| With the development of society and economy, the global steel industry facing the increasing shortage of resources and environmental load pressure, it has been earned widespread respect by person of insight, and therefore developing a new iron-making technology in keeping with contemporary trends to replace the traditional Blast Furnace Iron-making Technology is imminent. The new iron-making technology using untreated coal and iron ore as raw material directly which direct reduction iron ore to solid iron, or place reduction reaction in the high-temperature slag phase. So the new technology can omitt iron-making blast furnace process, iron ore sinter and coal coke program, which not only reduce the pollution generated during iron and can increase the economic benefits. After several decades of development, smelting reduction iron-making technology come to flexible with environmentally friendly, simple process, high-energy efficiency, high-melting process operating efficiency. This study is generated by this background.In this paper,using computational fluid dynamics (CFD) FLUENT software package,a numerical simulation study is carryed out on HIsmelt smelting reduction vessel and rich-oxygen top-blowing smelting reduction vessel.we have established two separate mathematical models:bath flow model and furnace fuel combustion model,which study on the bath flow behavior,furnace fuel combustion temperature field distribution and its influencing factors.Firstly, the CFD pre-processing software, GAMBIT is used to establish the geometric model based on the actual furnace structure,and execution mesh generation.In this process,the unstructured grid and structured grid with a mixed grid mesh to ensure the quality of the grid has been adopted.We choose a suitable fluid flow and fuel combustion mass and heat transfer mathematical model for the numerical simulation calculation. Through theoretical calculation, we achieve the theory air consumption of fuel combustion based on the fuel flow and the corresponding inlet air speed when excess air coefficient is different. These values are substituted into the mathematical model as a initial parameters.In this paper,The main conclusions are as follows:HIsmelt furnace "splash" phenomenon is more obvious under the side lance injection,and there is mass and heat transfer in the "splash" molten slag back to the bath process,which make bath area temperature rise about 40℃;When the 600mm lance position has the best mixing effect and the "pit" phenomenon is more obvious under only top lance injection in the rich-oxygen top-blowing smelting reduction vessel;With the excess air ratio increased,the average temperature of the furance increased in varying degrees in Gas combustion and oil combustion process.When gas combustion in excess air ratio is 1.4 and the fuel combustion in excess air ratio is 1.2, it has best combustion efficiency;As the oxygen concentration increased, the average temperature of the furnace was significantly higher.when the oxygen concentration is 46%, the effect is good.In addition, in the fuel combustion process, the selection of spray atomization method has a greater impact on the fuel combustion furnace temperature distribution.We also carry out experimental study on rich-oxygen top-blowing smelting reduction high-phosphorus iron ore.During the experiment, a thermocouple and flue gas analyzer are used for monitoring temperature and gas composition analysis parameters, and oxygen top-blown furnace smelting reduction compared numerical results show good agreement between the data. |
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