Effect of Heat Transfer on the Performance of Thermoelectric Heat Pumps

Abstract

AbstractThe performance analysis of thermoelectric (semiconductor) heat pumps is performedusing the combined method of finite time thermodynamics and non-equilibriumthermodynamics. The heating load and coefficient of performance (COP) expressionsfor the heat pump, which is composed of multi-elements, are derived with con-siderations of heat transfer irreversibility in the heat exchangers between the heatpump and the external heat reservoirs as well as the other internal irreversibilities.Numerical examples are provided. The effects of heat transfer, the number of elementsand the other design parameters on the performance of the heat pump are analyzed.IntroductionSeveral authors have applied the combined method of finite time thermodynamics orentropy generation minimization [1–6] and non-equilibrium thermodynamics [7–9] tothe analysis of thermoelectric (semiconductor) heat pump [10–13]. They analyzed theeffect of finite-rate heat transfer between the thermoelectric device and its externalreservoirs on the performance of the single-element thermoelectric heat pump. Inpractice, a thermoelectric heat pump is composed of many fundamental thermoelectricelements. It is a multi-element device. In the present paper we will investigate thecharacteristics of multi-element thermoelectric heat pumps related to the irreversi-bilities of finite-rate heat transfer, Joulean heat inside the thermoelectric device, andthe heat leak through the thermoelectric couple leg. The expressions for the heatingload and the coefficient of performance (COP) of the multi-element thermoelectricheat pump are derived. The effects of various design parameters on the performance ofthe heat pump are analyzed.