Waste heat recovery potential from industrial bakery ovens using thermodynamic power cycles

This paper investigates the potential for waste heat recovery from industrial bakery ovens and its conversion into electricity using thermodynamic power cycles. Three prominent cycles: supercritical CO₂ Brayton cycle (s-CO₂), trilateral cycle (TLC) and organic Rankine cycle (ORC) are selected and optimized for maximum net power to demonstrate the cycles’ performance under steady heat input conditions. This study is extended to perform sensitivity analysis of the cycles’ performance against a set of input variables. Results show that a higher thermal efficiency of 26.5% is achievable in the case of ORC cycle with n-pentane as a working fluid compared to s-CO₂ and TLC with a cycle thermal efficiency of 22.1% and 18.8%, respectively. Results also show that the ORC, the most preferable cycle, can avoid around £23,204 of annual electricity cost if the cycle is integrated with an industrial oven that generates waste heat at a mass flow rate and temperature of 1 kg/s and 250 ºC, respectively.