准二级压缩热泵热水机低温工况COP分析

Analysis of COP on quasi two-stage compression ASHPWH under low temperature condition

对准二级压缩热泵热水机进行建模,通过计算分析得到系统COP在低温工况下与内压比、水温的关系。得到了只有当水温超过一定温度时,喷气运行才具有较高的COP;而环境温度越低、水温越高时,内压比越高的压缩机具有较高的COP。

A model of quasi two-stage compression ASHPWH was established, some influence of the compressor inner pres-sure ratio and water temperature on system COP was obtained in low ambient temperature. Consequently, the results show that COP is larger during injection operation only when the water temperature exceeds a value. Also, the compressor with higher inner pressure ratio will have higher system COP while it runs under then condition of low ambient temperature and high water tempera- ture.