Numerical Simulation Of Blended Coal Combustion For 1110t/h Supercritical Boiler

At present,China has become the world's largest producer of energy.Wind,solar,biomass and other new forms of energy develop speedilly,but failed to achieve a breakthrough,so coal is still the main traditional energy in China,and thermal power still accounts for 47% of China's total consumption of coal resources,which is the largest coal consumption industry.With the rapid development of economy,China's demand for electricity has increased dramatically,and coal shortage often occur in large-scale power plants.Facing the huge demand for electricity and the contradiction between the tight supply of coal,it is difficult for the power plant to burn a single coal for a long time,so the way of blended coal combustion is usually adopted.In this paper,a 1110 t / h supercritical lignite boiler in a power plant is taken as the research object.Based on the existing coal,design a reasonable coal blending scheme for the power plant,and simulate the optimal ratio of coal blending scheme,to provide a certain reference for the actual operation of power plant,the specific contents are as follows:Firstly,introduce the models involved in the process of simulation theoretically,select suitable mathematical model for numerical simulation,at the same time,establish the physical model of boiler based on the physical dimensions.The high quality mesh lay the foundation for the numerical simulation calculation.Secondly,according to the mathematical model established and boundary conditions,the boiler were simulated under BMCR conditions,and the simulation results were verified according to the test results of boiler cold air dynamic field and the output test results under BMCR thermal conditions of the boiler.The location and size of the tangential circle and the temperature distribution at different elevation in the furnace were compared mainly with the experimental results to verify the accuracy of the numerical simulation results of the test.Finally,based on the actual burning coal in the power plant-Xingan coal,Shaertala coal,Wula coal and Neimeng bituminous coal,use the multi-objective decision method of fuzzy mathematics to determine the optimal proportion of three kinds of lignite and bituminous coal.It is the best proportion when Xingan coal and Inner Mongolia bituminous coal is 3:2,Tara and Inner Mongolia bituminous coal is 2:3,and Ural and Inner Mongolia bituminous coal is 4:1.Based on the calculation model of numerical simulation which has been verified,three kinds of optimized coal blending schemes are simulated and the design conditions of the boiler are analyzed from the ignition characteristics,burnout characteristics and emission characteristics and other aspects.At the same time,the air distribution modes were adjusted for three kinds of blended coal schemes according to the proximate analysis of the blended coal in order to select optimum air distribution modes for them,which provides some reference for the actual operation of power plant.