【作者】 杨睿；

【导师】 董长青； 杨勇平；

【作者基本信息】 华北电力大学（北京） ， 热能工程， 2009， 硕士

【摘要】 生物质气与煤粉混燃发电能够充分利用现有发电厂设备及技术,降低成本。与生物质直燃相比,能够避免直燃中燃料处理、燃料输送所带来的问题,缓解锅炉结渣等问题且使煤灰成分不受影响。成为生物质能利用的一个重要技术。本文以元宝山600MW机组3#四角切圆煤粉炉为例,采用了FLUENT软件对基于气化的混燃进行了数值模拟。计算结果表明,混烧生物质气后使得炉膛温度下降,降低了NO排放,随着混燃比例的提高,炉膛温度降低,混燃比例达到50%时,平均温度比燃煤工况下降300K左右。为了获得较高的锅炉效率,就需降低混燃比例或增加对流换热面。随着混燃比例的升高,NO的排放量也逐步降低,NO的脱除率最低可达71%。改变生物质气的喷口位置的计算结果表明,将生物质气从最下层喷口喷入可以得到较高的炉膛温度和较低的NO排放浓度。更多还原

【Abstract】 Gasification based biomass co-firing was a low-risk,low-cost technology that could make full use of the existing boiler system and technology.Compared to directly co-firing biomass and coal,it avoided biomass delivery into the boiler,reduced boiler slagging and avoided altered ash characteristics.In the study,numerical simulation of co-firing producer gas from biomass gasification and coal in a 600MWe tangential PC boiler was carried out with FLUENT software.The results showed that the reduction of NO emission could be achieved and the temperature decreased when co-firing.The effect of co-firing on combustion efficiency was slight.The temperature decreased with the proportion of biomass gas increased. The mean temperature decreased by 300K when the percentage of the biomass gas increased to 50%.The convection heat transfer area should be increased or the biomass gas should be limited to a low percentage to achieve higher boiler efficiency.NO emission decreased with the percentage of the biomass gas increased and the NO removal rate could reach 71%.The results showed that when the biomass gas was injected from the lowest layer of the burner,it could receive higher temperature and lower NO emission.更多还原