Numerical And Experiment Research For Soft Coal Under Condition Of Blending Lignite

In recent years, the rapid development of China's power industry, the fire power station installed capacity is growing, unit capacity of 300MW has been mainly the 90s to today's 600 ~ 1000MW for the main unit. Increasingly tight supply of coal, Power plant burning coal prices rise sharply, to reduce electricity costs, improve economic efficiency. Power Boilers Burning the phenomenon of non-design coal is very popular. According to the literature, some in 2003 the amount of coal combustion power plants have up to 64%,In 2008, nearly 75% of the power plant burn mixed coal and non-design coal.Lignite resources are mainly distributed in northeast of China, accounting for above 75% of lignite reserves. Lignite coal age is short, high volatile content, in general Vd af>40%, lower the temperature of precipitation volatile,and ignition and combustion are relatively easy. Lignite is flammable, explosive, big water, low heat value of coal. In the design of bituminous coal for the boiler burning lignite that will lead to the boiler and ancillary equipment to bring some security and the threat of economic operation. In general, bituminous coal boiler of lignite will have some impacts: 1) High volatile coal mixing, pulverizing system caused an explosion in spontaneous combustion. 2) Mixed coal with low calorific value, resulting in insufficient output milling system. 3) Blended with lignite, the coal characteristics will be biased, and it may result in poor combustion conditions, heating surface and burner slag problems.The paper adopts standard k ?εturbulence model and other mathematical models, and completing the blending lignite combustion numerical simulation of 600 MW boiler of one power plant. Three conditions are simulated in this paper, and these three conditions are compared and analyzed, the result shows that the combustion character of blending lignite is lower than burning soft coal. Burning lignite shows a decline furnace temperature,and the simulation results are consistent with the experimental results. The results of this paper on the understanding and optimization of tangentially fired boiler design, renovation and safe operation has important applications, can provide a reference and useful guide.