The Numerical Simulation Analytical Study On The Drying Process Of Dates

Dates is one of the characteristics products in china. its great nutritional value and medicinal value determines its importance in everyday life. As people increasingly demanding quality of life, dates's safety is concerned by people, drying is an important factor in dry and processing of dates, which involves heat and mass transfer, mechanics, information science and other subjects of the integrated technology, is important to the dry process of dates and the quality control. In china, the Most production of red dates is in the rural areas, and their drying technology is relatively weak. most of drying ways are more traditional as baking and drying. These ways led to more loss and lower quality of the dates in the drying process because of their less science technology and rough means. Although in some areas, the more formal barn is established, but there is high energy consumption and costs. and the technology is not mature. Therefore, it has become an important issue to explore the mechanism and characteristics of the dates and improve the drying efficiency dates in the drying process. Through analyzing the heat and mass transfer process of dates, This article established the mathematical model of heat and mass transfer which was based on Non-equilibrium irreversible thermodynamics.The main contents are as follows:1)It reviewed the major research and theory on the drying of porous media at home and abroad. We have detailed more analysis of the existing theory of porous media, such as liquid diffusion theory, evaporation condensation theory, the capillary theory, Luikov Theory, and so on. Luikov theory established differential equations of Unstable field in the heat and mass transfer on the base of Non-equilibrium irreversible thermodynamics. The first time that heat and mass transfer interactions were reflected in mathematical equations In this article, we will establish new dates drying model on the base of improving this model.2)By analyzing the theoretical drying model that has been established, we found the appropriate mathematical model of heat and mass transfer in dates drying process. In Modeling process, the dates was considered as a spherical. According to the conservation of mass and energy conservation law, mass and heat transfer equations in the drying process were established. The simulation system of heat and mass transfer drying process was got by using Chase method to analyze equations with the boundary conditions. The system can monitor and simulate the temperature and moisture content of changes in the dates drying process.3)We experimented on dates drying process and verified the simulate results. In the experimental stage there was a experiment on drying dates. Through drying experiment on the base of different conditions of temperature and wind speed, we got different data of temperature and moisture content in the drying dates process. Analyzing experimental data and comparing experimental with the theoretical simulation,The result shows that the theoretical simulation and experimental values have higher simulation accuracy, and further proved that the model reflects the nature of the drying dates process. It has a certain practicality.