Thermodynamic-Environmental-Economic Evaluations of a Solar-Driven Supercritical CO2 Cycle Integrated with Cooling, Heating, and Power Generation

The combined cooling, heating, and power system is based on the principle of energy cascade utilization, which is conducive to reducing fossil energy consumption and improving the comprehensive utilization efficiency of energy. With the characteristics of a lower expansion ratio and larger recuperation of a supercritical carbon dioxide (SCO2) power cycle, a combined cooling, heating, and power (CCHP) system is proposed. The system is based on a SCO2 cycle and is driven by solar energy. The system is located in Qingdao and simulated by MATLAB/Simulink software (R2022b). Firstly, the thermodynamic performance of the CCHP system at the design condition is analyzed. The energy utilization efficiency of the CCHP system is 79.75%, and the exergy efficiency is 58.63%. Then, the thermodynamic, environmental, and economic performance analyses of the system under variable conditions are carried out. Finally, the solar multiple is optimized. The results show that the minimum levelized cost of electricity is 10.4 ¢/(kW·h), while the solar multiple is 4.8. The annual primary energy saving rate of the CCHP system is 85.04%, and the pollutant emission reduction rate is 86.05%, compared with the reference system. Therefore, an effective way to reduce environmental pollution and improve the utilization efficiency of solar energy is provided.