新型煤气化炉内温度场影响因素研究

采用电热还原的方法将固体煤转化为可燃气体（煤气），为煤的气化提供了一条新思路．通过研究煤新型气化炉内温度场的成因以及各因素对温度场的影响，获取了不同高度空间温度场的主控因素．实验结果表明，气化功率、煤的种类、集气罩材料和排气速率等对气化炉内温度场均有较大影响；气化炉内的炉表近区域温度场主要由辐射场控制，集气罩近区域温度场受对流场控制．研究成果为煤新型气化温度场控制和气化炉经济密封高度的选择提供了依据．     

Texaco气化炉流场特性的模拟计算

采用CFD软件对Texaco气化炉进行建模,计算不同工况条件下的冷态流场特性,讨论了气体入口流速对流场影响的规律。模拟结果表明,Texaco气化炉燃烧室内存在射流区、管流区、回流区,回流区是影响气化炉内流场的主要因素,其面积随着入口速度增加而增大,而管流区面积随入口速度增加而减小;在径向流速分布图中,回流区气体流速具有明显拐点,管流区气体流速无明显拐点。     

渣油气化炉工艺分析

提出了对渣油气化炉气化结果进行分析计算的方法，建议以有效气产出率作为评价渣油气化炉气化结果的主要指标，该指标考虑了油品对有效气产率的影响，更据客观性。以此为基础，对国内５个采用不同气化压力厂家的渣油气化炉操作数据以及目前国外专利商的报价数据进行了分析。对国内不同厂家的操作结果分析表明，气化反应离平衡较远，有继续改进提高的可能；而对国外报价数据的分析则表明，不同专利商的报价数据均以平衡计算结果为依据，在实际操作中将无法达到。气化炉工艺条件的选择必须紧紧围绕气化温度这一中心，因此还计算了氧油比、蒸汽油比、气化炉热损失及原料预热等因素对气化炉出口温度的影响，探讨了气化炉工艺条件的选择     

顶置单喷嘴气化炉旋流场特征研究

受限旋转射流流场特征的研究对顶置单喷嘴气化炉的开发、结构优化以及长周期稳定运行有重要意义。本文对不同旋流数下顶置单喷嘴气化炉内的速度场和停留时间分布进行了实验研究。结果表明：随着旋流数的增加,切向旋转速度显著增加,气化炉内轴向速度衰减加快,回流区减小;气量一定时,随着旋流数的增加,气化炉内气体的最短停留时间显著增加,停留时间标准差减小。     

喷嘴入口位置对气化炉流场影响的实验研究

为了考察气化炉炉侧喷嘴入口位置对炉内流场和颗粒浓度分布的影响规律,在新型水煤浆气化炉冷模三维实验台上进行了大量的实验研究,并与数值模拟计算结果进行了对比,结果表明,当喷嘴距气化炉顶部0.9 m时,气化炉炉内流场分布最合理,颗粒浓度分布最均匀;实验测试结果和数值模拟计算结果非常接近,进一步验证了数值模拟计算结果的准确性.实验测试结果为气化炉的设计和运行提供了参考.     

FLUENT技术在工业管道设计中的应用

运用FLUENT流体动力学仿真软件对改进的三通管道进行了湍流模拟，得出了管中流场的压力场及速度场的分布图，计算结果验证了设计的合理性，可有效地避免回流现象，为工业管道设计与加工提供了科学依据，结果表明这种三通可以有效优化流场。     

射流速度对多喷嘴干粉气化炉内反应流动的影响

建立了描述气化炉内流动和反应的综合数学模型,对安徽科达洁能股份有限公司(以下简称"科达洁能")研制的旋流撞击式干粉气化炉进行了模拟计算,分析了不同气化剂射流速度对气化炉内流场和温度分布的影响。结果表明,提高气化剂射流速度能有效改善气化炉内的气固混合情况,回流区域变大,炉内整体温度水平上升,出口有效气组分提高;同时,射流速度的提高也导致气流冲击气化炉拱顶的速度变大,出口煤气的温度上升,对下游处理设备的要求提高。因此,应根据工艺要求,合理选择喷嘴气化剂的射流速度。     

