多喷嘴对置式气化炉与单喷嘴水煤浆气化炉运行分析

目前关于多喷嘴气化炉和GE单喷嘴水煤浆气化炉的优劣争论很多,特别是对于运行效率问题说法不一。本文通过生产中实测数据的对比,利用相对有效产气率这一概念,试图解决存在的争论,给出了分析煤气化效率的一个有效思路。     

多喷嘴对置式气化炉与单喷嘴水煤浆气化炉运行分析

目前关于多喷嘴气化炉和GE单喷嘴水煤浆气化炉的优劣争论很多,特别是对于运行效率问题,说法不一.本文通过生产中实测数据的对比,利用相对有效产气率这一概念,试图解决存在的争论,给出分析煤气化效率的一个有效思路.     

多喷嘴对置式气化炉内颗粒挥发分火焰可视化研究

基于实验室规模多喷嘴对置式水煤浆气化炉及其可视化装置,研究了气化炉喷嘴平面非射流区颗粒挥发分燃烧过程。结合图像处理技术,在气化条件下对粒径小于300 μm颗粒挥发分火焰尾迹形态及变化过程进行分析。研究结果表明,颗粒挥发分火焰非典型包络型火焰,而是形成挥发分火焰尾迹。颗粒挥发分尾迹形态受颗粒脱挥发分所处阶段和颗粒相对于气流的运动状态的影响,随时间不断变化。颗粒挥发分最大火焰尺寸随颗粒粒径增加而增加。气流床气化还原性气氛条件下颗粒挥发分燃烧时间较颗粒在富氧气氛中燃烧时间显著增加。     

新型多喷嘴对置式水煤浆气化炉

由我国科技人员自主开发建设、拥有10项自主知识产权、带压投料开创世界煤气化技术先河的我国首台新型多喷嘴对置式水煤浆气化炉，目前已在山东充州矿业集团所属的国泰化工公司投入生产，从此结束了我国引进国外煤气化技术的历史。日前，这项新技术通过了专家鉴定。     

多喷嘴对置式水煤浆气化炉操作温度的控制

介绍了多喷嘴对置式水煤浆气化炉工艺流程及气化炉炉温控制的重要性。分析了气化炉炉温控制的影响因素,介绍了多喷嘴对置式新型气化炉装置操作温度的控制方法,并阐述了更换煤种和炉壁超温工况下的炉温调整方法。     

多喷嘴对置式水煤浆气化炉工艺烧嘴的技改

介绍了多喷嘴对置式水煤浆气化炉工艺烧嘴结构及材质,从烧嘴头部、盘管结构形式、喷头间隙、冷却水盘管焊缝等方面进行改造,工艺烧嘴使用寿命由初期的15 d延长到约150 d,提高了新型气化炉稳定运行周期。     

多喷嘴对置水煤浆气化炉的开发与应用

介绍多喷嘴对置水煤浆气化炉的实验室研究及中试情况,并与Texaco水煤浆气化技术进行了比较,结果表明,多喷嘴对置气化技术优于Texaco技术。     

多喷嘴对置式水煤浆气化炉烧嘴技改小结

<正>1烧嘴头部保护若合成气夹带的灰渣进入烧嘴室,会腐蚀烧嘴冷却水盘管,并导致烧嘴拆装困难。对烧嘴头部冷却水盘管进行保护,使烧嘴室形成相对密闭的空间,可有效防止气化炉内灰渣进入烧嘴室,既减轻了烧嘴的腐蚀,又方便烧嘴的拆装,同时可延长冷却水盘管及外氧管的使用寿命。由于烧嘴头部处于气化炉内高温区,用于头部保护的材料应     

多喷嘴对置式水煤浆加压气化炉耐火材料的局部更换

介绍了多喷嘴对置式水煤浆加压气化炉耐火材料的结构和选用,简单分析了耐火砖的损蚀机理,并根据耐火砖在使用一段时间后的损蚀量计算了各部位损蚀速率,总结了耐火材料局部更换的经验,讲述了耐火材料局部更换时的拆除和回砌方法以及技术要点。     

多喷嘴对置式气化炉与单喷嘴水煤浆气化炉实际运行数据的比较与相关分析

目前关于多喷嘴气化炉和GE单喷嘴水煤浆气化炉工艺的优劣存在争议,特别是对运行效率问题,众说纷纭.本文通过实际生产中所测数据的对比,利用相对有效产气率这一概念,试图解决存在的争论,给出分析煤气化效率的一个有效思路.     

