Modeling Of Coal Combustion Near The Wall And Studying Of Burning Characteristics In The Liquid-bath Combustor

For the high price and big consumption of oil in oil-fired furnaces and severe environment pollution of dust, NO_x, SO_x, etc. emitted from coal-fired furnaces, the clean coal technology with high combustion efficiency, low pollution and oil consumption is required urgently in industrious furnace or kilns of China. During the "Eleven-five" period, the Chinese government is planned to put forward the continuable energy development stratagem that aimed at "Preference of Energy Conversion, Supply Ensurence, Structure Diversity of Energy Consumption, Environment Suitability", the researches and developments on coal clean technologies and the methods of "Substitution the coal for oil". So the studies in this dissertation have the great value of development and application.The Pulverized Coal Low Dust Combustion Technology based on liquid-bath way has some good advantages in the case of increasing combustion efficiency, decreasing the dust concentration, controlling the emission of SO_x and NO_x. During the "Nine-five" period, this technology has been studied by cold model experiment and primitive pilot-plant test with 200kg/h coal feed rate. The results show that the technology has well value of development and application. In recent researches, the initial pilot-scale investment is so high and the test method under high temperature is so incomplete that makes it difficult for us to develop the combustion technology further only by experimental means. Therefore, the numerical method was adopted in this dissertation, which was used to study some theoretical models and burning characteristics in the liquid-bath combustor.Conventional simulation method of coal combustion in STAR-CD platform was used to analyze the burning characteristics of combustor firstly in this dissertation. In addition to selecting several proper models for gaseous flow, solid phase flow, coal combustion and NO_x emission, the movement of coal particles near the wall was discussed by approximate method of factitious setup for wall boundary condition. Furthermore, the two-phase flow and combustion characteristics in the combustor were analyzed in detail and the predicted temperature and NO_x concentration were compared with the experimental data from the combustor. Based on the experimental...