TWO-DIMENSIONAL MODEL OF THE SOLID FUEL GASIFICATION IN A FIXED BED UNDER PRESSER. 1. INVESTIGATION OF SHUBARKOL COAL CONVERSION IN A STEAM-OXYGEN MIXTURE WITH THE MASS PART OF H2О/O2=45/55
A non-stationary model of the steam-oxygen gasification of solid fuel in a fixed bed under pressure has been developed with allowance for the interphase convective heat exchange, radiation-conductive heat transfer of the solid phase, radiant and conductive heat exchange of the bed with the reactor wall, heterogeneous and homogeneous chemical reactions, gravity and aerodynamic resistance. Temperature distribution of the phases, diameter of the coal particles, concentrations of the gas components over the bed height as a function of time during the gasification of Shubarkol long-flame coal under a pressure of 3 MPa at a ratio of mass fractions in the oxygen-oxygen mixture H2О/O2 = 45/55 is obtained. The obtained information can be used in the design of reactors, commissioning modes and the gas generator operation at various loads, when the process of steam-oxygen coal gasification is non-stationary due to the cyclical fuel supply and ash discharge by using a system of lock bins. It has been shown that the section of the oxidizing zone, where the temperature of the coal particles reaches its maximum value, is very narrow and is 10-11 mm. Two alternative modes of the gas generator operation are proposed. The first mode H2О/O2 = 40/60 is associated with an increase in the maximum temperature of the particles in a small area adjacent to the reactor bottom from to 1550 °C, which makes it possible to organize stable liquid slag removal from the gas generator. The second mode H2О/O2 = 72/28 is based on solid slag removal, when the temperature of the particles does not exceed 1000 °С. Referenses 11, tabl. 1, fig. 9.
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