焦炉燃烧室-炭化室耦合热过程模拟研究

利用仿真软件,模拟了结焦周期内焦炉燃烧室-炭化室耦合热过程,获取了炭化室内焦炭温度随时间的变化趋势,分析燃烧室内的温度场、流场,进一步探讨了燃料种类、供热结构等因素对焦饼温度场和结焦时间的影响。结果表明:模拟结果与测量数据、设计数据吻合较好,验证了数理模型的可靠性和准确性,多点供热结构较好改善了高向加热均匀性,改善了煤饼中心高向温差,优化了焦炉的运行。     

焦炉燃烧室-炭化室热过程数值模拟及解耦算法

考虑焦炉燃烧室-炭化室的复杂结构和多过程耦合的传输现象,建立了焦炉燃烧室-炭化室的数理模型,针对直接耦合数值模拟计算量大、难以收敛的问题,提出并采用两种解耦算法对焦炉燃烧室-炭化室的燃烧、流动和传热过程进行了数值模拟,并将计算结果与现场实测值进行了比较。计算结果表明,与直接耦合数值模拟相比,两种解耦数值算法具有简单易行、计算量小、能得到收敛和较精确的解等优点,算法二与算法一相比计算量有所增大,但由于其更接近实际工况,具有更好的通用性。本文提出的两种解耦数值算法,对焦炉燃烧室-炭化室等复杂结构、多过程耦合的数值模拟具有一定的理论指导意义,并期望为其他类似复杂传输过程的数值模拟简化处理提供参考。     

基于Aspen Plus的炼焦过程模拟与分析

建立了炼焦过程的Aspen Plus模拟模型,包括煤料预热模块、反应器单元模块、以及反应器单元模块间的耦合模拟;对炭化室和燃烧室两个反应器进行热力学耦合,并以产品产率为灵敏度指标对过程进行优化分析。结果表明,模拟结果与实际工业过程具有一致性,RStoic模型构建煤调湿反应器,所产出的干煤水分为2.78%;RYield模型模拟炭化室煤干馏过程,产出荒煤气温度为751.42℃;燃烧室向单孔炭化室提供的最佳热负荷为431.47 kW,此时主产品焦炭产率为83%,燃烧室平均温度为1 412℃,节能率为18.18%。     

降低焦炉炼焦耗热量的实践与探索

结合焦炉生产实践,通过降低焦饼中心温度、降低炉顶空间温度、提高炭化室单孔加煤量、稳定空气过剩系数等措施降低焦炉耗热量,取得了较好的经济效益。     

焦炉燃烧室—炭化室传热过程数学模型

建立了两个相邻炭化室和一对立火道的加热过程数学模型,其中炭化室内煤科的传热按导热过程处理,燃烧室内辐射传热用区域法求解。并对火道温度的模型计算结果进行了实测验证,结果表明两者吻合较好。     

SJ-96热回收炼焦炉温度场分布的数值计算

通过对SJ-96清洁型热回收焦炉传热过程的理论分析,建立了包括炉侧墙、炉底及煤料的两维传热数学模型,编写可用数值方法进行计算的Fortran程序,根据实际焦面温度测量结果,及结合文献的基础数据,求解了该焦炉在成焦过程中的温度场分布及结焦时间,结果表明：在成焦4h～64h之间,热量由煤料上部及炉墙、炉底向煤进行传热,到结焦64h,顶部焦面的温度达到最高,整个炭化室中温度也最高,焦炭已接近成熟,到100h,炭化室中全部焦炭已达到1000℃,而后随挥发分释放的减少,整体焦炭温度下降．随炭化时间的延长,炭化室中横向及竖直方向温差进一步减少．     

7.63 m焦炉炉温调节模型的建立与应用

针对7. 63 m焦炉的热工特点,在统计分析热工数据的基础上,利用暂停加热时间调整炉温的技术方法,建立多个炉温调节模型,以解决环境温度、原料水分的变化及生产波动等状态下焦炉炉温精确控制问题,该炉温模型改善了焦饼成熟状况,并有效降低了焦炉能耗。     

6m焦炉基础结构抗震设计探讨

目前,我国正在运行的焦炉已有1000多座,由于工艺生产的要求,焦炉一般建于钢筋混凝土构架基础之上,蓄热室、燃烧室、炭化室及入炉煤均可认为是均布荷载,总计可达210kPa,正常生产传给焦炉基础顶板的温度达100℃左右,顶板下表面温度达60℃左右,钢筋砼框架的温度变形及抗震问题一直受到关注.     

