Experimental Study And Optimization Of TGS-2 Type Alfalfa Solar Energy-heat Hump Drying Device

In this thesis,TGS-2 solar-heat pump combined drying system is taken as the research object.Through no-load test and on-load test,the distribution law of temperature and humidity field and airflow field of hot air in drying medium at different positions in drying chamber is studied,and the influence relationship between the structure of drying device and the temperature field and airflow field is analyzed.The temperature field and velocity field of airflow in alfalfa drying device were simulated by COMSOL Multiphysics simulation software.On this basis,the str ucture of the drying device was optimized and simulated.Through no-load test,it is concluded that the temperature field distribution rule of the two-stage circuitous cascade drying chamber is that the temperature in the plane along the direction of air flow in the first-stage chamber(chamber A)has A decreasing trend.The distribution law of airflow field is that airflow velocity decreases obviously along the direction of airflow,and the degree of airflow unevenness increases first and then decreases in the direction perpendicular to the direction of airflow.The temperature field distribution rule of the secondary chamber(room B)is that the temperature on the plane along the direction of air flow decreases first and then increases.The distribution law of airflow field is the same as that of chamber A,and the non-uniformity coefficient of airflow is higher than that of chamber A on the whole.Through the load test,it is concluded that the temperature distribution in room A has the same trend as that in the no-load test,and the temperature difference between adjacent locations increases.The distribution law of airflow field is that the airflow field decreases rapidly along the plane of the direction of airflow,while the airflow unevenness increases first and then decreases in the direction perpendicular to the direction of airflow.The distribution law of temperature field and airflow field in chamber B is the same as that obtained from no-load test,and the degree of airflow unevenness increases and then decreases in the direction perpendicular to the airflow.Through carrying alfalfa drying test,from studying the characteristics of the material weight change and dry as the breakthrough point,further analyzes the influence of TGS-2factors,the performance of solar heat pump drying chamber structure in drying chamber slow drying rate than the rest of the central location of the position,drying by the ministry of interior structure affect the distribution of temperature field and flow field,further affect the drying rate.COMSOL multiphysics software is used to analyze the no-load and on load simulation modeling of the drying chamber.The air distribution law of X-Y section with X=300mm,X=1700mm and X=3400mm is compared and analyzed.The error between the simulation results and the experimental results is less than 10%,which verifies the reliability of the numerical simulation method.The existing drying device is simulated and optimized by using the simulation model,and the scheme of adopting arc-shaped deflector and V-shaped deflector structure on the side wall of drying chamber is proposed to solve the problem of insufficient contact between medium and material in load test,and force the material to exchange heat and mass with hot air,so as to improve the performance of drying device.