CC THIT B O M LU LNG TI C MAU GDC

CC THIT B O M LU LNG TI C MAU GDCThc hin: Nguyn Hong Phng

K s vn hnh

PetroVietnam Gas C MauMC LC

ng ng PM-3 dn kh i vo trm phn phi GDC C Mau s c lc bi v nc, sau gia nhit, v c o lu lng - th tch nhit lng trc khi giao cho hai nh my in. Ngoi h thng o m kh cp cho nh my in, trm cn c mt s thit b o m lu lng khc. Bi vit sau y tng hp tt c cc thit b o lu lng ti GDC C Mau. Gm c:

I. H thng o m kh cp cho hai nh my inII. Thit b o m ti cm Instrument

III. Thit b o m ti ng ng Purge Gas v Pilot (duy tr ngn la mi cho Flare)

IV. Thit b o m ti ng ng Fuel Gas, cung cp kh t cho Heater

I. H THNG O M KH CP CHO HAI NH MY IN

1.1. Thnh phn cu to:

H thng o m kh cp cho mi nh my in gm c cc thnh phn nh sau:

Hai Ultrasonic Flow Meters.

Transmitter nhit , Transmitter p sut v ng h o nhit , p sut.

Cc Ball Valve ng vo v ra.

Mt my phn tch sc kh v mt my phn tch nhit im sng ca Hydrocacbon.

Mt ng kh ly mu phn tch.

Hai Flow computers.

Mt Station computer.

Hai my in

1.2. Nguyn tc tnh ton H thng o m lu lng da theo nguyn tc: tnh vn tc ca dng kh nh vo cc Ultrasonic Flow Meters, quy i chng v iu kin tiu chun (T = 15C, P = 101.325 Kpa) da vo cc gi tr nhit , p sut nhn c t cc Transmitter, t kt hp vi tit din ngang bit trc tnh c lu lng, v cui cng tnh c th tch kh theo thi gian.

V = F . t

= v . S . t

Trong : V: th tch kh (tnh theo tiu chun)

F: lu lng dng kh i qua USM

v: vn tc dng kh quy i v iu kin chun

S: tit din (trong) ng ng

t: thi gian

Ngoi ra , h thng cn c th tnh ton c lng nhit lng v khi lng cung cp nh vo kt qu phn tch thnh phn ca my sc k. My phn tch sc k (GC) s phn tch v tnh ton %mol ca cc thnh phn kh t C1 n C6+ (C6,C7,C8) sau gi v Flow Computer tnh ra nhit tr v khi lng ring ca chng. Sau kt hp vi lu lng ti tng thi im tnh ra nhit lng v khi lng cp cho nh my in.1.3. Ultrasonic Flow Meters

y l b phn quan trong nht trong h thng o m, cung cp gi tr vn tc tc thi ca dng kh phc v cho vic tnh ton th tch v nhit lng cung cp.Trm GDC s dng Ultrasonic Flowmeter ca hng Daniel, Model 3400. Mi mt b USM s bao gm 4 cp pht-nhn tn hiu siu m (Ultrasonic), chia thnh 2 nhnh: Pay v Check.Mt u pht tn hiu siu mNguyn tc hot ng V d minh ha 4 cp Ultrasonic: A-A, B-B, C-C, D-D

Ta s ni v 2 cp Ultrasonic A-A v B-B (nhnh Pay), nhnh check c nguyn l tng t).tn hiu i ngc chiu dng lu cht.

Tn hiu i cng chiu dng lu cht (A-A) c lu cht h tr thm, ngc li, tn hiu i ngc chiu (B-B) b cn tr bi dng lu cht, dn n s c tr khi nhn tn hiu gia hai cp Ultrasonic ny. Vn tc dng cng ln, tr cng nhiu. Lu cht khng chuyn ng, tr bng 0. V da vo tr ny, b x l s tnh ton c vn tc dng kh, cung cp cho qu trnh tnh ton lu lng. chu k tip theo, A v B s pht tn hiu, A v B s nhn, qu trnh din ra tng t.

