Countermeasures to the problems existing after the retrofit of boiler low nitrogen burner
The problems occurred in the application of the transformation of low nitrogen burners of boilers in thermal power plants are gradually exposed. For the problems, the following countermeasures are recommended:
1、 Adequate pre-modification evaluation.
The emission indicators of the boiler, especially the emission concentration of NO, are closely related to the coal type, boiler selection, and burner type. The type of boiler in operation has been determined. However, in recent years, most of the coal fired by coal-fired power plant boilers is mixed, and the performance is poor. Therefore, before using the low-nitrogen combustion technology transformation, the first is to conduct a comprehensive evaluation of the existing main coal types and common coal types of the boiler, and during the transformation feasibility demonstration, Due to improper coal preparation, the effect of NO emission reduction after transformation is not obvious, and there are many new problems. Then carry out a thorough test on the coal handling boiler, fully evaluate the existing problems in combustion performance, steam parameters, heating surface wall temperature, coking and slagging, operation regulation, thermal automation and other aspects, and put forward scientific and reasonable transformation objectives, weigh the economic indicators and environmental indicators of the boiler, gradually solve the existing problems and put an end to the generation of new problems.
2、 Optimize the adjustment and adopt scientific combustion method.
After the transformation of the low nitrogen burner of the boiler, its burner type has been determined, but under different working conditions, the amount of NO produced by burning different coals is different, which can be seen that the boiler operation mode plays a leading role. Therefore, in order to reduce the emission of NO, it is necessary to optimize the combustion mode. On the premise of meeting the emission of environmental protection, it is necessary to give maximum consideration to the operation economy.
1. The boiler is mixed with coal by layers.
When the emission gas concentration meets the environmental protection requirements and the combustion is stable, the most economical coal shall be used, and the stratified combustion in the furnace can not only ensure the stability of the boiler, but also control the generation of NO.
2. Optimization of thermal automatic control.
After the low nitrogen technology transformation, the boiler combustion time has been extended, and the thermal control system and control curve should be optimized and adjusted. In view of the problems encountered in the actual work of the boiler, the required control curve and control system should be optimized to improve its response capacity under load.
3. Continuous combustion optimization adjustment.
After the boiler low nitrogen combustion technology transformation, in addition to the type of coal used, it is mainly about the boiler operation mode, boiler operation oxygen content, air distribution mode, coal pulverizer operation combination mode and other coal type changes and load changes that need to be optimized. After the boiler combustion optimization adjustment test, the coal quality has changed greatly, which usually needs to be adjusted for nearly two months, Only then can we find out the law of giving consideration to the environmental protection emission index and the operation economic index, so continuous combustion optimization adjustment is very important.
The transformation of boiler low nitrogen burners has a short time, incomplete exposure, insufficient understanding, insufficient experience in solving problems, and insufficient experience in solving problems. In order to reduce the environmental pressure of thermal power plants, the emission reduction technology for reducing NO needs to be further studied and developed to reduce the environmental pressure of power plants, and more importantly, the problem handling capacity generated after the application of new emission reduction technology and environmental protection facilities should be further improved, Strive to achieve greater environmental benefits for the sustainable development of coal-fired power plants.