Design And Drying Chamber Simulation Of Stevia Rebaudiana Drying System Based On Solar Energy Heat Pump

China is a country with abundant solar energy resources.Regardless of the total annual radiation or the daily radiation,China will present more and more forms of new energy applications in the future,which use solar energy as a medium.As a hot research topic at home and abroad in recent years,heat pump technology has been applied for a long time.Hexi Corridor is located in the northwest of China.It has abundant solar energy resources and is an excellent place to grow sugar crops and medicinal materials.Stevia rebaudiana has been gradually utilized and developed because of its high medicinal and economic value.With the continuous expansion of market demand,the output of Stevia rebaudiana has also increased.Under the impetus of the larger market demand for Stevia products,the planting area of Stevia rebaudiana in Hexi Corridor has expanded rapidly,which actively promotes the vigorous development of related industries of Stevia rebaudiana.With the increasing market demand,the drying storage of Stevia rebaudiana leaves is particularly important.Quality and glycoside content are two indicators to test the practical value of Stevia rebaudiana,and drying treatment plays a decisive role.Therefore,it is very necessary to select appropriate drying methods and drying equipment to improve the quality of Stevia rebaudiana.In view of the problems in the drying process of Stevia rebaudiana in Hexi Corridor area,combined with the current domestic and foreign experimental study on solar heat pump combined drying,the research contents are as follows:Firstly,the drying characteristics of Stevia rebaudiana were analyzed by combining theory and experiment.According to the drying characteristics of Stevia rebaudiana,the influence of temperature and humidity on the drying characteristics of Stevia rebaudiana was found out.According to the drying characteristics of Stevia rebaudiana,the area of solar collector and the heat transfer area of compressor power,evaporator and condenser in heat pump system were determined by load calculation,and a set of feasible design was finally designed.Solar heat pump combined drying system for drying Stevia rebaudiana 20 kg.Secondly,on the basis of heat and mass transfer theory,air is selected as drying medium,the drying chamber is designed by software,and the drying chamber is modeled by Gambit software.Then,the air distribution in the drying chamber is simulated by Fluent software.Combining with the drying characteristics experiment of Stevia rebaudiana,the structure of the drying chamber is optimized,and the optimal drying process is obtained.Finally,the performance analysis of heat pump drying system,solar heat pump combined drying system and the matching relationship between solar energy and heat pump under different conditions are made,and then the economic analysis of the whole drying system is made.