【作者】 王智华；

【导师】 李耀明；

【作者基本信息】 江苏大学 ， 农业机械化工程， 2006， 硕士

【摘要】 本文介绍了国内外关于油菜联合收割机的研究动态以及清选装置的发展概况，分析了当前国内油菜联合收割机清选装置存在的问题，说明了进行油菜联合收割机清选装置研究的必要性。 从颗粒碰撞理论出发，在合理假设的前提下建立物料颗粒在筛面上的运动模型。分析影响筛面上油菜籽粒运动状态的主要因素，并通过运动稳定性分析，得出在不同抛射强度条件下颗粒的运动规律。运用ANSYS软件的FLOTRAN CFD分析模块，对清选室内气流场进行仿真分析，研究风力因素对清选气流场的影响，得出影响气流分布的主要参数。 在理论研究和气流场仿真分析的基础上，通过“DF-1.5型物料脱粒分离、清选仿真与控制装置试验台”进一步研究影响油菜清选效果的参数。采用正交试验的方法进行试验，并对试验数据进行极差分析和方差分析，找出适合油菜清选的最佳参数组合。更换具有不同筛孔形式的筛面，改变筛面的结构参数进行对比试验，得出比较适合油菜清选的筛面形式。 在对油菜风筛式清选装置清选性能主要影响因素研究的基础上，利用BP神经网络强大的非线性映射功能，建立了风力因素、振动筛结构参数和运动参数与清选效果之间的BP神经网络模型，并用试验数据进行了预测检验，结果表明，网络模型具有较高的预测精度，该模型的建立为复杂的脱出物清选规律的研究提供了一条新途径。更多还原

【Abstract】 In this paper, it is introduced the research status and cleaning device overview about the rape combine harvester both at home and abroad, and analyzes the problems existing in current combine harvester’s cleaning device at home. In order to show it is necessary to conduct theoretical and experimental studies of the cleaning device about the rape combine harvester.On the basis of analyses over the collision theory, a motion mathematical model of the mixture on the vibration sieve is established with proper assumption. By analyzing the major factors effect the motion state and motion stability of rapeseeds the motion regularity of rapeseeds with different ejection intensity is founded. A numerical simulation for cleaning airflow field is made by using FLOTRAN model within ANSYS software to investigate the effect which caused by air factors and structure of cleaning device. We can obtain the air distribution inside the cleaning device by changing the input and output condition of the model which is established to educe the major parameters related to it.Based on the theoretical study and numerical simulation to the air flow field and make a further study over the parameters through "Experiment device for threshing, separating、 cleaning simulation and control of DF-1.5". After orthogonal test, range analysis and variance analysis are both done for the test data. At last the best suitable parameters are founded for the cleaning device. Change the sieve surface with different sieve apertures in order to change the structural parameter of vibration sieve. Then compare the cleaning performance with each other to find the most suitable structural of sieve surface for rape cleaning.Based on the research of the major effecting factors relate to the performance of rape combine harvester cleaning device. Using the high non-linear mapping function of BP neural networks to create a model between airflow factors, structural & motion parameters of double vibration sieves and the cleaning results .The network model is trained and predicted by the experiment data. The results indicate the high precision of this model and it can be referred as a new and effective method for studying variations of material cleaning.更多还原