回热器对CO_(2)驻车空调系统制热性能影响的研究

Research on influence of internal heat exchanger on heating performance of CO_(2) parking air conditioning system

为了提升驻车空调的制热性能,搭建了一套带回热器的跨临界CO_(2)驻车空调系统,在焓差室中实验研究了有无回热器时气冷器出口温度与排气压力对系统的性能影响。结果表明:在排气压力分别为8.5、9.0、9.5 MPa时,气冷器出口温度从20℃升高至35℃时,制热COP_(h)降低幅度分别为29.7%、19.9%、16.4%;系统使用回热器后最优排气压力下降,下降幅度分别为4.4%、6.1%,对应的最大COP_(h)增加幅度分别为3.2%、3.7%。通过曲面拟合得到了系统使用回热器时提升制热性能的排气压力与气冷器出口温度关联式,该式对回热器在跨临界CO_(2)驻车空调系统制热模式下的实际应用有一定指导意义。

In order to improve the heating performance of parking air conditioning,a transcritical CO_(2) parking air conditioning system with the internal heat exchanger was built.The effects of gas cooler outlet temperature and exhaust pressure on the performance of the system with and without the internal heat exchanger were studied experimentally in the enthalpy difference chamber.The results showed that when the exhaust pressure was 8.5,9.0 and 9.5 MPa respectively,the outlet temperature of the gas cooler increased from 20℃to 35℃,the heating COP_(h) decreased by 29.7%,19.9%and 16.4%respectively.After the system used the internal heat exchanger,the optimal exhaust pressure would decrease by 4.4%and 6.1%respectively,while the corresponding maximum COP_(h) increased by 3.2%and 3.7%respectively.Further,the correlation between the exhaust pressure and the outlet temperature of the gas cooler which could improve the heating performance of the system when using the internal heat exchanger was obtained by surface fitting.The expression has certain guiding significance for the practical application of the internal heat exchangers in the heating mode of the transcritical CO_(2) parking air conditioning system.