焦炉扒焦机械

焦炭生产的经济效益在很大程度上取决于各工艺过程的协调性,当焦饼难推时可能破坏工艺过程的协调性。 焦化机械设计局调查了许多焦化企业,查明其中许多企业一年中不止一次地出现难推事故,一孔炭化室空号时间由5h延长到20h。扒焦时,操作人员是在高温和烟尘下工作的。 可惜,这种不良现象仍在继续和发展,这表现在焦炉自然磨损、原料质量下降和工艺受到破坏等方面。扒焦过程恶化了焦炉状况:焦炉耐火砌体产生裂纹,加热墙变形,而且在许多情况下加热墙上甚至出现贯穿孔。这样一来,     

炭化室清除石墨的新方法

1炭化室结石墨的原因焦炉荒煤气在高温作用下,某些大分子碳氢化合物分解产生甲烷,部分甲烷在高温作用下热解,析出游离碳和氢气,游离碳附着于炭化室炉墙砖和炉顶砖上,最终形成炉墙石墨和炉顶石墨。石墨能保持炉墙的严密,但随着石墨的过度生长,对焦炉生产带来的负面影响将越来越大。(1)在炭化室墙面的中上部由于石墨较其他部位多且厚,使炭化室在此区域变窄,造成推焦困难。(2)由于石墨的存在,炉墙热阻增大,只有提高炉温才能使焦饼按时成熟,不仅增加炼焦耗热量,而且温度高会促进石墨生长,导致恶性循环。(3)当加煤过满或平煤不良时,推焦过程中,顶…     

Coal blend moisture—a boon or bane in cokemaking?

A by-product coke making plant is required to supply sufficient coke of good quality and adequate gas of high calorific value for the integrated steel plant to be a going concern. The one element that influences the handling of coal and impacts the operation and efficiency of the plant is moisture. Compared to other important properties of the coal blend, moisture can be easily manipulated. The coal moisture can be increased simply by adding water through hose pipes. Also, it can be reduced to 5–6 mass percent using Coal Moisture Control (CMC) and 2–4 mass percent using Dry-cleaned & Agglomerated Pre-compaction System (DAPS). Moisture content is one among the many variables affecting the bulk density of coal blend and those controlling the coke qualities and yield. Increase in moisture reduces coal grindability, coking pressure and internal gas pressure; helps in dust suppression during charging and hence reduces jamming of ascension pipes and hydraulic main. Batteries charging coals with high moisture content are not troubled with roof carbon deposits. It was observed that when moisture content in coal blend of SAIL-Bokaro Steel Plant increased to more than 8.50%, the calorific value of coke oven gas improved. In the working moisture range of 9–11%, the increase of the yield of coke oven gas per 1% of working moisture is 5.2 m³. Studies have shown, however, that the increase in moisture content of coal beyond 8% hampers strong coke formation. Pre-carbonization preheating process generally showed an increase in the proportion of 40–80 mm coke, compared with wet charges. For SAILBokaro coke ovens, driving out 1% moisture from coal blend requires 125 Mega-calories of heat/oven. With lesser moisture, the emission of NO _x in atmosphere will also be low. On using dry to low moisture coal blend, the swelling of coke mass increases leading to difficulty in oven pushings. Hence, an optimum level of moisture content of charge coal needs to be maintained for improving coke oven productivity, coke quality and operational smoothness. The coke oven managers all around the globe maintain this optimum level according to their requirement, the operating conditions, the quality of product and by products, the oven health & age and the ease of handling.     

