双层半导体热电制冷的多物理场耦合建模与性能优化

发布时间：2018-04-01 04:17

本文选题：热电制冷　切入点：双层　出处：《华北电力大学》2014年硕士论文

【摘要】：随着微电子设备和大功率器件的发展,其相应制冷器的性能要求越来越高。热电制冷器以其体积小,无噪声,安全性高,制冷速度快等优点在军事、医学、生物、仪器、航空、工业等领域得到广泛应用。现阶段对双层热电制冷器的数值研究多采用热阻模型,无法考虑热电材料随温度变化的物性和半导体内电流密度分布的非均匀性等实际情况对制冷器性能的影响。本课题的研究采用温度场和电势场耦合的三维数值模型,分析了三种电流连接方式的双层TEC的性能,并结合简化共轭梯度法反向优化了制冷器性能。通过对串联式、并联式和分别式双层TEC的数值模拟,分析了结构参数和操作参数对制冷量、COP和最大制冷温差的影响,并根据其内部三维温度分布阐明不同的参数对制冷性能产生影响的机理。对于串联式双层TEC,主要的影响参数是两层热电单元个数比,为了提高制冷量和COP,靠近热端的热电单元个数与靠近冷端的个数比值大于1,本文中的最佳比值为1.73-2.33；并联式制冷性能通常较差,不推荐使用,本文解释了其内部原因；分别式双层TEC采用与串联式最佳结构相同的个数比,通过改变两层通入的电流比进一步提高制冷性能,通常靠近热端一层的电流值要高于靠近冷端的,本文的最佳比值为1.50-2.00。通过分析可知双层TEC中不同的结构参数和操作参数均对其制冷性能有影响,且相互之间关联紧密,因此为使双层TEC达到最大制冷量或COP需同时优化多个参数。本课题将简化的共轭梯度法和热电器件的多场耦合数学模型两个求解器通过Fortran语言集成,进行多参数反问题最佳化。首先通过单参数研究分析面积比γ,单层热电单元个数N,P型半导体横截面积比a=Ap/(An+Ap),上层热电单元高度比h=Hc/(Hc+Hh),以及操作参数电流Ic和Ih,六个参数对制冷量和COP的影响,然后分别以制冷量和COP为目标函数求取六个参数的最佳值。
[Abstract]:With the development of microelectronic devices and high-power devices, the performance requirements of the corresponding refrigerators are becoming more and more high. Thermoelectric refrigerators have the advantages of small size, no noise, high safety and high refrigeration speed in military, medical, biological, instrument, aviation, etc. Industry and other fields have been widely used. At present, thermal resistance model is widely used in the numerical research of double-layer thermoelectric refrigerators. The effect of physical properties of thermoelectric materials with temperature and nonuniformity of current density distribution in semiconductors on the performance of refrigerators can not be considered. The performance of the double-layer TEC with three kinds of current connection is analyzed, and the performance of the refrigerator is optimized by using the simplified conjugate gradient method. Through the numerical simulation of series, parallel and separate double layer TEC, the effects of structure parameters and operating parameters on the refrigerating capacity cop and maximum refrigeration temperature difference are analyzed. According to the three dimensional temperature distribution inside, the mechanism of the influence of different parameters on the refrigeration performance is explained. For the series double layer TECs, the main influence parameter is the ratio of the number of two layers of thermoelectric units. In order to increase the refrigerating capacity and COP, the ratio of the number of thermoelectric units near the hot end to the number near the cold end is greater than 1, the optimum ratio in this paper is 1.73-2.33.The performance of parallel refrigeration is usually poor and is not recommended for use. The number ratio of two-layer TEC is the same as that of series type. By changing the current ratio of two layers, the current value of one layer near the hot end is higher than that of the one layer near the cold end. The optimum ratio of this paper is 1.50-2.00. Through the analysis, it can be seen that the different structure parameters and operation parameters of double-layer TEC have influence on its refrigeration performance, and they are closely related to each other. Therefore, in order to achieve the maximum cooling capacity of double-layer TEC or COP, several parameters should be optimized at the same time. In this paper, the simplified conjugate gradient method and the multi-field coupled mathematical model of thermoelectric devices are integrated by Fortran language. The optimization of multi-parameter inverse problem is carried out. Firstly, the area ratio 纬, the number of single-layer thermoelectric units, the cross-sectional area ratio of single layer thermoelectric units, the height ratio of the upper layer thermoelectric units to h=Hc/(Hc HHH, and the operating parameter currents I c and I h, 6 are studied. The effects of these parameters on the cooling capacity and COP, Then the optimal values of six parameters are obtained by using the refrigerating capacity and COP as the objective function respectively.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657

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