Study On Photothermal Conversion Of Linear Cavity Collector And Combined Cooling Heating And Power System (CCHP)

Solar thermal power generation is a green power generation method with very few carbon emissions in the whole life cycle.And the Combined Cooling Heating and Power system(CCHP)is an effective way to improve energy efficiency.The combination of solar thermal utilization and CCHP will achieve energy conservation and emission reduction and green development at the source.For the trough solar collector system,a new linear cavity collector is proposed.The effects of the structure of the new linear cavity collector on the optical efficiency and heat loss are studied numerically by using Monte Carlo ray tracing method and thermal network model method.A theoretical model of the solar-powered CCHP system using linear cavity collector is established by numerical analysis,and the effects of evaporation temperature,condensation temperature,superheat of the Organic Rankine cycle and solar radiation on the performance of the system were studied by this model.Through the above research,it is showed that the new linear cavity collector has superior photothermal conversion efficiency when the arc shape is major arc,the focal length of the condenser is 2100 mm,the thickness of the insulation layer is 35 mm,and the opening width of the receiver is 70 mm.And it is revealed that the new linear cavity collector has better heat collecting performance than the vacuum tube.In addition,for the solar-powered CCHP system,it is found that the condensation temperature of the Organic Rankine cycle has the greatest impact on the system performance,and the system reaches its best performance when the condensation temperature is 90 °C.Finally,considering the climate condition in Hami area in Xinjiang,a set of solar-powered CCHP system with rated refrigeration capacity of 280 kW was designed.The rated total energy efficiency of the system is up to 62.5%,and the amount of solar radiation on the summer solstice day could support the system operating for 19.3 hours at rated conditions.The new linear cavity collector has good heat collecting performance,and its production and maintenance costs are lower than the vacuum collector tubes.Combined with the solar-powered CCHP system,the energy efficiency could be further improved,thus reducing the cost of solar thermal power generation and promoting the development of solar-related industries.