Developing Updated Performance Parameters for EPRI’s Heat Rate Improvement Guidelines
EPRI Heat Rate ImprovementConference - 2013
Bill Kettenacker, PEScott Nedrow
February 5-7, 2013
2
Introduction
3
Purpose of This Effort
Update 1986 Appendix B - “Performance Parameter Accounting Manual” in Heat Rate Improvement Guidelines for Existing Fossil Plants (EPRI CS-4554)
Purpose of Guidelines “. . . (to) develop generic guidelines enabling utilities to implement plant heat-rate improvement programs.”
Old Guidelines Based on Industry Experience (129 plants)
- No Specific Load- No Specific Plant Size
New Guidelines Based Solely on Computer Simulation- Many Loads- 3 Plant Sizes
Why is Heat Rate Important?0.5% Heat Rate Improvement = $750,000 / yr- 640 MW Coal Unit- $3.80 / mmBTU- 72% Capacity Factor- 9,900 BTU / kW-hr Heat Rate
Other Benefits- Increased Generation- Reduced Emissions
5
Parameters Studied
HP Turbine Efficiency
IP Turbine Efficiency
Main Steam Pressure
Main Steam Temperature
Reheat Temperature
SH Attemperation Flow
RH Attemperation Flow
Excess O2
Exit Gas Temperature
Condenser Backpressure
Unburned Carbon
Coal Moisture
Auxiliary Power
Makeup
Feedwater Heater Performance
Reduced Load Operation
How Study Was Performed
PEPSE Software Analysis 3 Different Plants for T/G Studies,
150 MW, 300 MW, 650 MW, Interpolate to 500 MW for Average
T/G - 9 Loads, 110% - 20% 1 Boiler for Its Studies – 4M lb/hr
Steam Flow Boiler – 1 Load, Variation in
Parameters Results Tabulated in a
Spreadsheet
Load BTU/kwh/°F
110% 1.972100% 14.98075% 122.24650% 400.01725% 891.393
PEPSE
Modular, steady-state, first-principle, energy balance program – Windows based
35+ yrs application by utilities, A-E’s, others
All types of plants• fossil• nuclear• gas turbine/combined cycle• heat recovery• geothermal• cogeneration• thermal solar
Representative Turbine Cycle
Representative Boiler
Procedure
T/G - PEPSE Model - Cases for Plant and Load- 150 MW, 300 MW, 650 MW- 110% Load to 20% Load- Results Interpolated to 500 MW
Boiler – PEPSE Model - Cases for Single Plant/Load
Results Tabulated in Spreadsheet- Heat Rate- Generation (Not in 1986 Report)
Correlations Developed from the Tabulated Results
Report Page – HP Efficiency
HP Efficiency – Heat Rate
HP Efficiency - Generation
Report Page - Condenser
Condenser Backpressure – Heat Rate
-50
0
50
100
150
200
250
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
∆ H
eat R
ate
(BTU
/kW
-hr)
∆ BP (in-Hg)
∆ HR vs. ∆ BP
150 MW
300 MW
650 MW
Condenser Backpressure - Generation
-10
-8
-6
-4
-2
0
2
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
∆ P
ower
(MW
)
∆ BP (in-Hg)
∆ MW vs. ∆ BP
150 MW
300 MW
650 MW
Turbine Cycle Results – 2012 vs 1986
Parameter Units 2012 PEPSE
1986Guidelines
1986 Guidelines
HP Efficiency B / kWh / % 15.4 18.8 17.9 ‐ 21.5
IP Efficiency B / kWh / % 11.3 14.5 11.0 ‐ 19.1
Main Steam Press B / kWh / psi 0.30 0.35 0.03 ‐ 0.65
Main Steam Temp B / kWh / oF 1.1 1.4 0.7 ‐ 1.7
Reheat Temp B / kWh / oF 1.0 1.3 0.9 ‐ 1.9
Condenser BP B / kWh / ''Hga Curve 204.0 42 ‐ 269
Make‐Up Flow B / kWh / % 54.9 24.0 4 ‐ 88
Auxiliary Power B / kWh / % 70.0 86.0 64 ‐ 97
Boiler Results – 2012 vs 1986
Parameter Units 2012PEPSE
1986Guidelines
1986Guidelines
SH Attemp Flow B / kWh / % MS Flow 3.0 2.5 1.3 ‐ 3.1
RH Attemp Flow B / kWh / % MS Flow 17.9 21.5 10.0 ‐ 36.6
Excess O2 B / kWh / % 26.7 29.4 10.0 ‐ 36.0
Exit Gas Temp B / kWh / oF 2.0 2.7 2.1 ‐ 4.2
Unburned C B / kWh / % 12.8 11.7 6.0 ‐ 12.8
Coal Moisture B / kWh / % 18.2 7.8 6.0 ‐ 10.0
FWHR Results – 2012 vs 1986
Parameter Units 2012PEPSE
1986Guidelines
1986Guidelines
FWHR 1 TTD B / kWh / oF 1.8 2.1 1.3 ‐ 2.3
FWHR 2 TTD B / kWh / oF 0.64 0.54 0.33 ‐ 0.63
FWHR 1 OOS B / kWh 117.6 94 ‐
FWHR 2 OOS B / kWh 23.1 70 ‐
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Conclusions
1986 vs 2012 Results – Very Close, a Few DifferencesSoftware Predictions (2012) = Industry
Experience (1986)New EPRI Guidelines Are Accurate Method to
Determine Performance Parameter ChangesSoftware an Accurate Way to Calculate
Performance Parameter Changes
Questions