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Particuology 2019年第5期17卷 22-29页

作者： M. Hafizur Rahman Lius Daniel Ujash Shah Xiaotao Bi John R. Grace C.Jim Lim Fluidization Research Centre Department of Chemical & Biological Engineering University of British Columbia 2360 East Mall Vancouver British Columbia V6T1Z3 Canada

Operation of a dual fluidized bed, consisting of a riser as combustor and bubbling bed as gasifier, for synthesis gas production from a solid fuel requires determination of the solids circulation rate and char transfer rate. The performance relies on supplying sufficient heat from the combustor to the gasifier by circulation of solids between these two reactors. The flow rate of char is required to track the heat generated in the combustor, which supports endothermic reactions in the gasifier. Direct measurement of these two critical parameters is difficult, with the number of reported techniques capable of working at high temperatures extremely small. An indirect method was developed, using mass and energy balances over the entire system and individual reactors, to estimate the solids circulation rate and char transfer rate. There was general agreement between heat losses estimated from energy-balance calculations and from direct measurement of the outer reactor surface temperature. Under typical gasification conditions, the solids circulation fluxes were estimated to be 45.2 and 55.6 kg/(m^2 s) in two independent tests, which were in good agreement with values obtained using a thermal tracer;char transfer rates were calculated to be 1.2 and 0.6 kg/h, which were in reasonable agreement with average biomass feed rates. This method can be applied to dual gasification systems at any temperature or flow rate.

关键词： Solids circulation rate Char transfer rate Pilot-plant gasifier Dual fluidized bed Mass and energy balance

Effects of coke charging pattern on burden movement in COREX melter gasifier based on physical simulation

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Journal of Iron and Steel Research International 2022年第6期29卷 907-913页

作者： Li-hao Han Yue-hua Li Li-ning Han Yan-xia Liu Wei-qing Huang Lei Cao Su-ci Qi Xin Guan Jian-lu Yuan Department of Material Engineering Hebei College of Industry and TechnologyShijiazhuang 050091HebeiChina Department of Basic Course Teaching Hebei College of Industry and TechnologyShijiazhuang 050091HebeiChina First Rolling Mill Anyang Iron&Steel Co.Ltd.Anyang 455000HenanChina

A three-dimensional semicircle cold model of COREX melter gasifier(MG)was established,and the effects of coke charging pattern on burden movement were investigated by adopting this *** burden flow pattern of packed bed was measured with different coke charging amounts,coke charging positions,and coke *** results show that the solid flow pattern presents a change from straight line type to reverse U type and finally to W type in MG with traditional coke charging,while the burden flow pattern experiences the change from straight line type to W type with platform and finally W type under center coke charging,and the solid flow pattern presents a change from straight line type to W type with platform and finally W type under intermediate coke *** difference demonstrates that coke charging pattern affects the uniform descending in MG to some *** burden in the coke charging zone keeps a straight line *** matter what kind of coke charging pattern is adopted,the burden residence time is shortened with the increase in coke charging amount,and the vertex of deadman decreases obviously,which is conducive to the renewal of the *** appropriate coke charging amount and coke size should be well controlled at 8.7%and 5 mm,*** results are useful not only in developing further understanding of solid flow in MG but also in verifying different mathematical models,particularly the coupled discrete element method with computational fluid dynamics simulation which has been increasingly used in the literature.

关键词： COREX melter gasifier Coke charging pattern Burden movement Flow pattern Physical simulation

Design and implementation of gasifier flame detection system based on SCNN

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High Technology Letters 2022年第4期28卷 401-410页

作者： WU Jin DAI Wei WANG Yu ZHAO Bo School of Electronic Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121P.R.China

Flame detection is a research hotspot in industrial production,and it has been widely used in various *** on the ignition and combustion video sequence,this paper aims to improve the accuracy and unintuitive detection results of the current flame detection methods of gasifier and industrial boiler.A furnace flame detection model based on support vector machine convolutional neural network(SCNN)is *** algorithm uses the advantages of neural networks in the field of image classification to process flame burning video sequences which needs detailed ***,the support vector machine(SVM)with better small sample classification effect is used to replace the Softmax classification layer of the convolutional neural network(CNN)***,a Dropout layer is introduced to improve the generalization ability of the ***,the area,frequency and other important parameters of the flame image are analyzed and ***,the experimental results show that the flame detection model designed in this paper is more accurate than the CNN model,and the accuracy of the judgment on the flame data set collected in the gasifier furnace reaches 99.53%.After several ignition tests,the furnace flame of the gasifier can be detected in real time.

