Strategies for Dealing with Problems in Low Nitrogen Burner Transformation of Boilers

Strategies for Dealing with Problems in Low Nitrogen Burner Transformation of Boilers
The problems that have arisen during the application of the transformation of low nitrogen burners in boilers in thermal power plants are gradually being exposed. For the problems that have arisen, it is recommended to take the following measures:
1、 Adequate pre renovation evaluation.
The emission indicators of boilers, especially the concentration of NO emissions, are closely related to coal type, boiler selection, and burner type. The type of boiler in operation has been determined. However, in recent years, most of the coal burned in coal-fired power plant boilers is mixed and has poor performance. Therefore, before using low nitrogen combustion technology for transformation, firstly, a comprehensive evaluation of the existing main coal types and commonly used coal types of the boiler should be conducted, and during the feasibility study of the transformation, Due to improper coal selection, the effect of NO emission reduction after renovation is not significant, and many new problems arise. Then, a comprehensive test will be conducted on the coal transportation furnace to fully evaluate the existing problems in combustion performance, steam parameters, heating surface wall temperature, coking and slagging, operation regulation, thermal automation, etc. Scientific and reasonable transformation goals will be proposed, balancing the economic and environmental indicators of the boiler, gradually solving existing problems, and eliminating the emergence of new problems.
2、 Optimize and adjust using scientific combustion methods.
After the modification of the low nitrogen burner of the boiler, the burner type has been determined, but the amount of NO produced by burning different coal types varies under different operating conditions, indicating that the boiler operation mode plays a dominant role. So, in order to reduce NO emissions, it is necessary to optimize the combustion method, while meeting environmental emissions, and maximizing operational efficiency.
1. Boiler layered coal blending and co firing.
When the emission gas concentration meets environmental requirements and combustion is stable, the most economical coal type should be used for stratified combustion in the furnace, which can ensure the stability of the boiler and control the generation of NO.
2. Optimization of thermal automatic control.
After adopting low nitrogen technology transformation, the combustion time of the boiler has been extended, and the thermal control system and control curve should be optimized and adjusted. In response to the problems encountered by boilers in practical work, the required control curves and control systems should be optimized to improve their response ability under load conditions.
3. Continuous combustion optimization adjustment.
After the transformation of boiler low nitrogen combustion technology, in addition to being related to the type of coal used for combustion, the main factors that need to be optimized include changes in coal type and load, such as boiler operation mode, boiler oxygen content, air distribution mode, and coal mill operation combination mode. After conducting boiler combustion optimization adjustment tests, the coal quality has undergone significant changes, usually requiring adjustments in the past two months, It is crucial to continuously optimize and adjust combustion in order to find a balance between environmental emission indicators and operational economic indicators.
The time for retrofitting the low nitrogen burner of the boiler is relatively short, with incomplete exposure, insufficient understanding, and insufficient experience in solving problems. In order to reduce the environmental pressure on thermal power plants, further research and development are needed to reduce the emission reduction technology of NO, reduce the environmental pressure on power plants, and more importantly, the problem-solving ability generated by the application of new emission reduction technologies and environmental protection facilities needs to be further improved, Strive to achieve greater environmental benefits for the sustainable development of coal-fired power plants.