定容湍流燃烧实验系统的研制

发布时间：2018-03-11 10:13

本文选题：氢气　切入点：湍流预混燃烧　出处：《北京交通大学》2016年硕士论文　论文类型：学位论文

【摘要】：石油资源的日益匮乏与汽车行业的迫切能源需求之问的矛盾已成为影响社会经济可持续发展的重要问题,“开源”——寻找新型可替代能源和“节流”——提高能源使用效率并行对促进经济的较快发展起着十分重要的作用。本研究以内燃机替代燃料的湍流燃烧基础机理研究为前提,针对实验系统存在的湍流分布均匀性较低、系统耐压不高、试验对象单一、系统可控变量少等问题,首先以定容湍流燃烧实验系统的总体设计为主要内容,依次对系统的总体设计方案、定容燃烧弹、配气系统以及数据采集系统等子系统的设计思路、结构组成、关键参数计算等方面展开详实的论证和评估。其次,在弹体密封上,设计双端盖密封结构实现燃烧腔室的有效密封及石英玻璃的便捷拆装：在弹体结构上,重点对定容弹本体、石英玻璃和固定螺栓进行设计和校核,确保实验系统的可靠性。此外,为消除气路容积对预混合气当量比的影响,设计了独立进气系统；对数据采集系统而言,设计并搭建了燃烧压力采集子模块,并采用纹影法和高速摄影仪配合使用的方式实现湍流燃烧火焰的采集。同时,以定容燃烧腔室内湍流氛围的营造为研究内容,以多种湍流营造方法的对比分析为基础,结合研究目的和工程实际,设计“会字塔”型风扇布局,以风扇扰动作为燃烧腔室内预混合气湍流流动的动力来源,采用风扇前端的孔板罩将风扇旋转形成的有序旋流转变为空间射流,多束射流在燃烧腔室中心区域碰撞形成无序的湍流流动,实现真正意义上的湍流氛围。此外,针对火焰图像数目多、火焰特征参数难以手工准确获取等问题,本研究基于MATLAB平台,编写火焰图像批处理算法,实现火焰图像的读取、火焰轮廓的检测、特征参数的计算、结果报表的生成等功能,提高了试验图像处理效率和精度。最后,以定容湍流燃烧试验平台为依托,以湍流氛围中氢——空预混火焰燃烧特性为研究内容,重点开展了初始湍流强度、初始湍流尺度、初始气体压力对火焰演变特性和传播特性的影响规律,实现实验系统性能的全面检测及火焰燃烧特性的研究。
[Abstract]:The contradiction between the increasingly scarce petroleum resources and the urgent energy demand of the automobile industry has become an important issue affecting the sustainable development of social economy. "Open Source"-to find new alternative energy sources and to "cut down"-to improve the efficiency of energy use. Rate parallelism plays a very important role in promoting the rapid development of economy. This study is based on the study of the basic mechanism of turbulent combustion of alternative fuels for internal combustion engines. Aiming at the problems of low uniformity of turbulence distribution, low pressure resistance, single test object and less controllable variables in the experimental system, the general design of the experimental system of constant volume turbulent combustion is taken as the main content. The whole design scheme of the system, the constant volume combustion bomb, the gas distribution system and the data acquisition system are discussed and evaluated in turn. Secondly, on the sealing of the projectile, the detailed argumentation and evaluation are carried out in the aspects of system design, structure composition, calculation of key parameters, and so on. The effective sealing of combustion chamber and the convenient disassembly of quartz glass are realized by the design of double end cover seal structure. In the structure of the projectile, the design and verification of the fixed volume bomb body, quartz glass and fixed bolt are emphasized. To ensure the reliability of the experimental system, an independent intake system is designed to eliminate the influence of the volume of the gas path on the premixed equivalent ratio. For the data acquisition system, the combustion pressure acquisition sub-module is designed and built. At the same time, the turbulent combustion flame collection is realized by using the schlieren method and the high speed photography instrument. At the same time, taking the building of turbulent atmosphere in the chamber of the constant volume combustion chamber as the research content, and based on the comparison and analysis of various turbulence construction methods, Combined with the purpose of the research and the engineering practice, the layout of the "Huizhi Tower" fan is designed, and the fan disturbance is used as the power source of the turbulent flow of the pre-mixed gas in the combustion chamber. The orifice plate cover of the front end of the fan is used to transform the ordered swirling flow formed by the fan into a space jet, and the multi-beam jet collides in the central region of the combustion chamber to form a disordered turbulent flow, which realizes the real turbulent atmosphere. Aiming at the problems such as the large number of flame images and the difficulty of obtaining the flame characteristic parameters by hand, this study is based on the MATLAB platform, compiles the flame image batch processing algorithm, realizes the flame image reading, the flame contour detection, the characteristic parameter calculation, and so on. Results the efficiency and accuracy of image processing were improved with the function of generating report forms. Finally, the combustion characteristics of hydrogen-air premixed flame in turbulent atmosphere were studied based on the constant volume turbulent combustion test platform. The effects of initial turbulence intensity, initial turbulence scale and initial gas pressure on flame evolution and propagation characteristics are emphasized.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U467.2

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