Analysis of the potential of thermoelectric generators for waste heat recovery from vertical surfaces

The article presents research on the utilisation of low-temperature waste heat from vertical industrial surfaces using a thermoelectric generator (TEG). This technology was chosen due to the possibility of directly converting thermal energy into electrical energy without interfering with the structure of the heat source. The system comprises thermoelectric modules, a copper heat exchanger, and a water cooler made of aluminium and copper. The study was conducted within a heat source temperature range of 100 °C to 350 °C and at three cooling water flow rates: 150, 200, and 250 dm³/h. The results showed that the number of modules in the generator significantly affects its efficiency. A generator with 20 modules produced less power than a system with 4 modules due to a reduction in the heat exchanger’s temperature caused by module densification. The highest power output – 12.41 W – was achieved with a generator containing 4 modules at the maximum temperature and the highest water flow rate. On the other hand, a water flow rate of 200 dm³/h proved to be the most optimal, providing a balance between performance and resource consumption. The developed TEG generator features a modular design, enabling flexible adaptation to various operating conditions and integration with existing heat recovery systems. This technology has the potential to significantly reduce operational costs in the industry and enhance energy efficiency, contributing simultaneously to minimizing energy losses and reducing CO₂ emissions.