关键词： support vector machine convolutional neural network(SCNN) support vector machine(SVM) flame detection flame image processing gasifier

CPFD simulation on particle behaviour in an entrained-flow gasifier

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Clean Energy 2020年第1期4卷 75-84页

作者： Yongshi Liang Cliff Y.Guo Xianglong Zhao Qiang Qin Yi Cheng Lixin He National Institute of Clean-and-low-carbon Energy Beijing 102211China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

A computational particle fluid dynamics simulation model for entrained-flow gasification was established in this *** simulation results agree with the experimental *** detailed particle information and residence-time distribution were obtained by injecting particle tracers in the *** results show that the particles in the gasifier can be classified into three flowing zones,i.e.a fast-flowing zone,a recirculation zone and a spreading *** criterion for this classification was also *** rapid gas expansion caused by the fast reactions plays a significant role in forming the particle stream into these three *** accelerates the particles in the centre of the gasifier while pushing the particles near the expansion edge into the gas ***,the concentrated oxygen distribution in the gasifier results in the formation of high-and low-temperature *** particles in the fast-flowing zone flow directly through the high-temperature region and most of these particles in this zone were fully reacted with a short residence *** particles in the recirculation zone are in a relatively low-temperature region,most of these particles are not fully gasified,although with a long residence *** rest of particles in the spreading zone show moderate properties between the above two zones.

关键词： CPFD simulation entrained-flow gasifier particle behaviour gasification process

Study on Microstructure and Slag Corrosion Mechanism of High Chrome Bricks for gasifier

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China's Refractories 2006年第1期15卷 15-20页

作者： XU Yanqing GENG Keming LI Hongxia WANG Jinxiang RUAN Bo CHEN Renpin University of Science and Technology Beijing SinoSteel Luoyang Institute of Refractories Research Tianjin University

Research was focused on slag corrosion mechanism of high chrome bricks used for different types of gasifier by comparing the structure of high chrome bricks for petroleum coke gasifier and water-coal slurry gasifier with slag corroded testing brick and water coal slurry gasifier through Scanning Electron Microscope （SEM） examination and X-ray diffi＇action. Results show that for high chrome brick used for petroleum coke gasifier, corrosion is mainly caused by Cr2O3 in the brick and V2O5 in molten slag and liquid phase generation at low temperature; for high chrome brick used for water-coal slurry gasifier, corrosion is caused by dissolution of Cr2O3 in molten slag and corrosion of ZrO2. For LIRR-HK95 brick, it performs better petroleum coke corrosion resistance than the others due to the optimal composition and structure.

关键词： High chrome brick gasifier Microstructure Corrosion

Design and Development of a Laboratory Scale Biomass gasifier

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Journal of Energy and Power Engineering 2010年第8期4卷 16-23页

作者： S.J. Ojolo J.I. Orisaleye Mechanical Engineering Department University of Lagos Lagos 101017 Nigeria Mechanical Engineering Department Lagos State University Lagos 101017 Nigeria

A laboratory scale downdraft biomass gasifier was designed to deliver a mechanical power of 4 kW and thermal power of about 15 kW. The gasifier was manufactured as a single piece having a water seal and cover. The gasifier was tested in natural downdraft and forced downdraft mode. Ignition of the fuel beneath the grate, during natural downdraft mode, using wood shavings as fuel, produced gas which burned with a blue flame for 15 minutes. Ignition at the throat, using either palm kernel shells or wood shavings, during the natural downdraft mode, the gasifier did not produce syngas. During the forced downdraft mode, fuel was ignited at the throat. Gasification was successful with the palm kernel shells, during forced downdraft, which produced gas which burned steadily with luminous flame for 15 minutes per kilogram of biomass fed. However, wood shavings experienced some bridging problems during the forced downdraft mode of operation. The fuel conversion rate of the gasifier, when using palm kernel shells as fuel in forced downdraft mode, was 4 kg/h. Forced downdraft mode of operation yielded better results and is the preferred operation of the gasifier.