Numerical study on the coal gasification characteristics in an entrained flow coal gasifier

The coal gasification process of a slurry feed type, entrained-flow coal gasifier was numerically predicted in this paper. By dividing the complicated coal gasification process into several simplified stages such as slurry evaporation, coal devolatilization and two-phase reactions coupled with turbulent flow and two-phase heat transfer, a comprehensive numerical model was constructed to simulate the coal gasification process. The k– turbulence model was used for the gas phase flow while the Random-Trajectory model was applied to describe the behavior of the coal slurry particles. The unreacted-core shrinking model and modified Eddy break-up (EBU) model, were used to simulate the heterogeneous and homogeneous reactions, respectively. The simulation results obtained the detailed information about the flow field, temperature and species concentration distributions inside the gasifier. Meanwhile, the simulation results were compared with the experimental data as a function of O₂/coal ratio. It illustrated that the calculated carbon conversions agreed with the measured ones and that the measured quality of the syngas was better than the calculated one when the O₂/coal ratio increases. This result was related with the total heat loss through the gasifier and uncertain kinetics for the heterogeneous reactions.     

多喷嘴对置式粉煤气化炉的数值模拟

采用k-ε湍流模型对多喷嘴对置式粉煤气化中试装置进行了三维数值模拟研究。引入了多反应进程变量MSPV方法分别模拟了煤的脱挥发分、焦炭与氧气、焦炭与二氧化碳和焦炭与水蒸气的4个过程;用截断高斯分布的PDF函数表示湍流对化学反应的影响。模拟结果显示:常压下,火焰主体温度约2 500 K;除喷嘴区域外,煤中释放的气体在气化炉内分布均匀;焦炭与二氧化碳、焦炭与水蒸气的气化反应主要集中在折返流区。喷嘴高度上移0.2 m,撞击流股速度增加约50%,拱顶附近温度上升108 K。氧煤比/水蒸气煤比增大,撞击流对炉顶的冲刷力显著增加。     

On the scaling-up of a two-stage air blown entrained flow coal gasifier

A two-stage air blown entrained flow gasifier is being developed in Japan for the IGCC process. However, its scale-up up faces significant difficulties because of ash/slag deposition problems. The ash/slag deposition in the gasifier depends on both the ash properties and entrainment produced by the swirling gas flow. Therefore, the flow hydrodynamics are critical issues for the control of the ash behavior. In this paper, a comprehensive simulation model is used to examine the effects of the gasifier geometry and jet configuration on the flow hydrodynamics in order to control the ash deposition on the gasifier walls. A swirl number for the multi-stage injection swirling gas flow is defined and proved to be the most important hydrodynamic scaling law for the entrained flow gasifier.     

水煤浆加压气化炉用高铬砖的优化

通过调整高铬砖中α-Al2O3微粉粒度分布和Cr2O3微粉的加入量,对水煤浆加压气化炉用高铬砖进行性能优化。结果表明,优化后的高铬砖显气孔率明显降低,抗热震性和抗侵蚀性显著提高。     

分级气流床气化炉模型研究

为了研究分级和气化炉结构对气化效果的影响,结合对分级气化炉内流动、燃烧和气化反应的分析,采用小室模型建立了分级气化炉的动力学模型,考虑了气化炉结构尺寸对气化过程和结果的影响。利用建立的模型,对等径结构、颈缩结构和渐扩结构3种形式的分级气化炉进行了计算,得到温度、气体组成及其体积分数、碳转化率等参数沿气化炉炉膛的分布情况,并和连续气化的结果进行了对比。结果表明氧气的分级给入加强了气化炉内的物料混和,提高了平均温度,有利于提高气化效率;同时最高点温度有所降低,有利于和延长耐火砖使用寿命。同样运行条件下分级气化得到的有效气体体积分数要高于连续气化。     

