The Design And Control Of Micro-freezing Preservation Technology In The Application Of Refrigeration System

The refrigeration system plays a vital role in modern life and industrial production.In daily life,the refrigeration system that people have the most contact with people are refrigerators and air conditioners.Among them,the refrigerator can save food in a low temperature environment to extend the shelf life of the food.This is essential for the busy people in modern life.However,as people’s requirements for food preservation quality are getting higher and higher,conventional freezing can no longer meet people’s needs,and micro-freezing fresh-keeping technology is a new type of fresh-keeping technology developed based on this requirement.Refined control to achieve better fresh-keeping effects.In accordance with the working principle of the refrigeration system and the technical requirements of the micro-frozen fresh-keeping system,this paper studied the micro-freezing fresh-keeping technology in the refrigerator refrigeration system scene.The main contents of this paper are as follows:1)Analysis on the influence of micro-freezing preservation requirement and multiple physical parameters of refrigerator based on temperature field simulation.Mainly model the structure of the refrigerator,analyzed the effects of the location and area of the air outlet on the temperature field of the refrigeration process,and then analyzed the effects of cooling air volume and cooling time on the temperature field,so as to obtained the most cooling speed at the current room size the chamber structure.2)Temporary temperature field reconstruction method based on temperature field simulation.According to the technical requirements of micro-frozen fresh-keeping and the working principle of the refrigeration system,built a temperature change function relationship between object temperature and measuring points during the temperature field simulation method and the layout of the measuring point,and proposed a temperature Field reconstruction method.3)Study on control methods of refrigeration system control based on temperature field reconstruction techniques.Design and construction of an experimental platform based on refrigeration system principles,and control strategy development for refrigeration systems considering delay and inertia characteristics,and disadvantages of segmented temperature control.The control strategy combined Smith predictor estimation and fuzzy PID control to improve the refrigeration system’s preservation performance,validated the feasibility of temperature field reconstruction methods.The simulation results show that the optimization of the cavity structure in the current simulation model can improve the refrigeration speed of the system to a certain extent,and the cavity wall surface and the surface temperature of the food have some function coupling relationship during the refrigeration process.Application experiments show that the temperature field reconstruction method temperature fitting advantages are93.75%,and the maximum error of the fitting value and actual value is 0.52 ° C to meet technical requirements.