Use of Performance Models for Powerplant Performance Testing

Abstract This paper shows that a thermodynamic performance model corrects test measurements more accurately than the customary correction curves. Traditional correction procedures use polynomial correction curves derived from various types of performance models. This paper compares the traditional polynomial correction curve-based approach against the direct use of a performance model for one composite correction factor for each performance indicator (power, heat rate, etc.). In addition, the paper demonstrates how the direct use of a performance model facilities the estimation of test result uncertainty, using Monte Carlo methods. The paper is based on ASME’s most recent Performance Test Code, PTC53-2022 for Mechanical and Thermal Energy Storage Systems, which permits the use of a performance model for correcting test results. Non-mandatory appendix A of PTC-53-2022 illustrates the customary approach of using correction curves for correcting performance of an Energy Storage Combined Cycle, where thermal energy storage is coupled with gas turbine exhaust heat. A performance model can aid the performance testing process by more accurately correcting test measurements for variations from the design or guarantee point and by preparing a stochastic ‘uncertainty cloud’ based on the uncertainty of the primary instruments used to correct the measured performance.