| The main reason of the uneven distribution of airflow in the interior part of the drying room is low drying efficiency, uneven drying and poor quality of drying. In order to overcome the problem of poor drying effect caused by the uneven airflow organization in the drying room, through the experimental test improved structure of the drying room in order to improve the uniformity of airflow organization, there is a heavy workload, long test period, high cost. By using the theoretical simulation method to optimize the structure of the drying room, it is a good method to improve the uniformity of airflow organization in the drying room.The chrysanthemum drying room as the research object, through the analysis of chrysanthemum of material parameters and a drying chamber of the internal structure, using FLUENT software to the drying interior airflow organization were analysis and simulation study, improve the uniformity of drying indoor airflow organization.The main conclusions are as follows:(1)The actual density and bulk density of chrysanthemum were measured by the static said method;porosity and mean diameter of Chrysanthemum by using the method of calculation and determination;By building a simple thermal conductivity measurement device, using Fourier’s law measured the thermal conductivity of chrysanthemum, were measured by means of the physical property parameters of chrysanthemum, provide the parameters for the setting of the FLUENT software to simulate the porous medium model.(2)The drying room was modeled by the pretreatment software GAMBIT, in drying chamber in fluid computational domain is simplified,by FLUENT software,based on the basic governing equations and the laws of fluid motion,select tandard k-ε turbulence model and SIMPLE algorithm,various boundary conditions of the simulation are set up according to the actual parameters,in this model,we use porous medium model instead of dates.(3)Numerical simulation of the airflow organization in the drying ro of chrysanthemum,Then the simulation results are compared with the experimentalresults, and the relative error between the simulation value and the experimental value is found to be less than 8%,So we can draw the following conclusions: The application of FLUENT software to the numerical simulation of the airflow organization in the drying room of chrysanthemum is feasible.(4)Through the simulation analysis of two kinds of inlet without guide plate and inlet set the guide plate, the following conclusions are drawn:There is no guide plate at the entrance of the drying room, and the airflow distribution in the drying room is poor,because there is no guide plate shunt, the airflow into the drying room to flow directly after drying room on the right side, leads to the right side of the drying room has large wind speed, drying room airflow organization is not uneven; by setting the guide plate at the entrance of the drying room, the airflow in the drying room is dispersed, so that the velocity field and the pressure field of the drying room are greatly improved.(5)Through the analysis of the airflow organization in the drying room with different guide plate angle, it is found that when upper guide plate is 60?、medium guide plate is 30?、lower guide plate is 15?, the uniformity of airflow organization in the drying room is the best.(6)The influence of the length of different guide plate on the airflow organization in the drying room under the optimum angle of the flow guide plate was studied, when the upper and medium and lower guide plate length were found for both the 280㎜ and 400㎜ and 400㎜, the uniformity of airflow organization in the drying room is the best.(7)The uniformity of air flow in the drying room is studied when the inlet air velocity is 1.5m/s, 2.5m/s and 4m/s, the study found that, when the inlet velocity is2.5m/s, the uniformity of airflow organization of indoor is good, chrysanthemum has the characteristic of high drying efficiency, good drying quality and Good uniformity of drying. |
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