Shaanxi Weihe Coal Chemical Corporation Group Ltd.
Ningxia Shenyao Technology Co.,Ltd.
Shanghai Ceo Environmental Protection Technology Co.,Ltd.

目前我国煤化工行业多年持续发展使得国内煤气化系统细渣处理量高速增加。气化细渣经真空带式或板框过滤机过滤后含水率普遍达到40%~60%,干基残碳质量分数通常在18%~50%。煤气化细渣的无害化处理和资源化利用已成为当前国内外煤化工行业亟待解决的痛点。以水煤浆气化细渣的特性为基础,从气化细渣的残碳(热值)、含水率、掺烧比例和混合燃烧特性等方面研究了水煤浆气化细渣对掺烧的影响。陕煤集团渭化公司水煤浆气化炉气化细渣经过深度脱水干化后含水率降低到28%,输送简单方便,与原料煤掺混后混合燃料的流动性不会造成堵煤断煤,调整混合燃料的含水率和热值等满足CFB锅炉要求后,对锅炉换热效率和运行寿命影响不大。针对气化细渣掺烧进CFB锅炉的运行情况进行分析,掺烧后锅炉运行参数如床层温度、烟气氧含量、排烟温度、床层差压等变化不大;烟气中SO2,NOx质量浓度未剧烈变化,不会影响到锅炉脱硫脱硝系统。掺烧前锅炉飞灰含碳量在10%~20%,掺烧后降低到5%~10%,证明合适的掺加量对燃烧有促进作用。气化细渣掺烧后,由于其灰分较原料煤高,进入烟道的飞灰总量将增加,在掺烧比例<15%时,布袋除尘器的设计裕量可以满足掺烧工况。将气化细渣的含水率一次性降低至28%左右,然后掺烧至CFB锅炉,可以节省细渣的处置费,并利用细渣内残碳燃烧产生蒸汽以达到节能的目的,掺烧后增加的灰渣可用于建材,经济收益和环保效益十分可观,是一条节能环保,切实可行的固废资源化利用途径。

At present,the many years’ development of China’ s coal chemical industry has led to a rapid increasein the amount of fine slag treatment in the domestic coal gasification system. After being filtered by vacuum belt orplate frame filter,the moisture content of gasification fine slag generally reaches 40% -60%,and the mass fractionof dry basis residual carbon is usually 18%-50%. The harmless treatment and resource utilization of coal gasificationfine slag has become a pain point that needs to be solved urgently in the coal chemical industry at home and abroad.Based on the characteristics of coal water slurry gasification fine slag,the influence of coal water slurry gasification fineslag on mixing combustion was studied from the aspects of carbon residue(calorific value),moisture content,mixingproportion and mixing combustion characteristics of coal water slurry gasification fine slag. After deep dehydrationand drying,the moisture content of the gasification fine slag of the coal water slurry gasifier of a group in ShaanxiCoal Group Weihua Company is reduced to about 28%. After blending with the raw coal,the blended fuel is easy tobe transported and its fluidity will not cause raw coal blockage and interruption. After adjusting the moisture contentand calorific value of the blended fuel to meet the requirements of the CFB boiler,it will have little impact on the heatexchange efficiency and operating life of the boiler. Based on the analysis of the operation of the CFB boiler blendedwith gasification fine slag, the boiler operation parameters such as bed temperature, flue gas oxygen content,flue gas temperature,bed differential pressure and so on have little change after blended combustion. The concentrationof SO2 and NOx in flue gas does not change dramatically and will not affect the boiler desulfurization and denitrificationsystem. The carbon content of boiler fly ash is reduced from 10%-20% to 5%-10% after blended combustion,whichproves that the appropriate amount of blending can promote the combustion. After the blended combustion of gasifica⁃tion fine slag,the amount of fly ash entering the tail flue will increase because its ash content is higher than that ofraw coal. When the mixing proportion is less than 15%,the design margin of bag filter can meet the mixing condition.Reducing the moisture content of gasification fine slag to about 28% at one time,and then burning it in the CFB boil⁃er can save the disposal cost of fine slag,and burning the residual carbon in fine slag to produce steam can achieve thepurpose of energy conservation,and the increased fly ash after burning can be used for building materials,so the eco⁃nomic and environmental benefits are very considerable. It is an energy⁃conserving,environment⁃friendly,and practicalway for the resource utilization of solid waste.

赵强,杜常宗,卢宇飞,等. CFB 锅炉掺烧水煤浆气化细渣的研究和运行分析[ J].煤炭学报,2023,48(S1):305-313.

ZHAO Qiang,DU Changzong,LU Yufei,et al. Study and operation analysis on blended combustion of coal waterslurry gasification fine slag in CFB boiler[J]. Journal of China Coal Society,2023,48(S1):305-313