The Combustion Characteristics Of A Single Pulverized Coal Particles In The Presence Of Acoustic Fields

With the rapid development of the global economy,the human demand for all kinds of energy is increasing.However,resources such as coal and natural gas in the world are gradually decreasing,and coal is an important part of the world's primary energy so far.How to improve the combustion efficiency of pulverized coal in power stations has become an important research topic.The value of Pulverized coal combustion efficiency depends on the material composition,ambient air oxygen content and pulverized coal particle temperature and many other factors.When the sound waves spread in the air,the medium air will produce reciprocating vibration to form a vibrating air flow,which directly leads to the pulverized coal particles with the outside air contact,the gas diffusion rate of the reaction and heat transfer efficiency are not same as when there is no sound field.Based on the effect of acoustic waves on the gas around the solid pulverized coal particles,this paper established physical model.The theoretical simulation of combustion of single pulverized coal particles under the condition of sound wave is discussed.On the existing conclusion of increasing the intensity of acoustic wave can increase the average Nusselt number of particle surface,it can be got that the increasing of acoustic intensity can increase the mass diffusivity of gas phase through the comparison of heat transfer and mass transfer.Finally,by using the theoretical model of single-particle carbon reaction,the combustion process of non-porous pure carbon particles in the air was simulated and the influence of the diffusion rate of the gaseous phase on the combustion of the carbon particles was obtained.It was concluded that increasing the acoustic intensity can improve the combustion of pulverized coal.The conclusion can provide theoretical basis for strengthening pulverized coal combustion in power plants.