玉米秸秆收获关键技术与装备研究及数字化仿真分析

发布时间：2018-01-20 12:54

本文关键词： 玉米秸秆收获技术切割与调质数字化设计仿真分析　出处：《中国农业机械化科学研究院》2013年博士论文　论文类型：学位论文

【摘要】：玉米秸秆是重要的生物质能资源,与矿物燃料相比,生物质能具有可再生、低污染和二氧化碳零排放等特点；与其它可再生能源相比,具有资源丰富、分布面广和用途广泛等特点。因此,许多国家都在大力发展生物质能技术,世界粮农组织(FAO)预测,到2050年,以生物质能为主的可再生能源将提供全世界60%的电力和40%的燃料。目前我国玉米秸秆的资源化收集利用尚未形成规模,主要有两方面原因：一是玉米摘穗收获期的秸秆含水率高达70%-80%,采用自然状态下晾晒,失水速度慢、干燥时间长,影响即时收获和打捆；二是玉米秸秆坚硬挺实,难于打捆,且打捆后因弹性变形应力作用易产生涨捆现象。本文在国家863计划和国家科技支撑项目的支持下,以实现秸秆规模化收集利用的技术突破为研究目标,针对上述问题展开研究。研究内容分为玉米秸秆收获关键技术研究和秸秆调质玉米收获机整机研制两个方面。主要研究结论及创新点如下：玉米秸秆收获关键技术主要研究秸秆切割技术和秸秆调质(指对玉米秸秆进行挤压、揉搓使其破节、裂皮的处理过程)技术,具体研究了秸秆切割和调质的技术原理和典型机构,开展了秸秆特性、秸秆切割部件以及秸秆调质部件等相关试验研究。首次开发出了玉米秸秆切割调质技术和部件,实现了玉米秸秆破节、裂皮的调质目标。玉米秸秆切割调质部件研究采用了三维实体造型技术、多体动力学计算机仿真技术和柔性体建模技术。首次建立了玉米秸秆柔性体仿真模型,开展了秸秆弯曲和调质的仿真台架试验,建立了切割调质台数字样机的秸秆柔性体模型仿真研究平台,对秸秆和样机模型进行了刚柔耦合仿真分析,实现了切割、输送、调质工作过程的虚拟再现,得出了秸秆的运动学和动力学参数,验证了仿真研究平台的有效性,为进一步深入研究提供基础和参考。秸秆调质玉米收获机整机研制过程集成了不分行摘穗台、秸秆切割调质台、高效清杂装置、果穗输送和收集装置、自走式全液压动力底盘等多项技术。样机通过田间性能试验测试,在收获果穗的同时,对玉米秸秆进行切割调质处理,使其破节、裂皮,加速秸秆的水分蒸发和减小变形应力,改变了其力学及物理状态,满足了玉米秸秆高密度成捆作业要求,促进了玉米秸秆规模化综合利用。首次实现了玉米摘穗收获技术与秸秆调质铺条技术的联合匹配应用,补充和完善了我国玉米收获技术体系。论文采用数字化设计新技术,探索了农机产品研发的新模式,为缩短农业装备开发周期和降低研制成本提供了技术支持。通过自主创新开发,获得具有完全自主知识产权、适合国情的核心技术和装备,为构建玉米秸秆收集固化成型装备技术体系做出了贡献。
[Abstract]:Corn stalk is an important biomass energy resource. Compared with fossil fuel, biomass energy has the characteristics of renewable, low pollution and zero carbon dioxide emission. Compared with other renewable energy sources, they are rich in resources, widely distributed and widely used. Therefore, many countries are vigorously developing biomass energy technology, the World Food and Agriculture Organization (FAO) forecasts. By 2050, biomass-based renewable energy will provide 60% of the world's electricity and 40% of fuel. At present, the collection and utilization of maize straw in China has not yet formed a scale, there are two main reasons: first, the moisture content of corn straw in the harvest period is as high as 70-80, the natural state of drying. Slow loss of water, long drying time, affecting immediate harvest and bundles; The second is that the corn straw is hard and solid, and it is difficult to bundle, and the elastic deformation stress can easily lead to the phenomenon of bundles. This paper is supported by the National 863 Program and the National Science and Technology support Project. In order to realize the technical breakthrough of straw collection and utilization on a large scale, the research aims at the above problems. The research contents are divided into two aspects: the research on the key technology of corn straw harvesting and the development of the whole machine for corn stalk conditioning and tempering. The main research conclusions and innovations are as follows: The key techniques of corn straw harvesting are straw cutting technology and straw conditioning technology (that is, the processing process of extruding, kneading and rubbing corn straw to break its joints and crack its bark). The technical principle and typical mechanism of straw cutting and tempering were studied, and the characteristics of straw were carried out. The technology and parts of corn straw cutting and tempering were developed for the first time to realize the target of corn straw cutting and tempering. Three-dimensional solid modeling technology, multi-body dynamics computer simulation technology and flexible body modeling technology are used in the research of corn straw cutting and tempering parts. The simulation model of maize straw flexible body is established for the first time. The simulation bench test of straw bending and tempering was carried out, and the simulation platform of straw flexible body model was established, and the rigid-flexible coupling simulation analysis of straw and prototype model was carried out. The virtual reproduction of cutting, conveying and tempering processes is realized, the kinematics and dynamics parameters of straw are obtained, and the validity of simulation research platform is verified, which provides the basis and reference for further research. The whole development process of corn harvester with straw conditioning and tempering is integrated with no branch picking table, straw cutting and tempering platform, high efficiency cleaning device, ear conveying and collecting device. The prototype was tested by field performance test, and the corn stalk was cut and quality adjusted at the same time, so as to break the node and crack the skin. Accelerate the evaporation of straw moisture and reduce the deformation stress, change its mechanical and physical state, meet the requirements of high-density corn straw bundles. It has promoted the comprehensive utilization of corn straw on a large scale. It is the first time to realize the joint matching application of corn picking and harvesting technology and straw blending and laying strip technology, which complements and perfects the maize harvesting technology system in China. The paper adopts the new technology of digital design to explore the new mode of agricultural machinery product research and development, which provides technical support for shortening the development cycle of agricultural equipment and reducing the development cost. The core technology and equipment with complete independent intellectual property rights and suitable for national conditions have been obtained, which has contributed to the construction of the technical system of corn straw collection and curing equipment.
【学位授予单位】：中国农业机械化科学研究院
【学位级别】：博士
【学位授予年份】：2013
【分类号】：S225.51

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