基于制冷剂充注量的复叠式高温热泵性能实验研究

Experimental evaluation of a high temperature cascade heat pump based on refrigerant charge

中文关键词: 复叠式高温热泵  制冷剂充注量  系统性能  不确定度分析

英文关键词: high temperature cascade heat pump  refrigerant charge  system performance  uncertainty analysis

中文摘要:

      为探究低温端制冷循(LS)制冷剂充注量对复叠式高温热泵系统(HTCHP)的系统性能影响，进一步提升热泵制热性能，本研究搭建了20kW 复叠式热泵实验平台，通过改变制冷剂的充注量对HTCHP系统的压力、输入功率、制热量及COP进行分析，并且对实验结果进行不确定度分析。结果表明：随低温端制冷循环制冷剂充注量增加，LS/HS（低/高温端制冷循环）的蒸发/冷凝压力、压缩比、LS的输入功率均随之升高，HS的输入功率没有明显的变化；HTCHP系统的制热量随着LS制冷剂的充注量的增加而增加，制冷剂的充注量每增加300g，系统的制热量增加2.35%~5.30%，由于制热量增长率低于系统总输入功的增长率，低温端制冷循环制冷剂充注量每增加300g， HTCHP 系统的COP随着低温端制冷剂的充注量增加而降低约为3.25%~5.77%。

英文摘要:

      In order to investigate the effect of refrigerant charge amount of the low-stage cycle (LS) on the performance of the high temperature cascade heat pump (HTCHP), an 20kW HTCHP test rig was built in this study. Several experiments were carried out to investigate the change of pressure, power input, heating capacity and COP the HTCHP with different refrigerant charge amount. The uncertainty calculation was done in this research to ensure the accuracy of the experimental results. The results showed that the evaporating/condensing pressure of LS/HS, power in put of LS increased accordingly with the refrigerant charge amount increasing of the LS while the power input of HS changed not obviously. The heating capacity of the HTCHP system increases as the LS refrigerant charge increases, and the heating capacity of the system decreased about 2.35-5.30% while the refrigerant charge amount increased by 300g. Since the increasing rate of heating capacity was lower than that of the power input, the COP of the HTCHP decreased about 3.25-5.77% while the refrigerant charge amount increased by 300g in LS.