化工学报2011，Vol.62Issue(7)：1879-1884,6.DOI:10.3969/j.issn.0438-1157.2011.07.014
蓄热型热泵热水器单级与复叠循环性能比较
Performance comparison of single stage and cascade heat pump water heater with PCM
摘要
Abstract
The energy stored and released process of cascade air source heat pump water heater with phase change material (PCM) was investigated experimentally. R404a was selected as refrigerant of lowtemperature stage and R134a as refrigerant of high-temperature stage. At different ambient temperatures, heat transfer processes and variation of parameters for the single and cascade heat pump systems were compared, and the optimum ambient temperature, at which the cascade system should be switched to single stage system, was analyzed in order to guarantee the best system performance. The results showed that in the cascade system the heat transfer presented time-lag behavior and the difference of heat transfer from the condenser to PCM and to water was in the range of 7％-10％. When the opening of electronic expansion valve at high-temperature stage was increased by 10％, the heat transfer difference decreased from 18％ to 6％, benefiting the heat balance of the condensation-evaporator and improving system efficiency. The cascade system took less time for energy storage than the single system. With the two cycles, the compression ratio and exhausting temperature increased as ambient temperature decreased. COP decreased as the water outlet temperature increased and increased with the ambient temperature. For this cascade system, the optimum ambient temperature for switching between the single and cascade systems was 7°C.关键词
热泵热水器/复叠式循环/单级循环/COPKey words
heat pump water heater/ cascade cycle/ single cycle/ COP分类
通用工业技术引用本文复制引用
巫江虹,游少芳,谢方,朱钰娟,肖皓斌..蓄热型热泵热水器单级与复叠循环性能比较[J].化工学报,2011,62(7):1879-1884,6.基金项目
广东省科技厅产学研项目(2009B090300380). （2009B090300380）
