300MW火电机组循环水系统最优运行方式的研究

从凝汽器最佳真空的原理入手,分析探讨了目前火电厂循环水系统的运行优化问题.对水量不连续变化的单元制循环水系统提出了一种离散优化模型,该模型以等效益点迭代计算来决定泵组切换时的临界工况.以十里泉电厂300MW机组为例,利用本模型对循环水系统进行了运行方式的优化研究,确定了机组在不同循环水温、不同负荷最经济的循环水泵运行编组方式,编制了循环水系统最优化运行工况图,为运行中实现指导循环泵的科学经济调度提供了量的依据.效益分析表明,对于300MW机组,循环水系统离散优化可使电厂标准煤耗降低0.5～0.7g/kW.h.实践表明该方法简便易行,运行可操作性强,节能效果明显,而且无须增加额外的支出,有很好的推广价值.

Study on Optimized Operation Mode for Circulating Water System of 300MW Thermal Power Generation Unit

This paper analyzes the question of optimization operation for circulating water system of current thermal power plant based on the theory of best vacuum for condenser.A discrete optimization model,which uses the iterative calculation results of equivalent benefits to determine the critical working condition for water pump switching is proposed for single circulating water system with discontinuous change of water volume.The model is used in the operation optimization study for the circulating water system of 300MW unit of Shiliquan power plant.Through this study,the most economical opera- tion mode of circulating water pumps is determined for the power generating unit at different circulating water temperature and at different load and the most optimized operation chart for circulating water system is prepared,which provides a quantitative basis for scientific and economic dispatch of circulating water pump.Benefit analysis indicates that the discrete optimization of the circulating water system can reduce coal consumption by 0.5-0.7 g per KWh for 300MW unit.The practice further indicates that this method is easy to operate and good in energy conservation result.It has no extra cost and therefore is valuable for promotion.