Thermodynamic Analysis Of Thermoelectric System And Experimental Study On Fresh Beer Preservation Device

With the progress of civilization, especially the growing awareness of environmental protection, the whole world advocates the harmonious development of science and environment to achieve sustainable development. In the 1980s, scientist had confirmed CFCs are the materials that deplete the ozone layer and cause the greenhouse effect, the governments have gradually forbidden its use. So the traditional refrigeration technology is facing the challenge to find new refrigerant. At the same time, the development of thermoelectric materials, promote the thermoelectric refrigeration technology widely use in practice, especially in the civilian applications. In this big background, this paper is focused on designing a new kind of thermoelectric refrigeration system for the fresh beer preservation device, and testing its refrigeration performance.This paper firstly introduces the development of thermoelectric theory, and the present development of thermoelectric materials, thermoelectric refrigeration technology, heat pipe and heat pipe exchanger in the world; Secondly, this paper analyzes the ideal thermal cycle process and the heat transfer characteristics of heat pipe exchanger, and simplify the thermodynamic model of a real refrigeration system and analyze the dimensionless current, dimensionless ZT merit figure, hot and cold side dimensionless thermal resistance, temperature ratio and other parameters that how to affect the performance of refrigeration; Finally, a thermoelectric refrigeration system for the fresh beer preservation device is developed and the test is carried out on the refrigeration performance by controlling the parameters: input current, hot side environment temperature, water flow rate, the way of convection, and the way of using the thermal conductive silicone. The obtained conclusions are as follows:(1) The analysis results of the ideal thermal cycle process show that the working current, the △T between hot and cold side, the Z-merit figure have a significant impact on the refrigeration performance of ideal system.(2) The analysis results of the real system dimensionless parameters show that the real refrigeration system has the best working current area, and the environment temperature and heat transfer condition have a significant impact on the refrigeration performance of the real system.(3) The measure results of the fresh beer cooling device show that the heat pipe fins using the natural convection makes the cooling worse and not be able to meet the requirements of preservation, but using the forced convection can, when the working current controlling between 6～7 A and under a normal environment temperature condition, the temperature of the liquid in the device can be keep in 3～5℃ and meet the requirement of keeping fresh.(4) The thermal conductivity silicone grease reduces the thermal resistance between the semiconductor and the exchanger plate that can improve the cooling performance of the cooler. Reducing the hot side thermal resistance can make the significantly improved.The experimental results of this paper provide the optimization direction for the thermoelectric refrigeration system.