利用循环水余热加热凝结水的改造方法及分析

Feasibility Study on Heating Condensed Water using Waste Heat of Circulating Water

为了解决北方地区夏季湿冷机组循环水温度偏高,凝汽器真空下降,导致机组出力不足,能耗增加的问题,结合机组利用热泵回收循环水余热技术,提出技术改造,并进行可行性分析。在供暖期,热泵回收循环水余热来加热热网水;非供暖期时,将八号低压加热器隔离,利用热泵回收循环水余热来加热凝结水。经计算,该方案可有效缩短热泵投资回报周期,并且在夏季投运4个月,循环水温度减低2.26℃,真空提升0.83 kPa,机组煤耗降低2.26 g/kWh,回收余热58015 kW,节约工业水377510.4 t、标煤4623.6 t,共计节省费用3052404.32元。

In order to solve the problem that the circulating water temperature of wet-cooling units in the northern area is too high in summer and the vacuum of the condenser is reduced, the unit output is insufficient and the energy consumption is increased. Combining this unit with the heat pump recovery technology of circulating water waste heat,the following technical transformations are proposed and the feasibility analysis is carried out. In the heating period, the heat pump recovers the waste heat of the circulating water to heat the heating network water;during the non-heating period, the No. 8 low-pressure heater is isolated, and the heat pump is used to recover the waste heat of the circulating water to heat the condensed water. According to calculations, this scheme can effectively shorten the heat pump investment return period, and put into operation in summer for 4 months, the circulating water temperature is reduced by 2.26℃, the vacuum is increased by 0.83 kpa, the unit coal consumption is reduced by 2.26 g/kWh, the waste heat is recovered by 58015 kW, and the industrial water is saved 377510.4 t, saving 4623.6 t standard coal, a total cost savings of 3052404.32 yuan.