Thermodynamic Performance Analysis of Integrated ORC–Heat Pump Systems for Industrial Waste Heat Recovery

This study presents a thermodynamic performance analysis of integrated energy systems for industrial waste heat recovery, combining an Organic Rankine Cycle (ORC), a heat pump (HP), and a building thermal load model under three configurations. An hourly quasi-steady simulation framework was developed, where component models were thermodynamically coupled and solved at the system level. The entire system, including all thermodynamic modeling and property evaluations, was implemented in MATLAB. A synthetic annual building thermal energy model was employed, with a total thermal demand of 8,820 MWh, of which 62% corresponds to cooling demand, consistent with the degree-day climatic characteristics of the selected location.In the baseline configuration, the ORC and air-source HP operate independently, resulting in substantial heat rejection. The second configuration introduces a cascaded approach, directly utilizing part of the waste heat for building heating. The third configuration represents a fully integrated system with a shared water loop between the ORC and a water-to-water HP.Results show that integration significantly improves performance. The cascaded configuration reduces HP electricity consumption by approximately 42%, achieving a net positive electricity balance despite lower ORC output. The fully integrated configuration enhances thermodynamic synergy, and improves HP operating conditions.