75t / h slime circulating fluidized bed boiler passed the 168-hour trial operation assessment and reached

Recently, the Xinglongzhuang 75t / h slime boiler demonstration project of the circulating fluidized bed high temperature and low nitrogen combustion technology independently developed by the Institute of Engineering Thermophysics of the Chinese Academy of Sciences successfully passed the 168-hour trial operation assessment and was put into commercial operation under full load of the boiler. The original NOx emission concentration reached 38mg / m3. The successful operation of the boiler fully verified the superiority of the circulating fluidized bed high temperature and low nitrogen combustion technology, directly achieving ultra-low NOx emissions of less than 50mg / m3, and the boiler thermal efficiency reached more than 90%. This technology provides a new technical approach for the clean and efficient combustion of coal-fired circulating fluidized bed industrial boilers in China, and its wide application will effectively drive the transformation and upgrading of coal clean combustion technology equipment. The boiler is a demonstration project of the strategic leading science and technology special project of the Chinese Academy of Sciences undertaken by the Institute, "High efficiency and low nitrogen combustion technology and demonstration of coal-fired industrial boilers."

Existing ultra-low emission technologies widely use ammonia injection or tail flue gas denitration devices to achieve NOx removal, which is expensive and expensive, and is very likely to cause secondary pollution. In 2015, the research institute proposed a circulating fluidized bed high-temperature and low-nitrogen combustion technology. This technology is based on the characteristics of circulating fluidized bed combustion and the principle of NOx generation control. During the combustion process, the reduction strength and increase of reduction in the dense phase area of ​​the circulating fluidized bed are enhanced. The reaction zone achieves the significant effects of deep NOx suppression in the main combustion zone, efficient reduction in the reburn zone, and ultra-low NOx emissions. The 75t / h slime boiler incorporates high-temperature ultra-low nitrogen technology, uniform top coal slime technology, primary air back wall uniform air inlet technology, anti-wear and leak-proof slag embedded countercurrent column wind cap technology, and high-efficiency insulated volute cyclone A series of original key combustion technologies such as separator and separator optimal layout technology, feeder ash discharge control technology, etc., while ensuring the efficient combustion of pulverized coal, greatly reduce the original NOx emission concentration in the combustion process, and completely solve the combustion efficiency And emissions control. Adopting this technology boiler can save the investment cost of the flue gas denitration device by nearly 4 million yuan, and the operating cost by nearly 300,000 yuan / year. The technology is extended to the national circulating fluidized bed industrial boiler, which can save nearly 10 billion yuan for the industry.

This demonstration project is aimed at the technical problems of low thermal efficiency, difficult control of pollutant emissions, and high operating costs of existing coal slime circulating fluidized bed industrial boilers. It focuses on breakthroughs in high-efficiency low-nitrogen combustion, high-efficiency gas-solid separation and uniform gas-solid flow in the furnace. Performance and other key technologies, a high-efficiency and low-nitrogen cooperative control technology for full slime circulating fluidized bed was developed. Since the implementation of the project, the demonstration project has completed feasibility study report, implementation plan review, demonstration project environmental assessment, boiler basic design and other work. The project started construction at the beginning of 2019. By the beginning of November, all the preparations for the trial operation were completed. It passed the 168-hour trial operation assessment in early December and has been put into commercial operation. The 75t / h full-slime circulating fluidized bed boiler is energy-saving, environmentally friendly, economical and reliable, which fully proves the technical advantages of the high-temperature post-combustion technology in the ultra-low NOx original emissions. The engineering demonstration of fluidized bed industrial boilers provides important support.

Studies have shown that NOx emissions from coal-burning are one of the main pollutants that form smog, while NOx emissions from coal-fired industrial boilers account for about 12% of the country ’s total emissions. In view of the characteristics of China ’s coal-fired industrial boilers, such as large holdings, wide distribution, low overall level of energy efficiency and pollution control, and huge potential for energy saving and emission reduction, the Chinese Academy of Sciences launched the strategic pilot technology special project "Transformative Clean Energy Key Technologies and demonstration". As one of the pilot special topics, this topic focuses on key technologies for the efficient control of coal-fired industrial boilers and the collaborative control of ultra-low NOx emissions. It is expected that the original NOx emission concentration will be less than 50mg / m3 and the boiler thermal efficiency will not be less than 90 % Technical indicators, and achieve technical demonstration of 75t / h, 130t / h, 220t / h series capacity coal-fired circulating fluidized bed industrial boiler project, the project execution period is from July 2018 to June 2023. The demonstration project was also included in the Yankuang Group's major science and technology project in 2019, and was constructed by Yankuang Zhongke Clean Energy Technology Co., Ltd.