Experimental Investigation of Solar Assisted Transcritical CO2 Heat Pump and Refrigeration System

摘要

CO_2 is an ideal refrigerant with zero ODP and very low effective GWP, is not toxic and has no unexpected long-term effects on health or the environment. Solar energy is a clean, renewable energy source. This paper describes a combination of this ideal refrigerant and this renewable energy source in a solar assisted air source CO_2-heat pump water heater and air-conditioning system. The system provides hot water, heating and refrigeration throughout the year. An experimental test rig for studying the solar assisted CO_2 heat pump and refrigeration system was used to model the water to water heat pump and refrigeration cycle, the air to water heat pump and refrigeration cycle, and the solar and air compound source heat pump cycle. The effect of gas cooler outlet temperature, evaporation pressure, high side pressure and internal heat exchangers on the system COP were studied based on the water to water cycle. The solar collector system noticeably increased the system heating COP at night.