Foundry heat converted to electricity
Forges and foundries use large amounts of heat to melt metals and create castings, much of which is released unused into the environment. Heat can, however, be recovered from hot streams such as flue gases from generators or steam from cooling towers. The EU-funded FOUNDENERGY (Waste heat recovery power generation based on ORC technology in foundry industry) project aimed to transform heat recovered from foundries into electricity. Researchers developed a cost-effective and low-maintenance waste energy recovery boiler (WERB) suited to the highly corrosive and abrasive environment of a foundry. The WERB transfers heat from a furnace's flue gases to a fluid, which is then vaporised inside a turbine that drives a generator, producing electricity. The spent vapour is then condensed to liquid and recycled to repeat the process. During the project, researchers constructed, optimised and tested three different WERBs designed to function at different power ranges and in various situations. They developed protective coatings for the heat exchange pipes, built a computer-controlled waste heat recovery system and, finally, tested a prototype within a foundry. In these trials, the heat exchanger prototype achieved 82 % efficiency, close to its theoretical maximum 85 % conversion efficiency, even in conditions simulating extreme wear and tear. Once implemented, FOUNDENERGY's system could be used to produce electricity for sale to power grids or for internal consumption. It could also produce hot water for purposes such as preheating smelting components. This technology should significantly cut operational and energy costs, boosting the competitiveness of small and medium-sized foundries while reducing heat waste and benefiting the environment.
Keywords
Foundry, electricity, waste heat, FOUNDENERGY, waste energy recovery boiler, heat exchanger
