Experiment Research On Miniature Refrigeration System And Design Of High-Efficiency Heat Exchanger

With the development of science and technology, people set a higher request to the ambient temperature in the fields such as energy and power, military, aviation, astronautics and so on. With some advantages including compactness, lightness, high performance and cost effectiveness, the miniature refrigeration system can be widely used for personal cooling and high power electronic components cooling. Compared with other cooling methods, vapor compression refrigeration has advantages of high efficiency and compactness.In this paper, a miniature refrigeration system was integrated using miniature compressor developed by TECO Energy, Inc. A testing system was set up and performance experiments of miniature refrigeration system with different operating parameters were conducted. The curves against the refrigerant charging quantity, ambient temperature, chilled water temperature and flux were obtained. Experimental results show that the optimal charging quantity of this cooling system is 40g; with ambient temperature raising, system power consumption increases, cooling capacity decreases, and COP also decreases; with the chilled water temperature raising, system power consumption decreases, cooling capacity increases and COP increases rapidly. With the mass flow of chilled water increasing, cooling system pressure ratio increased slightly, system power consumption decreases, cooling capacity increases and COP increases.In this paper, a heat transfer model of 450W heat load heat pipe condenser was established. The heat transfer performance and mass curves against condensation tube diameter, heat pipe diameter, fin width were obtained by simulation. Ultimately, the best parameter combination and structural optimization design plan were selected. The simulation results show that the heat pipe condenser can reduce the refrigerant side pressure and then improve the efficiency of refrigeration system.In this paper, two types of spiral-tube evaporators heat transfer model were established and analyzed. From the analysis, the mode of that water flowing inside the pipe and refrigerant flowing outside the pipe can greatly increase the overall heat transfer coefficient. Decreasing the length of spiral tube and the pressure of refrigerant side can meet the requirement of designing micro refrigeration system. Meanwhile, one micro spiral-tube evaporator with 300W cooling load was designed and established. To facilitate the practical processing, the detailed designing process and the structure diagram of evaporator were presented.