An Experimental Study on the Heating Performance Characteristics of a Vapor Injection Heat Pump for Electric Vehicles

Abstract Considering the issues of environmental pollution and energy efficiency, heat pumps are gradually replacing traditional coal combustion for heating at low ambient temperatures. In this paper, eco-friendly CO2/HCs with large temperature glides are applied in a single-stage recuperative heat pump water heater. Its heating performance is theoretically investigated under the working condition of producing circulating hot water in typical winter of northern China, with medium temperature difference between supply/return water and large temperature difference between air inlet and water inlet. Due to its simple structure, low initial investment and high efficiency, its potential for producing circulating hot water is demonstrated. Exergy analyses are conducted to reveal the significant influence of the exergy losses of heat exchanger on system performance. For specified CO2/HC, optimal COP is obtained through global optimization of cycle pressures and mixture concentration. The heating performances of different CO2/HCs are compared, among which CO2/R600 and CO2/R600a behave better. Meanwhile, a typical vapor-injection cycle is used to demonstrate priorities on the heating performance of this recuperative cycle, in which the COP of recuperative cycle using CO2/R600 is more than 3.4% higher than that of the vapor-injection cycle. The results obtained in this paper provide a simple and efficient solution for producing circulating hot water at low ambient temperatures.

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Experimental Study on Effect of Water Flow Rate on Heating Performance of a Series Bathing Wastewater Source Heat Pump Hot Water Unit

Environmental Science and Engineering - Proceedings of the 11th International Symposium on Heating, Ventilation and Air Conditioning (ISHVAC 2019) ◽

10.1007/978-981-13-9524-6_81 ◽

2020 ◽

pp. 781-789

Author(s):

Liangdong Ma ◽

Tixiu Ren ◽

Tianyi Zhao ◽

Jili Zhang

Keyword(s):

Experimental Study ◽

Water Flow ◽

Heat Pump ◽

Flow Rate ◽

Water Flow Rate ◽

Hot Water ◽

Heating Performance ◽

Effect Of Water

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Experimental Investigation on Heating Performance of Newly Designed Air Source Heat Pump System for Electric Vehicles

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4047821 ◽

2020 ◽

Vol 13 (2) ◽

Author(s):

Kang Li ◽

Jun Yu ◽

Rong Yu ◽

Lin Su ◽

Yidong Fang ◽

...

Keyword(s):

Heat Pump ◽

Electric Vehicles ◽

Flow Characteristics ◽

Cold Climate ◽

Positive Temperature ◽

Pump System ◽

Cooling Performance ◽

Heat Pump System ◽

Heating Performance ◽

Driving Range

Abstract Utilizing the heat from air source with heat pump system in electric vehicles shows a significant advantage from thermoelectric heat source for heat supply in cold climate. It could improve the driving range of electric vehicles considerably in winter and replace the positive temperature coefficient (PTC) heater with an acceptable cost and reliability. In this work, a newly designed heat pump system was first introduced with less components and cost. Second, experiments were conducted to investigate its cooling performance, and subsequent heating performance from −10 to 10 °C. The typical heat transfer and flow characteristics of refrigerant were recorded, and the behavior of each component including compressor, evaporator, condenser, and outside heat exchanger were analyzed and interpreted. The results showed that the heating and cooling performance of the new heat pump system could almost remain the same with traditional air-conditioning system in automobile and surely satisfy with the heat requirement of electric vehicles. In the heating mode, the maximum heating capacity increases by 13% at 400 m3/h air volume from 300 m3/h at the ambient temperature −10 °C, while the outlet air temperature decreases by 4–6%. In addition, using a heat pump system showed an increase in the driving range of electric vehicles by 25–31% as compared to PTC heaters.

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