关键词： Biomass gasifier design downdraft energy.

Designing and Performance Evaluation of Biochar Production in a Top-Lit Updraft Up-scaled gasifier

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Journal of Sustainable Bioenergy Systems 2015年第2期5卷 41-55页

作者： Hussein Kisiki Nsamba Sarah E. Hale Gerard Cornelissen Robert Thomas Bachmann Malaysian Institute of Chemical and Bioengineering Technology (MICET) Universiti Kuala Lumpur Kuala Lumpur Malaysia Section of Industrial Chemistry Department of Chemistry Makerere University Kampala Uganda Invention Plus Limited Kampala Uganda Norwegian Geotechnical Institute (NGI) Oslo Norway

The Original Belonio Rice Husk gasifier (OBRHG), initially of height of 0.6 m, diameter of 0.15 m and thickness of 0.025 m was tested for biochar production through air gasification of rice husk (RH) and the design was upscaled to height of 1.65 m, diameter of 0.85 m and thickness of 0.16 m. A total of 27 experiments were conducted to monitor the gasifier performance and the system can operate with the centrifugal blower operating at a power input of 155 W and a maximum flow rate of 1450 m3/hr regulated according to the air requirement. Building the UBRHG is simple and inexpensive to fabricate and with the fairly satisfactory performance and ease of construction along with the convenience of operation, the UBRHG with RH as feed would find abundant avenues of applications in a rural setting for biochar production alongside thermal, mechanical and electrical energy delivery.

关键词： Biochar Equivalence Ratio Yield Upscale Belonio Rice Husk gasifier

Implementation of a Demoisturization and Devolatilization Model in Multi-Phase Simulation of a Hybrid Entrained-Flow and Fluidized Bed Mild gasifier

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International Journal of Clean Coal and Energy 2013年第3期2卷 35-53页

作者： Jobaidur Khan Ting Wang Energy Conversion & Conservation Center University of New Orleans New Orleans USA

A mild gasification process has been implemented to provide an alternative form of clean coal technology called the Integrated Mild Gasification Combined Cycle (IMGCC), which can be utilized to build a new, highly efficient, and compact power plant or to retrofit an existing coal-fired power plant in order to achieve lower emissions and significantly improved thermal efficiency. The core technology of the mild gasification power plant lies on the design of a compact and effective mild gasifier that can produce synthesis gases with high energy volatiles through a hybrid system: utilizing the features of both entrained-flow and fluidized bed gasifiers. To aid in the design of the mild gasifier, a computational model has been implemented to investigate the thermal-flow and gasification process inside this mild gasifier using the commercial CFD (Computational Fluid Dynamics) solver ANSYS/FLUENT. The Eulerian-Eulerian method is employed to model both the primary phase (air) and the secondary phase (coal particles). However, the Eulerian-Eulerian model used in the software does not facilitate any built-in devolatilization model. The objective of this study is therefore to implement a devolatilization model (along with demoisturization) and incorporate it into the existing code. The Navier-Stokes equations and seven species transport equations are solved with three heterogeneous (gas-solid) and two homogeneous (gas-gas) global gasification reactions. Implementation of the complete model starts from adding demoisturization first, then devolatilization, and then adding one chemical equation at a time until finally all reactions are included in the multiphase flow. The result shows that the demoisturization and devolatilization models are successfully incorporated and a large amount of volatiles are preserved as high-energy fuels in the syngas stream without being further cracked or reacted into lighter gases. The overall results are encouraging but require future experimenta

关键词： Multi-Phase Simulation Gasification Simulation Entrained-Flow gasifier Fluidized Bed Mild gasifier Clean Coal Technology

