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 ‐

20

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