Dynamic Simulation And Performance Optimization Of Scraped Surface Ice Slurry System Based On Simulink

Development of ice slurry dynamic energy storage technology is an effective way to alleviate the burden of heat loading in summer and reduce the building energy consumption in our country.Wall scraping type which is one of the main methods of slurry extraction has been widely used for extracting slurry in stable way.At present,in addition to the need of experimental research,but also need the thermodynamic analysis of ice-making system on the research of ice-making machine.The rapid development of computer simulation technology provides a new way for the research of the ice-making system.In this paper,the mathematical model of the heat exchanger was established by moving boundary method.The model gives consideration to the efficiency and the accuracy of calculation.In addition,two boundary smooth switching conditions were used in the model to considerate the non-normal conditions caused by the two-phase state in export.And the steady state model of the ice storage cylinder was established according to the energy equation of the solution crystallization.On the basis of the model,the matrix equation was used to simplify the model,and each part of the model in the system was established in Simulink software.According to the simulation model,the time of solution crystallization in the crystallizer and the ice storage cylinder could be well predicted,and the dynamic response characteristics of the system were analyzed.The results show that compared with step change of the speed of compressor,the change of cooling water temperature has greater influence on each parameter,and the response time is longer.This result can provide reference for the further analysis of the system performance in scraped surface ice slurry system.In this paper,the application of some low-temperature chamber refrigerant such as R22,R134 a,R32,R161 and R1234 yf is considered,the application of these refrigerant in the ice-making system was analyzed.The results show that the refrigeration capacity of R134 a and R1234 yf is too small,the critical temperature of R32 is lower,the tube length that R161 required is longer.The application of these refrigerants in ice slurry generator should be optimized.The influence of the parameters of the solution side on the system performance was analyzed.The results show that reducing the initial solution of mass fraction or the flow rate of the solution can increase the cooling capacity and ice production efficiency appropriately.Finally,the air-cooled condenser in the ice-making system was analyzed in this paper,and addition of a parallel flow micro-channel condenser was proposed.The analysis show that two parallel flow condensers can be used in parallel on the basis of original system,and the heat exchange capacity can satisfy the operating conditions of the ice making system.Under the condition of keeping the other parameters of the system constant,reducing the inlet air temperature or the wind speed can increase the heat transfer coefficient and reduce the pressure drop in the refrigerant pipe.