Suggestions for Low Nitrogen Burner Transformation and Operation Measures
Suggestions for Low Nitrogen Burner Transformation and Operation Measures
1、 Research and analysis on fly ash and boiler efficiency.
The main factors affecting the formation of nitrogen oxides include combustion flame temperature, oxygen concentration in the burner section, time of combustion products in high-temperature areas, and coal quality. Based on these influencing factors, nitrogen oxides can be reduced in two ways: firstly, by appropriately reducing the combustion flame temperature to avoid local overheating; The second is to control the air coefficient in the combustion environment, limit the oxygen content, and ensure that coal powder burns in an oxygen deficient environment. After renovation, the main combustion zone generally adopts low oxygen combustion with low air coefficient. Only the top burning air can burn, and coal powder combustion will not be exhausted. Online fly ash collection shows that the fly ash is too large. The increase in fly ash content in boilers can lead to incomplete combustion of coal powder, thereby limiting the combustion efficiency of the boiler. During the operation of the boiler, excessive fly ash particles can also shorten the wear and service life of the heating surface at the tail of the boiler.
2、 Optimization and adjustment of combustion after the transformation of low nitrogen burners.
After the low nitrogen transformation of the burner, the original combustion method must be modified to ensure that the adjusted plan can meet safety requirements and comply with relevant ultra-low nitrogen emission standards. Specifically, the emission of NOX should be controlled within the safe concentration index. The following points should be noted:
1. The operation mode of the burner. For the transformation of low nitrogen burners, the focus is on how to improve the rated temperature of the furnace and the stability of coal powder combustion, and try to avoid sudden shutdown or insufficient power of the burner.
2. Boiler secondary air distribution method. The secondary air distribution method of the boiler should meet certain basic needs to ensure that the excess air coefficient in the main combustion area is within a reasonable range; When the burner is shut down, the corresponding air door should be appropriately closed, and the degree of opening and closing of the air door is determined by the corresponding flow curve; During the operation of the boiler, it is necessary to ensure that the air pressure in the air box is normal and the air pressure is normal.
3. Oxygen level during boiler operation. Control the oxygen content during boiler operation within a reasonable range, and the optimal oxygen content during boiler combustion needs to be determined based on actual combustion test results.
4. Control the accuracy of coal powder. If SOFA combustion classification technology is adopted, it is necessary to adjust the accuracy of coal powder.
3、 Burner renovation and installation work.
During the installation phase, the horizontal angle of the burner must be strictly calibrated according to the design requirements. Measure and verify the installation deflection angle of the burner, measure and verify the synchronization of the same angle and swing of the burner on the same layer, and ensure that the nozzle size, nozzle shaft, and burner diameter meet the design requirements.