基于凝汽器压力估计算法的循环水泵最优运行

The Optimum Running of Circulating Water Pumps Based on Estimated Condenser Pressure

确定循环水泵最优运行方式的关键在于计算循环水泵在不同运行方式时的凝汽器压力估计值。现有文献在利用凝汽器变工况计算凝汽器压力估计值时,认为汽轮机低压缸排汽和凝结水之间的焓差保持不变,同时还难以准确计算出凝汽器总体传热系数。针对上述问题,该文基于换热理论提出了一种新的凝汽器压力估计值计算方法。同时考虑闭式循环水系统中冷却塔对循环水入口温度的影响,确定出循环水泵最优运行方式。并将该方法应用到某2×600MW机组中。

The key to determine optimum running mode of circulating water pumps is to calculate the estimated value of condenser＇s pressure when pumps are running in different modes. The existing literature assumed enthalpy difference between low pressure （LP） cylinder exhaust steam and condensate stayed the same when calculating the estimated value of condenser pressure through the variable condition calculation of condenser. Meanwhile, it was hard to accurately calculate the heat transfer coefficient of condenser. In allusion to the problems above, a new method on the basis of heat transfer theory to calculate the estimated value of condenser pressure was put forward. Cooling towers＇ influence on the inlet temperature of circulating water was also considered to determine optimum running mode of circulating water pumps. The new method was applied in 2×600 MW power plant.