surface act as another protective measure.

On the walls at the boiler furnace, horizontal flue and back pass roof enclosure,

30 boiler tube leakage automatic alarming devices are provided to detect any

leakage or leakage pre-alarming at the tubes of the heating faces such as

in-boiler waterwall, superheater, reheater and economizer in real time. For the

specific arrangement of the measurement points, refer to Fig. 502730-E1-10

“port arrangement drawing”.

3.6.2 Maintenance SH and RH external and internal cleaning is related with reasonable structural

arrangement, for instance: fly ash slagging leads to flue gas uneven，ineffective

heat conduction and potential local overheating. Reasonable sootblower

arrangement and appropriate periodicity sootblowing are major means to keep

external surface clean.

Periodic inspecting SH and RH appearance cleaning, reasonably use

sootblower can minimize slagging, immediately remove severe slagging, local

slag leads to tube local overheating and tube damage. in addition，slag may

blocking flue gas flow, cause uneven heat transfer and made operation

difficulty.

Reasonable water treatment，qualified steam and control of carrying are major

factors to assure SH internal surface clean. overload in operation, load swing,


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high water level,high concentration and water foaming etc. would influence

internal surface's cleanness, forming sediment，sediment collection in tubes

leads to boiler accident. so，spray attemperator installing shall made sure

condensate water used to avoid solids carry in SH，RH and turbine. Regular

checking SH and RH steam pressure drop under identical load. Markedly

increased pressure drops means depositions exist.

If tube element has trouble, it's best to inspect and analyses reason, also can

discuss the overhaul procedure and accident prevention adequate measures

with the manufacture.

3.6.3 Inspection In order to assure boiler long-term continuous operation, the customers

shall observe normal maintenance and inspection manual.

a. Check SH and RH when the boiler is shutdown.

b. Check tubes regularity， reeling and rugged evidence. Replace them or

the one with other superheated evidence.

c. check position and behavior of hanger and support， clamp device and

seal plate, timely repair and replace damaged pieces.

d. check internal surface's cleanness (by pressure drop) or exam deposit

in steam drum, if any, it must be removed.

3.7 Desuperheater 3.7.1 SH steam Desuperheater SH system is equipped with 2 stages of spray desuperheaters. The quantity of

primary spray desuperheater is one. It is arranged at the connecting piping

between low temperature SH and division panel SH. The spray nozzle of

primary spray desuperheater adopts the flute-type tube structure with multiple

pores. The flute-type tube is of OD.108mm, thickness 5mm, on which 135 pores

of size OD.7.5mm are arranged. The primary spray desuperheater header

adopts size of OD.610mm, thickness 65mm, material of SA335-P22. The

quantity of secondary spray desuperheater is one too. It is arranged at

connection pipe of final stage SH inlet. The spray nozzle of secondary spray

desuperheater adopts the flute-type tube structure with multiple pores. The

flute-type tube is of OD.76mm, thickness 7mm, on which 48 pores of size


69

OD.5mm are arranged. The secondary spray desuperheater header adopts size

of OD.610mm, thickness 90mm, material of SA335-P22.

The spray direction of desuperheater is the same as the flow direction of steam.

After spraying from the pores of flute-type tube in the form of fog, the sprayed

water is mixed with the steam and then flow tighter with the steam inside the

shell course of desuperheater to reduce the steam temperature. The amount of

water spray is different at different working loads. The amount of water spray

can be adjusted by using the adjusting valve of desuperheater system.

3.7.2 RH Desuperheater RH Emergency desuperheaters are arranged at the piping of RH cold end. That

is to say, one RH emergency desuperheater is located on the left, while another

one on the right. The spray of RH emergency desuperheater is not needed in

the normal working condition. It is used only for the emergency. The header of

RH emergency desuperheater adopts size of OD.559mm, thickness 26 mm

material of SA106-B. The spray direction of RH emergency desuperheater is

the same as the flow direction of steam.

3.7.3 Maintenance Each desuperheater is equipped with a replaceable liner, so as to avoid the

alternating stress caused by the contact between spray water and the inner wall

of shell course, and to prevent the wear caused by the spray water flow. In this

way, the main shell of desuperheater is protected. If there is very loud noise

coming from the inside of desuperheater, that means the liner has been worn.

In that case or any abnormal case, the manufacturing plant shall be contacted,

and the liner shall be replaced if necessary.

