Research On The Bi-objective Optimizaiton Of Thermoelectric Cooler

Thermoelectric cooling which is a new-type refrigeration method with some advantages, such as emission reduction and environmental protection?light mass and compactness?high reliability and stability etc., has been widely used in aerospace?biological medicine and electronic heat dissipation etc. However, because of being limited by inherent properties of thermoelectric materials, the cooling capacity and coefficient of performance(COP) of thermoelectric cooling is pretty low and cannot be achieved maximum value simultaneously. Therefore, in order to balance the conflict between the two performance indexes, the idea of multi-objective optimization was adopted to achieve the goal.The main content of this paper is based on the ideal and non-ideal mathematical model of thermo-element respectively. Firstly, the effect of critical parameters, containing the operating parameters including current and the allocation ratio of heat transfer area of cold side and hot side, and the structural parameters including the length of thermo-element and the area ratio of air interlayer and thermo-element on the performance indexes of thermoelectric cooler were analyzed respectively. Then, the cooling capacity and COP were integrated into one total optimization objective by the method of linear weighted sum. Finally, the simplified conjugate gradient method was adopted as the optimization technique to accomplish the numerical optimization to obtain optimum operating and structural parameters.The results showed that the contradiction between the refrigerating capacity and COP cannot be balanced by single variable and objective optimization. Thereby, the optimum operating parameters under different weight coefficient and the optimum physical dimension of thermo-element under different current that can lead to the increment of the total objective function were achieved by bi-objective optimization based on module- level and unit- level respectively. For example, compared with single-objective optimization, when the weight factor is 0.3, though the COP decreased by 39.6%, the cooling capacity increased by 204.92%, the total objective function enhanced by 7.3%. And compared with initial structure, when the operating current is 3A, the cooling rate and COP improved by 7.5% and 61.8% respectively, and the whole objective function increased by 27.7%. Meanwhile, the degree of improvement of the cooling capacity and COP varied with the weight coefficient and the current. Through the study of the paper, the optimization of structural and operating parameters based on the unit- level and module-level respectively can provide theoretical direction for the design and operating of thermoelectric module.