The increasing scarce of conventional energy resource and deteriorating environmental problem push the world toward more and more sustainable way in energy conversion and utilization. Close Brayton cycle using super-critical CO2as working fluid is a promising technology for coal-fired, renewable energy-driven, waste energy-driven power production. Heat integration inside the CO2power cycle or with external resources are effective way in improving the super-critical CO2power cycle (SCO2) performance. In the present study, an integration system of solar thermal collector, SCO2, and organic Ranking cycle(ORC)is proposed. An equation of state-based model is developed for the simulation and simultaneous optimization of the proposed integration system. A case study is elaborated to test the superiority of three integration systems with different SCO2structure and validate the effectiveness of the proposed optimization model. The working fluid of ORC are screened and sensitivity analysis of key parameters on the integration system performance are conducted.
Keywords Super-critical CO2, Organic Rankine cycle, integration, optimization, solar energy