Effect of geometry and applied currents on the exergy and exergoeconomic performance of a two-stage cascaded thermoelectric cooler

Exergy and exergoeconomic analysis are performed for an electrically separated two-stage thermoelectric cooler (STTEC). Exergetic efficiency and cost of cooling power are considered as the main target of exergy and exergoeconomic analysis, respectively. The effects of important design variables on the STTEC exergy and economic performance are investigated. These variables are applied currents to the stages, geometric characteristics, i.e. electrodes length and cross section area ratios between the stages and first and second stages electrode numbers. Also, effects of applied currents on the optimum values of geometric characteristics to obtain the minimum cooling cost have been analyzed. For achieving maximum exergy efficiency and minimum cooling cost, applied current of hotter (second) stage would stand at a higher level than that of colder (first) stage. The higher the ranges of applied currents, the lower the accessible cooling cost in comparison to exergy efficiency.