Analysis of dynamic and reliability indicators of a thermoelectric cooler at minimization of a complex of three basic parameters

Abstract

The inclusion of a thermoelectric cooler in the thermal mode control circuit of a heat-loaded element operating in a pulsed mode makes the requirements for dynamic characteristics and reliability indicators more stringent. The main parameters of thermoelectric devices that provide a given thermal mode of operation include: the number of thermoelements, the magnitude of the operating current and the heat dissipation capacity of the radiator. With the optimal design of a thermoelectric cooler, one should strive to reduce the number of thermoelements, the magnitude of the operating current and the heat sink surface of the radiator. With a given geometry of thermoelement legs, a decrease in the number of thermoelements leads to a decrease in the specified cooling capacity or heat load. This can be compensated by an increase in the operating current, and, conversely, a decrease in the operating current leads to the need to increase the number of thermoelements, which affects the reliability indicators. The possibility of controlling the thermal regime of single-stage thermoelectric cooling devices while minimizing this complex is considered. The number of thermoelements, the magnitude of the operating current and the heat dissipation capacity of the radiator were investigated in the range of temperature drops from 10K to 60K at a thermal load of 0.5 W for different geometry of thermoelement legs. A relationship is obtained to determine the optimal relative operating current corresponding to the minimum of the complex of the number of thermoelements, the value of the operating current and the heat sink surface of the radiator. The analysis of the model revealed that with an increase in the relative operating current for different geometry of thermoelement legs, the required number of thermo-elements decreases, the time to reach a stationary mode, the relative value of the failure rate increases, and the probability of failure-free operation decreases. The functional dependence of the coefficient of performance has a maximum; the heat sink capacity of the radiator has a minimum, and does not depend on the geometry of thermoelements and the amount of energy expended. It is shown that the use of the current mode of operation at the minimum value of the complex provides optimal control of the thermal mode of the thermoelectric cooler with a minimum amount of consumed energy.