摘要
结合BFA和OFA技术,并采用计算流体软件FLUENT 6.3,选择合理的数学模型,对420t/h切圆燃烧锅炉炉内的流动、传热及燃烧进行了数值模拟。数值模拟采用三维稳态计算,SIMPLEC算法,湍流模型采用可实现k-ε双方程模型,NOx的生成采用后处理方法计算。计算结果表明,改造后炉膛中心温度降低,炉膛出口NOx排放量降低了约30%,炉膛出口的CO浓度接近零。但是,由于底部BFA二次风的直接扰动,使切圆直径增大,会造成锅炉结渣。因此,在改造过程中应适当减小下一次风截面的设计切圆直径。
Combined with BFA and OFA technology, and adopting fluid calculation software FLUENT 6.3, se- lecting proper mathematic model, a numerical simulation of flow, heat transfer, and combustion in the furnace of a tangential firing 420 t/h boiler has been carried out. The said simulation adopts three - dimensional steady - state calculation and SIMPLEC algorithm, the turbulent model uses the double - equation realizable k - e model, and the formation of NOx is calculated by using post - processing method. The results of calculation show that the temperature at center of the furnace decreases after retrofit, the NOx emission at exit of the fur- nace reduces about 30 ~, the concentration of CO at exit of the furnace is near to zero. However,owing to di- rect disturbance of the secondary air from BFA at the bottom, making the diameter of tangential circle to be enlarged, this phenomenon may result in slagging in the furnace. Therefore, in the process of retrofitting, the designed diameter of tangential circle at lower cross - section of the primary air has to be properly reduced.
出处
《热力发电》
CAS
北大核心
2011年第8期12-16,共5页
Thermal Power Generation
基金
国家高技术研究发展计划(863计划)项目2008AA05Z304