4 Others 4.1Steel Structure Boiler frame is stand-alone type. Load-bearing member is connected with high

strength bolts. The diameter of high strength bolts are M22. The whole boiler

frame can be divided into five installation layer, including: each vertical bracing,

horizontal bracing, roof hanger and support, level, stairway, boiler roof, etc.

Vertical bracing is composed of steel column and intercolumnar bridging,

respectively disposed along boiler depth and width direction. Earthquake force

and air force are transferred to boiler foundation through vertical bracing.


70

Horizontal bracing is composed of five rigidity levels along boiler short

transverse. It helps support and transfer horizontal loading, control boiler

expansion, keep structural stable.

Roof hanger and support level is composed of roof steel frame，pressure parts

hanger and support level, roof support etc. boiler heating surface is suspended

at pressure parts hanger and support level via hanger rod, roof steel frame is

composed of main beam, secondary beam and level support，forming a rigidity

level，hanger and support level beam of pressure parts is connected to

secondary beam with high strength bolt.

The boiler main stairways are concentrately disposed at boiler both sides, near

front furnace. Together with the platform, the boiler stairways form the passage

system for boiler maintenance, oversee and overhaul.

The roofing located at the top of the boiler adopts pestle structure. The roof

surface adopts galvanized undulated plate, enclosure plate is setuped around

the bottom of roof.

Boiler steel frame has 6 main beams in total. The steel columns adopt H bars.

The platform adopts galvanized grid. Among them, the biggest width is 1200mm.

The inclined angle of main stairways is 42 digress.

4.2 Sealing and Insulation Boiler air membrane type heating surface sealing adopt internal casing and

tightness, reliable expansion joint etc. Internal casing are disposed at roof, arch

nose, furnace chamber bottom, back pass etc. Back pass, joint at front

waterwall with roof use corrugated-type expansion joint. Use all-welded

structure for expansion joint between roof tube and side wall, expansion cubicle

is used at radiate RH threading out roof. Metal penthouse is arranged at the

boiler roof, to centralize the heat preservation. It also ensures no flue gas and

ash leakage. Boiler proper adopt high grade low-duty insulation material，

outside is metal external casing, when ambient temperature is 27, furnace

outer wall shall be not more than 50.

For the details, refer to 730-1-8607 “furnace wall and insulation manual”.

4.3 Air preheater (APH) The boiler is equipped with two trisection rotary Air Preheaters. For the details,


71

refer to 770059-2-7201”APH technical document list for user”

5 Boiler Hydro Test After installation, all the pressure parts of the boiler shall conduct a hydro test.

The water circulation system, SH and ECON shall conduct the hydro test as an

integrated individual. RH shall conduct the hydro test independently.

5.1 The Pressure of Hydro Test For the primary steam system, the pressure of hydro test shall be 24.74MPa,

which is 1.25 times of the designed boiler pressure

For the secondary steam system, the pressure of hydro test shall be 6.30MPa,

which is 1.5 times of the designed boiler pressure

5.2 Water Quality The water shall be treated condensate water or de-mineralized water, added by

10PPm ammonia or 200PPm hydrazine treated filtering water. The PH value of

the water shall be about 10, the solid contents of the water shall be no more

than 1PPm, the organic matter density shall be about zero, the chlorine ion

contents shall be no more than 25ppm, and the water temperature shall not be

less than 35

5.3 Notices a. Solid-chemical treated water shall not be used, so as to avoid the solid

matter deposit in SH or RH.

b. The metal temperature of pressure parts shall be no less than 35

during hydro test.

c. Ensure all foreign material in steam drum and header are removed

before boiler filling.

d. Before a hydrostatic test with pressure higher than the normal operation

pressure is carried out, plugs and tightening devices should have been

installed on all the safety valves as per the instruction manual of the

manufacturer (730-1-8609 “Safety valve instruction manual” and

730-1-8610 “Powered relief valve instruction manual”).

e. ECON recirculation pipeline valve shall be fully open if filling the boiler

via economizer, which not only easy to do, but also reduce carried air as

much as possible.


72

5.4 Water Volume of Boiler Pressure Parts

Water-circulation

system

190m3 (wherein steam drum owns

50m3)

SH system 220m3

Economizer system 50m3

RH system 90m3

Total water volume 550m3

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