A thermodynamic interaction intelligence framework for advanced exergy‐based assessment of waste heat‐driven ORC – ERC and ORC – VCR systems

Abstract

Abstract Integration of organic Rankine cycle (ORC) systems with refrigeration technologies offers a viable solution to recover low‐grade waste heat, while supporting cooling, heating and power generation. The article provides a comparative thermodynamic evaluation of waste‐heat driven organic Rankine cycle‐ejector refrigeration (ORC–ERC–WH) and organic Rankine cycle‐vapor compression refrigeration (ORC–VCR–WH) systems on the basis of a common conventional exergy, advanced exergy, exergoeconomic and exergoenvironmental framework. The thermodynamic interaction features of the two configurations are further assessed using the Exogenous Exergy Fraction (EEF) (ISI) and the Exogenous Exergy Contribution Factor (EECF). With the increase of ORC mass flow rate from 0.019 to 0.042 kg/s the cooling capacity increased from 0.45 to 1.42 kW and the ORC evaporator heat input increased from 11.19 to 24.73 kW. The conventional exergy analysis showed that turbine, evaporator and condenser are the main thermodynamic bottlenecks. The advanced exergy analysis revealed that more than 75% of the total exergy destruction was avoidable, showing a large improvement potential. Conversely, the ORC–ERC–WH system had a more concentrated improvement structure with specific improvements to the turbine, evaporator and condenser, while the ORC–VCR–WH system had a broader multi‐component improvement requirement. The average aggregate ISI values derived from the uncertainty analysis were 3.75 and 3.60 for the ORC–ERC–WH and ORC–VCR–WH systems, respectively. Overall, results show that the proposed interaction‐based framework provides a systematic basis to identify priorities for thermodynamic improvement at the component level in integrated waste‐heat‐driven refrigeration systems.