Comparative analyses of two improved CO2 combined cooling, heating, and power systems driven by solar energy

Abstract

To make use of solar energy fully and efficiently, the two improved combined cooling, heating, and power systems (CCHP) are proposed by adding a gas heater and an extraction turbine, based on the transcritical CO2 ejector refrigeration system. A relatively high pressure fluid is extracted by the extraction turbine as a primary stream of ejector to improve the ejector performance. In the meantime, the gas heater absorbs low temperature exhaust heat to increase the extraction turbine's output work. Comparative studies on the thermal efficiency and exergy efficiency of the two improved systems show they are more efficient alternatives for the transcritical CO2 ejector refrigeration system. The CCHP-B system has relatively broad working condition, higher thermal efficiency and exergy efficiency than that of CCHP-A system.