scholarly journals A Study on Performance Characteristics of a Heat Pump System with High-Pressure Side Chiller for Light-Duty Commercial Electric Vehicles

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1237 ◽  
Author(s):  
Moo-Yeon Lee ◽  
Kunal Sandip Garud ◽  
Han-Byeol Jeon ◽  
Ho-Seong Lee
Keyword(s):  
High Pressure ◽  
Heat Pump ◽  
Air Temperature ◽  
Electric Vehicles ◽  
Coolant Temperature ◽  
Pressure Side ◽  
Ambient Conditions ◽  
Pump System ◽  
Heat Pump System ◽  
Light Duty

One of barriers for the present heat pump system’s application in an electric vehicle was decreased performance under cold ambient conditions due to the lack of evaporating heat source. In order to improve the heat pump’s performance, a high-pressure side chiller was additionally installed, and the tested heat pump system was modified with respect to refrigerant flow direction along with operating modes. In the present work, the performance characteristics of the heat pump system with a high-pressure side chiller for light-duty commercial electric vehicles were studied experimentally under hot and cold ambient conditions, reflecting real road driving. The high-pressure side chiller was located after the electric compressor so that the highest refrigerant temperature transferred the heat to the coolant. The controlled coolant with discharged refrigerant from the electric compressor was used to heat up the cabin, transferring heat to the inlet air like the internal combustion engine vehicle’s heating system, except with unused engine waste heat. In the cooling mode, for the exterior air temperature of 35 °C and interior air temperature of 25 °C, cooling performance along with the compressor speed showed that the system efficiency decreased by 16.4% on average, the cooling capacity increased by 8.0% on average and the compressor work increased by 27% on average. In heating mode, at the exterior and interior air temperature of −6.7 °C, compressor speed and coolant temperature variation with steady conditions were tested with respect to heating performance. In transient mode, to increase coolant temperature with a closed loop from −6.7 °C, tested system characteristics were studied along the compressor speed with respect to heating up the cabin. As the inlet air of the HVAC was maintained at −6.7 °C, even though the heat-up rate of the cabin room was a little slow, the cabin temperature reached 20 °C within 50 min and the temperature difference with the ambient air attained 28.7 °C.

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

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.

Air-water heat pump applied as water boiler in single-family house, coefficient of performance analysis under the real conditions

2018 ◽  
Vol 3 (2) ◽  
pp. 58-61
Author(s):  
Agnieszka Lisowska-Lis ◽  
Robert Leszczyński
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Air Temperature ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Single Family ◽  
Pump System ◽  
Heat Pump System ◽  
System Temperature ◽  
Family House

The subject of the research was an air-water heat pump, model PCUW 2.5kW from HEWALEX, installed in a single-family house. The pump is only used for heating water. The research was carried out from 25-08-2017 to 18-09-2017 in the village of Zborowice, in Malopolska region, Poland. The data were recorded from the heat pump system: temperature of the lower heat source (external air), temperature of the upper heat source (water temperature in the tank), time of heat pump was calculated during the analysed cycle of work and electrical energy consumption. The Coefficient Of Performance (COP) of the analysed air-water heat pump was determined. The analysis of the results was carried out using the MATLAB and EXCEL statistical tools. The correlation between COP coefficient and external air temperature is strong: 0.67.

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