Experimental Study Of Microscale Diffusion Flame In The Electric Field And Limited Space

At present, MEMS devices are causing more and more attention from scholars, and the micro-combustion research is the basis for manufacturing MEMS devices. The characteristics of micro combustion and micro burner technology is very important for micro-power systems based on hydrocarbon fuel combustion. The characteristic length about micro-combustion system is small, and its flow, heat transfer and combustion has many different characteristic that large size of the combustion systems has. The basic research about liquid fuel combustion characteristics in the small scale is a little few at home and abroad, so it is very important to research about the structural characteristics and extinguishing properties of micro flame.The first chapter introduces background significance of this research, the mechanism of diffusion flame, describes the main research results and the latest developments of domestic and foreign scholars in the field of micro-combustion. Through analysis, we find that many key issues on micro combustion and micro-burner have not been resolved yet, carrying out experimental research about microscale flame is of great significance to understand micro-combustion characteristics more comprehensive and to the design of the micro-burner, further defining the task of this study.The second chapter describes the details of the experimental device system. Conducting a simple improvements about syringe pump in the fuel supply system, achieves the desired results. Introduced the main experimental methods, experimental procedures, data measurement, and the issues need to pay attention to in experiments.Chapter III introduces techniques in the experimental data processing from the experimental basic data treatment, dimensionless treatment, flame image processing.Chapter IV first carry out a detailed experimental study about the micro diffusion flame in confined space, investigate microscale effect of the combustion process in the aspect of structure characteristics and extinction characteristics about flame. The results show that: Confined Space has important impact on the micro diffusion flame height, aspect ratio, temperature, stable combustion flow range, and structural characteristics and extinguish characteristics of the flame is different with the size of the limited space. Second, study the effects about needle-shaped electric field and flat field acting on the micro flame, analyse comparatively about the effect of electric field angle acting on the structural and extinction characteristics about the flame, and the characteristics that needle and plate electrode acting on the flame. Analysis of the experimental results: Needle-shaped electric field effects flame characteristics by the ion wind, and flat field influences flame characteristics by the electrostatic force on the role of ions in flames, there are essential differences between the two. Appropriate electric field can strengthen the micro diffusion flames, but as the characteristic scale of micro diffusion flame is small, too strong electric field will cause combustion instability, even out. Compared with the flat field, ionic wind generated by needle-shaped electric fieldplay a greater impact on the flame. Finally, under the current experimental progress, make recommendations for further work.