水煤浆气化炉的形式和新型气化炉的开发

对目前世界上3种主要的气化炉--德士古(Texaco)水煤浆气化炉、道(Dow)水煤浆气化炉和多喷嘴对置式水煤浆气化炉,从工艺流程到气化炉内流场结构都进行了比较说明,同时分析了各种气化炉的优缺点,在此基础上,结合各种气化炉的优点,自行开发设计了一种新型水煤浆气化炉.后期的冷态和热态数值模拟计算以及实验测试结果表明,该气化炉具有流场分布合理、颗粒平均停留时间长、出口粗煤气有效气成分高等优点.     

科林炉停车概述

粉煤气化炉停车过程中涉及到的步序和注意事项繁多，不同炉型之间的停车步序也各不相同且不同操作人员的操作手法也存在差异，这使得气化炉整个停车过程存在优化空间。介绍科林气化炉停车过程中减负荷、退气、烧嘴停车、保压置换，降温和泄压等主要步骤和注意事项，在保障整个系统负荷、压力稳定和操作安全的前提下，通过操作人员在各个环节的人为干预，有效减少了气化炉停车过程中对前、后系统造成的波动，加快了停车置换、降温所需的时间，为气化炉停车检修进度节约了时间成本，也为气化炉下次开车投料时的工况稳定奠定了基础。     

浅谈壳牌气化炉内流场特征及其影响因素

介绍了壳牌气化炉内的流场特征;分析了影响壳牌气化炉内流场稳定的因素及流场波动造成的危害。     

Markov chain model of residence time distribution in a new type entrained-flow gasifier

A continuous-time Markov chain has been used to establish the residence time distribution (RTD) model in a new type entrained-flow gasifier, which is called entrained-flow gasifier with opposed multi-burner. According to the measurement results of the flow fields in the gasifier, the state transfer diagram of Markov chain formed in the case of the flow fields are simplified. The results show that this method is feasible in modeling the flow system which consists of ideal mixing cells and plug flow regions. The flow pattern of the gasifier is closed to continuous stirred tank reactor (CSTR). The simulation results are in good agreement with the experimental data. The established model has been applied to forecast the RTD in the industrial gasifier.     

A mathematical model of a spouted bed gasifier

A mathematical model of the spouted bed gasifier has been constructed based on simplified first order reaction kinetics for the gasification reactions and the stream tube hydrodynamic model of Mathur and Lim. This two region model treats the spout as an isothermal plug flow reactor with cross flow into a series of streamtubes forming the annulus. Each streamtube is considered as a plug flow reactor. The effects of kinetic and hydrodynamic parameters on model predictions are illustrated, and a comparison made with experimental gas composition profiles obtained in a 0.30-m dia. gasifier.     

Stochastic Modeling of the Particle Residence Time Distribution in an Opposed Multi‐Burner Gasifier

The gasification technology of impinging streams has been extensively applied to chemical production and power generation. Particle residence time distribution (RTD) is an important parameter required for modeling, designing and optimization of an impinging stream gasifier. A stochastic mathematical model based on the Markov chains model is developed for the opposed multi‐burner gasifier (OMBG), which closely describes the behavior of the flow pattern and particle RTD in the gasification system. The model simulates the motion of single particle moving in the gasifier using the Markov chains. The predicted results give a reasonable fit to the experimental data. This shows that the flow process of particles in the gasifier has recirculation eddies, which have a downward flow direction near the downflow core and an upward flow direction near the wall, but no short‐circuit. Finally, the effect of particle flux rate on the RTD is predicted, and the contrast between gas and particles RTDs at a laboratory scale and in an industrial gasifier are presented.     

应用炉膛压力诊断气流床气化炉的火焰状态

气化炉是煤气化技术中的关键设备 .气化炉内火焰燃烧稳定性下降 ,会出现燃烧噪音增加、气化燃烧效率降低及熄火等现象 ,对安全性和经济性产生严重的影响 .对气流床气化炉内不同气化燃烧状态下的火焰压力信号进行了小波分析 .结果表明 ,压力信号在一定频段内的分布与气化炉内火焰燃烧的状态密切相关 ,发现随着火焰燃烧稳定性加强 ,气化炉内压力信号向高频方向移动 ,以此可以建立气流床气化炉燃烧诊断模型 .     

