Study On Drying Characteristics Of Kelp And Air Distribution In Heat Pump Drying Chamber

China is a big fishery country.Dry and semi-dry aquatic products account for a large proportion of aquatic products exported in China.However,the existing drying technology is far from meeting the requirements of domestic and foreign markets for its export and quality.Practice has proved that the heat pump drying method can not only save energy,but also greatly improve the quality and added value of seafood.However,there is little research on this technology in China.Therefore,using heat pump drying method to study the drying of seafood is of great significance to promote the development of fishery economy in China.In this paper,the drying characteristics of a single kelp sheet during drying process are studied.The grids with different spacing are applied to the heat pump kelp drying chamber,and their optimum effects on air distribution and drying effect of kelp material layer in the drying chamber are analyzed.Firstly,based on the experimental data,the physical model of a single kelp sheet was established,and the moisture content of a single kelp sheet was simulated and analyzed under different working conditions.The effects of temperature,velocity and relative humidity of the drying airflow on the drying characteristics of kelp sheets were mainly analyzed,and the drying characteristics curves of kelp sheets under different working conditions were drawn.Secondly,taking a heat pump kelp drying room in Shandong Province as a prototype,the physical model of the drying room was established by SolidWorks.Based on the finite volume method and CFD numerical simulation software such as Fluent,the air distribution and kelp drying in the drying room were analyzed,and the air distribution in the drying chamber was evaluated by the velocity non-uniformity coefficient method.Finally,three different spacing grids are added to the air inlet of the drying chamber,and the corresponding physical models are established and meshed respectively.The change of air distribution and moisture content of kelp material layer in drying chamber under different grid spacing was simulated and analyzed,and the reasonable method of optimizing air distribution and drying effect in drying chamber was discussed.The research results have great reference value for optimizing the air distribution and drying efficiency of heat pump kelp drying chamber,and have certain guiding significance for the optimum design of other types of drying chamber.