Design and characterization of a novel finned tubular thermoelectric generator for waste heat recovery

Abstract

Most commercial thermoelectric modules have a flat design that complicates their integration into gas/liquid thermoelectric conversion systems. The aim of the present study is to develop a robust, compact, and cost-effective design that is easier to incorporate into gas/liquid thermoelectric energy recovery systems. The description entails a novel finned tubular thermoelectric generator (FTTEG) prototype with three distinguishing characteristics: (i) quadratic-profiled thermoelectric legs arranged axially, (ii) a resin-based semi-rigid assembly, and (iii) annular heat exchange fins.

Module properties such as contact resistance, resin properties and heat exchanger performance were investigated using a numerical model developed with ANSYS-Fluent. Exchanger thermal efficiency was thus found maximal at a fin spacing of 2–3 mm and a fin height of 11–13 mm at the conditions of operation defined.

A test bench was built to evaluate the ability of the module to generate electrical power from hot water against forced ambient air. An output power of 16 mW at 600 mV open-circuit voltage was generated during tests with a temperature gradient of 60 °C.