Experimental Study And Structure Optimization Of Solar Hot Air Drying Oven Based On Multi-physical Field Analysis

Material drying oven is solar hot air drying operation of the place,the rationality of the structure directly affects the quality and efficiency of material drying,in order to stay dry material can contact with the hot air evenly,fully,improve the uniformity of moisture content after drying of material,often in drying chamber internal wind velocity field,temperature field distribution uniformity degree as a measure of criteria for drying box structure.In order to solve the problem of uneven wind speed distribution in the existing drying oven,on the basis of no-load and on-load test research,this thesis analyzed the structural reasons of uneven wind speed field in the drying oven with the help of COMSOL Multiphysics simulation platform,and redesigned and optimized the drying oven based on the numerical simulation method.The main research contents are as follows:(1)based on the existing drying oven for no-load test,the flow area have different wind speed and different outlet under the condition of the distribution of wind field and temperature field inside the drying chamber,analyses the distribution regularity and reasons,on this basis,the object and conducted by ryegrass and dry oven belt load test,the corresponding was obtained under the condition of different wind speed wind velocity field inside the drying chamber and the distribution of material drying,found that uneven distribution of wind velocity field inside the drying chamber,a little influence on the distribution of temperature field,but uneven drying raw materials that have directly led to the grass.(2)The numerical simulation of the drying oven is carried out to get the specific distribution of the wind speed field and temperature field in the box under no-load condition.Through comparative analysis,it is found that the relative error between the no-load test results and the simulation results is small,and the numerical simulation method is reliable.On this basis,the introduction of porous media model is the grass under the condition of loading materials drying process is simulated,and the uneven distribution of hot wind speed influence on material drying rate,the simulation results with experimental results,further verified by the numerical simulation of the accuracy of the simulation method,for the subsequent drying box structure optimization of virtual simulation technology provides support.(3)The design optimization scheme of changing the air inlet position of the drying oven and increasing the flow baffle chamber was proposed,and the physical field simulation of the improved drying oven was completed based on COMSOL Multiphysics platform.It was found that the air inlet was set on one side of the bottom of the drying oven,which was helpful to improve the uneven flow rate when hot air entered.At the same time,by adding an equal height opening baffle to partition the bottom of the drying oven,the uniformity of the wind speed field in the drying oven can be further significantly improved,and the drying performance of the hot air drying oven and the drying quality of grass materials can be improved.