汽动给水泵流量分配对机组热经济性的影响分析

Analysis on the Influence of Unit Thermal Economy of Turbine Driven Feed Water Pump Flow Distribution

不同的流量分配使汽动给水泵出口压力发生变化,给水泵的效率随之改变,因此会影响机组的热经济性。以N1000-26.25/600/600超超临界机组为例,考虑了给水母管管道水力特性影响,建立了机组热经济性模型;计算出了6种不同给水方案的机组热经济指标,确定了给水泵的最佳运行方式。结果表明:两台汽动泵给水流量不同时,会导致与给水泵相连的除氧器和高压加热器抽汽量发生变化,进而引起机组热经济性的改变;不同工况下,当两台给水泵流量相同时,机组热经济性指标最佳,所对应的给水系统运行方式亦最优。

The different of flow distribution cause feed water pump outlet pressure changes lead to the efficiency of the pump changed. So the thermal economy of unit is affected. Taking N1000 -26.25/600/600 unit for example,considered the characteristics of hydraulic pipe water pipe, established the model of unit heat economy; calculated the thermal economic index of six different supply schemes, determined the optimal operation mode of the feed water pump. The results showed that different flow of two feed water pumps lead to connected to the import and export of high pressure heater extraction steam quantity and oxygen remover is different, thereby caused the change of unit heat economy; under different working conditions,when the feed water flow of two pumps is the same, the thermal economy of units is the better, meanwhile the method of feed water pump operation is the best.