Correlation Model of the Thermal Elements Branches Geometry and Reliability Indicators for Two-Stage Cooler Design in the Q0MAX Mode

Influence of the thermoelements branches geometry in cascades at (l / S) 1 = (l / S) 2 on the reliability parameters of two-stage thermoelectric cooling devices for various temperature drops ΔT = 60; 70; 80; 90 K for the ratio of the height of the thermoelement to the area l / S = 40; 20; 10; 4.5; 2.0, the thermal load Q0 = 2.0 W in the maximum cooling capacity Q0max with a series of electrical cascades has been considered in the paper. A reliability-oriented model of a two-stage cooler has been developed that relates the relative intensity of failures to energy and design parameters. The effect of the ratio of the thermoelement length to the cross-sectional area on the working current, the total number of required thermoelements, the relative failure rate and the probability of failure-free operation of the device have been studied. It is shown that with a decrease in the l / S ratio in cascades of a two-stage thermoelectric cooler for various temperature differences ΔT and a fixed thermal load Q0, the failure rate λ decreases, and, consequently, the probability of failure-free operation of P increases.