Environmental Impacts (ER CO<sub>2</sub>) of an Improved Multi-Fuel gasifier Forced Air Cookstove in the City of Kinshasa

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Journal of Environmental Protection 2018年第6期9卷 619-635页

作者： Oscar Mulumba Ilunga Hurtado Pérez Elías José Instituto de ingeniería energética Universidad Politécnica de Valencia UPV Valencia Spain Mechanical Department Higher Institution of Applied Techniques ISTA Kinshasa D.R. Congo

Sub-Saharan African countries depend 80% on the biomass-wood to meet their daily needs in terms of cooking foods. Traditional cookstoves are much more used to this effect. Many change programmes for replacing cookstove model have been planned. Yet many of these programmes have not been preceded by environmental impact studies. This work offers high-performance cookstove models and determines their impact on the reduction of CO2 emissions, a very harmful greenhouse gas causing the planet warming and climate change. Replacing the traditional cookstove by an improved stove may lead to an economy in terms of fuel ranging from 33.2% to 75.4% according to the model of cookstoves. Yet the gasifier using pellets as fuel remains the most beneficial stove in terms of fuel saving (75.4%) and in terms of ER CO2, i.e. 2748 t CO2/Year. An improved gasifier cookstove is multi-fuel. He can use charcoal, pellets and wood. This is an indispensable cooking tool with alternative fuels. In this work, the ER CO2 was evaluated using two methods. The KPT, which is a field method and the CCT which is a laboratory method. By the KPT method a gasifier ICS/GAS/P records up to an ERCO2 of 2748 t CO2/Year, while with the same gasifier, an ERCO2 of 2619 t CO2/year is found by the CCT method. The comparison between the two methods shows the same trend but with very high values of ERCO2 for the KPT method results. The variation between the two methods ranges between 1% approximately to 6.9 percent.

关键词： Improved Cookstove Biomass gasifier CO2 Emissions

Analysis and Design Innovation on Underground gasifier for Medium-Deep Coal Seam

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China Oil & Gas 2019年第6期26卷 32-37页

作者： Kong Lingfeng Zhan Enqiang Zhao Chenhui CNPC Planning Department CNPC Offshore Engineering Company Ltd

Over the past 80 years,dozens of underground coal gasification(UCG)mine field tests have been carried out around the ***,in the early days,only a small number of shallow UCG projects in the former Soviet Union achieved commercialised *** this century,a few pilot projects in Australia also achieved short-term small-scale commercialised production using modern UCG ***,the commercialisation of UCG,especially medium-deep UCG projects with good development prospects but difficult underground engineering conditions,has not progressed smoothly around the *** investment economy,a single gasifier must realise a high daily output and accumulated output,as well as hold a long gasification tunnel to control a large number of coal ***,a long gasification tunnel can easily be affected by blockages and failure,for which the remedial solutions are difficult and expensive,which greatly restricts the investment *** design of the underground gasifier determines the success or failure of UCG projects,and it also requires the related petroleum engineering *** the advantages of the linear horizontal well(L-CRIP)and parallel horizontal well(P-CRIP),this paper proposes a new design scheme for an“inclined ladder”underground *** is to say,the combination of the main shaft of paired P-CRIP and multiple branch horizontal well gasification tunnels is adopted to realise the control of a large number of coal resources in a single *** completion of the main shaft by well cementation is beneficial for maintaining the integrity of the main shaft and the stability of the main *** branch horizontal well is used as the gasification tunnel,but the length and number of retracting injection points are limited,effectively reducing the probability of blockage or *** branch horizontal well spacing can be adjusted flexibly to avoid minor faults and large cracks,which is conducive to inc

关键词： Underground Coal Gasification(UCG) Medium-deep Coal Seam Controlled Retracting Injection Point(CRIP) Parallel Horizontal Well Pair Branch Horizontal Well “Inclined Ladder”Underground gasifier Cluster Coiled Tubing Flexible and Combustible Tubing Gasification Tunnel Gasification Chamber Coal-based Syngas