ملخص
Abstract
The contribution of this thesis is to improve the understanding of flame dynamics in the gas turbine combustor. The dynamic of diffusion flame or the flicker of a flame, as they are called in the research community is an important physical parameter associated with the characteristics of a combustion process. The flicker frequency of a flame reflects its oscillation of radiation, pressure and other characteristics, and plays an important role in flame structure, radiation field and energy efficiency. In addition, flickering frequency could be an indication of flame instability. It is therefore important to be able to measure the flicker of a flame in order to achieve an in depth understanding of the fundamental aspects of combustion processes and to develop a technique suitable for advanced flame monitoring in electrical power generation, gas turbine, boiler, and etc... To understand the phenomena related to thermoacoustic, a simple Rijke-type tube combustor was built and studied. Extensive experimental results, as well as theoretical analyses related to the Rijke tube is presented in this project. The results, attributable to both the analyses and the experiments, help explain all the phenomena affecting the acoustic pressure in the combustor. The conclusion is that there are three separate yet related physical processes affecting the acoustic pressure in the tube. To understand this parameter, a simple system was built and studied. Extensive experimental results are presented in this project to measure a flicker signal. In order to begin to understand what flicker parameter is, it was necessary to collect and analyze the light signal produced by light cell from burner which operates on diffusion flame, the chosen method for data collection was a light data acquisition system, the acquired light signal was then analyzed with Lab VIEW software, the software’s main feature is that it was capable of defining the light signal in many parameters, the most important of which were: power spectrum, cross correlation and the light wave shape. The power spectrum gave a concise presentation of the main frequencies which constituted the flicker signals, and their relative amplitudes. this was very helpful in determining the frequency of the diffusion flame (flicker signal).flame height and flame lift off also have been studied in this project. Finally applied this technique and all this Procedures at alkhoms power plant gas turbine combustor and then we compare the results with other technique like CCD camera and Photomultiplier we option the same results with cheaper devices