防爆柴油机进气系统的优化分析

发布时间：2018-05-13 12:27

本文选题：防爆柴油机 + 进气系统　；参考：《太原理工大学》2015年硕士论文

【摘要】：防爆柴油机是矿业生产的主要动力源之一，凭借其燃烧热效率高、燃油消耗率低以及使用安全、操作方便等优点，应用范围越来越广。但防爆柴油机进气系统内加装了进气栅栏、空气关断阀等防爆装置，增加了进气系统的进气阻力，降低了柴油机的进气充量和燃烧热效率，导致其动力性和经济性降低。所以，探究如何减小防爆柴油机进气系统的进气阻力，对提升防爆柴油机的性能具有深远的意义。本文以6100型防爆柴油机为研究对象，运用计算流体动力学(CFD)和FLUENT分析软件，对防爆柴油机进气系统的进气栅栏和进气歧管进行内部流场分析，选择合理的进气栅栏和进气歧管结构参数，增加进气充量，提高各缸的进气均匀性；从而改善防爆柴油机的性能。本文的主要研究内容如下： 1）利用UG建模软件建立6100防爆柴油机进气防爆栅栏的流体动力学模型，应用FLUENT软件对进气栅栏内部流场进行了模拟研究，通过压力分布、速度分布、湍动能分布来分析不同栅栏间隙对进气量的影响。最终得出0.30mm栅栏间隙的进气栅栏较为合理。 2）为了解决进气防爆栅栏背压大、进气量小的问题，本文对进气栅栏的结构进行分析，选取进气栅栏的进气管长度、稳压腔角度以及栅栏缝隙间距这三个比较重要的因素，每个因素选取三个水平进行正交试验分析，得出各因素对进气量影响的主次顺序，从而确定进气栅栏最佳的结构匹配方案。 3）应用FLUENT软件对6100防爆柴油机进气歧管进行流场模拟计算，对歧管内部进行流动特性分析，以流体力学为依据，对原设计进行改进，并对比分析了改进前后两种进气歧管结构的出口截面速度、歧管内的气流流速及湍流动能。结果表明，减小稳压腔体积，在稳压腔与歧管之间设置一部分过渡段有利于改善柴油机各缸的进气均匀性，增加进气充量，进而提高柴油机的性能。 4）改变进气总管和歧管的长度与直径，运用GT-POWER软件对其进行仿真优化，之后根据动力性、燃油经济性为依据，挑选出最佳尺寸。根据整机的布置情况及分析结果表明，，减小总管和歧管长度，增加歧管直径有利于提升发动机的性能。
[Abstract]:Explosion-proof diesel engine is one of the main power sources in mining industry. Because of its high combustion heat efficiency, low fuel consumption rate, safe use, easy operation and other advantages, the application of diesel engine is becoming more and more extensive. However, in the intake system of explosion-proof diesel engine, the blast proof devices such as intake fence and air shutoff valve are installed, which increases the intake resistance of the intake system, reduces the intake air charge and combustion heat efficiency of the diesel engine, and results in the decrease of its power and economy. Therefore, exploring how to reduce the intake resistance of explosion-proof diesel engine is of great significance to improve the performance of explosion-proof diesel engine. In this paper, the internal flow field of intake fence and intake manifold of intake system of explosion-proof diesel engine is analyzed by using computational fluid dynamics (CFD) and FLUENT software, taking 6100 type explosion-proof diesel engine as the research object. Reasonable intake fencing and intake manifold structure parameters are selected to increase intake air charge and improve the air intake uniformity of each cylinder so as to improve the performance of explosion-proof diesel engine. The main contents of this paper are as follows: 1) the fluid dynamics model of 6100 explosion-proof diesel engine is established by using UG modeling software, and the flow field inside the inlet air fence is simulated by FLUENT software. The pressure distribution and velocity distribution are used to simulate the flow field. The distribution of turbulent kinetic energy is used to analyze the influence of different fencing gaps on air intake. Finally, it is concluded that the air inlet fence with 0.30mm gap is more reasonable. 2) in order to solve the problem of high back pressure and low intake, the structure of intake fence is analyzed, and three important factors, such as the length of intake pipe, the angle of stable cavity and the gap spacing of fence, are selected. Three levels of each factor are selected for orthogonal experimental analysis, and the primary and secondary order of the influence of each factor on the air intake is obtained, so as to determine the optimal structure matching scheme of the air intake fence. 3) the flow field of intake manifold of 6100 explosion-proof diesel engine is simulated by using FLUENT software, and the flow characteristics inside the manifold are analyzed. Based on hydrodynamics, the original design is improved. The exit cross section velocities, the flow velocity and turbulent kinetic energy of the two kinds of intake manifold structures before and after the improvement are compared and analyzed. The results show that reducing the volume of the steady pressure chamber and setting a part of transition section between the stable pressure cavity and the manifold is beneficial to improve the uniformity of the intake of the diesel engine cylinder, increase the intake volume, and then improve the performance of the diesel engine. 4) changing the length and diameter of intake manifold and manifold, using GT-POWER software to simulate and optimize them, and then selecting the best size according to power performance and fuel economy. According to the arrangement of the whole machine and the analysis results, it is shown that reducing the length of the manifold and increasing the diameter of the manifold are beneficial to the performance of the engine.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD684;TK423

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