配置吸收式热泵的余压梯级利用供热系统优化设计

Optimal Design of Residual Pressure Cascade Utilization Heat Supply System with Absorption Heat Pump

针对中排抽汽在减温减压过程中?损失较大的问题,提出一种余压梯级利用供热系统,使用2台背压式小汽轮机分别回收进入热泵和尖峰加热器前抽汽经减温减压的余能。以耦合吸收式热泵的600 MW热电联产机组为研究对象,使用EBSILON软件建立该供热系统的变工况模型,对其进行能量分析、?分析、经济性及敏感度分析。结果表明:在基准供热工况下,新型余压梯级利用供热系统的供电标准煤耗率较案例系统降低10.02 g/(kW·h),热泵和尖峰加热器前2台减温减压器内的?损失分别降低了77.77%和78.99%,全生命周期内的净现值有望达到13 924.22万元,动态回收周期为3.27 a;随着机组供电负荷的降低以及热网供、回水温度的增加,新型余压梯级利用供热系统的节能效果提高。

In view of the large exergy loss of steam extraction during the process of temperature and pressure reduction,a residual pressure cascade utilization heat supply system was proposed,in which two back-pressure small steam turbines were used to recover the residual energy of the extracted steam after temperature and pressure reduction before entering the heat pump and the peak heater.Taking a 600 MW cogeneration unit coupled with absorption heat pump as the research object,the off-design model of the heating system was established using EBSILON software,so as to analyze the energy,exergy,economy and sensitivity.Results show that under the benchmark heating condition,standard coal consumption rate of the new residual pressure cascade utilization heat supply system is 10.02 g/(kW·h) lower than that of the case system,and the exergy loss in the two temperature and pressure reducers before the heat pump and the peak heater is reduced by 77.77% and 78.99%,respectively.The net present value in the whole life cycle is expected to reach 139.242 2 million yuan,and the dynamic recovery period is 3.27 a.With the reduction of the unit power supply load and the increase of the supply and return water temperature of the heat network,the energy saving effect of the new residual pressure cascade utilization heat supply system can be improved.