Challenges in Evaluating Heat Rate Performance of New Technologies in Real World Applications

EPRI Heat Rate Improvement ConferenceFebruary 5-7, 2013Scottsdale, Arizona

Brad Woods – McHale & AssociatesMary Glass – Mexel USADennis Pednault – McHale & Associates

• Background

• Project Approach

• Project Results

• Lessons Learned

Discussion

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1675 MW PWR – 2 units

2.4 million GPM Circ Water

75,000 l/s CW/Condenser

396,000 GPM/Condenser

6 condensers with continuous mechanical ball-cleaning systems

Treated one condenser on Unit 2 with Mexel.

Nuclear Power Plant Case Study

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Condenser Data

4

Condenser – Shell Side

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Condenser – Tube Side

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Objectives Measure fouling rates Compare efficacy of Mexel against non-treated

Instrumentation (Temporary vs. Station) Accuracy vs Repeatability (Uncertainty) Timing

ASME PTC 12.2 Steam Surface Condensers

Project Background

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Project Approach

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Plant Goals•Down power events•Macro-fouling•Micro-fouling

Protocol/Planning Work PackagesInstallationMonitoringResults

Expected Results

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• Fouling Resistance

Test Approach

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( )p h cQ UA LMTD mc T T

( )P h cmc T TUA LMTD

1o

m t s fi

U DR R R RD

11

EFF

fClean

UR

U

•.Differential Pressure

Test Approach

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1.8M

C Mo

WdP dPW

Corrected LMTD

Temperature

Velocity

Load

Test Approach

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C M T W QLMTD LMTD f f f

0.25

O

S MT

S O

T LMTDfT LMTD

0.5T

WO

VfV

OQ

T

QfQ

Permanent Plant

Temporary Test

Instrumentation

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Humidity Data LossWaterDrivers

Hydroids Trends Fouling Events

Hydroids Grass Horseshoe crabs Blue crabs

Project Experience

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Test Interruptions

Issues

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Crabs

Issues

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Grass

Issues

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Data Acquisition

Issues

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LMTD

TTD

Heat Transfer Coefficient

Fouling

Expected Power Benefit

Paired t-Test

Test Results

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Test Results

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Test Results

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Test Results

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Test Results

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Test Results

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Test Results

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Test Results

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Test Results

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Test Results

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Plant Observed Results Plant personnel reported no discernible improvement Overall plant output

Conclusions Small proportion of plant treated Condenser Interconnection affected pressure Statistical tests

Results

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Paired t-test

Assessment

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t-Test: Paired Two Sample for Means

Variable 1 Variable 2Mean 0.87 0.77Variance 0.06 0.07Observations 63.00 63.00Pearson Correlation 0.95Hypothesized Mean Difference 0.00df 62.00t Stat 9.80P(T<=t) one-tail 1.65E-14t Critical one-tail 1.67P(T<=t) two-tail 3.30E-14t Critical two-tail 2.00

Instrumentation Data Acquisition Data

Nuclear limitations Performance monitoring Correlations

Methods Quick /relative to demonstrate expectations. Small difference but statistically significant Verification

Lessons Learned

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Assume 300 MW Assume summer peak Energy = $80/MWAssume 4 month period = 2,920 hours

Expected Power difference = 2.2% (6.6 MW)

Summer Savings = $0.77 million

Expectations

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Contact Information

McHale & Associates, Inc.www.mchale.org18378 Redmond Way, Redmond, WA 98052(425) 883-2058

Mexel USAhttp://www.mexelusa.com/1655 N. Fort Myer Drive, #350Arlington, VA 22209(703) 349-3347

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