Study On Multi-physics Coupling Calculation Of Wood Microwave Drying

Microwave drying is a new drying technology,which is widely used in various fields such as materials,food,and chemical industry.Wood drying is an important link to ensure and improve wood quality,reduce wood loss,and increase wood utilization.At the same time,the process of the largest energy consumption in the production of wood products is wood drying.Traditional steam drying has high energy consumption,low efficiency,and poor drying quality,while microwave drying has low energy consumption,fast drying speed,and high drying quality.It has always been the focus of research by many scholars.The occurrence of drying defects,such as cracking,carbonization,etc.,hinders the pace of large-scale industrial application of wood microwave drying.Therefore,in this thesis,through multi-physics coupling calculation,the electromagnetic field,temperature field,seepage field and deformation field involved in the wood microwave drying process are coupled to simulate the process of wood microwave drying,and explore the best process conditions of wood microwave drying.At the same time,the uniformity of wood microwave drying is improved.The calculation results can provide some theoretical guidance for the practical application of wood microwave drying.The main research contents of the paper are as follows:(1)The frequency domain-transient one-step solution method is used to couple the electromagnetic field equation,heat conduction equation,seepage field equation and deformation field equation to realize the solution of the transient physical quantities of each field during the microwave heating process.(2)Establish a geometric model of wood microwave drying,set the boundary conditions and physical property parameters of the model,perform multi-physics coupling calculations on isotropic wood and anisotropic wood,and compare and analyze the calculation results.On the one hand To study the influence of different characteristics of wood on microwave drying results,on the other hand,to study the optimal process conditions of wood microwave drying.(3)Improve the uniformity of wood microwave drying.By changing the angle between the wood and the waveguide feed port to improve the uniformity of wood microwave drying,the best process conditions for wood microwave drying are finally obtained,which provides a theoretical basis for its large-scale industrial application.