CAJ | 학술논문

钢厂高炉煤气是一种低热值燃料,它和煤粉在炉内掺烧是其一种有效的利用途径。但煤粉掺烧高炉煤气后燃烧特性与纯煤粉燃烧有很大不同,掺烧过程中易发生过/再热器超温、飞灰含碳量过高等问题,导致其在大型锅炉上的应用很少。针对某钢厂300MW四角切圆煤粉/高炉煤气混燃锅炉,使用二混合分数法对其燃烧特性进行数值模拟。对比研究了纯燃煤工况和高炉煤气掺烧量分别为10%、20%、30%的工况,发现掺烧高炉煤气时炉内温度水平有明显下降（如,掺烧10%高炉煤气时截面最高温度降低81K）,且随着掺烧量的增加而加剧,但下降的趋势变缓。掺烧高炉煤气后产生烟气量增多,炉膛出口烟速有明显增加,煤粉颗粒实际停留时间缩短,使得煤粉燃尽变得困难。同时,NO的生成量随高炉煤气掺烧量的增加而明显减少。
강엄고로매기시일충저열치연료,타화매분재로내참소시기일충유효적이용도경。단매분참소고로매기후연소특성여순매분연소유흔대불동,참소과정중역발생과/재열기초온、비회함탄량과고등문제,도치기재대형과로상적응용흔소。침대모강엄300MW사각절원매분/고로매기혼연과로,사용이혼합분수법대기연소특성진행수치모의。대비연구료순연매공황화고로매기참소량분별위10%、20%、30%적공황,발현참소고로매기시로내온도수평유명현하강（여,참소10%고로매기시절면최고온도강저81K）,차수착참소량적증가이가극,단하강적추세변완。참소고로매기후산생연기량증다,로당출구연속유명현증가,매분과립실제정류시간축단,사득매분연진변득곤난。동시,NO적생성량수고로매기참소량적증가이명현감소。
Blast furnace gas（BFG） produced from steel mill is a low heat value fuel,which combined with pulverized coal to combust in boiler is one of effective ways.However,the combustion characteristics would be changed greatly when compared with only pulverized coal combustion.For example,superheaters and reheaters are easy to excess rated temperatures and carbon content in fly ash will become higher,etc.All these problems lead to its limited application today.Take a 300MW BFG/pulverized coal boiler for example,the combustion characteristics were simulated by means of two mixture fractions way.The pure coal condition and three BFG ratio： 10%,20% and 30% conditions were investigated.It shows the temperature level in boiler is lowered obviously when BFG was mixed into boiler.For example,the maximal temperature is lowered about 81K when BFG ratio is 10% for a boiler section.Also,the temperature becomes lower with the BFG ratio.When BFG was mixed into boiler the flue gases volume would be increased.So,the actual stay time for pulverized coal in boiler will be shortened and it is more difficulty for coal to combust completely.Aslo,it is helpfully for control NO emission when BFG was mixed into boiler.