| Tobacco curing is the first process after the tobacco is air-cured,and it has a nonnegligible effect on the quality of the subsequent processed tobacco.Due to its unique and excellent performance in tobacco leaf curing,the dense curing barn is currently developing rapidly and widely used in my country.This subject is based on the CFD method to study the internal environment of the airflow down-type dense curing barn.The porous medium model is used to replace the tobacco leaves to be cured,and the discrete phase model is used to simulate the evaporation mode of moisture in the tobacco leaves.The validity of the model is verified based on the test data,the internal flow field of the no-load curing barn and the multi-field environment of the heat-fluid-solid coupling inside the barn during the baking process are analyzed,and factors such as air intake volume,air inlet position,roof angle,baffle angle and other factors are studied.The airflow and velocity field,pressure field,temperature field,etc.inside the barn are affected,and the structure of the dense barn with descending airflow is improved.The main research results of this paper are as follows:(1)Based on the basic assumptions,after completing the creation of the numerical simulation model of the dense curing barn,it is found through experiments that under a certain period of forced ventilation,any position in the smoking room of the dense barn can be raised to the preset temperature,but due to the smoking The indoor area is too large,and the temperature rises at different locations at slightly different speeds,and the ceiling temperature is higher than the bottom at the same time.And according to the experimental data,it is verified that the model can effectively simulate the real situation of the intensive curing barn.(2)Numerical simulation study on the flow field of no-load curing barn by orthogonal experiment.The research results show that for the air-flow down-type intensive curing barn,the position and angle of the air inlet and the size of the air intake per unit time have almost negligible influence on the temperature field of the smoking room inside the no-load barn,but it has a negligible effect on the inside of the barn.The influence of the airflow velocity field on the installation is very large.The position of the air inlet has the greatest influence on the airflow velocity field inside the smoking chamber of the roasting barn,followed by the angle of the air inlet duct,and the airflow volume has relatively the smallest effect.The study found that when the angle of the air inlet is 9°,the position of the air inlet is 0mm,and the air inlet volume is 20412m~3/h,the airflow velocity field distribution inside the barn is the most uniform.(3)Thermal-fluid-solid coupling multi-field analysis and structural improvement research inside the dense curing barn.Analyze the numerical simulation results of the baking process of the intensive curing barn with a complete cycle,and study the influence of the roof inclination angle and the deflector angle on the baking effect.The study found that the excessively large roof inclination or deflector angle will cause the airflow turbulence in the barn.,Affect the heating effect of individual tobacco leaf area.When the roof angle of the barn is 1° or the angle of the deflector is 10°,the baking effect of the dense barn is the best.Compared with the dense barn with no improved structure,the heating effect is improved to a certain extent,and the interior of the barn is improved.The uniformity of airflow distribution. |
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