In the previous article, we had a basic understanding of some basic conditions of the low-nitrogen burner in the power plant before the renovation. Next, we will talk about the specific modification measures of the low-nitrogen burner in the power plant. The transformation of the low-nitrogen burner in the power plant is divided into the following four points:
1. Horizontal deflection adjustment of separated exhaust air
Separated exhaust air each layer is divided into three small air Chambers, each of which is equipped with an adjustable exhaust air nozzle, and can be adjusted in a wide range of horizontal direction by hand. Run at a certain requirements of the hearth, in order to guarantee the burning wind nozzle on the tilt Angle adjustment can meet these requirements, the nozzle to adjust the horizontal tilt Angle in strict accordance with the chamber of a stove or furnace to limit the corner shape. Normally, burning wind nozzle should be clockwise tilted in order to ensure the combustion efficiency inside the furnace, because if not tilt straight to burning wind blast after burning gas, can lead to three jet fuel wind influence each other, as a direct result of originally with good organization structure between the pulverized coal and air are destroyed. However, if the exhaust air nozzle is tilted, it can ensure that the fuel air from the nozzle rotates clockwise in the furnace, thus ensuring the normal operation of fuel air combustion. That is to say, at the beginning of the start experiment and low NOx coaxial combustion system can determine the separate burning wind vents in the process of debugging the best Angle, horizontal deflection once you determine the best Angle of horizontal deflection, in the later in the operation of the don't have to readjust. Said above is clockwise tilted condition, but in reality there are a few counter-clockwise tilted layered separate burning wind and power plants generally do not work in this way, because this way counterclockwise tilt causes of fuel in the burners wind counterclockwise, in contrast to the earth's rotation, can't make the fuel burn adequately.
2.Vertical deflection adjusts separate exhaust air
To realize the adjustment of deflection, the connecting rod of the separated exhaust air nozzle can be directly connected to the body of each separate exhaust air nozzle by adjusting the connecting rod of the separated exhaust air nozzle and adjusting the horizontal direction. Each layer separate burning wind wind chamber below, there are two separate burning wind nozzle, adjust the connection rod in horizontal direction, and connect them to the characteristic of the crank structures, the crank structure is fixed by the burning wind bellows locating pin for the structure of the shaft. The three nozzles and three connecting crank structures in each separate layer are connected to the vertical deflecting drive structure connecting rod of the separate exhaust fan box in this layer. The upper nozzle crank in each separate layer of exhaust air chamber is connected to a "shaft connecting through the side of the bellows to the external drive structure of the bellows".
3. Use flame attached coal burner nozzle
By reducing the distance between the ignition point of coal powder flow and the nozzle, the attached flame coal burner nozzle plays an auxiliary role in controlling the generation of nitriding gas. And the process of implementation needs the help of air deflector, in nozzle exit location to install the air deflector increasing the vent area of turbulence effect, and can effectively brief pulverized coal stream ignition of the distance from the nozzle. By adjusting the opening degree of wind chamber damper to pull into the ignition distance of the nozzle, secondary air can blow to the pulverized coal flow around and behind, so that the wind of the internal structure and control of fuel, so as to determine the fuel nozzle wind of the shape of the flame. Accurate control of the shape of the flame in the hearth is the basis of meet the demand of the fuel burning in the hearth, the whole low NOx coaxial combustion system as a whole, the overall control, the operation of the attached type pulverized coal flame burner nozzle and adjust to the appropriate pulverized coal burner nozzle exit of a wind wind speed and air volume and proper pulverized coal fineness is closely related. The optimization is realized by using the opening degree of the fuel air flap door to adjust and maintain the proper ignition point position in the combustion regulation test.
Through the unified control of the four bellows, every the flame shape of nozzle is strictly accurate control, to ensure that the combustion temperature of the flame in the hearth and the contact area and shape for precise control, meet the demand of the power plant.
4. Application of horizontal grading ventilation technology
The technology is being improved continuously, and the technology of horizontal grading air distribution has been popularized in power plants. Horizontal classification air distribution technology is part of the secondary air in furnace from the main combustion zone, reduce the coal and wind, that is, the contact between the pulverized coal flow, which reduces the volatilization pulverized coal flow out of the stage combustion chemical equivalent ratio, Grosvenor LTD is generated in the pulverized coal flow in the natural volatile fuel flame, and maintain the furnace water wall surrounding the oxidizing atmosphere. This method can not only by maintaining the furnace water wall surrounding the oxidizing atmosphere, reduce the probability of corrosion and slagging in the hearth, keeping water wall relatively clean, and this method can make the secondary air and pulverized coal flow no longer contact, indirect for effective control of NOx, so after the burning will not have too much harmful pollutants, to fit the current social advocate environmental protection in the production of green economy development concept.