350MW燃煤锅炉在富氧下掺烧生物质气的数值模拟  

Numerical Simulation of Biomass Gas Blending in 350MW Coal-Fired Boiler under Oxygen Enrichment

作　　者：曹广懿德 陈帅 胡超 

机构地区：[1]上海工程技术大学机械与汽车工程学院,上海

出　　处：《建模与仿真》2023年第5期4294-4304,共11页Modeling and Simulation

摘　　要：为了研究火力燃煤锅炉的碳减排与低氮燃烧技术,本文通过数值模拟方法研究了不同O2/CO2体积分数比的富氧条件下四角切圆锅炉内生物质气与煤粉混燃情况。结果表明:当O2浓度高于29%时,炉膛整体速度梯度提高,有利于煤粉的充分混合燃烧,从而改善了煤粉的燃烧特性;随着O2/CO2体积分数比的增加,炉膛内温度整体是提高的,有利于提高炉膛内的换热性能;随着O2/CO2体积分数比的增加,炉膛内整体的CO2浓度逐渐提高,炉膛出口的CO2浓度是70%~77%,有利于CO2的捕集,同时,炉膛内NOx的浓度也逐渐提高,主要原因是炉膛内的温度随着O2浓度的增加而上升,由此热力型NOx的产生量更大。In order to study the carbon reduction and low-NOx combustion technology of thermal coal-fired boiler, this paper investigates the mixing and combustion of biomass gas and pulverized coal in a four-corner cut circle boiler under oxygen-rich conditions with different O2/CO2 volume fraction ra-tios by numerical simulation, and analyzes the flow, heat transfer and combustion processes in the furnace. The results show that: when the O2 concentration is higher than 29%, the overall velocity gradient in the furnace increases, which is favorable to the full mixed combustion of pulverized coal, thus improving the combustion characteristics of pulverized coal;with the increase of O2/CO2 vol-ume fraction ratio, the overall temperature in the furnace is increased, which is favorable to the improvement of heat transfer performance in the furnace;with the increase of O2/CO2 volume frac-tion ratio, the overall CO2 concentration in the furnace gradually increases. The CO2 concentration at the furnace outlet is in the range of 70% to 77%, which is conducive to the capture of CO2. Mean-while, the concentration of NOx in the furnace chamber also gradually increases, mainly because the temperature in the furnace chamber increases with the increase of O2 concentration, and thus the generation of thermal NOx is greater.

关 键 词：燃煤锅炉 混合燃烧 CO2浓度 生物质气 低氮燃烧技术 炉膛出口 燃烧特性 速度梯度 

分 类 号：TK2[动力工程及工程热物理—动力机械及工程]