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Low NOx combustion technology gaseous fuels What?

Writer: admin Time:2021-04-14 00:00 Browse:

Gas burner with respect to fuel burners, industrial gas burners some more, you know fuel gas low NOx combustion technology What?
	Low NOx combustion technology gaseous fuels What?

Low NOx combustion technology gaseous fuels What?
Nitrogen oxide combustion technology to improve combustion control apparatus or combustion conditions, the technique to reduce the NOx concentration in the combustion exhaust gas. The main factors affecting the NOx generated in the combustion process is the combustion temperature, the residence time in the high temperature region, the concentration and the degree of mixing of the various components of flue gas, thus changing the air - fuel ratio, the combustion air temperature, the combustion zone the cooled and shaped to the extent of the burner can reduce the formation of nitrogen oxides during combustion. Multi industrially employed to reduce excess air, and staged combustion, flue gas recirculation and low-temperature air preheat burner or the like special purpose. Combustion technology abroad low NOx combustion technology development has experienced three generations. The first generation of combustion systems are not big changes; second-generation technology for air-staged combustor is characterized; third generation technology is simultaneously air, fuel staged combustion three (or burner) in the furnace. The first generation low NOx combustion technology generation technique does not require big changes to the combustion system, just to make adjustments on the operation of combustion apparatus or part of the operation mode or improved. Thus simple, active device can be easily used, but the magnitude of NOx reduction is limited, mainly by the concentration of NOx emission reduction achieved in several ways. (1) a low excess air ratio is an optimization which runs combustion apparatus, a simple method of reducing the amount of NOx generated. It does not require structural changes to the combustion apparatus to make a low excess air ratio operation inhibiting NOx generation amount and the amplitude of the type of fuel, combustion and slag related manner. Excess air ratio of the actual operation of the power station boiler can not make any big adjustments. For coal-fired boilers, to reduce the excess air ratio can result in soiling slagging and corrosion of the heating surface, steam temperature changes due to the fly ash properties and increased fuel economy caused decreased. For gas, boiler fuel, the main limitation is that the concentration of CO exceeded. (2) reducing the temperature of combustion air preheating combustion air preheat temperature can be lowered to reduce the peak flame temperature zone, to reduce thermal NOx generation amount. This measure should not be used in coal-fired, oil-fired boiler for gas boilers, there are lower NO. Significant effect emissions. (3) Such bias combustion method is to let a part of the fuel under conditions of insufficient combustion air, i.e., fuel rich combustion; another portion of the fuel in the combustion air excess conditions, i.e. combustion of the fuel is too short. Either too light or rich combustion burner, excess air ratio α which is not equal to 1. The former α & lt; 1, the latter α & gt; 1, it is also called non-stoichiometric combustion or the combustion variation. When shading combustion, fuel rich portion due to lack of oxygen, the combustion temperature is not high, the fuel NOx and thermal NOx will be reduced. Fuel too weak in part by excessive air, the combustion temperature is low, the thermal NOx generation amount is reduced. The overall result is lower than the conventional combustion NOx production. (4) incorporated into the flue gas flue gas recirculation combustion air to the furnace, the oxygen concentration of the combustion air, a reducing furnace slagging coal fired, gas in particular an oil-fired boiler NOx emissions. The usual practice is out of the flue gas from the economizer outlet grapefruit, adding a secondary air or wind. When the addition of secondary air, the flame center unaffected, its only function is to reduce the flame temperature and helps to reduce thermal NOx generation. For the dry bottom boilers, about 80 percent of the fuel NOx is generated by nitrogen, the effect of this method is very limited. For ungraded burner, in a wind incorporation flue gas is better, but because the combustion conditions in the vicinity of the burner will change, to adjust the combustion process. (5) Out of this portion of the burner method is applicable to the burner utility boilers multilayer arrangement. This is done to stop the fuel supply or the uppermost layers of the combustor, sending only air. So that all the fuel into the furnace from below the burner, the burner below the combustion zone to achieve the fuel-rich, upper layer away form the air blowing classification. This method is especially suitable for gas and oil-fired boiler fuel delivery system without having a major transformation. Germany put this method on a large lignite units, good results. The second generation low NOx combustion technology generation technique wherein an oxygen concentration in combustion air classifier away combustion apparatus, thereby reducing the initial combustion zone (also called a region), and accordingly also reduces the peak flame temperature. Belong to this generation measures are widely used in various stage air-staged low NOx burners Utility. The main features of the third generation low NOx combustion technology generation technology is an air and fuel are graded away furnace. In one area, the main fuel under a lean phase conditions of combustion, after the reduction of the fuel input, is formed under the oxygen reduction zone, at a high temperature (& gt; 1200 ℃) precipitated and under a reducing atmosphere NH3, HCN, CmHn other atomic group derived from a the reaction zone generated NOx to produce N2. Overfire air into the forming burnout zone, to achieve complete combustion of the fuel. This generation is a measure of air / fuel swirl burner rating Low NOx combustion mode and a three inscribed circle. If you want to learn more knowledge about low nitrogen burners, please consult.