Detect And Analysis Of Flame Emissivity Of Burning Mixture Of Pulverized Coal And Gas Fuel Based On Image Processing

In order to make good use of industrial waste gas coal-fired power plant boilers have to change the tradition that they only burn coal,but now they have to burn industrial waste gas, such as blast furnace gas and coke oven gas.Combustion of pulverized coal in furnace is a complex physical and chemical process. The process of burning with mixed gas is much more complex. We need to study the heat transfer property in furnace and the flame emissivity is a important parameter reflecting the heat transfe of furnace. In power plant boiler,when fuel is burning in furnace,it releases a lot of heat. The heat transfer between flame and water-wall is mainly depends on radiation.Flame emissivity reflects the combustion condition of particles in furnace and radiative properties of pulverized coal particles.In recent years, the three-dimensional image process based on the flame temperature measurement developped, which provides a new method to analysis the combustion in furnace.The image processing technology which provides a non-contact measurement has a well prospect. In this paper, we use the industrial system which has been applied to record the furnace flame images through which we compare a wide range of combustion conditions and analysis the flame emissivity. Respectively, we use portable systems and on-line monitoring system in the image analysis.In this paper, we add a calculation procedure in existing software to calculate flame emissivity.The experiment was done in a 670t/h boiler furnace of a 200-MW power generation unit to analysis the flame emissivity with both portable system and on-line monitoring system and some useful conclusions have been obtained.In the combustor region,the flame emissivity will decrease with the increase of blast furnace gas and increase with the increase of coke oven gas.In the same pulverized coal boiler,burning with blast furnace gas,coal combustion will be inhibited while coke oven gas will promote of coal combustion.In a certain load,the more gas we added,the less coal we need which can help the plant to save fuel.Also,in order to enhance burning effect we need more coke oven gas instead of blast furnace gas.The flame emissivity increases with the decrease of the excess air ratio;if ratio of C/H less than 10,the flame emissivity increases with the decrease of the ratio.