摘要
通过实验对比研究了循环加热和一次加热热水时,水箱水温对CO2热泵热水器性能的影响。循环加热工况时,随着水温的升高,压缩机的进、排气压力逐渐升高,功耗增加;气体冷却器的CO2进、出口温度升高,内侧CO2和外侧水的温差逐渐减小,换热量减小;CO2热泵系统的COP下降。一次加热工况时,进水温度一定,系统的各项运行参数稳定,COP基本保持不变。以水温度17℃为例,系统COP在3.5左右,远远高于循环加热的COP。实验结果表明水箱水温对系统的性能有一定影响。根据实验结果提出了水箱结构改进方案,使气冷器入口水温稳定在较低水平,可有效提高系统的性能。
The performance of CO2 heat pump water heater was studied experimentally in this paper by comparing a loop heating and a direct heating hot water. In the loop heating mode, with an increase of the water temperature, the compressor inlet and exhaust pressure increased gradually, the power consumption increased and the gas cooler inlet and outlet temperature increased, too. The temperature difference between carbon dioxide and cooling water and heat transfer decreased, the COP of CO2 heat pump system decreased. The operating parameters of the system were stable and the COP remained unchanged in direct heated condition. When the water temperature is 17℃, the COP of the system is about 3.5, much higher than that in loop heating. The results show that the lower inlet temperature can be obtained by modifying the water tank structure and it is a very effective way to improve system performance.
出处
《制冷学报》
CAS
CSCD
北大核心
2012年第6期73-78,共6页
Journal of Refrigeration
关键词
热工学
CO2热泵热水器
循环加热
一次加热
水箱水温
COP
Pyrology
CO2 heat pump water heater
Loop heating mode
Directed heated condition
Water tank temperature
COP
