Co-optimized design of microchannel heat exchangers and thermoelectric generators

Abstract

Designs of heat exchangers have mostly been disconnected to the performance of thermoelectric generator (TEG) systems. The development work, mostly focused on thermoelectric materials, required a significant amount of engineering parametric analysis. In this work, a micro plate-fin heat exchanger applied to a TEG is investigated and optimized to maximize the output power and the cost performance of generic TEG systems. The cost per performance is counted by a measure of price per power output ($/W). The channel width, channel height, fin thickness of heat exchanger, and fill factor of TEG are theoretically optimized for a wide range of pumping power. In conjunction with effective numeric tests, the model discusses the optimum size of the system components' dimensions at two area sizes of the substrate plate of heat exchanger. Results show that at every pumping power, there are particular values of channel width and fin thickness that provide maximum output power in the TEG. In addition, for producing maximum cost performance at lower pumping power, larger channel width and channel height and smaller fill factor are required. The results also illustrate that there is a unique pumping power for fixed thickness of fin and ceramic substrates that provides minimum cost per performance for the TEG systems. The theoretical results of the micro heat exchanger are in a good agreement with the experimental investigation data.