Energy, exergy and environmental life cycle assessment on the valorization of an ejector integrated CCHP system with six sustainable refrigerants

An ingenious ejector-integrated organic Rankine cycle-based combined cooling, heating, and power generation system (ERORC-CCHP) is proposed to empower rural habitats and make them self-sustainable owing to the difficulties of providing grid power. For this, comprehensive energy, exergy, economic, and carbon footprint analyses of the proposed system are carried out to examine the impact of operating conditions with six ORC-compatible and environment-friendly zero or nearly-zero ODP refrigerants, namely R600a, R245fa, R236fa, R1233zd, R124, and R142b. The variation in thermodynamic performance is assessed across a broad range of evaporator, condenser, and boiler temperatures and turbine first-stage expansion pressure. The findings of evaporator and condenser temperatures indicate that R124 and R142b attain the highest cooling efficiency, heat recovery ratio, overall system's COP, and economic efficiency, while R1233zd achieves higher power and exergy efficiencies. However, R1233zd is not recommended for higher condenser temperatures. Similarly, the environmental impact of R124 and R142b is a major concern due to their higher total equivalent warming impact (TEWI) values. Whereas, R124 and R600a exhibit the lowest life cycle environmental impact potentials. Meanwhile, maximum cooling, heating, and power capacities with refrigeration COP and minimal TEWI are achieved with R600a. Further investigation with R600a establishes maximum second law efficiencies of 52.76 % at a turbine first-stage expansion pressure of 11.35 bar. A combined energy and exergy flow diagram showcases that the turbine produces 15.7 kW of power, accounting for 45.64 % of the system's total exergy input, while the boiler and ejector together destroy 12.3 kW (35.61 %).