The mechanism of coking pressure generation I: Effect of high volatile matter coking coal, semi-anthracite and coke breeze on coking pressure and plastic coal layer permeability

One of the most important aspects of the cokemaking process is to control and restrain the coking pressure since excessive coking pressure tends to lead to operational problems and oven wall damage. Therefore, in order to understand the mechanism of coking pressure generation, the permeability of the plastic coal layer and the coking pressure for the same single coal and the same blended coal were measured and the relationship between them was investigated. Then the ‘inert’ (pressure modifier) effect of organic additives such as high volatile matter coking coal, semi-anthracite and coke breeze was studied. The coking pressure peak for box charging with more uniform bulk density distribution was higher than that for top charging. It was found that the coking pressure peaks measured at different institutions (NSC and BHPBilliton) by box charging are nearly the same. The addition of high volatile matter coking coal, semi-anthracite and coke breeze to a low volatile matter, high coking pressure coal greatly increased the plastic layer permeability in laboratory experiments and correspondingly decreased the coking pressure. It was found that, high volatile matter coking coal decreases the coking pressure more than semi-anthracite at the same plastic coal layer permeability, which indicates that the coking pressure depends not only on plastic coal layer permeability but also on other factors. Coking pressure is also affected by the contraction behavior of the coke layer near the oven walls and a large contraction decreases the coal bulk density in the oven center and hence the internal gas pressure in the plastic layer. The effect of contraction on coking pressure needs to be investigated further.     

SWDJ625-1型捣固焦炉技术特点及工艺分析

介绍了SWDJ625-1型捣固焦炉的火道、蓄热室、炭化室等炉体结构设计、炉体主要尺寸及焦炉基本工艺参数,并重点分析了装煤除尘、出焦除尘等环节采用的M型管导烟车、SOPRECO^■单炭化室压力调节系统、配套除尘地面站及抗形变多段式保护板等环保除尘技术,认为该型捣固焦炉可有效降低炼焦能耗和环保排放指标等,符合国家产业政策和焦化行业的发展方向。     

入炉煤水分对炼焦过程及焦炭质量的影响

通过测定入炉煤水分分别为1%、6%和12%时煤料堆密度、升温速度及坩埚焦性质,得出入炉煤水分对其性质的影响。降低入炉煤水分虽然对煤料本身性质影响不大,但是其在炭化室内结焦过程的动态发生了显著变化,可显著提高焦炉生产能力及改善焦炭质量。入炉煤水分为1%时,煤料堆密度、升温速度及坩埚焦的性质都大大好于入炉煤水分为6%和12%这两种情况。     

中国炼焦煤资源与焦炭质量的现状与展望

从我国炼焦煤资源和炼焦工业现状角度论述了二者间存在的矛盾.概述了国内外诸如提高焦炉炭化室高度、捣固炼焦、煤调湿、配型煤炼焦、干熄焦以及利用焦炉处理有机废弃物等措施扩大炼焦煤源的总体情况,以及这些措施对焦炭提质的作用效果,展望了今后焦化工业的技术发展趋势.     

焦炉立火道温度变化规律探讨

以太原市煤气化股份有限公司第二焦化厂JN60型焦炉为例,介绍了立火道温度的测量方法及原理,通过实时检测燃烧室温度和相邻上升管粗煤气温度的变化,系统地分析了立火道温度波峰、波谷与炭化室的结焦状态之间的对应关系,以对调火操作、稳定焦炉温度和保证焦炭质量起到指导作用。     

焦炉烟道废气-流化床式煤调湿技术的应用

利用焦炉烟道废气为热源及动力源,在流化床设备内对捣固焦炉配合煤进行预处理。生产应用表明,流化床煤调湿技术对配合煤调湿及分级作用明显,调湿后配煤水分降低2.2%,减少回炉煤气用量1474×104m3,CO2减排8750t,减少焦化废水处理量2万t,焦炉生产能力提高5%,排空废气粉尘含量〈50mg/m3。