烧结烟气氨法脱硫塔内流场模拟与优化研究
发布时间：2018-07-27 21:14
【摘要】：烧结工序作为钢铁工业产生SO2的主要来源，控制烧结烟气中SO2的排放已经成为我国环境保护和实现钢铁冶金行业持续发展的必然选择。氨基湿法烟气脱硫是目前应用较广的烧结烟气脱硫技术，但存在比较严重的“氨逃逸”现象，特别是对单塔氨法脱硫工艺来说，更为严重。本文根据某钢铁企业大型烧结机烟气氨法脱硫塔运行情况，分析脱硫运行中存在问题，采用CFD技术对脱硫塔工艺运行参数及塔体几何结构变化对塔内气液流场的影响进行数值模拟研究，并通过与实际操作数据的对比对模拟结果加以验证。 脱硫塔工艺运行参数优化模拟结果表明：对于大型喷淋吸收塔宜选择高位喷淋；综合考虑塔内液膜覆盖效果、传热以及系统阻力情况宜选择喷淋角度为90°或120°；烟气入口流速的波动对塔内流场的影响较大；在不考虑液滴蒸发的稳态模拟系统下，烟气入口温度的变化对塔内气流分布均匀性与进出口压损基本没有影响，烟气入口温度越高，塔内温度降低的越快；提高液气比可以促进传热、提高脱硫效率，但会降低塔内流场的均匀性、增加阻力，在满足环境保护要求的情况下，该脱硫系统液气比控制在5~7L/m3较适宜。 脱硫塔几何结构优化模拟结果表明：双入口吸收塔相对于单入口吸收塔具有更好的气流分布以及传热效果，同时，，切向双入口可以避免直向双入口时由于两股烟气对冲而造成烟气局部过于密集的现象；对于大型脱硫塔，入口角度的改变对塔内整个流场分布的均匀性及进出口压损的影响不大，但是烟气入口向下倾斜可以避免浆液池液位异常波动造成浆液进入入口烟道的情况，建议入口角度选择10°左右为宜；烟气入口区上方增设挡板可以有效隔挡喷淋浆液的进入以及有利于塔内流场均布，档板宽度宜取0.5m~1.0m，同时可以考虑设定一定倾角安置挡板；在入口段增设结构简单、操作简便、呈阶梯状分布的导流板结构可以改善塔内气流分布均匀性，促进传质传热；烟气出入口同侧且顶侧出口方式下的塔内流场相对合理。
[Abstract]:Sintering process is the main source of SO2 in iron and steel industry. Controlling the emission of SO2 in sintering flue gas has become an inevitable choice for environmental protection and sustainable development of iron and steel metallurgical industry in China. Amino wet flue gas desulfurization (WWFGD) is a widely used technology for flue gas desulfurization (FGD), but there is a serious "ammonia escape" phenomenon, especially for the single-tower ammonia desulfurization process. According to the operation of ammonia desulfurization tower in a large scale sintering machine of iron and steel enterprise, the problems existing in desulfurization operation are analyzed in this paper. The effects of operation parameters and geometric structure of the tower on the gas-liquid flow field in the tower were simulated by CFD technology, and the simulation results were verified by comparing with the actual operating data. The optimum simulation results of the operation parameters of the desulfurization tower show that the spray angle should be 90 掳or 120 掳for the large spray absorption tower, and the spray angle should be 90 掳or 120 掳for the comprehensive consideration of the effect of liquid film covering in the tower, the heat transfer and the resistance of the system. The fluctuation of flue gas inlet velocity has a great influence on the flow field in the tower, and the change of flue gas inlet temperature has no effect on the uniformity of air flow distribution and the pressure loss of inlet and outlet in the tower without considering the steady state simulation system of droplet evaporation. The higher the inlet temperature of flue gas is, the faster the temperature in the tower decreases. Increasing the liquid-gas ratio can promote heat transfer and increase the desulfurization efficiency, but it will reduce the uniformity of the flow field in the tower and increase the resistance, which can meet the requirements of environmental protection. It is suitable to control the ratio of liquid to gas in 5~7L/m3. The simulation results show that the double inlet absorber has better gas distribution and heat transfer effect than the single inlet absorber. Tangential double entrances can avoid the phenomenon of local concentration of smoke due to two streams of flue gas in the direct direction of double entrances; for large desulphurizing towers, The change of inlet angle has little effect on the uniformity of flow field distribution and the pressure loss of inlet and outlet in the tower, but the downward inclination of flue gas inlet can avoid the slurry entering the inlet flue caused by abnormal fluctuation of liquid level in the slurry pool. It is suggested that the inlet angle should be about 10 掳, that the addition of baffles above the flue gas inlet area can effectively block the entry of spray slurry and that the flow field in the tower can be evenly distributed, and that the width of the baffle should be 0.5 m or 1.0 m, at the same time, a certain inclination angle can be considered to set the baffle. The structure of the inlet section is simple and easy to operate. The flow field in the tower is relatively reasonable under the same side of the flue gas inlet and outlet and the top side exit mode, which can improve the uniformity of the air flow distribution in the tower and promote the mass transfer heat transfer.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X757
