Numerical Simulation And Experimental Verification Of The Air Duct Structure Of Self-lifting Refrigerating Cabinet

With the rapid development of China's economy,people increasing high demands on the quality of life,"Food is the paramount necessity of the people",the quality and safety problems in the food field begin to enter people's view.In recent years,the vigorous development of China's logistics industry,and fresh and cold chain logistics has entered the stage of rapid development.However,ordinary logistics terminal distribution often meets the problems of hoarding,disjunction of distribution and the decay of fresh food caused by equipment failure.To solve the "last kilometer"problem of distributing food such as fresh and fruits and vegetables,people began to explore new solutions.Then,a kind of similar to the cabinet to the freezing freezer began to appear in the residential,office buildings and other areas,to the freezing freezer,as a kind of convenient,efficient and environmental friendly at the end of the distribution interaction mode came into being.The internal temperature,humidity,wind speed and freezing speed are the main factors affecting the quality of fresh food.However,since the mention freezing freezer in such aspects as structure of research there are still some shortcomings,such as temperature and humidity factors leads to uneven distribution of food refrigerated inconsistent quality,and further to bring the breeding of microorganism,lead to food deterioration,so keep to the freezing freezer internal flow field,temperature and humidity field distribution uniformity is important.The optimization of the structure of the refrigerator can make up for the market vacancy of high efficient and stable refrigerated freezer in the future.The temperature,humidity,wind speed and freezing speed of self-pickup freezer are the main factors affecting the quality of fresh food.However,the spatial uniformity of air velocity and temperature and humidity is the technical problem of fresh food.Uneven distribution of temperature and humidity and so on can lead to food refrigerated inconsistent quality,and further to bring the breeding of microorganism,lead to food deterioration,so keep to the freezing freezer internal flow field,temperature and humidity field distribution uniformity is important.However,there are still some deficiencies in the research on the structure,the temperature and the uniform distribution of the flow field.The improved optimization of this product can make up for the future efficient and stable market vacancy of self-pickup freezers.The change of air duct structure can effectively improve the air flow inside the self-pickup freezers and optimize its thermal environment performance.The fresh-keeping quality of fresh meat,fruits and vegetables are determined by the temperature and wind speed set by the self-pickup freezers.so that the distribution of internal air flow and temperature fields is of the utmost importance.In this paper,under the condition with M test package,air duct structures are changed of the axial baffle angle(30°,45°,60°,90°),the perforation rate(10%,15%,20%)and opening mode of the back orifice plate(non-uniform openings with upper sparse and lower dense,lower centralized openings and equally spaced openings).8 kinds of models are established and compared to find out the optimal structure model.The original structure(axial baffle angle of 45°,the method of centralized openings,perforation rate of 15%)is compared with the measured results to verify the correctness of the model.Research shows that when the return air plate Angle of 30 °,air distribution plate is equally spaced opening type and perforation rate of 20%,to the frozen inside freezer relatively reasonable air distribution,thermal environment ideal performance.In addition,this paper proposes using the average temperature,the overall uniformity and non-uniformity coefficient evaluation index for different air duct structure model to evaluate the temperature distribution of internal food packages load analysis,to reflect the degree of ideal freezer thermal environment.At first,this paper under the original to the freezing freezer structure,the correctness of the numerical model is verified by experiment design,in order to further the structure optimization design of air-conditioner numerical model under different structure foundation,and then separately from the velocity field,temperature field uniformity of internal air distribution and temperature characteristic of air-conditioner in make a comparative analysis of the final through different evaluation index to the freezing freezer internal load thermal environment.Provide design reference for the internal structure of similar use freezer.