Thermo-economic-environmental analysis of an innovative combined cooling and power system integrating Solid Oxide Fuel Cell, Supercritical CO2 cycle, and ejector refrigeration cycle

Abstract A novel combined cooling and power system integrating Solid Oxide Fuel Cell (SOFC), Supercritical CO2 (SCO2) partial heating cycle, and ejector refrigeration cycle is proposed, and the energy, exergy, exergoeconomic, and environmental analysis is performed to evaluate the system performance comprehensively. The parametric analysis is conducted to investigate the effects of six thermodynamic variables (i.e. fuel flow rate, excess air ratio, fuel utilization factor, turbine inlet temperature, SCO2 cycle pressure ratio, and SCO2 cycle split ratio) on the system performance. The results indicate that the lower total product unit cost conflicts with the higher thermodynamic efficiencies and lower CO2 specific emission. Therefore, multi-objective optimization is carried out to obtain a trade-off among thermodynamic, exergoeconomic, and environmental performances. Under the optimal condition, the exergy efficiency, total product unit cost, and CO2 specific emission of the system are 63.77%, 36.37 $/GJ, and 298.77 g/kWh respectively, and the system can achieve the power output of 168.95 kW and cooling output of 12.48 kW. The SOFC accounts for the largest part (15.72%) of the total exergy destruction and achieves the highest cost rate (6.90 $/h) with a high exergoeconomic factor of 90.90%, indicating its capital investment can be reduced for improving system cost-effectiveness.