| With the rapid development of modern society,the global demand for energy is increasing,but the traditional fossil energy is decreasing year by year.In recent years,more and more attention has been paid to the application of renewable energy.Solar energy has been widely studied for its abundant reserves,convenient access,low pollution and good safety.In engineering applications,the system that meets the refrigeration demand through solar energy has the biggest advantage of good season matching,that is,the supply of solar energy in summer has a better consistency with the refrigeration demand of buildings,the hotter the weather,the greater the cooling capacity of the system.Among them,solar lithium bromide absorption refrigeration system is the most widely studied,but the poor energy utilization rate and low thermal coefficient limit its further application,how to optimize the operating parameters of solar lithium bromide absorption refrigeration system is particularly important.This topic takes solar lithium bromide absorption refrigeration system as the research object,uses MATLAB/SIMULINK simulation software to simulate it,and uses ISIGHT optimization platform to optimize the system parameters.The main research contents and results are as follows:(1)On the basis of summarizing the existing research on solar absorption refrigeration system,the dynamic mathematical model of solar bromine cooler is established by using lumped parameter method,and the thermal physical parameters of lithium bromide solution are fitted and calculated.The dynamic performance of solar lithium bromide absorption refrigeration system in typical summer days was simulated based on MATLAB/SIMULINK simulation software.The correctness of the simulation model was verified by comparing the model with the literature data,and the input parameters of the simulation conditions were set according to the actual application.The simulation results of system performance parameters such as hot water,chilled water,cooling water,and refrigeration capacity were obtained,and the heat exchange components of the system were exergetic analyzed,which provide data support for the optimization of system operating parameters.(2)Based on the ISIGHT optimization platform,the coupled optimization workflow of ISIGHT and SIMULINK is constructed,and several single-objective optimization algorithms and multi-objective optimization algorithms are compared.For the simulation optimization problem of the small solar lithium bromide absorption refrigeration system studied in this subject,the single-objective optimization problem is suitable for adopting the NLPQL algorithm(sequential quadratic programming algorithm)and the multi-objective optimization problem is suitable for adopting the NSGA-II algorithm(non-dominated sequential genetic algorithm).The results show that the optimal temperature of hot water is93.45℃in the range of 90℃to 100℃,and the optimal area is 34.56 m~2 in the range of 20m~2 to 40 m~2 considering the efficiency of solar collector.(3)Based on MATLAB/SIMULINK simulation software,a solar single and double effect switching absorption refrigeration system was simulated.Based on typical clear sky and cloudy weather data in Qingdao during summer,simulation results were obtained for parameters such as hot water,chilled water,cooling water,cooling capacity,etc.An economic and environmental analysis was conducted on the solar energy single and double effect switching absorption refrigeration system.The investment payback period of the system is 17.2 years,and compared with traditional compression refrigeration systems,the carbon dioxide emission reduction ratio of the system is 86.6%. |
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