Study on Economized Vapor Injection Heat Pump System Using Refrigerant R32

2016 ◽  
Vol 24 (01) ◽  
pp. 1650006 ◽  
Author(s):  
Yaoguang Shi ◽  
Xianmin Guo ◽  
Xinyu Zhang
Keyword(s):  
Heat Pump ◽  
Injection Pressure ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Efficiency ◽  
Discharge Temperature ◽  
Vapor Injection ◽  
Potential Alternative ◽  
Low Global Warming Potential ◽  
Injection Ratio

The refrigerant R32 is considered as a potential alternative refrigerant of R410A because of its low global warming potential (GWP) and the basic thermodynamic parameters. It can effectively improve the heating efficiency and reduce the discharge temperature of the compressor to use the economized vapor injection (EVI) refrigeration system. In this paper, the performance of the EVI heat pump system using refrigerant R32 is investigated experimentally under the conditions of the evaporating temperature ranged from [Formula: see text]C to [Formula: see text]C. The experimental results indicate that the injection ratio, heat capacity and power consumption of the EVI heat pump system increase with the injection pressure. The maximum injection ratio of the EVI heat pump system is about 33% under the evaporating temperature of [Formula: see text]C. For the EVI heat pump system, the system COP achieves the maximum value as the injection pressure ranges from 1.48[Formula: see text]MPa to 1.54[Formula: see text]MPa when the evaporating temperature is lower than [Formula: see text]C. The discharge temperature of the EVI heat pump system drops by 11[Formula: see text]C under the evaporating temperature of [Formula: see text]C. As the evaporating temperature is below [Formula: see text]C, the COP of the EVI heat pump system is higher than that of the traditional single stage heat pump.

scholarly journals Enhancing Heating Performance of Low-Temperature Air Source Heat Pumps Using Compressor Casing Thermal Storage

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3269 ◽  
Author(s):  
Zhongbao Liu ◽  
Fengfei Lou ◽  
Xin Qi ◽  
Yiyao Shen
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Waste Heat ◽  
Thermal Storage ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Discharge Temperature ◽  
Vapor Injection

Air source heat pumps (ASHPs) are widely recognized as energy-saving and environmentally friendly heating and air-conditioning equipment with broad applications. However, when conventional ASHPs are operated at a low ambient temperature, they suffer from problems such as high discharge temperature and low heating efficiency. To address these problems, this study designed a new type of dual evaporator combined with a compressor casing thermal storage heat pump system (DE-CCTS) on the basis of a low-temperature air source heat pump water heater with enhanced vapor injection (EVI). The proposed DE-CCTS used thermal storage phase change material (PCM), which was filled in the secondary evaporator (the thermal storage heat exchanger), to recover the waste heat of the compressor casing. Unlike that in the original system under different ambient temperatures, the suction temperature increased by 0.1–1 °C, the discharge temperature decreased by 0.1–0.5 °C, and the coefficient of performance (COP) of DE-CCTS increased by 0.85–4.72% under the proposed system. These effects were especially evident at low temperatures.

The Heating Coefficient Experimental Analysis of Solar Water-Assisted Low Temperature Air Source Heat Pump System

2014 ◽  
Vol 953-954 ◽  
pp. 136-143
Author(s):  
Jin Shun Wu ◽  
Yue Bo Hu ◽  
De Zhi Hu ◽  
Hong Wei Liu
Keyword(s):  
Comparative Analysis ◽  
Low Temperature ◽  
Heat Pump ◽  
Compression Ratio ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Efficiency ◽  
Evaporation Temperature ◽  
Air Source Heat Pump

In winter,Many families use air source heat pump because of the low evaporation temperature of the system, resulting in lower heating efficiency of system. To solve this problem, the low temperature solar assisted hot water was added to the project which is on the basis of air source heat pump, and the system has been tested. After analysis of the collection efficiency of solar collectors at low temperatures and comparative analysis of the temperature cycle, pressure, energy consumption of the low-temperature solar-assisted systems and air source heat pump system, the optimal collector temperature and law of heat pump refrigerant cycle changes of the system were obtained. Theoretically, comparative analysis of low temperature air source heat pumps and solar hot water secondary air source heat pump compression ratio and COP. It gives the key parameters affecting the compression ratio and COP, pointing out ways to improve the heat pump COP. Finally, a key measure to improve the thermal performance of the unit system is proposed, to provide a reference for future practical applications and research. Foreword Air source heat pump in ambient air contains rich low grade solar potential as a source of heat, it has inexhaustible characteristics [1] . The main reason for restricting the use of air source heat pump in northern area of our country is when the outdoor air temperature is low in winter, the outdoor coil frost severe heating efficiency air source heat pump is greatly reduced. Martinez suggested experimental study on the application of solar radiant floor heating systems , solar water temperature is 50-60°C, low efficiency, especially when overcast snow lower system efficiency [2] .In view of the outdoor coil frosting problem, direct expansion solar assisted heat pump water heater system using the proposed by Li Yuwu, from a certain extent alleviated the problem of heat in winter for coil winter fros, improving the heating coefficient and improved the operating characteristics of the unit. However, this system requires the direct absorption of heat in air tube, and the specific heat of air is small, difficult to heat storage, illumination by solar radiation impact, unstable system operation [3]. Based on the above issues, for the low-level office building , the new rural residential , this study presents low temperature solar auxiliary air source heat pump system , the device uses low-temperature solar hot water heat pump system as low , both full use of solar energy , but also eliminates the original system frost problems and improve the efficiency of solar collectors and heat set to improve the evaporation temperature of the evaporator , thereby increasing the compression ratio of the heat pump unit .

scholarly journals Performance and Optimization Study of R290 as Alternative Refrigerant for R22 in Low Temperature Heat Pump System

2021 ◽  
Vol 2108 (1) ◽  
pp. 012089
Author(s):  
Yun Zhang ◽  
Cichong Liu ◽  
Wanyong Li ◽  
Junye Shi ◽  
Jiangping Chen
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Exhaust Temperature ◽  
Discharge Temperature ◽  
Temperature Environment ◽  
Temperature Heat ◽  
Overall Performance ◽  
Temperature And Pressure

Abstract This paper mainly studies the replacement performance of R290 in R22 low temperature heat pump system from the experimental point of view. By comparing the performance differences under different working conditions, it is found that when R22 is directly extracted from the original system and filled with R290, the heat capacity and COP of the system are attenuated, and the compressor discharge temperature and pressure of the R290 system are higher than those of the original R22 system in low temperature environment. Through the analysis of the system components, it can be considered that the main reason for the above phenomenon is that the compressor displacement of the R22 system is too large and does not match the R290 system. Therefore, in order to meet the safety requirements of the system and improve the overall performance of R290 in the low temperature heat pump system at the same time, it is considered to replace the compressor with a smaller displacement which is more matched with R290 in the system. The experimental results show that the compressor displacement optimization of the R290 low temperature heat pump system can effectively reduce the exhaust temperature and pressure of the system and improve the overall performance of the system. The COP of the optimized R290 low temperature heat pump system is 6.5% higher than that of the original R22 system, and the exhaust temperature in the low temperature environment is reduced by 36% to below 80 C.

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