Self powered furnace

Abstract

A self-powered combustion furnace unit. A combustion furnace providing circulating hot fluid heating is equipped with a thermoelectric generator comprised of a plurality of thermoelectric modules mounted on the furnace. The heat from the combustion provides a high temperature hot side heat source for the thermoelectric modules and the fluid of the circulating hot fuid system provides the cold side heat sink for the thermoelectric modules. Electric power produced by the thermoelectric modules powers a motor driving a pump which circulates the circulating hot fluid. In a preferred embodiment low cost, high temperature thermoelectric modules are provided which comprise thermoelectric elements installed in injection molded eggcrates. The thermoelectric modules are held in close contact with the hot side heat exchanger and the cold side heat sink with a spring force such as that provided by Belville springs. The eggcrate is molded from a high temperature plastic with ridges provided for extra strength and tapered walls to permit ease of installation of the thermoelectric elements and stop tabs assure correct positioning of the elements. Electrical connections at hot and cold surfaces of the modules are preferably made by thermal spraying metallized coatings on the surfaces and then surface finishing the module to expose the walls of the eggcrate.