燃煤电厂循环水回水系统扩大单元制运行研究与应用

自然通风冷却塔出水温度高于设计值，会严重影响机组经济性。为解决河源电厂这一问题，从减少进入冷却塔循环水量入手，结合机组调停备用次数增多，单机运行时间增长的现状，论证并实施了循环水回水系统扩大单元制改造，将循环水分流到2座冷却塔进行换热降温。实验结果表明，循环水回水系统扩大单元制运行后，进入单个冷却塔的水量显著降低，循环水系统运行安全可控；在各典型工况下，凝汽器背压下降0.42~0.96 kPa不等，机组负荷越高，循环水量越大，凝汽器背压下降幅度越明显，因而显著提高了机组运行的经济性。

Research and Application of Expanded Unit Element System in Circulating Water Drainage System for Coal Fired Power Plant

Higher than designed water temperature at the outlet of the natural draft cooling tower will seriously affect the economic efficiency of the unit. In order to solve such problem in Heyuan power plant, the amount of circulating water into the cooling tower was first reduced. Then by taking account of the current situation of more frequent standby dispatch whereas more hours of operation for a single unit, this paper demonstrates and implements the expanded unit system transformation of the circulating water drainage system, in which the circulating water were diverted to two cooling towers for heat exchange and cooling. The experimental results show that the amount of water entering each cooling tower decreases significantly while the operation of the circulating water system is still safe and controllable after the expansion of the unit operation of the recirculating water drainage system. Under various typical operating conditions, the condenser back pressure decreases by 0.42~0.96 kPa. Particularly, the higher the unit load, the more the circulating water volume and the more significantly the condenser back pressure decreases. Therefore, the economy of the unit operation is greatly improved.