基于供热负荷的吸收式热泵供热机组变工况性能分析

Off–design performance analysis of absorption heat pump heating supplying units based on heating load

利用吸收式热泵回收循环水中的余热能够提高系统供热能力,增加发电量,提高能源利用率。以东北地区某2×350 MW供热机组为例,对1号机组进行供热系统改造,增加吸收式热泵回收循环水余热。建立热力计算模型,基于供热负荷的变化,对热泵供热系统供暖期内的变工况进行模拟。比较改造前后两种供热模式在相同热负荷下的热经济性能;发掘并对比不同供热模式的最大供热能力。结果表明:随着供热负荷的增加,热网回水温度升高,热泵性能系数COP下降。改造后的热泵供热模式热经济性能要优于传统供热模式,在相同供热负荷下,热泵供热模式的总的供热抽汽量明显低于传统抽凝供热模式;总的发电量比传统抽凝供热模式增加3%左右;发电标准煤耗比传统抽凝供热模式最大降低近3%。改造后的热泵供热模式能满足的最大供热面积比传统抽凝供热模式增大17.5%,表明对机组进行热泵改造能够有效增加机组最大供热能力。

Heat recovery from circulating water utilizing absorption heat pump can improve heating supplying capacity of the system and increase power generation and energy utilization efficiency.Taking a 2×350 MW heating supply power units as example,the heating supply system of unit 1 was reformed,and an absorption heat pump was added for recovery of waste heat from circulating water.According to the established thermodynamic model,the off-design performance was simulated based on heating load.The thermal economic performance was compared between the two heating models before and after the reformation under the same heating load.Calculate and compare the maximum heating area of the both heating model.Results show that with the increasing of heating load,the temperature of heating network water rises up,and the heat pump COP decreases.The absorption heat pump heating supplying model is superior to the traditional extraction heating supplying model.Under the same heating load,the total heating extraction volume of heat pump hating model is significantly lower than the tradition extraction heating model,the total power generation increases by about 3%the tradition extraction heating model,and the maximum reduction of standard coal consumption rate is nearly 3%.The maximum heating area of heat pump hating model can be increased by 17.5%compared with the traditional extraction heating model,and the maximum heating capacity of the original unit is obviously increased.