Experimental And Numerical Simulation Of A Compact Solar Energy Drying Device

Compared with the traditional natural drying,the solar energy drying device has a wide range of advantages due to its small pollution,high drying efficiency,excellent drying quality,efficient use of solar energy,and most cases without weather restrictions,So it is applied to various dry production.In this paper,the drying oven as the research object combined with white radish,Which was used to study the temperature,drying speed,relative humidity and other changes during the drying,and the porous media model also was used.So far,we have achieved more results and profit.However,in recent years,with the social progress,technological development,people are increasingly concerned about their own health,food storage requirements are getting more and more higher,In addition,drying is an important stage in the food storage process,which changes with the diversity and complexity of the material,and this feature led to the current stage of the drying process is mostly based on the experimental,the collection and the analysis of data have a greater workload,In the work which is prone to error.Researchers have owned more study and analysis methods with the extensive application and development of Computational Fluid Dynamics about the complex drying process,and Computational Fluid Dynamics was applied to the drying field and other fieldsIn this paper,the drying device combined with white radish was studied by the combination of theory,experiment and numerical simulation.The main contents are:(1)For the existing compact solar energy drying device,the heat analysis of the device is carried out from the aspects of structure,white radish displacement,air consumption and heat conservation,and the thermal efficiency was defined.(2)The existence and the migration mechanism of the internal moisture of the white radish were analyzed during the drying and the three stages of drying were discussed.The dry curve was analyzed by using a constant temperature blast oven on white radish under different temperature and thickness conditions.Experiments show that the higher the drying medium temperature,the thinner the slice thickness,the higher the drying rate,the faster the wetting rate of the wet base,the shorter the drying time was required for the white radish to achieve the same moisture content.(3)The effects on drying about the temperature about inlet and outlet and at different heighof the drying oven during the drying were studied by used compact solar energy drying device and the drying efficiency of each day was calculated during drying.We got the results that: the temperature difference is small at the same time in the inlet,the maximum difference of about 3?,the minimum difference is basically 0 ?,indicating that the heat medium can through the collector to inlet position evenly;the vertical temperature of the drying chamber gradually decreased from bottom to top,the highest temperature appears in the first layer on the first day of 14:30,the temperature reached to 70?,the minimum temperature about 65?at the same time,the maximum temperature difference during;The maximum temperature difference appeared in 12:00 in the day and the value is 10 ?;the maximum efficiency of drying is 20.71% at the first day,the minimum is 0.09% at the last day.(4)Through the simulation analysis about the drying oven under the same size,structure and parameters,and compared with the experimental data,the results show that the temperature coincidence was good at the outlet of the drying chamber,in addition the model and the parameter setting and Hypothesis of correctness were verified.(5)In terms of numerical simulation,the temperature field,the velocity field and the relative humidity field of the drying chamber were simulated in different ways In this paper.The speed of the inlet was 0.3m/s and the temperature were 40?,50?and 60?,the distribution characteristics of the drying chamber were obtained under different conditions.