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Despite the growing industrial demand for high-temperature heat pumps (HTHPs), systematic studies that simultaneously evaluate thermodynamic performance and economic viability of CO 2 -based zeotropic mixtures which includes condenser pressure drop effect remain scarce. The lack of studies comparing pure refrigerants with zeotropic mixtures by accounting condenser pressure drop effects, limits the ability to make informed refrigerant selection decisions. This study presents a comprehensive thermodynamic and economic comparison between pure acetone and CO 2 /acetone zeotropic mixture for HTHPs. A consistent cycle configuration was applied for all fluids, and condenser sizing was iteratively determined. Thermodynamic analysis reveals that introducing CO 2 improves both Coefficient of Performance (COP) and effective COP, with optimal performance observed at 8–10% CO 2 mass fraction at the specified boundary conditions to achieve a lift temperature of 70K. At an evaporator outlet temperature of 140 °C, the COP peaks at 4.8 for 10% CO 2 , compared with 3.1 for pure acetone. Accounting for condenser pressure drop reduces pure acetone COP by 12–16%, whereas mixtures with 6–12% CO 2 experience reductions below 5%. Economic analysis mirrors these trends the 8% CO 2 /92% acetone mixture achieves the lowest levelized cost of heat (0.055 €/kWh), shortest payback (3.02 years), and highest net present value (851.5 k€) outperforming pure acetone. Inclusion of condenser pressure drop raises pure acetone's LCOH by 13.6%, while zeotropic mixtures containing 4 – 8% CO 2 remain below 5%, and mixtures with 8–12% CO 2 show increases under 3%. These findings identify 8–10% CO 2 balances thermodynamic efficiency and economic advantage under specified conditions.
Meshesha et al. (Fri,) studied this question.