Pulsed current effect on the performance of conical inhomogeneous thermoelectrics

•Two power profiles are compared for their effects on TEC system performance.•Inhomogeneous material properties, pulse shape, conical TE are analyzed.•Supercooling is incorporated in the overall TEC performance analysis.•Heat conduction and Joule heating compete for an optimum system.•Electric resistivity and thermal conductivity act in opposition manner in system COP. A study of an inhomogeneous thermoelectric cooler (TEC) with conical thermoelectric elements (TEs) and temperature-dependent materials was conducted by the authors previously to obtain the TE temperature distribution profiles. As an accompanying investigation for the purpose of completeness, the overall system performance (the coefficient of performance) of a TEC device, in terms of the semiconductor geometric shape and its inhomogeneous material properties for two pulsed current profiles are explored in this study. Results concluded that a cost-effective TEC should consist of several features: the TE material with a large Seebeck coefficient offer favorable Peltier cooling power, a TE with a smaller cold end cross-section creates a lower transient temperature at the cold junction, and TEs with low material thermal conductivity minimize heat conduction to the cold junction. A customized selection of these design features, with a balance of the Peltier power, heat conduction, and distributed Joule heat within the TECs, produces an optimal thermoelectric cooling system.