Heat rate in a power plant cycle is a calculated value expressed as the ratio of the amount of heat supplied to the cycle divided by the amount of power that is generated. It is directly affected by the heat source and associated auxiliaries, the prime mover, the regenerative feedwater heating cycle and, the heat sink.
Heat rate computations also suffer from imprecision/time lags associated with fuel flow measurements, difficulties/uncertainties in determination of the actual amount of heat supplied to the power plant cycle and, measurement of the power that is generated. Consequently, many power plant owners and operators have reservations as to the intrinsic value of heat rate as a performance metric, since detailed analysis and evaluation of the underlying causes and issues are essential to account for deviations from predicted or expected values.
Several innovations and advances have paved the way for real-time monitoring, trending, analyzing, evaluating, diagnosing and optimizing power generating asset performance. Using a coal-fired unit as a representative case study, this paper provides an overview of how technical/technological advances in optimizing power generating asset performance facilitate concomitant optimization of heat rate.
