Experimental investigation on the heating performance of a CO2 heat pump system with intermediate cooling for electric vehicles. (5th January 2021)

• Record Type: Journal Article
• Authors: Chen, Yiyu; Zou, Huiming; Dong, Junqi; Wu, Jiang; Xu, Hongbo; Tian, Changqing
• Is Part Of: Applied thermal engineering. Volume 182(2021)
• Publication Date: 2021-01-05
• Subjects: CO2 heat pump -- Intermediate cooling compressor -- Electric vehicles -- Heating performance -- COP optimal control strategy; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.116039
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlight: A comprehensive CO2 heat pump system with intermediate cooling compressor for electric vehicle is proposed. A strategy of optimal COP of the system with ICC is provided. The system performs significant advantages over the basic cycle. The COP of the system with ICC reaches 1.70 under −20 °C/20 °C condition. Abstract: This study proposed an improved CO2 heat pump system for electric vehicles by introducing the concept of two stage compression with intermediate cooling. A coefficient of performance optimal control strategy was proposed based on the discovered feature that the changing trend of the COP is consistent with that of the inlet temperature of the electronic expansion valve. Contrast experiments between the heat pump with intermediate cooling compressor and the basic heat pump were conducted. Result shows that the two stage compression with intermediate cooling contributes to 50–132% increment in the heating capacity and 18.9–61.9% improvement in the COP over the basic system as the ambient temperature decreases from 0 °C to −20 °C. The advantages increase with the decrease in ambient temperature. The typical COP of this system under −20 °C ambient temperature and 20 °C in-car temperatures condition is approximately 1.70 while the discharge temperature is controlled well within 100 °C.