Performance Analysis Of Solar Ejector And Vapor Extracting Compression Coupling Refrigeration System

In order to effectively use solar energy to improve the performance of the refrigeration system,a solar ejector and vapor extracting compression coupling refrigeration system is proposed,the energy analysis model and exergy analysis model of the system are established,the calculation program is written in Fortran language,and the system is simulated and analyzed.The main research contents and conclusions are as follows:（1）A solar ejector and vapor extracting compression coupling refrigeration system is constructed,and the working principle of the system was explained.The one-dimensional calculation model of the gas ejector,the calculation model of the intermediate exhaust scroll compressor,and the thermodynamic model of the remaining components are established.（2）The influence of the structural parameters of the scroll compressor in the solar ejector and vapor extracting compression coupling refrigeration system on the performance of the system is analyzed.The calculation found that when the radius of the compressor base circle increases,its internal volume also increases,and the system cooling capacity Q_e and compressor power consumption W_com increase accordingly;when the height of the compressor scroll body increases,the volume cavity of the compressor increases.the system cooling capacity Q_e and compressor power consumption Wom increase,and the internal pressure ratio of the compressor remains unchanged.When the compressor involute angle increases,the compressor compression chamber volume decreases,the system cooling capacity Q_e decreases,and the compressor power consumption W_com shows an overall upward trend.（3）The influence of changes in operating parameters on system performance is studied.When the intermediate exhaust angle increases,the value range of the intermediate exhaust rate increases.Under the same working condition,the greater the intermediate exhaust angle,the greater the system mechanical performance coefficient COP_m.When the intermediate exhaust rate is constant,the system thermal performance coefficient COPh increases with the increase of the intermediate exhaust angle.When the evaporation temperature increases,the system mechanical coefficient of performance COP_m first increases and then decreases,and the system thermal coefficient of performance COPh increases.When the condensing temperature rises,the mechanical coefficient of performance COP_m and the thermal coefficient of performance COPh as well as the cooling capacity all decrease.The coefficient of mechanical performance COP_m increases first and then decreases with the increase of the generation temperature.When the generation temperature is 92℃,the coefficient of mechanical performance reaches the optimum.The coefficient of thermal performance COPh and cooling capacity both increase with the increase of the generation temperature.When the solar radiation intensity increases,the system cooling capacity and thermal coefficient of performance COPh both increase,while the mechanical coefficient of performance COP_m first increases and then decreases,reaching the optimal value when the solar radiation intensity is 600W/m2.When the refrigerant is different,the thermodynamic performance of the system is different.R1234ze has a higher mechanical performance coefficient than R1234yf,and R1234yf has a higher thermal performance coefficient than R1234ze.（4）The exergy efficiency of the system and the exergy destruction of each component change with operating parameters are studied.The exhaust efficiency η_sys of the system decreases with the increase of the intermediate exhaust rate.When the intermediate exhaust rate is the same,the greater the intermediate exhaust angle,the higher the exhaust efficiency η_sys of the system.The system exergy efficiency η_sys first increases and then decreases with the increase of the evaporation temperature,and the smaller the intermediate exhaust rate,the lower the evaporation temperature corresponding to the maximum exergy efficiency η_sys.When the condensing temperature increases,the exergy efficiency η_sys and the total exergy destruction both decrease.As the generation temperature increases,the exergy efficiency η_sys and the total exergy loss increase.The exergy efficiency η_sys and total exergy destruction increase with the increase of solar radiation intensity.Among the components,the ejector and condenser account for a larger proportion of the total exergy loss.