Research On The Stability Of Combustion Flame

In this paper, thermoacoustic instability phenomenon and the induced mechanism of combustion instability are first introduced. We summarize the status of experimental research on thermoacoustic instability. The advantages and disadvantages of flame heat release characteristics are also analyzed. Fiber optic spectrometer is put forward to measure flame heat release characteristics online.The low NOx emission of heavy-oil-fired flame is an important physical parameter associated with the characteristics of a combustion process. The steam boiler using heavy oil fuel or gas fuel is prone to thermoacoustic instability. Experiments were carried out on a9MW heavy-oil-fired combustion test facility. The impact of over fire air (OFA), water and steam on the NOx emission was studied. The flame flicker signal was obtained by fiber optic spectrometer. Results show that OFA can effectively reduce the NOx emission. However, water and steam both have little effect on the NOx emission when OFA is applied. The flame oscillation frequency is increased when water is injected, while the flame oscillation frequency is decreased when steam is injected. The flame instability becomes worse with the flame oscillation frequency decreasing.Coal-fired power generation still occupies an important position in the domestic power. And the coal-fired plant units develop to the direction of high parameter. large capacity. Experiments were carried out on a one-dimensional furnace. The impact of excess air coefficient, coal feed rate, coal type and the ratio of primary and secondary air on the combustion flame was studied. Results show that the combustion flame temperature and light intensity in furnace firstly increase and then decrease with the increase of excess air coefficient. The flame temperature and light intensity are both improved with the boiler load increases. and the load also changes the flame oscillation frequency. The ratio of primary and secondary air has a certain effect on combustion process. There exists an optimized ratio can make the combustion better. The impact of mixed coal type on the flame spectral is small. The experimental results provide a reliable basis for laboratory research and industrial application. Since the test condition is simple, it can provide reference for practical application and further research.