CFD-based Simulation And Experimental Research On The Temperature Field In The Seed Soaking And Pre-germination Box

Rice,as an important food crop,is widely planted at home and abroad.In recent years,the mechanization level of rice production has been significantly improved.In cold regions of Northeast China,the temperature of spring sowing is slowly warming up,which can not reach the temperature required for rice germination,resulting in low germination rate of high-quality seedlings and affecting the yield of high-quality rice seeds.Seed soaking and germination promotion is an important part of rice seedling raising.This study analyzed the influencing factors of temperature distribution in germination box,which laid a foundation for the development of rice seed soaking and germination promotion technology.In this paper,the temperature field in the large-scale seed soaking and germination test box of farm was simulated by using finite element analysis software CFX.Firstly,the governing equation of CFD numerical simulation is determined.By choosing appropriate boundary conditions and mathematical model,the temperature field in the test box is simulated numerically.Finally,the visual simulation of the internal temperature field is realized by software.The main contents of this paper are as follows:（1）The determination of simulation parameters of temperature field in germinator.According to the principle of similarity,the edge ratio coefficient 5 was used to process the germinating box,and the three-dimensional volume of the model was determined to be08.?12.?.03m³.Similar treatment of the intake flow was carried out with the flow ratio coefficient of 55.9.The results showed that the intake flow was0.089m³/h、0.0179m³/h、.0268m³/h、.0358m³/h和.0448m³/h.（2）The CFD mathematical model of the temperature field in the germinator was established.The turbulence model and convective heat transfer model suitable for seed soaking and germination chamber were determined.Workbench three-dimensional modeling module was used to model the size of seed soaking germinating box after similarity theory,meshing model was used to determine the basic parameters and boundary conditions of numerical simulation.（3）CFX software was used to analyze the temperature field of the water in the seed soaking accelerator.The influence of different inlet location and flow rate on the variation of humidity field was studied.The validation test was carried out using the same test scheme as the simulation.The temperature uniformity in the seed soaking accelerator was selected as the evaluation index.By comparing the experimental results with the simulation results,it was found that the corresponding temperature uniformity was the best when the intake locationL₁ and the intake flow rate were15m³/h,and the temperature uniformity was 1.42.