【作者】 黎粤华；

【导师】 王述洋；

【作者基本信息】 东北林业大学 ， 机械设计及理论， 2009， 博士

【摘要】 能源是人类社会生存、国民经济发展的必备资源和重要战略物资。我国经济的快速发展已经带来能源短缺和严重的环境污染问题,因此,寻求和开发适合我国国情的可再生能源及化石能源替代品迫在眉睫。我国生物质资源十分丰富,研究开发生物质高效利用技术对促进能源结构改善,保证未来能源供应,提升我国农村经济发展水平和环境质量,建设和谐社会具有重要意义。生物质固化成型技术是生物质能转换技术研究的一个重要分支,对开发利用我国丰富的生物质资源具有重要意义。黑龙江作为我国重要的粮食生产基地,农林废弃物资源丰富,但闲置现象较为严重。本文以“863”科技项目“斜板槽式低能耗精控加热型生物质快速裂解制生物燃油及混合乳化燃料新技术”和黑龙江省重点项目“生物质成型燃料制造关键技术”为依托,以生物质秸秆为研究对象,进行了固化成型的实验研究,考察了不同原料粒度、不同含水率、不同模具长径比、不同模孔开口锥度等主要因素对成型制品的压缩密度的影响；具体分析了不同因素对固化成型的影响规律,并对秸秆压缩成型过程的松散、过渡和压紧三个阶段的压力与压缩密度关系进行回归分析,得出拟合方程。生物质固化成型过程表现为非线性问题,用非线性有限元理论对生物质固化成型过程进行分析,确定屈服准则和强化规律,建立基本方程和虚功方程。在此基础上,利用市场占有率极高的大型通用有限元分析软件ANSYS对生物质固化成型过程进行模拟,得到不同模具长径比、不同模孔开口锥度等影响成型的主要因素对原料内部应力应变的影响规律,进而与实验得出的影响生物质固化成型的主要因素的影响规律相比较,发现有限元软件能够较好的模拟生物质在压缩成型过程中的内部变化情况,对研究压缩成型规律非常有效。并利用ANSYS的热分析模块模拟加热后生物质内部温度场的分布情况,考察了温度因素对生物质固化成型的影响,推断生物质各断面的木质素软化和熔融情况,为挤压工艺提供参考。模孔壁受力分析对确定成型模具模孔分布非常重要,通过对成型孔变形、应力进行仿真,得出成型孔内壁位移变形、最大应力呈现小范围连续变动规律,为成型孔结构的设计提供参考依据。通过对现有平模辊压式成型机压辊的特性分析,得出压辊相对于平模纯滚动的设计条件,为生物质平模辊压式成型机降低功耗、提高产量提供指导。本文所做的研究不仅为生物质固化成型原理提供理论依据,而且为广泛推广辊压式成型机应用和实现生物质资源规模化利用提供重要基础理论、设计方法和参考依据。更多还原

【Abstract】 Energy is one of the most necessary resources and an important strategic material for the survival of human society and national economic development. Rapid economic development in China has resulted in energy shortages and serious environmental pollution problems, so seeking and developing renewable energy and substitute for fossil energy that appropriating our national conditions is urgent.Biomass energy resources are very rich in China, researching and developing high utilization technology of biomass energy can promote the improvement of energy structure,ensure future energy supply and raise the level rural economic development and environmental quality. It is significance for building a harmonious society.Biomass briquetting is an important branch of biomass energy conversion technology. It is significance for the development and utilization of straw biomass resources. Heilongjiang is the major grain production base in China. The agricultural and forestry waste resources are rich. The idle phenomenon is much serious. In this paper, it is base on"863" science and technology projects "The new technologies of inclined plate-type heat trough low-power precision control of biomass fast pyrolysis system for bio-fuel and hybrid emulsion fuel", and research project in Heilongjiang province "The key technology of biomass briquette manufacturing". The research object is straw. We conducted a experimental study of compression molding, investigated the impact of different raw material particle size, different moisture content, aspect ratio of different molds, different openings taper of mold to compressed density of the molding products, resolved the impact of factors for compression molding, analysed different factors on the influence of the compression molding, analysed the relationship of compression and compressed density in the loosing,transition and compressing stages in compression molding process. In the end, we derived fitted equation.Biomass briquetting expressed as geometric large deformation, elastic-plastic of materials, and the complexity of the boundary. Using nonlinear finite element theory, we analysed biomass briquetting process, determined the yield criterion and the strengthen laws, established the basic equations and the virtual work equation. Basing on finite element analysis of biomass compression molding process, we used large-scale finite element analysis software ANSYS to simulate biomass briquetting processes, investigated the impact of different raw material particle size, different moisture content, aspect ratio of different molds, different openings taper of mold to compressed density of the forming products, and compared the biomass briquetting law derived from experiments with the best value of the main impact parameters. We found Finite element software can simulate internal change in the biomass compression molding process. It is very effective for studying the law of biomass compression molding. We used large-scale finite element analysis software ANSYS to simulate internal stress-strain of biomass raw material in briquetting processes, and the temperature distribution within the material after heating, observed the impact of biomass briquetting by temperature factors, inferred soften and melt information in various sections of biomass, provided a reference for the extrusion process. It is very important that stress analysis of mould hole wall for determining pore size distribution. By forming hole deformation, stress simulation, we drawed a continuous change law of mould hole wall displacement deformation, the maximum stress in small-scale, provied reference for forming hole structure design. Through the mechanical analysis and numerical simulation for roller of flat mould forming machine working status in existing roller, we completed improved design of the roller. In the end we provide theory and reference of manufacturing flat and roll-type forming machine.This study has important strategic significance. It is not only good for providing a theoretical basis for the principle of biomass briquetting, but also for applicating widely flat mould forming machine and realizing large-scale utilization of biomass resources.更多还原