Study On Drying Equipment Of Vacuum Flat Glass Solar Collector

Grain drying is the necessary work before grain storing. Conventional grain drier use the electric as the energy, result in high energy consumption. With the growing global energy and environmental problems, it’s necessary to develop a new drying process is requisite for the better results of drying and saving energy.This article researches a new drying process feeding on solar energy aim to save energy and high efficiency. The process use a combination of solar air heater, Finned liquid-gas heat drying bed and insulate vacuum glass. Simulate heat exchange and fluid flow in storage which explains the structure design scheme of drying storage, and analysis technology and technical route of grain drying equipment.Finned liquid-gas heat drying bed is one of the most important parts in grain drying process, the facts such as the angle of condenser, laminar flow velocity and thickness of grain, ventilation rate and speed of hot air all have great impact on dying. Researched on the process of heat exchange between hot water with cold air, calculated the coefficient of heat exchange between water with condenser and condenser with cold air, and study the impacts of water temperature and flow on heating cool air, calculated the outlet air temperature of every layer of condenser. Using the thin layer drying equations to establish internal moisture of grain flow model, study the influence of drying cycle times and drying time on grain moisture content.The calculations show it’s efficiency and have good quality of grain drying when finned liquid-gas heat drying bed’s slant angle is30degrees. Under this condition, the ventilating speed of main vents was16.11m/s, the mass flux was13.56kg/min, the thickness of grain was315mm, air quantity in dying house can meet the requirements of grain drying. By means of ventilation system calculation and simulation, the total resistance pressure of ventilation system drop to430.38Pa, the total resistance pressure of heat transfer bed drop to1.17Pa, the resistance pressure drop of grain was7564.6Pa.Simulated the situation of the hot water flows and the process of heat exchange between air with fins in condenser by finite element analysis, it shows that when heat source temperature in flat tube is80℃, flow rate is0.4kg/s, the layers of condenser air outlet temperature can meet the requirements of grain drying. Do condenser heat transfer experiments to verify the condenser heat transfer calculation. The experimental results show that the lowest layer of condenser ventilation outlet temperature can reach45.1℃, the second layer is54.2℃, the top layer can reach57.9℃, results was consistent with calculations.The research shows that the moisture content of grain decreased with the increase dry cycles. But the reduction decreases continuously, the moisture content of grain was12.9%after12drying cycles. It can achieve the aim of grain drying.