变温热源热管式热电制冷器结构设计和性能分析

Structure design and performance analysis on heat pipe-cooled thermoelectric refrigerator with variable temperature heat source

基于有限时间热力学理论,设计了一种冷却空气的通道结构,建立了基于热管散热的变温热源热电制冷器有限时间热力学模型.通过数值模拟方法对装置冷、热端热阻进行了分析,得到了沿管道流动方向制冷模块冷、热端温度和冷空气温度的变化规律;以制冷率密度和制冷系数为性能指标,分析了输入电流、入口温度、空气流速等关键运行参数和模块填充系数、热电单元长度、管道宽度和吸液芯厚度等设计参数对装置性能的影响,并讨论了空气间隙热漏影响.结果表明:入口温度为290 K时,0.2 m宽的管道管内冷空气温度每米流程下降约14 K;与同工况下不考虑空气间隙热漏情形相比,考虑空气间隙热漏时最大制冷率密度和最大制冷系数分别为0.48 W/cm^(2)和1.11,分别降低了4.00%和5.13%.

Based on the finite-time thermodynamics theory, a channel structure of cooling air is designed, and a finite-time thermodynamic model for the thermoelectric refrigerator is established based on heat pipe heat dissipation with variable temperature heat source. The thermal resistances at the cold and hot ends of the device are analyzed by numerical simulation, and the variation laws of the temperatures at the cold and hot ends and the temperature of the cold air of the refrigeration module along the flow direction of the pipeline are obtained. The effects of key operating parameters, such as input current, inlet temperature and air velocity, and design parameters, such as module filling factor, thermoelectric element length, pipe width and wick thickness on the refrigeration performance of the device are analyzed with the cooling density and the coefficient of performance(COP) as performance indicators. In addition, the effects of air gap heat leakage are discussed. The results show that when the inlet temperature is 290 K and the channel width is 0.2 m, the cold air temperature in the pipe decreases by about 14 K per meter. Compared with the situation without considering the air gap heat leakage under the same working conditions, the maximum cooling density and the maximum COP can only reach 0.48 W/cm^(2)and 1.11 when the air gap heat leakage is considered, which are reduced by 4.00% and 5.13%, respectively.