矿用混凝土运输车搅拌筒结构参数优化及内部流场模拟试验

发布时间：2019-06-29 18:05

【摘要】：矿用混凝土运输车采用轨道式电机车牵引,车身整体的高度较低,适用于隧道、矿井、国防工程等工作环境下的混凝土运输的问题。针对市场上矿用混凝土运输车搅拌筒寿命短、耗能大、卸料速度慢等缺点,结合2m3矿用混凝土运输车的相关参数,运用现代设计方法对原设计机型进行了产品优化和改进,主要内容包括以下几个方面:(1)对2m3矿用混凝土运输车进行了整体方案的设计,选择和确定了搅拌筒体的工作参数。对矿用混凝土运输车的主要零部件进行了三维建模设计,整机装配建模设计,完成了整机的工程图设计并进行了样机制造。(2)推导了满载工作状态下搅拌筒的驱动阻力矩与其工作参数之间的数学关系表达式。以驱动阻力矩的值最小为目标,运用MATLAB优化了搅拌筒的工作参数,并数值模拟了优化前后两种搅拌筒结构的内部流场,验证了优化方法和仿真结果的正确性。优化结果表明:满载工作状态下优化后的搅拌筒驱动阻力矩降低了14.7%。(3)对混凝土搅拌筒在两种典型工况进行静力学分析,得到两种典型工况下搅拌筒的受力情况和变形规律。以筒体质量最小为目标,对搅拌筒壁厚及易损部件进行了结构优化。通过增大搅拌筒在前锥段与前端板焊接处的强度,解决了混凝土运输车在实际工作中搅拌筒出现的前端板与前锥段焊接部位焊缝开裂、滚道与支撑托轮的接触表面损伤等问题。优化后搅拌筒的质量减轻14.02%;最大等效应力减少20.79%;搅拌筒应变量减少17.33%。(4)为研究搅拌筒内叶片形态及搅拌筒转速对其工作性能的影响,对搅拌筒卸料过程及搅拌过程进行数值模拟,得到了两种工况下速度场、压力场等分布情况,定量地分析了卸料工况下的搅拌速度、搅拌工况下的搅拌筒内各锥段混凝土离析程度。利用正交试验法分析了叶片主要参数及搅拌筒转速对于卸料速度及混凝土离析程度的影响,结果表明:后锥段叶片螺旋角对搅拌筒卸料速度影响最大,搅拌筒转速对搅拌工况下预拌混凝土均匀程度影响最大。优化后的叶片结构参数为:后锥段叶片螺旋角1?=65°,圆柱段叶片螺旋角2?=70°,前锥段叶片螺旋角3?=72°,叶片安装角?=82.5°;搅拌筒转速参数为:搅拌工况下的搅拌筒转速为2v=0.7rpm,卸料工况速度1v=9rpm。
[Abstract]:The mine concrete transport vehicle adopts a rail type electric locomotive for traction, and the overall height of the vehicle body is low, and is suitable for the problem of concrete transportation in the working environment such as a tunnel, a mine, a national defense engineering and the like. Aiming at the defects of short service life, large energy consumption and slow discharge speed of the concrete transport vehicle for mine, the product optimization and improvement of the original design model are carried out by using the modern design method in combination with the related parameters of the 2m3 mining concrete transport vehicle, and the main contents include the following aspects: (1) The design, selection and determination of the working parameters of the mixing cylinder are carried out for the 2m3 mine concrete transport vehicle. The three-dimensional modeling and design of the main parts of the mine concrete transport vehicle are carried out, and the design of the whole machine assembly and the design of the engineering drawing of the whole machine are completed and the prototype manufacture is carried out. (2) The mathematical relation between the driving resistance moment and the working parameter of the stirring cylinder under full load is derived. The working parameters of the stirring cylinder are optimized by using MATLAB, and the internal flow field of the two stirring cylinder structures before and after the optimization is simulated by using MATLAB, and the correctness of the optimization method and the simulation results is verified. The optimization results show that the drive-resistance moment of the stirring cylinder is reduced by 14.7% under the full-load working condition. (3) The static analysis of the concrete mixing drum under two typical working conditions is carried out, and the stress and deformation law of the stirring cylinder under two typical working conditions are obtained. The structure of the wall thickness and the vulnerable parts of the mixing cylinder was optimized with the goal of the minimum cylinder mass. By increasing the strength of the stirring barrel at the welding position of the front cone section and the front end plate, the problems of cracking of the weld joint between the front end plate of the concrete transport vehicle and the welding position of the front cone section, the contact surface damage of the raceway and the support riding wheel, and the like in the actual operation of the concrete transport vehicle are solved. The mass of the stirring cylinder is reduced by 14.02% after the optimization, the maximum equivalent effect is reduced by 20.79%, and the variable of the mixing cylinder shall be reduced by 17.33%. (4) In order to study the influence of the shape of the blade and the rotating speed of the stirring cylinder on the working performance of the stirring cylinder, the unloading process and the stirring process of the stirring cylinder are simulated numerically, and the distribution of the velocity field and the pressure field in the two working conditions is obtained, and the stirring speed under the discharging working condition is analyzed quantitatively. And the degree of segregation of the concrete in each cone section in the stirring cylinder under the stirring condition. The influence of the main parameters of the blade and the rotating speed of the mixing drum on the unloading speed and the degree of segregation of the concrete is analyzed by means of the orthogonal test. The results show that the spiral angle of the blade of the rear cone has the greatest influence on the discharge speed of the mixing drum. The rotating speed of the mixing drum has the greatest influence on the uniformity of the pre-mixed concrete under the stirring condition. The optimized blade structure parameters are: the spiral angle of the blade of the rear cone section is 1? = 65 掳, the spiral angle of the blade of the cylindrical section is 2? = 70 掳, the spiral angle of the blade of the front cone section is 3? = 72 掳, and the blade installation angle? = 82.5 掳; the rotating speed parameter of the stirring drum is: the rotating speed of the stirring drum under the stirring condition is 2v = 0.7 rpm, and the unloading working condition speed is 1 v = 9 rpm.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD524

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