Numerical Simulation And Experiment Of Temperature And Humidity Field Of Cool Storage Refrigerator

Refrigerator was the main energy-consuming equipment in cold chain logistics.In today’s energy shortage and increasing emphasis on energy saving and emission reduction,cold storage technology could balance grid load,reduce power distribution during peak hours,and reduce operating costs.The important application value and broad development prospects of the refrigerator.At present,most of the cold storage refrigerators relied on the temperature difference between the cold source and the storage environment to form natural convection to release the cold energy in the cold source.This method easily led to uneven distribution of the storage environment temperature,thus affecting the quality of the stored goods.To solve this problem,this paper adopted the method of forced convection,that was,by adjusting the wind speed of the fan,the opening area of the return air passage,and the temperature of the cold strip,the release speed of the cold energy was controlled,so as to achieve the uniform temperature of the storage environment.The main research works were shown as follows:(1)Temperature and humidity field coupling modelling based on CFD.Combined with the retainer cooler test platform,a 3d model was established by COMSOL Multiphysics,a multi-physics coupling simulation software.The model was calculated using k turbulence model and SIMPLE algorithm,and the wall function method was used to solve the model.The distribution characteristics of velocity field,temperature field and humidity field in the storeroom were analyzed.(2)Numerical simulation and test of velocity fieldThe populations of different grid numerical simulation model was established to evaluate,through the analysis of the grid number of reasonable choice model,and back to the area of the wind speed of the export of wind channel test,on the basis of this model for different return air duct opening area,air pressure,velocity field under the condition of cargo was studied,and the change law of the velocity field is obtained for the study of temperature field and humidity field to provide the reference.(3)Numerical simulation and test of temperature and humidity field couplingCool storage type cooler temperature and humidity coupling model was established and the storage room cooling process were simulated,analyzed the cooler temperature field and humidity field and the change of moisture content,models:as the growth of the cooling time,store the better the uniformity of air temperature,air relative humidity lower first,then gradually increase;In the area directly opposite the outlet of the return air duct,the air temperature and humidity content are lower,the relative humidity was higher,and the distribution in other areas was more uniform.In the cooling process,23.6 g of water vapor in the storage room condenses in the cooling process in the storage room and adheres to the cold strip.(4)Experimental study and numerical simulation of temperature and humidity controlThe experiment of temperature and humidity regulation of the cold storage compartment refrigerator was carried out.The results show that the larger the wind speed of the wind turbine was,the larger the opening area of the return air duct was,the lower the cold strip temperature was,the shorter the cooling time of the storage room was,and the faster the relative humidity change rate was.The uniformity of the temperature field in the storage room under various parameters was simulated and analyzed.It was concluded that the temperature field uniformity becomes better with the increase of the wind pressure of the fan,and becomes better after the opening area of the return air passage increases.With the decreased of the cold strip temperature,the combined test and numerical simulation show that the wind speed of the wind turbine was 4.5 m/s,the open air passage opening area was0.0256 m~2,and the cold strip temperature was-30℃.The room temperature humidity adjustment performance was best under the 30°C parameter.The numerical simulation of the cargo condition of the refrigerator was carried out,and the temperature changes of the cargo in three different areas were analyzed.The simulation showed that the average temperature of the cargo near the return airway area decreased the fastest,followed by the cargo near the wind turbine area,and the middle position.The average temperature of the cargo was reduced the slowest.Through the analysis of the surface temperature and humidity field of the cargo,it was found that the surface temperature of the cargo at the position of the tuyere was the lowest,reaching zero,the relative humidity was higher,and the upper surface temperature of the cargo in the middle position was higher,Comparing the goods in the area,the surface temperature and relative humidity distribution of the cargo near the fan position were the most uniform.