Nguyn l hot ng ca thit b o m USM c th c tham kho trong cc Video Clip di y: (bm Ctrl + Click xem)http://www.youtube.com/watch?v=Bx2RnrfLkQg&feature=relatedhttp://www.youtube.com/watch?v=uvOW-7G_yG8&feature=related1.4. Transmitter nhit , Transmitter p sut: c chc nng o nhit v p sut, gi cc tn hiu ny v b x l phc v cho qu trnh tnh ton chuyn i v iu kin tiu chun (T = 15C, P = 101.325 Kpa).1.5. Cc Ball Valve ng vo v ra: C tc dng c lp Metering khi cn thit, ng thi dng iu chnh cc ch hot ng ca hai Metering (ni tip hay song song).1.6. My phn tch sc kh (GC): C nhim v phn tch v tnh ton %mol ca cc thnh phn kh t C1 n C6+ (C6, C7, C8) sau gi v Flow Computer tnh ra nhit tr ca dng kh trong tng thi im.1.7. Flow computer: Mi Metering s c mt Flow computer km theo, c nhim v nhn cc gi tr vn tc t c hai pay v check meter, cng cc thng s nhit v p sut t cc transmitters v cc thnh phn kh t hai my phn tch sc kh tnh ra sn lng kh cung cp cho nh my in.

Mt Flow computer s nhn mt gi tr Pay t mt USM v nhn mt gi tr Check t USM cn li kim tra, d hai USM c chy ni tip hay song song th vn gi quy tc nh vy. Cn gi tr nhit v p sut c s dng cho c hai Pay meter v Check meter.Pay meters dng o lu lng tnh tin vi khch hng.

Check meters dng kim tra li lu lng c o t Pay meters, phng trng hp tn hiu nhnh Pay b li, hoc Flow computer ca nhnh Pay b li.

Cc gi tr flow computers tnh gm c: Tng tch ly (cumulative totals)

Th tch th (gross volume) m3/h

Th tch iu kin chun (standard volume) kSm3/h (15oC, 1amt)

Khi lng v nng lng (mass & energy) Ton/h, GJ/h

Tng ca tng gi (hourly totals)

Tng ca tng ngy (daily totals)

Tng ca tng tun (weekly totals)

Tng ca tng thng (monthly totals1.8. Station computerStation computer ng vai tr nh mt cu ni trung gian gia ngi dng vi cc thnh phn khc ca thit b o m, bao gm nhng chc nng sau y:

Chuyn d liu ti Flow computer v nhn d liu t Flow computer

Cung cp cho ngi vn hnh mt giao din thn thit v h thng metering

To ra report ti thi im hin ti, tng gi, ngy, tun, thng, danh sch cc s kin v cc cnh bo

Cung cp kh nng lu tr nhng file reports theo mt th t c th tm li mt cch d dng.

Hin th v in report.

Hin th d liu phn tch ca my phn tch sc kh (GC).

Ly cc gi tr tnh nh: khi lng, nng lng,th tch th v th tch iu kin chun, t Flow computer1.9. My in: H thng metering gm hai my in, c chc nng nh sau:

Mt ci c ni ti Ethernet Switch in report cho station computer

Ci cn li c ni ti GC controller bng ng parallel printer in kt qu phn tch, cc cnh bo, kt qu khi ta hiu chun, hiu chnh GC.

II. THIT B O M TI CM INSTRUMENTCm Instrument ti GDC s dng thit b o m c tn gi Coriolis Flowmeter, thuc b The ROTAMASS 3 ca hng Yokogawa.

Coriolis Flowmeter gm 2 b phn chnh: B phn o: cu to gm hai ng nha hnh ch U dn hng cho dng chy, hai sensor cm bin, mt b phn kch thch. B phn ny c nhim v o cc gi tr lch pha, tn s dao ng v gi tn hiu v b x l.

B phn x l v mn hnh: c chc nng tnh ton cc gi tr lu lng, th tch, khi lng ring ca dng chy da vo cc tn hiu truyn v t cc sensor.

2.1. Nguyn l CoriolisCoriolis Flowmeter hot ng da trn nguyn l Coriolis ca nh bc hc cng tn, c pht hin cch y hn 200 nm. Vy nguyn l Coriolis l g?

i vi s t ngi, nguyn l Coriolis l mt nghin cu khoa hc chun xc, nhng vn cn xa l vi hu ht chng ta. Th tng tng, c mt dng chy (vi vn tc V) ang chy trong mt ng nha do c quay quanh trc (vi vn tc gc W) nh hnh v bn di.

Kt qu l dng chy s un cong on ng.

By gi, nu ta xt mt vt c khi lng M di chuyn t tm ra ngoi ra ca mt chic a ang quay, vt M s v ln ng B nh hnh v.

Nhng nu ta nh hng vt M trong mt rnh A, th vt M s i thng, v sinh ra mt lc tc dng vo rnh A, ta gi l lc Coriolis.

