Extreme working temperature differences for thermoelectric refrigerating and heat pumping devices driven by thermoelectric generator

摘要

The extreme working temperature differences of combined thermoelectric devices, i.e. thermoelectric generator driven thermoelectric refrigerator or heat pump, are analysed using non-equilibrium thermodynamics. The extreme working temperature differences versus the ratio of numbers of thermoelectric elements, i.e. the ratio of the number of thermoelectric elements of the generator to the total number of thermoelectric elements of the combined devices, of the two models are obtained. The effects of the hot junction temperature of the generator on the extreme working temperature differences are analysed. The results show that, if a thermoelectric generator works under a condition of 150 K temperature difference, ～60 K temperature difference for cooling or 200 K temperature difference for heating could be reached. The coefficient of performance can reach to 0·08-0·15 which is considerable for application in a wide scale for specific purposes. For a fixed ratio of numbers of thermoelectric elements, there is a fixed extreme working temperature difference, the larger working temperature difference, the smaller cooling (heating) load and coefficient of performance. The results obtained herein may provide guidelines for the design and application of practical combined thermoelectric devices.