Influence of the near-surface water film thickness on the characteristics and conditions of water-coal fuel particles inflammation

The results of experimental studies of thermal pretreatment processes complex and inflammation of water coal fuel’s particles (WCF), which surface is covered with water film, have been presented there. The research has been carried out with using of three fuel types (cannel coal, coal B and filter cake): they have essentially different thermo physical characteristics. The results of our studies have been shown that the dynamics of the near-surface water film evaporation and fuel inflammation depends significantly on coal type. It has also been analyzed the influence of water layer thickness on the conditions of WCF particles inflammation. It has been established the time of water film evaporation is about 70% due to the whole induction period

Influence of the near-surface water film thickness on the characteristics and conditions of water-coal fuel particles inflammation

The results of experimental studies of thermal pretreatment processes complex and inflammation of water coal fuel’s particles (WCF), which surface is covered with water film, have been presented there. The research has been carried out with using of three fuel types (cannel coal, coal B and filter cake): they have essentially different thermo physical characteristics. The results of our studies have been shown that the dynamics of the near-surface water film evaporation and fuel inflammation depends significantly on coal type. It has also been analyzed the influence of water layer thickness on the conditions of WCF particles inflammation. It has been established the time of water film evaporation is about 70% due to the whole induction period

Influence of Absorption of Thermal Radiation in the Surface Water Film on the Characteristics and Ignition Conditions

The results of the mathematical modeling of homogeneous particle ignition process of coal-water fuel covered with water film have been presented in article. The set co-occurring physical (inert heating, evaporation of water film) and thermochemical (thermal degradation, inflammation) process have been considered. Heat inside the film has been considered as the model of radiation-conductive heat transfer. Delay times have been determined according to the results of numerical modeling of the ignition. It has been shown that the water film can have a significant impact on performance and the ignition conditions. It has been found that heating main fuel layer occurs in the process of evaporation of water film. For this reason, the next (after the evaporation of the water film) thermal preparation (coal heating, thermal decomposition of the organic part of the fuel) and inflammation occur faster

Mathematical modeling of the electric spark ignition of the coal-water particle fuel under conditions relevant to the internal combustion engines

The results of the mathematical simulation of the coal-water fuel particle in the conditions of electric-spark discharge have been given. It has been found that the CWF particle can ignite even in a relatively low (Tg<500K) ambient temperature. It has been shown that the strength of the current and ambient temperature have a significant effect on the characteristics and conditions of ignition

Influence of a wet wood particle form on the characteristics of its ignition in the high-temperature medium

The results of the experimental and theoretical studies of the processes of the single particles ignition of the wood biomass of various forms (a cube, a cylinder and a sphere) have been presented. According to the results of the experimental studies, it has been established that the particles form can have a fairly significant effect on the characteristics and conditions of ignition. It has been shown that the wood particles in the form of a sphere are ignited much faster than cylindrical and cubic ones (ignition delay times are less by 56%). Such a tendency is maintained for particles sizes from 1 · 10-3?m to 3 · 10-3?m. According to the results of the experiments, the mathematical model for ignition of a particle of wet wood biomass has been formulated, taking into account the joint occurrence of the main processes of the thermal preparation (radiation-convective particle heating, evaporation of water, thermal decomposition of the organic part of the fuel, output, ignition and combustion of gaseous pyrolysis products, ignition of the char residue)

Initiation of Ignition of Highly Fuel Particles in The Flow of High Temperature Medium

An approximate analytical solution of ignition of the fuel porous particles has been brought. The impact of thermal radiation on the characteristics and conditions of the ignition has been considered. The verification of the solution has been obtained by comparing the calculated characteristics (delay time of ignition and the ignition temperature) with similar values obtained using the previously derived formulas

Terms and Characteristics of Homogeneous Ignition of Coal-Water Particles Coated with a Water Film

The problem of coal-water fuel ignition of particles in a high-temperature heating has been solved numericallyin the framework of a two-layer model of "coal-water". The basic characteristics of the integrated ignition has been shown. The influence of the vaporization process of the water film on the ignition conditions has been shown

Effect of structural heterogeneity water-coal fuel conditions and characteristics of ignition

The problem of the particle ignition of coal-water fuel (CWF) with a joint course of the main processes of a thermal (thermal conductivity, evaporation, filtration heat and mass transfer, thermal decomposition of the organic part) has been solved. According to the results of numerical simulation ways of describing the extent of the influence of the thermophysical properties on the characteristics and conditions of ignition WCF have been set

Influence of the near-surface water film thickness on the characteristics and conditions of water-coal fuel particles inflammation

The results of experimental studies of thermal pretreatment processes complex and inflammation of water coal fuel’s particles (WCF), which surface is covered with water film, have been presented there. The research has been carried out with using of three fuel types (cannel coal, coal B and filter cake): they have essentially different thermo physical characteristics. The results of our studies have been shown that the dynamics of the near-surface water film evaporation and fuel inflammation depends significantly on coal type. It has also been analyzed the influence of water layer thickness on the conditions of WCF particles inflammation. It has been established the time of water film evaporation is about 70% due to the whole induction period