Research On Novel Ejection-Compression Refrigeration System Utilizing Solar Energy With High Efficiency

Building energy consumption has always accounted for a large proportion in the entire energy consumption structure,and the energy consumed by air conditioner refrigerating and heating has accounted for a large proportion in building energy consumption.Recently,ejection-compression refrigeration system driven by clean energy such as solar energy have become more and more popular.However,the current research on solar ejection-compression refrigeration system mainly focus on coupling the system to improve the efficiency,and ignores the requirement of plenty of thermal energy in the process.Under this circumstances,solar collectors usually have large area,which lead to the limitation in practical applications and difficult to be generalized in urban building.Therefore,this paper proposes a novel type of ejection-compression refrigeration system that can efficiently use solar energy.The main work and conclusions are as follows:1.Considering that the current solar ejection-compression refrigeration cycle cost a lot of heat,and the heat provided by solar energy is unstable due to the inconstant weather conditions,the operation efficiency of the ejection-compression refrigeration system is also unstable.By adding a gas-liquid separator device in the circulation,the heat required by the ejector can be adjusted at any time.Additionally,the novel ejection-compression refrigeration cycle is compared with the traditional ejection-compression refrigeration cycle.The analysis results show that under the basic operating conditions,the thermal conversion rate of the novel ejection-compression refrigeration cycle is three times of the traditional ejection-compression refrigeration cycle,and the comprehensive performance coefficient COP_g is 144%higher than the traditional ejection-compression refrigeration cycle.As a result,the novel ejection-compression refrigeration cycle can use electric and solar energy more efficient.2.Establish a system model of the ejection-compression refrigeration cycle combining in a building.It is found that the energy-saving advantages of the novel ejection-compression refrigeration system become more obvious as the number of building floors increases according to the calculating result.The best comprehensive improvement rate of electric energy on 3-story buildings is 21.2%;and the heat conversion ratio of the novel ejection-compression refrigeration system increases with the number of building floors.Compared with the traditional ejection-compression refrigeration system,the same amount of solar heat can be converted into more refrigerating energy by the novel ejection-compression refrigeration system.Combining the refrigeration system with simulated regional meteorological data,the refrigeration system is optimized in real time to analyze its seasonal operating conditions;the results show that the optimized refrigeration system operates stably and has excellent performance in the cooling season;on the sixth-story building,the heat energy required by the novel ejection-compression refrigeration system is only about one-tenth of traditional ejection-compression refrigeration system.3.A ejector refrigeration experimental platform was designed.The experimental data of the ejector were compared with the simulation data to verify the reliability of the model.As a result,the average error of back pressure at the exit of the ejector is 2.68%,and the average error of the ejection coefficient of the ejector is 6.56%.It can be seen that the simulated data agree well with the experimental data.