MATHEMATICAL MODELLING OF A ROTARY SWIRL CYCLONE SCRUBBER

A Rotary Swirl Cyclone Scrubber (RSCS) is a device designed to remove SO₂ and ash from the combustion products of an entrained-flow gasifier. It uses a combination of highly swirling flow and water sprays to produce high heat and mass transfer rates. In order to develop a better understanding of the operation of this device, modelling has been performed using an extended version of CFX-F3D. Simulations have been performed to examine the flowfield in the device and to determine SO₂ and ash capture efficiencies. The simulations show that the water jets used to remove the SO₂ from the gas completely change the direction or swirl in the device, resulting in a highly turbulent flow. The experimental SO₂ capture efficiency and the outlet temperature are well reproduced using a water droplet size of 60 μm, with this value being determined via fitting to a particular experiment. Predictions of ash particle capture are found to be in good agreement with the experimental data.     

Opposed multi-burner gasification technology:Recent process of fundamental research and industrial application

Opposed multi-burner (OMB) gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights.It has been widely used around the world,involving synthetic ammonia,methanol,ethylene glycol,coal liquefaction,hydrogen production and other fields.This paper summarizes the research and development process of OMB gasi-fication technology from the perspective of the cold model experiment and process simulation,pilot-scale study and industrial demonstration.The latest progress of fundamental research in nozzle atomiza-tion and dispersion,mixing enhancement of impinging flow,multiscale reaction of different carbona-ceous feedstocks,spectral characteristic of impinging flame and particle characteristics inside gasifier,and comprehensive gasification model are reviewed.The latest industrial application progress of ultra-large-scale OMB gasifier and radiant syngas cooler (RSC) combined with quenching chamber OMB gasifier are introduced,and the prospects for the future technical development are proposed as well.     

气流床煤气化炉壁面反应模型

建立了气流床煤气化炉煤灰渣颗粒沉积和壁面反应模型,相应完善了渣层流动、传热传质和相变模型,发展了数值模拟方法,并以国内某型两段式干煤粉加压气流床煤气化中试炉为对象进行了模拟。利用建立的模型可以得到壁面反应速率、渣层含碳量、固态渣层厚度、液态渣层厚度、渣层平均温度和液态渣层平均速度等。结果表明:氧煤比升高,渣层平均温度升高,固态渣层厚度、液态渣层厚度和气化炉出口灰渣含碳量降低。计算得到的灰渣含碳量在14%左右,整体碳转化率为95.2%左右,与实际值相近。通过模拟发现壁面反应对于所分析气化炉的碳转化率、排渣含碳量、壁面渣层流动和温度状态具有重要影响,进而影响气化炉的安全稳定运行。     

浅谈Shell气化炉温度的控制

论述控制气化炉炉温的重要性,分析气化炉温度控制要点,提出炉温调整的方法.     

EQUILIBRIUM MODELING OF A DOWNDRAFT GASIFIER I—OVERALL GASIFIER

A model, based on the thermodynamic equilibrium of the C-H-O-Inert system and mass and energy balances, has been applied to the air-blown downdraft gasification of wood. The model predicts the temperature, gas composition and char yield at the exit of the gasifier for a specified set of heat loss and input condition. A parametric study has been conducted to simulate the influences of the air/feed mass ratio and moisture/feed mass ratio on the gasifier's performance. The model predictions are compared with a comprehensive set of experimental data obtained from the gasification of wood in a commercial-scale downdraft gasifier; the air/feed ratios range from 1.1 to 2.1 and the moisture/feed ratios range from 0.05 to 0.3. The predicted trends for variations in the operating parameters are in general agreement with the experimental data. The results of comparisons also indicate that the performance of the wood gasifier can be approximated reasonably well by the equilibrium model.