36 research outputs found

    Mathematical modelling of sparkplug ignition of a coal-dust monodisperse suspension in a methane-air mixture

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    The paper provides the numerical simulation of a coal-dust monodisperse suspension sparkplug ignition in a methane-air mixture. The methane-air mixture is not stoichiometric. The aim of the research is a design-theoretical determination of the minimum ignition energy of coal-dust-methane-air mixture (CDMAM) depending on the methane volume fraction. Simulation has shown that the increase of the methane volume fraction leads to the decrease of the CDMAM minimum ignition energy, and with the expansion of coal particles the minimum ignition energy rises

    Effect of coal dust on the air-methane mixture combustion in the Swiss-roll burner

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    The 2-D numerical model has been developed to simulate the combustion of lean coal-methane-air mixture in “Swiss-roll” burner and investigate the effect of coal particles content and mixture feed rate on the stable burner operation. Five homogeneous and three heterogeneous chemical reactions are considered. The Eulerian model for gas phase and the discrete particle model (Lagrangian) for particle phase taking into account the radiation are used in this study. Simulations are performed for the two turns “Swiss roll” burner with heat insulated outer wall, channel width of 6 mm and inner wall thickness of 2 mm. It is shown that the presence of coal particles in a lean methane-air mixture expands the range of stable operation of the "Swiss-roll" burner. It is found that an increase in the content of coal particles reduces the combustion time of the particles by in-creasing the combustion temperature, changes the shape of the reaction zone, and shifts it to the burner inlet

    Numerical investigation on burning stability of the coal-dust methane-air mixture in a recuperative burner

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    The paper is devoted to numerical investigation on combustion singularities of the bi-dispersed coal-dust methane-air mixture in a slot recuperative burner. The aim of the research is to determine the stable combustion conditions of the methane-air mixture depending on the fuel flow rate at the inlet of the burner and on the parameters of the mixture (the particle size and the mass concentration of the coal particles, the percentage composition of inert particles and the methane volume content). The problem was solved by finite difference method. The regimes of stable combustion for the coal-dust methane-air mixture depending on the fuel content and the fuel flow rate at the inlet of the burner the have been defined

    Investigation of the combustion stability of methane-air mixture in recuperative burners of different geometries

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    The results of numerical investigations of 5.5% methane-air combustion stability in heat recuperative burners (counter flow burner, U-shape burner and Swiss-roll burner) are presented in this paper. The investigation is carried out with the use of commercial CFD package Ansys-Fluent. The boundaries of combustion stability of 5.5% methane-air mixture depending on the gas flow rate at the inlet of the burners are determined

    Thermal interaction of biological tissue with nanoparticles heated by laser radiation

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    We explore the problem of thermal interaction of nanoparticles heated by laser radiation with a biological tissue after particle flow entering the cell. The solution of the model equations is obtained numerically under the following assumptions: a single particle is located in a neighborhood exceeding the particle size; the environment surrounding the particle is water with the conventional thermal characteristics. The model equations are deduced from the particle and the environment energy conditions taking into account the heat transfer in the particle and in its environment by conduction. We also assume that at the boundary between the particle and the surrounding water the perfect thermal contact takes place

    Mathematical modelling of sparkplug ignition of a coal-dust monodisperse suspension in a methane-air mixture

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    The paper provides the numerical simulation of a coal-dust monodisperse suspension sparkplug ignition in a methane-air mixture. The methane-air mixture is not stoichiometric. The aim of the research is a design-theoretical determination of the minimum ignition energy of coal-dust-methane-air mixture (CDMAM) depending on the methane volume fraction. Simulation has shown that the increase of the methane volume fraction leads to the decrease of the CDMAM minimum ignition energy, and with the expansion of coal particles the minimum ignition energy rises
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