660MW超超临界机组循环水系统节能优化分析

冷端系统是火电厂发电机组重要的辅助系统,它的工作状态和运行特性对整个电站机组的稳定性、安全性和经济性都有较大的影响。对某660 MW超超临界机组两台循环水泵电机进行改造,增加了循环水泵运行方式(单机运行时一小、一大、一大一小;双机运行时二小、一大一小、二大、二大一小);建立了机组冷端性能分析计算模型,结合实际运行状况,给出了不同负荷、不同温升等工况下循环水泵组合优化运行方式;针对机组频繁启停状况,通过合理利用运行机组循环水,达到降低开停机过程循环水泵耗电量的目的。研究为同类机组冷端系统运行方式提供借鉴。

Energy-saving optimization analysis of circulating water system in a 660 MW ultra supercritical unit

The cold-end system is an important auxiliary system of the generating unit in the thermal power plant. Its working conditions and operation characteristics have great influences on the stability, safety and economy of the whole power plant unit. In this paper, two motors of the circulating water pumps from a 660 MW ultra supercritical unit were reformed by adding the operation modes. The modes included one small, one large, or one small and one large when single motor run, while they contained two small, one large and one small, two large, or two large and one small when two motors run. The calculating model of the cold-end system was established. The optimized operation modes of the water pump combination under different loads, temperature rising and so on were determined by considering the actual operation conditions. As for the frequent startup/shutdown condition of the unit, the power consumption of the circulating water pumps could be reduced by reasonably utilizing the unit circulating water. The results can provide a reference for the operation mode of the cold-end system in the similar units.