Study Of Double Temperature Cooling Source System Based On Large Temperature Glide Zeotropic Mixture

Considering disadvantages of liquid desiccant and solid desiccant in tranditional temperature and huimdtiy independent control system, liquid dehumidification systems have some problems such as corrosion of pipeline and the low efficiency which limit its applications. There are many problems for solid adsorption desiccant too, such as the big equipment and large amount of adsorbent filling increase the costs. In addition, solid desiccant regeneration calls for high temperature and high-grade heat consumption. However, tranditional compressing air conditioning system can not control the temperature and humidity accurately indoor. In additional, the low coefficiency of performance and unfriendly of environment are the problem should be sovle too. In this paper, a novel double cooling source refrigerate system based on large temperature zeotropic mixture was proposed. This system can be applied for hot summer and cold winter region household dehumidifiers radiation air conditioning system, achieved temperature and humidity independent control to improve the efficiency of the air conditioning system and air quality of the room.The performance of the system were analyse though the therectical and experimental way. The heat transfer property of the large temperature zeotrpic mixture was studied too. The main study content and results as the follow shown:The relevant background of THICS and the application of zeotropic mixture in air conditioning have been reviewed, including the disadvantages and advantages of various THICS and the related theoretical and experimental research. A novel double temperature cooling source refrigerating system was posposed base on the present study. The principle of the system was explained and a test-bed us R32/R236fa as the refrigerant was established, the main component of the system are introduced in detail, including compressor, evaporator, condenser and the throttling device. The erros under the typical experimental conditions data are analyze, the result indicates that the maximum average relative error of the main performance parameters is within 10%. So the experimental data have high accuracy and reliability.The heat transfer characteristic of large temperature zeotropic mixture in condenser was studied base on the established test-bed, including the mass fraction ratio, the temperature of high-low temperature chilling water and the flow-rate of cooling water. The results shows that zeotropic mixture R32/R236fa have the obviously temperature glide during the condesning process. During the condesening process, the heat transfer efficiency will deteriorate under different operating condition.The performance of system was studied base on the test-bed. The results shows that the temperature of the high temperature chilling water is about 15?19?? the temperature of the low temperature chilling water is about 6?8?. The system can be applied in temperature and humidity independent control system. When This 17? and Tlis 7?, the mass fraction of R32 is 50%, the COP of system is 3.82. The exhausting temperature is about 70?, so the system operating safety.Finally, this paper established the exergy analysis model of the double cold source refrigerate system, analyse the exergy loss and exergy efficiency of the system part, the results of this paper provides guidance for optimization of double cooling source system which using large temperature glide zeotropic mixture as the refrigrant.