再热汽温变化对机组热耗率影响的修正分析

A Analysis for Correction of the Effect of Reheat Steam Temperature on Steam Turbine Heat Rate

以火电机组热经济性分析的统一物理模型和数学模型为基础,根据多元扰动下的热力系统能效分析模型,得到再热蒸汽温度变化对机组热耗率修正的计算模型。并以某660 MW机组为例,计算得到了三阀全开工况下机组再热蒸汽温度对热耗的修正曲线,结果与厂家提供的热耗修正曲线相比误差较小,能够满足工程实际的需要。计算得到了此机组不同工况下再热蒸汽温度对热耗的修正曲线,得出负荷越低,再热蒸汽温度的变化对机组热耗率的影响越大,应密切监视低负荷时再热蒸汽温度的偏离。

Based on the unified physical model, mathematical model for thermal economy analysis of thermody namic system and energy efficiency analysis model of thermodynamic system under multivariate disturbances, cor rection of reheat steam temperature on heat rate calculation model has been built. Taking a 660 MW power unit as an example, heat rate correction curves for reheat steam temperature were calculated and drawn under the three valve full working condition. Compared with the curve provided by manufacturers, the errors are smaller. The mod el can meet calculation requirements of actual engineering projects. Heat rate correction curves for reheat steam temperature under different working conditions have been calculated and drawn. Then analyzed out that the load is lower, the effect of heat rate on reheat steam temperature deviation is greater, so it should be important to closely monitor the deviation of reheat steam temperature under lower load.