Research On Mechanics And Parameter Optimization Of Die Hole In The Process Of Biomass Briquetting

Loop die is the key parts of biomass briquetting machine. The deformation and failure of peripheral densely die hole of loop die is caused by its structure, so the die need to be often changed, thus the production cost of briquetting increased, which is the bottleneck that constrains the industrialization process of briquetting. The main process of briquetting is completed in the die. The structure of loop die mainly consist of numerous die hole structure, and the structural parameters of die hole directly restricts the material flow, service life of ring die, the yield of briquetting machines, and the quality of the briquetting fuel etc. Because loop die is easy to deformation, and its low service life, high energy consumption and high cost, the research of mechanical characteristics and the failure mechanism to the hole of loop die is of important theoretical significance and practical economic benefits.This paper depend on the key project of heilongjiang province "key technology of biomass briquetting fuel manufacture", take energy conservation and emission reduction, reducing the production cost as a starting point, based on the rheological and elastic-plastic mechanics theory, using nonlinear finite element method, using ANSYS finite element software to do numerically simulation and stress analysis for the process of briquetting, explore the stress and deformation law of die hole, simulate and calculate the key parameter of die hole failure, and design optimized loop die. The thesis mainly contains the following parts:(1)Do stress analysis to the key parts (loop die) of biomass briquetting machine at different positions. Combine mathematics method with the experiment, abstract biomass briquetting process into nonlinear problem, use the theory of nonlinear finite element to do experiment and theoretical analysis for die hole deformation and stress, and test the various parameters in the briquetting process, and seek the law that briquetting pressure influence on the briquetting process. Analysis the distortion of the die hole under the action pressure load, simulate the distribution situation of stress and strain of die hole in shaping process with complex stress state, analysis factors that influence the fatigue life of die hole combining with finite element simulation condition, and establish geometry model of die hole.(2)Using the independent design of biomass briquetting machine to do processing experiment for raw material. Through the experiment, The pressure at different position in the die hole and the structure of the die hole are research object, we do the detection of the forming process of biomass force (detection of force sensor) at die hole position, measure wear weightlessness of different heat treatment material. Analysis ratio length and diameter of the die hole, the moisture content of material, confirm the relationship between the stress and model hole wear in different position, find experimental condition that influence the wear extent, make sure the experiment parameter of die failure, and provide data base for doing quantitative analysis for the failure forms of die hole.(3) Analysis the failure mechanism of die hole and the structure that influence the life of die hole, use Weibull equation build the S-N curve of fatigue failure of die hole, use rain-flow counting method and ANSYS software to do the numerical analysis and calculation of structural parameters of die hole in different conditions, and obtain fatigue life data of die hole in different structural parameters. Quantifying the fatigue life of die hole, offers method and theoretical basis for the development of biomass briquetting theory, and establishes the theoretical foundation for the commercial promotion of biomass briquetting fuel.This text use the independent die machine to do experience, do the research on the mechanical properties and the failure mechanism of die hole, confirm the influence law of briquetting pressure to briquetting process, confirm the best parameters of briquetting, establishes the relationship of mechanical properties and structure parameters, and puts forward the improved die hole design, striving for the ideal die hole.