Evaluation of a Thermoelectric Generator for Waste Heat Recovery in Low-Temperature Industrial Pipelines

This research proposes the design of a thermoelectric generator for waste heat recovery in low-temperature industrial piping. For the development of the research, a series of numerical simulations have been carried out in which the energy conversion efficiency, electrical characteristics, and the influence of variables such as the cooling fluid, construction materials, and clamping pressure have been analyzed. The analysis of the electrical characteristics shows that a 30 °C increase in inlet temperature allows a doubling of the voltage and electrical power. For an inlet temperature of 180 °C, a maximum electrical power of 61.6 W is achieved. The cooling fluid velocity positively affects the energy recovery capability, reaching an average increase of 4.35% and 9.2% in voltage and electrical power when 1 m/s increases the fluid velocity. Using high thermal conductivity materials such as brass causes a 34.3% and 73.6% increase in surface temperature and output voltage compared to materials such as stainless steel. Electrical power can be increased by 10.1% by increasing the clamping pressure by 100 kg/m2. The energy conversion efficiency is approximately proportional to the hot air inlet temperature. It is shown that a 25 °C increase in hot air temperature causes a 22.60% increase in efficiency. In general, it is demonstrated that the proposed thermoelectric generator can recover the waste energy from the industrial pipelines, affecting normal operation.