A review on recent developments in new refrigerant mixtures for vapour compression-based refrigeration, air-conditioning and heat pump units

It has been demonstrated in the literature that significant energy savings can be achieved in air-conditioning through the use of so-called hybrid systems, in which a chemical dehumidification system is combined with a vapour-compression heat pump. The advantage of such systems lies in the fact that the heat pump can operate at a higher evaporation temperature than that of a traditional system in which dehumidification is achieved through condensation, thereby achieving higher coefficients of performance. The hybrid system described in the present paper operates as follows: the air supplied to the conditioned ambient is simultaneously cooled and dehumidified in an air-solution membrane contactor. The LiCl solution is cooled by means of a vapour-compression heat pump using the refrigerant KLEA 410A. The solution is regenerated in another membrane contactor by exploiting the exhaust air and the heat rejected by the condenser. A study of the steady-state behaviour of the system in summer climatic conditions was carried out, on varying some significant operating parameters, such as the thermal efficiency of the heat exchangers, the outdoor temperature and the sensible load of the conditioned room. The performances of the hybrid system were compared with those of a traditional direct-expansion air-conditioning plant; the results of the simulations reveal that, in particular operating conditions, energy saving can exceed 50%.

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Recent Advances on the Electric Vehicle Heat Pump Air Conditioning Systems

Recent Patents on Mechanical Engineering ◽

10.2174/2212797614666210125142854 ◽

2021 ◽

Vol 14 ◽

Author(s):

Bin Peng ◽

Yubo Zhang ◽

Pengcheng Zhang ◽

Hanif Ullah

Keyword(s):

Electric Vehicle ◽

Heat Pump ◽

Electric Vehicles ◽

Air Conditioning ◽

New Technology ◽

Research Work ◽

High Energy ◽

Air Conditioning System ◽

Electrical Vehicle ◽

Recent Developments

Background: Heat pump air conditioning technology has broad application prospects and high market value in the field of electric automobiles owing to its increasing performance and energy saving. Pure electric vehicles require high-energy consumption at low temperatures, which seriously affects the popularity of electric vehicles with a heat pump air conditioning system. Objective: The aim of this research is to describe the recent developments in the study of the heat pump air conditioning system for electric vehicles. Methods: This paper summarizes the research work of scholars published worldwide based on the electric vehicle heat pump air conditioning system, premised on lately published patents and journal articles. Starting from the components of the air conditioning system, focus on the research results and development trends that have been achieved in this field. Results: The new technology path and pattern of the electrical vehicle heat pump air conditioning system provide methods and suggestions for future growth, put forward by the current development situation. Conclusion: The latest progress of the electric vehicle heat pump air conditioning system has been summarized and prospected. There are still some problems and technical bottlenecks in heat pump air conditioning system. It is of great significance to improve the environmental adaptability of electric vehicles and optimize the reasonable heat pump air conditioning system for the endurance of electric vehicles.

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WAYS OF NEXT GENERATION REFRIGERANTS AND HEAT PUMP/REFRIGERATION SYSTEMS

International Journal of Air-Conditioning and Refrigeration ◽

10.1142/s2010132511300023 ◽

2012 ◽

Vol 20 (01) ◽

pp. 1130002 ◽

Cited By ~ 19

Author(s):

AKIO MIYARA ◽

YOJI ONAKA ◽

SHIGERU KOYAMA

Keyword(s):

Global Warming ◽

Heat Pump ◽

Social System ◽

Air Conditioning ◽

Next Generation ◽

Present Stage ◽

Refrigerant Mixture ◽

Refrigerant Mixtures ◽

Operation Modes ◽

Technical Innovations

Since measures of the global warming are becoming urgent issues, various technical innovations and social system reformations are being promoted. In the engineering fields of heating, refrigerating, and air-conditioning, the global warming caused by the refrigerants is a big problem that must be solved. At the present stage, however, there are no perfect solutions for next generation refrigerants and heat pump/refrigeration systems by which the global warming is successfully prevented. Therefore, we have to search possible ways to the next generation. In this paper, important four ways which are (1) natural refrigerants, (2) low GWP synthetic refrigerants, (3) refrigerant management, and (4) refrigerant mixtures are introduced. For the refrigerant mixture which are CO2 /DME and HFO-1234ze(E)/HFC-32, cycle simulations have been conducted under different operation modes. COP of the mixtures has a maximum at certain concentration and they are higher than those of conventional refrigerants. From a drop-in test of HFO-1234ze(E)/HFC-32, feasibility of the refrigerant mixture has been proved.

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