Experimental Study Of Miniature Evaporator

With the development of economy and advancement of society, research and development of miniature heat exchangers have been very popular in the field of motor vehicles, aero-space, cryogenics and refrigeration, and so on. Miniature evaporator is a compact exchanger with small volume, light weight, and big heat transfer area per unit of volume. It is an important application in the field of cryogenics and refrigeration.The design and experimental study of miniature evaporator were done in this thesis. First, the design work was done according to the working conditions, and related correlative formulae were taken. In view of the manufacture, size, weight and other related confined conditions, miniature coiled tube evaporator was developed.To test the performance of miniature evaporator, an experimental system was built. In this thesis, experimental study on single-phase balance heat transfer, two-phase balance heat transfer, and pressure drop was finished. At the same time, experimental study on boiling heat transfer by changing mass flow of refrigerant, mass flow of water, and inlet temperature of water was also finished. And then the performance of miniature evaporator was estimated.The results show that while the mass flow of refrigerant is 1.85g/s, the inlet temperature of refrigerant is 18.9℃, the evaporating pressure is 0.62MPa, the mass flow of water is 31.1g/s, and the inlet temperature of water is 36.9℃, the refrigerant of miniature evaporator wholly vaporizes in the tube, and the heat transfer rate is 342W. It achieved the demand of design.Experimental study of miniature coiled tube evaporator will provide some reference for improving performance of evaporator and constituting suitable design criteria. So, the result has a certain value for theory study and some other field.