煤焦颗粒燃烧模拟在W型火焰锅炉炉膛设计热力计算中的应用

分析了炉膛设计热力计算中引入煤焦颗粒燃烧模拟的可能性和必要性,探讨了采用早期的锅炉机组热力计算标准进行新型的W型火焰锅炉炉膛热力计算的可行性及经验系数的取值问题,分析、比较了煤焦颗粒在实验室和炉膛内燃烧环境的差异,并引入氧量分布不均系数、区段充满度系数来考虑炉膛内颗粒表面氧浓度、停留时间等方面与实验环境的差异.在此基础上,建立了适合于炉膛分区段热力计算的煤焦燃烧模型,并最终将煤焦非均相反应的实验室数据应用于炉膛分区段热力计算,克服了目前炉膛设计热力计算仅考虑传热所带来的不足.在一台W型火焰锅炉上的应用表明,颗粒燃烧和炉膛传热相耦合的分区段热力计算模型能够揭示过量空气量、煤粉细度、煤种、负荷等因素对燃尽和传热的影响,适合工程应用.

Application of Coal Char Combustion Simulation in Thermal Calculation for W Flame Furnace Design

Probability and necessity of introducing coal char combustion simulation to thermal calculation in furnace design is analyzed.Feasibility of using early boiler thermal calculation criterion for W flame furnace is discussed,which shows that some coefficients should be set specially for this kind of boiler.Coal char combustion environment in furnace is compared with that in laboratory.Oxygen uniformity ratio and effective section volume percentage are used to correct the difference of oxygen content around particles as well as combustion time between laboratory and furnace condition.Coal char combustion model fitting sectioned furnace thermal calculation is developed using laboratorial kinetic data of char combustion.It elimi- nates the limitation of single heat transfer calculation in furnace with current criterion.This one-dimensional model with particles combustion coupling heat transfer is used for sectioned furnace thermal calculation in a W flame boiler,and the re- sult shows that it can reveal distinct effects of excess air,particle fineness,coal characteristics,boiler load on combustion efficiency and furnace heat transfer,suiting engineering usage.