On June 3, the 40t/h pulverized coal preheated combustion boiler of Yankuang Baodian Coal Mine Power Plant, using the preheated combustion technology of the Institute of Engineering Thermophysics, Chinese Academy of Sciences, was tested by a third party to show that it uses bituminous coal as fuel and does not use flue gas purification measures The original emission concentration of boiler nitrogen oxides (NOx) is between 82.3~94.5mg/m3 (converted by oxygen concentration of 6%). This indicates that the boiler has become the world's first pulverized coal boiler with an initial emission concentration of nitrogen oxides of less than 100 mg/m3. The boiler is a demonstration project of the strategic leading technology special project "Key Technology and Demonstration of High-efficiency Clean Combustion" of the Chinese Academy of Sciences.
The average NOx emission level of existing pulverized coal boilers is around 200-450mg/Nm3, and it must be achieved through selective non-catalytic reduction (SNCR), selective catalytic reduction (SCR) and other flue gas purification systems. The initial investment of the purification system is high and the operating cost is high, which seriously affects the efficiency of the enterprise. And in order to control the ultra-low NOx emissions, it is often necessary to put in excess ammonia water, which causes ammonia to escape and cause boiler tail corrosion and secondary air pollution.
With the support of the pilot project, the Institute of Engineering Thermophysics developed the pulverized coal preheating combustion technology, which aims to achieve the original ultra-low NOx emissions through the control of the combustion process. This transformative technology changes the way conventional coal powder is introduced into the furnace and combustion. On the one hand, part of the nitrogen in the coal powder is converted into nitrogen by preheating, which realizes the early removal of coal nitrogen and controls the generation of NOx from the source; on the other hand Significantly improve the combustion characteristics of the fuel entering the furnace, the strong combustion stability increases the depth classification control of NOx generation, and weakens the influence of coal type on the combustion process. This combustion technology integrates efficient combustion and NOx control. Compared with the existing technology, it eliminates the nitrogen oxide purification system, eliminates the need to use purification equipment and ammonia and other reducing agents, and the operating cost is greatly reduced, and there is no secondary pollution. Clean, efficient and low-cost, will effectively promote the upgrading of the industry's technical equipment.
The popularization and application of preheating combustion technology will bring significant social and economic benefits. Taking a 40t/h pulverized coal boiler as an example, compared with the existing technology, the use of preheating combustion technology can reduce the generation of NOx by about 200 tons, save 800 tons of ammonia, and reduce maintenance and operating costs by about 1 million yuan. There are about 490,000 industrial boilers with a capacity of less than 60t/h in China, with a total scale of 4.5 million t/h. If 10% is reformed with preheating combustion technology, it can reduce the production of NOx by about 2.25 million tons per year and save 900 ammonia 10,000 tons, 10 billion yuan for the industry to reduce maintenance and operation costs.
Prior to this, the pulverized coal preheating combustion technology has achieved NOx emissions of less than 50mg/Nm3 at the MW-scale pilot scale; project demonstrations of coal-burning and pure-burning ultra-low volatile fuels have been carried out in Shandong, Shaanxi and other places to achieve NOx emission is less than 200mg/Nm3, and successfully verified the technology's super adaptability of coal and super wide load regulation. This third-party test showed that the original NOx emission level of the actual furnace of the technology has been advanced to a level of less than 100mg/Nm3, and the next step of the research and development team will launch an impact to achieve the original NOx emission of less than 50mg/Nm3.
milling cutter,Indexable Ball Nose End Mill,Corn Teeth End Mills.Diamond Coated Drill Bit
JIANGYIN GOLD STAR INDUSTRY CO.,LTD , https://www.goldstarmilling.com