Study Of Heat Transfer Enhancement About Semiconductor Refrigerating System

The semiconductor refrigeration has been used in some fields. However, there are someproblems during the use of semiconductor refrigeration, and the main problem is heat transfer,which results in the decrease of refrigerant efficiency. Consequently, some measures of heattransfer enhancement should be used to improve the performance of semiconductorrefrigerating system so as to increase the refrigerant efficiency. The main work of this thesisis as follows:1.The composition of thermoelectric effect about semiconductor refrigeration wasexpounded, and the heat transfer's features and refrigeration's features of semiconductorrefrigeration system were analysed. Besides, the connection types about refrigerationequipments and heat dissipation equipments were analysed.2. The temperature fields of those heat dissipation equipments with different structureswere simulated by ANSYS software, and the thesis got the optimized structure of heatdissipation equipments with the certain volume.3. Through the establishment of experimental platform about the semiconductorrefrigeration system, experimental data was measured and analysed, and the results wascompared with numerical simulation's.Through above analysis the thesis found that the experiment results agree well withnumerical simulation results, the main conclusions of the thesis are as follows:1. Through numerical simulation, if the volume of a aluminous heat dissipationequipment is V=9×10⁴mm³, limiting both the length and width of the base is x₁=100mm,x₂=100mm, and the optimized structure of the equipment is that the thickness of the base isx₃=4.6mm, the height of fins is x₅=40mm, the number of fins is x₆=22, the bottom thicknessof fins is x₄=0.7mm, and the top thickness of fins is x₇=0.3mm.2. Adopting forced air cooling, if the refrigeration equipment's power of semiconductorrefrigeration system is less than 60W, so as to attain the highest cost performance, the coolingfan could take 12V/0.2A. Besides, the size of the cooling fan should be matched with the heatdissipation equipment.3. Under the same volume,the heat dissipation effect of square structure is better thanthe effect of ladder type, and the number of the fin is the more the better. Besides, with thesame refrigerating output, the power of the refrigeration equipment could be reduced by acertain degree so as to reach a high refrigeration efficiency.4. Silica gel is helpful to semiconductor refrigeration system's heat dissipation. With the use of silica gel, the system's COP increases to 36% from 22.5% for forced air cooling, andincreases to 48% from 24% for water cooling.