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Experiments on filtration combustion of car tires mixed with a solid coolant are carried out. The mass content of tire particles in a mixture varies from 10 to 70%. Particles of chemically inert sapphire (Al2O3) and sulfur-absorbing marble (CaCO3) are used as a heat carrier. Optimal conditions for the filtration combustion of car tires are determined (the tire content in a mixture is 50%, combustion temperature is approximately 1000°C, the mass burning rate is 0.40 kg/m3 of supplied air). It is established that the replacement of a solid inert coolant with marble has practically no effect on the combustion temperature. In this case, the composition of combustion products changes: the CO2 content in gaseous products increases (their combustion heat decreases from approximately 2.5 to 2.2 MJ/m3), the yield of liquid pyrolysis products decreases approximately from 45 to 40%, and the sulfur content in solid combustion products increases from 28 to 40%. [ABSTRACT FROM AUTHOR]

Using ANSYS Fluent software, numerical simulation has been conducted for flow and burning processes in combustion chambers of gas-turbine power plants designed to recover oil-associated (casing-head) gas. The working process equations are considered in the Euler approach. The system of partial differential equations describing a threedimensional burning turbulent flow contains the laws of conservation of total mass, the mass of separate combustion product components, the combustion product momentum, the combustion product energy, the law of conservation of fuel composition elements, mixture fraction, turbulence kinetic energy. and dissipation of turbulence kinetic energy. The introduction of mixture fraction simplifies substantially the solution of the problem of turbulent mixing of the oxidizing agent and the fuel. Scalar quantities (density, temperature, and mass concentrations of components) are determined using the probability density function in accounting for the final chemical reaction rate of an unpremixed mixture. The flow velocity field is calculated using the "realizable" k–ε turbulence model. The results have been obtained for different schemes of component supply into the combustion chamber. A comparison of calculated and experimental data is given. [ABSTRACT FROM AUTHOR]

An analytical study has been made of the operating processes of burning of natural gas in the furnace of a steam water-tube boiler. The authors have determined the fields of the combustion-product temperature and of the heat-flux density in the furnace volume, and also the thermodynamic parameters of the reaction of combustion of methane and the enthalpy and entropy change of combustion products in the furnace with a secondary radiator and without it. The distribution of the entropy fields has been given and the regions of high entropy production near heat-transfer surfaces during the heat exchange of combustion products have been determined. To obtain optimum results, the authors used the model of minimum entropy generation in the thermodynamic system. An exergy analysis has been made of the operating processes of the chemical reactions of combustion and heat exchange of the combustion products with the tubular surfaces of the steam boiler. The influence of structural and regime parameters of the boiler furnace on the exergy loss has been shown. [ABSTRACT FROM AUTHOR]

Combustion of vapors of a flammable liquid whose temperature is below the flash point is under study. In this case, the flame propagates along the surface of the liquid due to being heated by combustion products. The velocities of an oxidizer moving towards the flame, which propagates at velocities comparable to the laminar burning rate of premixed hydrocarbon flames, are measured. The measurements show that the gas flow is laminar. There is a correlation established between the flash point of a flammable liquid and the flame propagation velocity. On the basis of the data obtained, it is assumed that the main mechanism of formation of a flammable mixture ahead of the combustion front is a diffusion mechanism. [ABSTRACT FROM AUTHOR]

This paper describes the experimental study of amplitude (with a frequency of up to 50 kHz) and integral characteristics of the self-magnetic field of high-temperature combustion products of hydrocarbon fuel, which flow out of the nozzle of a standard liquid-propellant engine (LPE) with simulation of the heat of a combustion chamber with injection of aluminum-magnesium alloy particles (c-phase) into the combustion chamber. It is determined that the amplitude of the magnetic field intensity generated by high-temperature (up to 3500 K) combustion products depends on the LPE operation modes and the presence of k phase particles in the particle flow. The magnetic field amplitude increases by 20% during the LPE burnout ≈0.2 s earlier than the pressure drop in the combustion chamber. The total volumetric electric charge generated by the combustion product flow with the c-phase is estimated. [ABSTRACT FROM AUTHOR]