WEBJul 1, 2021 · The thermal diffusion in coal and gas obeys the conservation of energy theory during coal combustion. A heat transfer model was established and the schematic diagram of the model is shown in Fig. 2. The open cyclic calorimeter with circulating water consisted of a combustion system, two cylinders and a laser.
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WEBOct 25, 2022 · Reaction heat release and variations in fluid composition within the thermal boundary layer lead to a slight enhancement of heat transfer. This work reveals and quantifies the main mechanisms affecting the exchanges between a reacting coal particle and surrounding supercritical water regarding both thermal and chemical aspects.
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WEBJun 15, 2007 · Modeling of a natural circulation boiler for a coalfired thermal power station is presented here. The boiler system is divided into seven subcomponents, and for each section, models based on conservation of mass, momentum, and energy are formulated. The pressure drop at various sections and the heat transfer coefficients are computed .
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WEBDec 9, 2023 · In the fluidized bed, coal gas from the final reduction furnace is cooled by a cooler with water as medium. With ore powder heated and reduced, the coal gas is injected into horizontal final reduction furnace. At the same time, the heat of cooling gas is recovered in the form of high compressed steam.
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WEBApr 1, 2022 · The heat and gas transfer characteristics of coal seam under MI heating is analyzed. What's more, the impacts of key parameters on gas production, ... Microwave irradiation on pore morphology of coal powder. Fuel, Volume 227, 2018, pp. 434447.
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WEBAug 1, 2021 · The comprehensive results show that the intense heat transfer concentrate in a rather small region after the mixing of hot air and pulverized coal. The gassolid mixed temperature decrease 100°C ...
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WEBEnergy generation. For use in thermal power plants, coal is ground into dust using a device called a powdered coal mill. The resulting product, called powdered coal or pulverized coal, is then generally used in a fossil fuel power plant for electricity coal is a significant dust explosion hazard, as large quantities are suspended in air for .
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WEBFeb 1, 2013 · 1. Introduction. Coal is an abundant fossil energy resource, and represents about 70% of the world's proven fossil fuel resources. Today 23% of the world's primary energy comes from coal, about 36% of the world's electricity is produced using coal and the energy for the production of 70% of the world's steel is provided by coal [1].The negative .
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WEBJun 29, 2022 · The corresponding views of the coal core are shown beneath each contour. Fig. 5 depicts the electric field intensity along the vertical central line. As. Conclusions. A coupled electromagnetic, multiphase heat and mass transfer model was established for the sensitivity analysis of the microwave heating of moist coal.
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WEBJul 1, 2015 · LES and RANS of air and oxycoal combustion in a pilotscale facility: Predictions of radiative heat transfer ... coupled with the discrete element method is utilized to investigate the flow behavior of a coaxial jet composed of powder and coal within an annular pipe. The influence of particle diameter on particlescale information is .
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WEBJul 15, 2017 · The spontaneous combustion of coal powder involves complex heat transfer, mass transfer, and physicochemical reactions, which can be influenced by coal properties, ambient temperature, deposition thickness, and other factors [19–21]. Therefore, methods including the thermal analysis of hot plates, have probed the spontaneous .
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WEBFeb 1, 2013 · Two different models are proposed for the unclosed terms in the gasphase PDF transport equation due to the mass transfer from the solid to the gas phase through devolatilization and char combustion.
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WEBDOI: / Corpus ID: ; Intensifiion of hydrodynamics and heat transfer characteristics of coalchargas flow in a high solidsflux downer with swirling blade nozzle
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WEBDec 3, 1997 · The coal powder was continuously fed into the bed, in which alyst particles were fluidized. ... Heat transfer rate is improved in MSFB by increased heat capacity and interparticle convective heat transfer, whilst enhanced gassolid contact in MSFB leads to the improved mass transfer efficiency. Correlations for mass and heat .
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WEBJan 1, 2016 · As shown in Fig. 2, the heat transfer mechanisms in rotary kilns are very complex, which include conduction, convection, and processes will usually appear under actual operating conditions: radiation and convection between the bulk gas and the exposed particle bed (Q g–eb), radiation and convection between the gas and .
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WEBAug 1, 2022 · Using Geldart A group magnetite particles with a size range of 45–75 μm, Choung et al. [26] formed a stable fluidized bed in a small column of 4 cm in diameter and realized a coal separation of – mm. Mohanta et al. [19] also used smaller magnetite powder (mean particle sizes of 33 μm and 53 μm) for coal separation in the GFBCB but ...
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WEBDec 1, 2010 · Heat transfer, coal reactivity and emissions differ in oxyfuel combustion compared to air because of differences in combustion conditions resulting from reduced volumetric flue gas flow, enhanced oxygen levels and the presence of recycled flue gas. ... Powder Coal Combustion Projects Final Report, ISBN, 1997. Google .
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WEBDec 1, 2023 · The heat transfer in fluidized beds has an important part of many investigations in the past. It usually includes several subprocesses: heat transfer between solid particles and gas, heat transfer between the bed and the surfaces (walls or immersed surfaces), and heat transfer inside the solid particles [29,30].
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WEBDec 15, 2010 · Weiping Yan, Xining Yu. A novel method for analyzing the heating of coal particles in a coal powderladen jet in the nearburner region is proposed. This method takes into account both the time delay due to coal particle unsteady heating and the induction period needed for the coal particle to ignite from the practical engineering .
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WEBJun 21, 2017 · The moisture content of coal (MCC) has an important effect on the thermophysical properties and the granular flowability. However, it brings both active and negative influence to the heat transfer between the fluidizing moist coal and the immersed tubes in the fluidized bed. Four groups of bituminous coal with same size distribution .
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WEBThe erosion characteristics of circular heat transfer tubes in the backpass of coal fired boilers due to fly ash are addressed in this paper. Aerodynamic flow field, eroding particle, and heat exchanger tubing variables were investigated. Experimental results from a test facility designed to test tubes at actual boiler backpass conditions over a wide range of .
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WEBJul 1, 2019 · Densephase pneumatic conveying of pulverized coal experiments with superficial gas velocity ranged from m s −1 to m s −1 were carried out on the selfestablished 50 mm industrial pipe facility. The fluctuations of pressure, solid velocity, solid concentration and the average crosssection concentration were analyzed in terms .
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WEBDec 1, 2023 · After undergoing gassolid heat transfer, the hightemperature coal gas is obtained. Subsequently, the particles are introduced into the particle heater and heated by the combustion of blast furnace gas. The present study focuses primarily on investigating the gassolid flow and heat transfer in the riser. ... Adv. Powder Technol., 30 (2019 ...
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WEBComputational Particle Fluid Dynamics (CPFD) simulation was performed to study coal pyrolysis in a Circulating Fluidized Bed (CFB) downer containing binary particles (coal particles and heat carrier particles). A suitable drag model, which considers the cluster effect by assuming dynamic equilibrium for particles in and out cluster, was incorporated .
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WEBJan 1, 2009 · For instance, as the HP inserted scale is 1:4, outside air velocity is m/s, the maximum heat transfer radius in the coal stockpile is cm, the overall heat transfer effect enhanced by 79% ...
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WEBAug 1, 2021 · Agarawal et al. [8] differentiated coal powder into ten size groups, divided the bowl mill into four zones, and developed a unified model. Palizban et al. [9] derived nonlinear differential mass equations of raw coal, recirculation coal and suspension coal in coal mills. ... However, both types of models ignore the effect of the heat transfer ...
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