Coal powder is mainly used to offer heat for wood chip dryer. In order to accelerate the burning process of coal powder, the convective heat transfer should be intensified by reasonably arranging the air flow in furnace. The coal powder with qualified size should be prepared in advance. For coal powder with low volatile content, the primary air ...
Reduced iron powder under heat treatment improved the desulfurization effect. ... As the particle size of the coal powder was more acceptable, the larger contact area between the sulfur in the coal and the reduced iron powder improved the efficiency of the reaction Liu et al., 2020. A 2PLF70100 crusher first crushed 50 kg of raw coal, and a ...
Phase change materials (PCMs) provide a good resolution for the latent heat storage system which can be used in many application fields such as solar energy utilization and waste heat recovery. This study presents an experimental investigation on the heat transfer performance of paraffin with ceresin (PC) and influence of graphite powder on the thermal characteristics of PC.
Ž . Powder Technology 102 1999 266273 Radiative heat transfer in a circulating fluidized bed coal combustor Gui Young Han a, ), Yong Jun Cho b a Department of Chemical Engineering, Sungkyunkwan Uni Õ ersity, Suwon, South Korea b Samsung Hea Õ y Industries, Taejon, South Korea Received 23 February 1998; received in revised form 18 September 1998; accepted 15 October 1998 Abstract In ...
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.
The interaction between the optical thickness and the radiation pulsation of pulverized coal particles during the combustion process is studied to learn the influences of turbulent particle combustion on radiative heat transfer.
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.
The spontaneous combustion of coal powder involves complex heat transfer, mass transfer, and physicochemical reactions, which can be influenced by coal properties, ambient temperature, ... the oxygeninduced heat release of coal powder can be inhibited, which is not enough to make up for the increase of heat dissipation induced by temperature ...
Coal powder is held in a large container. The thickness of the coal powder layer is L = 2 m. The effective thermal conductivity of the coal powder is k = W/mK. The heat transfer coefficient between the upper surface of the powder (at x = L) and the surrounding air is h= 5 W/m2K. The surrounding air is at Tamb = 20ºC.
A 3D grid model was established and the Discrete Particle Model (DPM) was employed to simulate the gassolid twophase flow and heat transfer behaviors in the riser. The results demonstrate that the gassolid flow within the circulating fluidized bed (CFB) heat exchanger is capable of achieving rapid heat transfer. The gas was effectively ...
The heat produced by the interaction between alternating electromagnetic field and polar molecules will increase rapidly when the coal seam was heated by MI. Due to the water molecules' strong ability of absorbing microwave energy, MI heating can effectively dry coalbed and remove the water lock damage provided by hydraulic fracturing fluid ...
The reason may be that the sintered coppered powder itself was favorable heat transfer carrier to show better heat transfer performance [27]. 5. Conclusions. In this paper, multiscale composite copper powders were developed via the sinteringalloyingdealloying method. Nanostructures could be formed on the porous sintered copper powders, and ...
The 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 operating variables are presented ...
However, the hightemperature exhaust gas contains a large amount of coal ash particles and corrosive impurities, which makes them easy to deposit scale on the surface of the metal heat exchanger to block the pipeline, reduce heat exchange efficiency [ 1, 2 ], and in addition, the fly ash particles in the flue gas to the heat exchange tube bundl...
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Computational particle fluid dynamics (CPFD) simulation was performed to study coal pyrolysis in a circulating fluidized bed 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 of the cluster, was incorporated into the CPFD model, which shows acceptable ...
Reliable feeding of pulverized coal into the entrainedflow gasifier is of great importance for the gasification process because powder feeding properties can affect the gasification performance index and the final product quality directly. With the background of the industrial demonstration of SE gasification technology, this paper focuses on its densefeeding system which consists of the ...
In order to explore the heat transfer mechanism during the coal combustion process in the fluidized bed, comprehensive thermochemical submodels are needed to be integrated with the CFDDEM. The heat transfer submodel consists of conduction, convection, radiation, and heat of reaction, while the chemical reaction submodel involves the fuel ...
Pulverized Coal Combustion. PCC technology is a widely utilized technology to generate energy from fossil fuel, especially coal [15]. In this technology, pulverized coal is injected to combust in a furnace in the presence of a controlled level of air. The heat generated is used to produce highpressure steam driving a steam turbine to ...
Combi ovens in the convection mode, the oven circulates dry heat. The steam mode injects water into the oven to keep the food moist. SOUS VIDE In sous vide cooking food is vacuum sealed in a plastic bag and then cooked in water that is a specific temperature. Heat is transferred from the water to food via conduction.
The coal is pulverized to a fine powder, usually so that 70% is less than about 75 μm in size, before being carried by part of the combustion air stream to the burners. ... High temperature heat transfer: furnace performance assessment, First Heat Transfer Conf., Leeds. Dryden, L. G. C. Ed. (1975) The Efficient Use of Energy, Press ...
Introduction. Dense gassolid reacting flow is widely practised in many chemical engineering processes, such as gasification and combustion of solid fuel (, coal or biomass), chemical looping combustion, and solid waste thermochemical conversions of solid fuel involve complex multiphase flow, intensive heat and mass transfer, and complicated chemical reactions, posing a ...
Introduction. Fly ash (FA), also known as pulverized fuel ash, is a fine powder obtained from the combustion of powdered coal in an electricity generating plant. Temperature may exceed 1600°C during the burning process and may melt most of the inorganic materials present in the coal.
This transfer has also been the subject of several publications. Chang et al. [100] presented a computational study of heat transfer, with emphasis on the direct particletoparticle heat transfer between different classes of particles in a dense gassolid fluidized bed of binary particles using the computational fluid dynamics (CFD) method ...
Therefore, after adding pulverized coal, the heat transfer coefficient increased. However, the larger the coaltoair ratio, the temperature rise of the aircoal mixture was lower, so the heat transfer efficiency gradually decreased. ... Powder Technol, 361 (2020), pp. 782790. View PDF View article View in Scopus Google Scholar [16]
The feasibility of using carbon dioxide (CO 2) as a heat transfer fluid by organic Rankine cycle (ORC) in enhanced geothermal systems (EGS) in arid regions is explored in this paper. As CO 2 is available for sequestration at high pressures from an Integrated Gasification Combined Cycle (IGCC) plant, this idea is examined by pairing an IGCC plant with an EGS plant to facilitate both the ...
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