Thermal characteristics of combined thermoelectric generator and refrigeration cycle

A combined thermal system consisting of a thermoelectric generator and a refrigerator is considered and the effect of location of the thermoelectric generator, in the refrigeration cycle, on the performance characteristics of the combined system is investigated. The operating conditions and their influence on coefficient of performance of the combined system are examined through introducing the dimensionless parameters, such as λ(λ = QHTE/QH, where QHTE is heat transfer to the thermoelectric generator from the condenser, QH is the total heat transfer from the condenser to its ambient), temperature ratio (θL = TL/TH, where TL is the evaporator temperature and TH is the condenser temperature), rC (rC = CL/CH, where CL is the thermal capacitance due to heat transfer to evaporator and CH, is the thermal capacitance due to heat rejected from the condenser), θW (θW = TW/TH, where TW is the ambient temperature), θC (θC = TC/TH, where TC is the cold space temperature). It is found that the location of the thermoelectric generator in between the condenser and the evaporator decreases coefficient of performance of the combined system. Alternatively, the location of thermoelectric device in between the condenser and its ambient enhances coefficient of performance of the combined system. The operating parameters has significant effect on the performance characteristics of the combined system; in which case temperature ratio (θL) within the range of 0.68-0.70, rC = 2.5, θW = 0.85, and θC = 0.8 improve coefficient of performance of the combined system.