Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| 多孔介质表面火焰特性及其稳定性实验研究 | |
| Alternative Title | Experimental Studies for the Combustion |
| 王勇 | |
| Thesis Advisor | 赵黛青 |
| 2009-05-31 | |
| Degree Grantor | 中国科学院广州能源研究所 |
| Place of Conferral | 广州能源研究所 |
| Degree Name | 硕士 |
| Keyword | 微燃烧器 多孔介质 平面火焰 点火距离 熄火距离 |
| Abstract | 多孔介质表面形成的预混平面火焰具有燃烧稳定、火焰面薄、火焰高度低，多孔壁面温度低等特点，非常适合在狭小空间内组织燃烧。深入研究这种火焰结构特性和稳定性是研发高性能基于多孔介质表面火焰微燃烧器基础。 本文以甲烷/空气预混气为燃料，对多孔介质表面火焰形成特性和稳定性进行实验研究。对于1mm厚度级别的平面火焰采用基于Matlab的一种火焰灰度图像处理方法进行了测量，获得了更为精确的火焰高度和厚度值。通过比较多孔介质表面不同火焰形态和结构特征，得知平面火焰具有最小的火焰高度和厚度。论文侧重考察了获得平面火焰的极限条件及其影响因素，包括燃料当量比、混合气流速、预混气的预热温度、多孔壁面材料种类和厚度等，同时考察了有限空间内多孔表面平面火焰的最小稳燃距离，得出如下结论： （1）贫燃料下，获得平面火焰极限范围随当量比减小而减小，预混气初始温度升高可以有效的拓宽平面火焰形成范围。预混气流量和当量比增加，火焰温度升高，平面火焰高度降低贴近壁面，但多孔壁面温度仍然可以保持低的温度范围。 （2）不同导热系数多孔板材料对火焰的影响在低混合气流速下明显，导热系数越小和壁面越厚，多孔壁面温度越低。 （3）采用与多孔介质表面的平行可控温的铜板来模拟微燃烧室壁面，从点火间距和熄火距离特性及其影响因素确立了平面火焰最小稳燃空间尺度范围。 |
| Other Abstract | The premixed flat flame formed on the porous surface has advantages such as stable combustion, thin flame front, low flame height and low temperature of the wall, which makes it suitable for organizing combustion in narrow space. In order to design a high-performance micro-combustor whose chamber wall is made of porous material, which had been designed and studied experimentally in our primary work, it's necessary to investigate the characteristics of combustion stability and flame structure of porous surface flame thoroughly. The formation characteristics and combustion stability of methane/air premixed flames on porous wall surface had been investigated experimentally. For the flat flame of millimeter size, a digital image processing method based on Matlab software was used to analyze flame image. The flame height and thickness were obtained accurately based on the linear relationship between image grey value and flame temperature. According to the comparison of the flame morphology and structure characteristic of the porous surface flame, it has been clarified that the flat flame has the lowest flame height and thickness. This thesis focuses on the limited conditions for flat flame formation and the influence factors, including equivalence ratio (), mixture flow velocity (υ), initial temperature of the mixture, porous wall characteristic, and the wall thickness. Meanwhile, the smallest distance for stable combustion in a limited space was investigated. The conclusions are as follows: (1) For fuel-lean condition, the range of mixture flow velocity for flat flame formation decreased with the decrease of equivalence ratio. This range could be expanded by preheating the mixture to higher initial temperature. With the increase of flow velocity and equivalence ratio, the temperature of flat flames increased and the flames moved closer to wall with a decrease of flame height. However, the temperature of wall surface could still keep at a low level. (2) The thermal conductivity of the material for porous wall has significant effect on flames at low flow velocity. The smaller thermal conductivity and the thicker of porous wall, the lower wall temperature was. (3) A temperature-controlled copperplate which paralleled to porous wall surface was used to simulate the wall of combustor. The range of smallest special scale for a stable combustion was defined based on the characteristics of igniting distance and quenching distance. |
| Pages | 61 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/5858 |
| Collection | 中国科学院广州能源研究所 |
| Recommended Citation GB/T 7714 | 王勇. 多孔介质表面火焰特性及其稳定性实验研究[D]. 广州能源研究所. 中国科学院广州能源研究所,2009. |
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