生物质(气)耦合燃煤锅炉燃烧特性数值模拟  

Numerical Simulation of Combustion Characteristics of Biomass(Gas)Coupled Coal-fired Boiler

作　　者：张小桃[1] 张程俞 黄雪琦 刘昊明 王爱军[1] ZHANG Xiaotao;ZHANG Chengyu;HUANG Xueqi;LIU Haoming;WANG Aijun(North China University of Water Resources and Electric Power,Zhengzhou 450045,China)

机构地区：[1]华北水利水电大学,郑州450045

出　　处：《能源研究与管理》2021年第4期47-51,57,共6页Energy Research and Management

基　　金：河南省高等学校重点科研项目(21A480006);河南省科技攻关项目(212102311055)。

摘　　要：为了研究不同类型生物质对煤粉耦合生物质再燃锅炉燃烧特性的影响,基于FLUENT模拟软件,选取某超超临界660 MW锅炉作为研究对象,搭建煤粉锅炉耦合生物质(气)再燃模型,对锅炉进行改造,在最顶层二次风喷口和燃尽风之间增添生物质(气)再燃喷口,分别对纯煤燃烧,生物质固体再燃,生物质气体再燃等不同工况的燃烧特性进行数值模拟,研究燃烧区温度场,组分分布以及炉膛出口烟气中CO_(2)和NO_(x)质量浓度分布的变化规律。结果表明:生物质再燃降低锅炉煤粉消耗量,使得主燃区燃烧温度降低,同时使得炉内燃烧火焰中心上移,炉膛出口CO体积分数上升,增加了排烟热损失;相比于纯煤工况,生物质固体和生物质气再燃均可以使炉膛出口CO_(2)和NO_(x)的体积分数降低,但是生物质气效果要明显高于生物质固体。其中食物垃圾气体再燃减少CO_(2)排放与降氮效果最好,CO_(2)减排率可达13.87%,降氮率可达24.13%。In order to investigate the effects of different types of biomass on the combustion process of boiler,numerical simulation was carried out for re-burning process of an ultra-supercritical 660 MW coal-fired coupled biomass(gas)boiler,on the basis of establishing a model for the boiler using Fluent software.The boiler was reformed by adding a biomass(gas)re-burning nozzle between the top secondary air nozzle and the burn-out air.The combustion characteristics of solid biomass re-burning and biomass gas re-burning conditions were numerically simulated to research the law of change on temperature field in combustion zone,component distribution and concentration distribution of CO_(2) and NO_(x) in flue gas at the outlet of furnace.The results show that the biomass re-burning reduces the pulverized coal consumption and the combustion temperature in the primary combustion zone,and it will increase the volume fraction of CO in the furnace.But at the same time,the center of the combustion flame in the furnace moves up,increasing the exhaust heat loss.Compared with pure coal conditions,both solid biomass and biomass gas re-burning can reduce the volume fraction of CO_(2) and NO_(x) at the outlet of the furnace,but the effect of biomass gas is significantly higher than that of solids biomass.Among them,food waste gas re-burning has the best effect on reducing carbon emission and nitrogen emission,with carbon emission reduction rate reaching 13.87%and nitrogen reduction rate reaching 24.13%.

关 键 词：再燃 生物质耦合 数值模拟 NO_(x)排放 

分 类 号：TK62[动力工程及工程热物理—生物能]