| Abstract: |
Processes in the industrial sector account for about 30% of global primary energy consumption, with as much as 20–50% of this energy being lost to the environment as waste heat. With a significant share of this thermal energy being recoverable and reusable through Waste Heat Recovery Systems (WHRS), there is ample room for improvement in terms of efficiency, operational cost savings, and reduced greenhouse gas emissions. This paper presents an empirical study on designing and optimization of not only a WHRS which is implemented at a medium scale cement production plant in Madhya Pradesh, India. We develop a thermodynamic model, conduct experimental measurements and then utilize multi-objective optimization techniques to assess the performance of an ORC-based recovery unit with a shell-and-tube heat exchanger network. Over a six-month period of operation (January–June 2025), field data were obtained from five process streams: kiln exhaust, clinker cooler air, and preheater off gases. To carry out the optimization of working fluid selection, evaporator pressure and mass flow using RSM with GA. The results show that, the optimized WHRS achieves 18.7% thermal efficiency with about 4.82 MW electrical power recovered and 14.3% reduced specific energy consumption. Payback was projected at 3.6 years, with annual CO₂ emissions reduced by 28,400 tonnes. Comparison with earlier studies provides a reassurance of the findings that the choice of working fluid (R245fa outperforming both R134a and toluene for the set boundary conditions) and evaporator pressure were also found to be most crucial parameters regulating system outputs. It offers actionable design guidelines for industrial practitioners while also providing empirical evidence in favor of WHRS deployment within energy-intensive sectors of developing economies. |
