低品位余热回收高温热泵系统能效分析

Energy efficiency analysis of high temperature heat pumpsystem for low grade waste heat recovery

针对矿山行业的冶炼厂低品位的热水,如设备的冷却循环水、矿井井下涌水等,本文采用单级和两级蒸气压缩高温热泵系统进行余热回收,建立了系统热力性能计算模型,并对2种系统能效进行了分析比较。结果表明,系统性能系数(COP)受冷凝器出口温度、冷凝器进口温度、窄点温度、等熵效率等因素影响显著,两级蒸气压缩热泵系统(TS)的性能优于单级蒸气压缩热泵系统(SS),在热水进口温度85℃、出口温度115℃时,TS系统相对于SS系统COP提升幅度为22.60%,在等熵效率为0.7时,TS系统COP比SS系统COP提高了21.07%。

In view of the fact that there are many low-grade hot water in smelters in the mining industry,such as cooling circulating water of equipment and underground water inflow in mines,in this study,the single-stage and two-stage vapor compression heat pump systems for waste heat recovery is compared,and a calculation model of the thermal performance of the system is developed.Then the energy efficiency of the two systems is compared.The results show that the performance of the two-stage vapor compression heat pump system(TS)is better than that of the single-stage vapor compression heat pump system(SS).When the hot water inlet temperature is 85℃and the outlet temperature is 115℃,the COP of the TS system is increased by 22.60%compared with the SS system when the hot water inlet temperature is 85℃and the outlet temperature is 115℃,and the COP of the TS system is increased by 21.07%compared with the SS system when the isentropic efficiency is 0.7.