A Thermoelectric-Based Point of Use Power Generator for Steam Pipes

Abstract

A robust thermoelectric-based point of use power generation system with no moving parts that is designed to be clamped onto the outer wall of a steam pipe with a temperature of 160°C plus was built and tested in ambient temperatures from 30 to 85°C. The system consists of a pair of assemblies mounted on opposite sides of a pipe. Each assembly consists of a hot block, an array of three thermoelectric modules wired in series and a cold block heat pipe system. The steel hot block creates a thermal channel to the hot plates of the modules. The cold block consists of a 14 inch long heat pipe onto which 41 square fins are attached with a spacing of 0.25 inches. The first iteration produced a steady state direct current voltage of 17.2 (open circuit) and an amperage of 0.64 (short circuit) after more than a year of continuous operation. Later versions produced 31.5 volts (open circuit) and 0.89 amps (short circuit), and 21.36 volts open circuit volts and 1.14 short circuit amps in steady state. Additional installations using low temperature geothermal steam and hot water pipes in Iceland were also successful with ambient temperatures below zero degrees Celsius. For comparison purposes with other thermoelectric generators, this thermoelectric generator system produces more than 1 watt per thermoelectric module without any moving parts. These thermoelectric generators produce 6.9 watts steady state and the higher amperage unit produces 6.1 watts steady state.