Numerical Simulation And Experimental Study On Temperature Field Of Insulation Box

In recent years,with the continuous development of fresh market and e-commerce in China,the volume of cold chain transportation has shown a significant growth trend.under the huge demand of cold chain transportation,the cold storage incubator has been paid more and more attention and favored by people.It is widely used in pharmaceutical products and fresh agricultural products and other fields.Cold storage insulation box is the use of thermal insulation materials and phase change cold storage agent to protect and transport temperature sensitive products,its size is small,easy to carry,for small batches,refrigerated products transport has a unique advantage.Moreover,this cold chain method can solve the problem of "last kilometer" cold chain interruption to a certain extent and ensure the integrity of the cold chain.In the process of cold chain transportation,there are many factors that affect the thermal insulation performance of the insulation box,including the type of insulation material,the wall thickness of the insulation box,the ambient temperature,the phase transition temperature and latent heat of the cold storage agent,the quality of the cold storage agent and so on.In this paper,based on the ANSYS FLUENT finite element analysis software,the numerical simulation method is used to analyze the different factors that affect the thermal insulation performance of the incubator in the process of transportation,and the mathematical models of holding time,equilibrium temperature and various influencing factors are established by OriginThe main results are as follows:(1)According to the experimental and simulation results,the accuracy of the phase transition model is verified,and the radiative heat transfer in the process of air cooling in the incubator is verified by experiments.(2)The finite element model of the incubator is established based on the ANSYS FLUENT finite element analysis software,and the corresponding incubator experiments are designed to verify the material properties and boundary conditions.The results show that the temperature-time curve of the simulation data is basically consistent with the experimental temperature-time curve,and the maximum temperature difference is 0.8K,which proves the accuracy of the finite element model.(3)On the basis of the finite element model,Changing the thermal conductivity of the thermal insulation material,the wall thickness of the insulation box,the ambient temperature,the phase change temperature and latent heat of the cold storage agent and the quality of the cold storage agent affect the thermal insulation performance of the thermal insulation box in the process of transportation.The results show that the effects of different effects on heat preservation duration and equilibrium temperature are different,and the mathematical model is established after observing the influence trend of different factors on heat preservation performance.(4)Through the analysis of the influencing factors,it is found that there may be a relative optimal thickness of the wall thickness of the incubator.By changing the wall thickness of the insulation box,the ambient temperature and the thermal conductivity of the thermal insulation material to explore the influence of the wall thickness of the insulation box on the thermal insulation performance under the condition of different ambient temperature and material thermal conductivity.The results show that when the ambient temperature is 20℃ and 50℃,the thermal conductivity is 0.01%0.075W/(m·K),and the wall thickness increases from 10 mm to 35 mm,.When the wall thickness increases from 35 mm to 45mm,the thermal insulation performance changes slowly,so it is determined that the best wall thickness of the incubator is 35-40mm.