Lc Coriolis c tnh nh sau: FC = -2.M.V.W

Vi: FC : Lc Coriolis

M : Khi lng vt M

V : Vn tc ca cht lng

W : Vn tc gc ca chuyn ng quay

Da vo nguyn l trn ngi ta thit k mt thit b o lu lng vi tn gi Coriolis Flowmeter.2.2. Coriolis Flowmeter

i su vo cu to ca b phn o, chng ta c: Hai ng Plastic dn hng dng chy Mt thit b kch thch (Impulse), tc ng mt xung thch hp ln ng Plastic. Hai sensor t ti u vo v ra ca ng, nhn cc tn hiu chuyn ng ca ng

Khi lu cht ng yn, thit b kch thch s tc ng mt xung thch hp khin ng Plastic dao ng ng u v ghi nhn li tn s ny (ng mu hng bn di). Hai sensor cm bin hai u cng s ghi nhn tn hiu (ng mu xanh l v xanh dng) vi lch pha bng 0. Lc ny c ba th bn di s trng nhau ti v tr ca ng mu hng. Ta s dng tn s ny tnh ton khi lng ring ca lu cht.

Khi lu cht chuyn ng, chuyn ng ti ca dng lu cht kt hp vi dao ng to ra ca thit b kch thch s khin ng dao dng khng u hai u ng, dn n hai sensor ghi nhn cc tn hiu vi lch pha ( (ca ng mu xanh l v xanh dng), vn tc dng cng ln, lch pha cng ln, v gi tr ny s c dng suy ra vn tc ca dng lu cht.

Cc tn hiu s c gi v b x l suy ra lch pha, tn s dao ng v t tnh c cc gi tr lu lng, khi lng ring, th tch,

Nguyn l hot ng ca thit b o m Cloriolis c th c tham kho trong Video Clip di y: (bm Ctrl + Click xem)

http://www.youtube.com/watch?v=XIIViaNITIwIII. THIT B O M PURGE GAS V PILOT CHO FLARET cm Instrument, mt nhnh kh c a vo ng ng gp ui Oxi, mt nhnh khc c tc dng nh la v duy tr ngn la mi cho Flare. c hai nhnh ny u s dng cng mt loi thit b o m, l lu lng k dng phao (Variable Area Flowmeter), c tn Rotameter ca hng Yokogawa.

Nguyn tc hot ng:

Cu to chnh ca thit b l mt chic phao nm bn trong ng dn lu cht, c th chuyn ng ln xung trn mt trc c t ngay ti tm ng. Phao nh c lu cht c th i qua khong trng gia thnh ng v phao. Khi lu cht chuyn ng t di ln cng ng thi s nng phao ln. Vn tc dng cng ln th phao cng c nng cao. Khi lu cht khng chuyn ng, phao nm st pha di.Phao c kt ni vi mt c cu truyn ng ra bn ngoi (dng t trng), chuyn thnh chuyn ng quay v kch hot ln kim ch lu lng dng chy.

Nguyn l hot ng ca thit b o m lu lng dng phao c th c tham kho trong Video Clip di y: (bm Ctrl + Click xem)

http://www.youtube.com/watch?v=dQ5KQEdwM4U&feature=relatedIV. THIT B O M FUEL GAS, CUNG CP KH T CHO HEATER

T cm Instrument, mt nhnh kh na c dn ti Heater, nhm cung cp kh t cho qu trnh lm nng. Trc khi t, kh s c o lu lng bi mt lu lng k dng Turbine, c tn MC-II Plus EXP Flow Analyzer ca hng NuFlo.Nguyn tc hot ng

B phn chnh ca thit b l mt turbine cnh qut c t trong lng ng, chuyn ng trn xoay quanh trc ng. hai u l cc b m hm c tc dng n nh dng.

Khi c lu cht chuyn ng qua ng, turbine s quay. Vi vn tc v tnh cht ca dng khc nhau, turbine s quay vi cc tc khc nhau.

Mt b phn s ghi nhn s vng quay ca turbine v gi n b x l tnh ton ra lu lng ca dng chy nh vo cc h s turbine, tit din, c ci t theo khuyn co ca nh sn xut.Nguyn l hot ng ca thit b o m lu lng dng turbine c th c tham kho trong Video Clip di y: (bm Ctrl + Click xem)

http://www.youtube.com/watch?v=quKveqsgbek

Flow

A

B

A

B

Thit b kch thch

Sensor