Performance enhancement investigation of thermoelectric cooler with segmented configuration

In analogy to segmented thermoelectric generator, the segmented thermoelectric cooler is proposed to enhance the cooling performance without increasing overall figure of merit. The physical model and governing equations of the segmented thermoelectric element are established according to internal heat distribution and transport. The performance enhancement of segmented thermoelectric cooler is investigated by comparing with the traditional thermoelectric coolers. The interactive effects between segment number and thermal physical properties, working conditions and dimension on the cooling performance are discussed. The results show that the segment number is more sensitive to the thermal conductivity of thermoelectric material, and the maximum cooling capacity and temperature difference of segmented thermoelectric element are larger than that of traditional thermoelectric element. The optimum two-segmented thermoelectric element is studied to further optimize the performance of thermoelectric cooling. It is found that the maximum cooling capacity, temperature difference and coefficient of performance of two-segmented thermoelectric element could be remarkably improved by 118.1%, 118.1% and 2.1% when the overall figure of merit remains unchanged. Thereinto, the proposed optimal two-segmented structure modifies the standard thermoelectric energy balance equation with 0.35 of Joule heating traveling back to the cold side instead of 1/2 for the internal heat redistribution.