[Abstract]:Sintering process is the main source of SO2 in iron and steel industry. Controlling the emission of SO2 in sintering flue gas has become an inevitable choice for environmental protection and sustainable development of iron and steel metallurgical industry in China. Amino wet flue gas desulfurization (WWFGD) is a widely used technology for flue gas desulfurization (FGD), but there is a serious "ammonia escape" phenomenon, especially for the single-tower ammonia desulfurization process. According to the operation of ammonia desulfurization tower in a large scale sintering machine of iron and steel enterprise, the problems existing in desulfurization operation are analyzed in this paper. The effects of operation parameters and geometric structure of the tower on the gas-liquid flow field in the tower were simulated by CFD technology, and the simulation results were verified by comparing with the actual operating data. The optimum simulation results of the operation parameters of the desulfurization tower show that the spray angle should be 90 掳or 120 掳for the large spray absorption tower, and the spray angle should be 90 掳or 120 掳for the comprehensive consideration of the effect of liquid film covering in the tower, the heat transfer and the resistance of the system. The fluctuation of flue gas inlet velocity has a great influence on the flow field in the tower, and the change of flue gas inlet temperature has no effect on the uniformity of air flow distribution and the pressure loss of inlet and outlet in the tower without considering the steady state simulation system of droplet evaporation. The higher the inlet temperature of flue gas is, the faster the temperature in the tower decreases. Increasing the liquid-gas ratio can promote heat transfer and increase the desulfurization efficiency, but it will reduce the uniformity of the flow field in the tower and increase the resistance, which can meet the requirements of environmental protection. It is suitable to control the ratio of liquid to gas in 5~7L/m3. The simulation results show that the double inlet absorber has better gas distribution and heat transfer effect than the single inlet absorber. Tangential double entrances can avoid the phenomenon of local concentration of smoke due to two streams of flue gas in the direct direction of double entrances; for large desulphurizing towers, The change of inlet angle has little effect on the uniformity of flow field distribution and the pressure loss of inlet and outlet in the tower, but the downward inclination of flue gas inlet can avoid the slurry entering the inlet flue caused by abnormal fluctuation of liquid level in the slurry pool. It is suggested that the inlet angle should be about 10 掳, that the addition of baffles above the flue gas inlet area can effectively block the entry of spray slurry and that the flow field in the tower can be evenly distributed, and that the width of the baffle should be 0.5 m or 1.0 m, at the same time, a certain inclination angle can be considered to set the baffle. The structure of the inlet section is simple and easy to operate. The flow field in the tower is relatively reasonable under the same side of the flue gas inlet and outlet and the top side exit mode, which can improve the uniformity of the air flow distribution in the tower and promote the mass transfer heat transfer.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X757
【参考文献】
相关期刊论文 前10条
1 詹秋月;;660MW机组烟气循环流化床干法脱硫塔入口气流分布的试验研究[J];电力科技与环保;2010年01期
2 贾勇;钟秦;杜冬冬;何川;;氨法烟气脱硫模型的研究[J];动力工程;2009年10期
3 洪文鹏;何慧颖;刘广林;王海刚;;基于Aspen Plus的氨法脱硫单塔系统流程模拟[J];动力工程学报;2013年02期
4 洪文鹏;高天聪;张伟玲;;氨法烟气脱硫喷淋塔烟气流场的数值模拟[J];东北电力大学学报;2014年01期
5 范学友;贾勇;钟秦;;氨吸收法同时脱硫脱硝的实验研究[J];化工进展;2012年01期
6 王海风;张春霞;齐渊洪;;氨法脱硫研究进展[J];环境工程;2010年06期
7 赵U
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