摘要推进剂的螺杆挤压过程是整个推进剂生产过程中事故多发环节。由于挤出过程中推进剂流体为高温高压且湍流状态,同时推进剂的多组分间还进行混合、熔融、剧烈摩擦、剪切等作用,现阶段通过实时测量流体各部位的温度、压力等重要参数还较为困难。目前实际生产中,单螺杆挤出机与双螺杆挤出机都有大量的运用,而单螺杆挤出机主要用于推进剂、火炸药等高能量含能材料的挤出制造。论文的选题旨在针对推进剂的单螺杆螺压工艺安全进行研究,通过选择合理的模拟工具对该工艺过程进行数值模拟。与开展相应的试验研究相比,能够节省大量费用,同时也能避免试验过程的风险。19522
毕业论文利用Polyflow软件对单螺杆挤出机的挤出工艺段进行仿真模拟,主要得出以下结论:
(1)等温挤出过程中,温度文持在一个温度域。生产中,实际平均温度与流体自反应温度之间应该有较大的差值。
(2)螺纹处附近剪切速率明显大于周围,摩擦加剧,造成螺纹损耗,摩擦生热,摩擦起电等现象,进而引起机器损坏,燃爆事故等危险现象。
(3)螺杆螺纹两端压力存在差异,长期处于工作状态易导致螺纹变形,产生安全隐患。应该定期检查螺杆状况。
(4)螺杆转速增大,生产效率会上升,但损耗加大;螺杆转速减小,黏度会增加,易导致堵塞。应在两者之间寻找最佳转速。
关键词:单螺杆 Polyflow 挤出工艺 数值模拟 推进剂
毕业设计说明书(论文)外文摘要
Title Security screw on the pressure process simulation
software based Polyflow
Abstract
Screw extrusion process of propellant is a link with accidents in the production of the propellant. Due to propellant fluid for high temperature and high pressure in the extrusion process and the turbulent state, at the same time, also between propellant of multicomponent mixed molten, friction, shear, and so on, At the present stage through real-time measurement of each part of the fluid temperature, pressure and other important parameters is more difficult. At present, in the process of production of single screw extruder and double screw extruder has a lot of use, and single screw extruder is mainly used in propellant, such as high-energy can contain fire explosive materials extrusion manufacturing. Thesis topic selection of single screw screw press process aimed at propellant, to study the safety, by selecting reasonable simulation tool for numerical simulation of the process. Compared with the corresponding experimental study, can save a lot of cost, but also can avoid the risk of the test process.
Paper using Polyflow software of single screw extruder extrusion process simulation of duan, mainly the following conclusions:
(1) Isothermal extrusion process, the temperature at a temperature field. In production, since the reaction temperature should be between the actual average temperature and fluid have larger difference.
(2) In thread near the shear rate significantly greater than the surrounding, friction intensified, causing loss of thread, friction heat production, the phenomenon such as triboelectrification, thus cause machine damage, and explosion accidents of dangerous phenomenon.
(3) Pressure difference on both ends of the screw thread, in working conditions long-term deformation, cause the thread safe hidden trouble. The screw should be inspected periodically.
(4) The screw rotation speed increases, the production efficiency will rise, but loss increase; The screw rotation speed is reduced, the viscosity increases, easy to cause congestion. Should be to find the best speed between the two.
Keywords: Single Screw, polyflow, Extrusion process, Numerical Simulation, The propellant.
目 次 I 基于ployflow模拟软件对螺压工艺的安全性研究:http://www.751com.cn/huaxue/lunwen_10913.html