Optimization of Performance and Economic Viability in Trans-critical CO2 Air Conditioning Systems Incorporating Solar-Powered Mechanical Subcooling

This study investigates the thermodynamic performance and economic feasibility of a trans-critical CO2 air conditioning system integrated with a solar-powered mechanical sub-cooler, developed to enhance cycle efficiency and reduce energy consumption under Jordan's climatic conditions.The system introduces a novel hybrid approach by incorporating R-423A as an environmentally friendly substitute for R-22, alongside a solar-assisted mechanical sub-cooling cycle.Unlike conventional approaches that assess sub-cooling or refrigerant replacement in isolation, this study examines the combined effect of both, under varying operational and environmental parameters.The influence of ambient temperature, gas cooler pressure, evaporation temperature, and sub-cooling degree on the system's combined coefficient of performance (COPcomb) is thoroughly analyzed.In addition, the effects of solar time and solar panel area on COP and compressor power consumption are evaluated.Results indicate a substantial improvement in system performance, with COP increasing by 70-75% when the subcooling temperature reaches 14C.However, raising the sub-cooling temperature from 0 to 16C at an ambient temperature of 35C increases combined cycle power consumption by 25.7%.The system, equipped with a 6.4 m solar panel, achieves a maximum utility power savings of 68.3%.An economic analysis demonstrates annual energy savings of 2,310 kWh, with a favorable payback period, affirming the system's financial viability.Overall, the integration of solar energy and mechanical sub-cooling offers a promising, sustainable solution for enhancing CO2 system performance and reducing operating costs in hot climates.