旋流在气流床气化炉中的应用

在气流床气化炉内高温高压的环境下,气固混合是影响气化炉效率的重要因素,而旋流在强化气固混合方面已在燃烧中得到广泛使用,文中综述了旋流在气流床气化炉中的应用。首先介绍了旋流的数学描述,包括旋流的概念,旋流N-S方程的表示方法以及其解析解,旋流的解析解均是在一定假设前提下得到的,具有一定的局限性;其次,介绍了旋流的特性和生成方式,主要通过切向入口、旋流叶片和机械旋转引入旋流;然后介绍了旋流在气化炉中的应用,包括喷嘴旋流和炉膛旋流2种,并结合具体结构展示了旋流的作用,主要有增强混合和便于排渣;最后对旋流在气化炉中的应用进行了总结和展望。     

多喷嘴对置式气化炉中飞灰性质

On a laboratory scale opposed multi-burner gasifier (OMBG), the fly ashes at different sampling mouths are collected and analyzed by SEM, EDS, XRF and Malvern mastersizer. Most fly ash particles produced in the gasification are irregular, aggregate or spherical. As for the composition of the particles, carbon is the main content, while S, Fe and Na get enriched. At the same time, the concentration of Al and Si in the fly ash particles is lower than that in the original slag. From the nozzle plane to the exit of gasification chamber, the carbon content of particles decreases along the axes of gasifier. The carbon content of particles decreases rapidly from the nozzle plane to No. 7 sampling mouth and declines slowly from No. 7 sampling mouth to the chamber exit. The size of particles generated in the gasification appears a triple-humped-distribution with peaks at 0.1—0.2 μm, 2 μm and 14 μm. The particle size distribution in different sampling places is different. Above the impact plane, more ultra-fine particles are found and coarse particles are larger in location near the impact plane. In symmetrical up and down locations of the impact plane, the particle size distributions are similar, but there are more coarse particles below the impact plane. The coarse particle size decreases and the proportion of fine particles increases below the impact plane, while the proportion of coarse particles increases at the chamber exit.     

Numerical simulation of coal gasification in entrained flow coal gasifier

This paper presents modeling of a coal gasification reaction, and prediction of gasification performance for an entrained flow coal gasifier. The purposes of this study are to develop an evaluation technique for design and performance optimization of coal gasifiers using a numerical simulation technique, and to confirm the validity of the model. The coal gasification model suggested in this paper is composed of a pyrolysis model, char gasification model, and gas phase reaction model. A numerical simulation with the coal gasification model is performed on the CRIEPI 2 tons/day (T/D) research scale coal gasifier. Influence of the air ratio on gasification performance, such as a per pass carbon conversion efficiency, amount of product char, a heating value of the product gas, and cold gas efficiency is presented with regard to the 2 T/D gasifier. Gas temperature distribution and product gas composition are also presented. A comparison between the calculation and experimental data shows that most features of the gasification performance were identified accurately by the numerical simulation, confirming the validity of the current model.     

Modeling and simulation of an entrained flow coal gasifier

A mathematical model has been developed to simulate the Texaco downflow entrained-bed pilot-plant gasifier using coal liquefaction residues and coal-water slurries as feedstocks. This model describes the physical and chemical processes occurring in an entrained coal gasifier. The gasification kinetics describes different complex reactions occurring in the gasifier and the hydrodynamics describes mass, momentum and energy balances for solid and gas phases. Temperature, concentration and velocity profiles along the reactor height were obtained by solving the mass, momentum and energy balances. Parameter studies were made to provide a better understanding of the reactor performance for various inlet feed conditions utilizing the model.     

多喷嘴对置式水煤浆气化装置的优化与运行

兖矿国泰化工有限公司多喷嘴对置式水煤浆气化装置于2005年7月23日一次化工投料成功,现处于良好的运行状态,工艺指标先进,系统运行安全稳定,操作控制手段先进灵活。本文介绍了在该气化装置上关于气化炉带压连投、预热口封堵砖、工艺烧嘴头部的保护、振动筛换型、过滤机换型等方面所进行的优化和改进。