湿式电除尘器泄爆过程的模拟研究

发布时间：2018-05-30 22:09

本文选题：湿式电除尘器 + 预混燃烧　；参考：《河北科技大学》2013年硕士论文

【摘要】：本课题来源于河北省科技厅重大技术创新项目。针对50MW以上大型燃气—蒸汽联合循环发电机组的湿式电除尘器内发生的高炉煤气爆炸问题，对其泄爆过程进行了理论分析和数值模拟，通过分析整个过程流场的温度、压强等发展特征，得到了煤气爆炸和泄爆过程的流场状态。根据模拟结果对除尘器泄爆阀的设置进行了优化，验证了湿式电除尘器在高压强、高流速、高爆炸性极端条件下运行的可靠性，为除尘器泄爆装置的设计和安装提供了依据。本文依据流体动力学软件FLUENT首先模拟了高炉煤气在湿式电除尘器内正常情况下的流动状态，并与现场实验进行对比，验证了软件模拟的可行性；然后根据预混气体燃烧中的涡耗散模型，对高炉煤气的爆炸进行了模拟，，探索了高炉煤气爆炸的机理，分析了在可燃物CO的浓度、初始压强、当量比和点火位置等影响因素下爆炸的火焰发展特征和流场发展特征，确定了各个因素对爆炸发展的影响；最后根据开口泄爆模型，对泄爆阀在不同直径、数量和位置下的泄爆方案进行了模拟，得到了泄爆过程中压强下降规律，并对泄爆阀在除尘器上的设置提出了优化方案。在爆炸强度模拟中，分析了爆炸燃烧温度和压强的生成和发展规律，得出当量比影响最大，其后依次为CO浓度、初始压强和点火位置。最高温度发展速率达到1.9×10~6K/s，最高压强发展速率最高达到9×10~5KPa/s。在泄爆模拟过程中，研究了湿式电除尘器上泄爆阀直径、个数和位置对泄爆过程的影响。结果表明，增加泄爆阀直径和数量都会提高泄爆的效率，缩短泄爆时间。考虑泄爆阀恢复原位的重复性，最终优化确定采用2个直径D=600mm的泄爆阀，此方案模拟得到的泄爆过程压强发展满足湿式电除尘器极限压强的要求。
[Abstract]:This topic comes from Hebei province science and technology department major technology innovation project. In view of the blast furnace gas explosion in the wet electric precipitator of large gas-steam combined cycle generator set above 50MW, the explosion process of blast furnace gas is analyzed theoretically and numerically. The temperature of the flow field is analyzed by analyzing the temperature of the whole process. The flow field state of gas explosion and explosion discharge process is obtained by pressure and other development characteristics. According to the simulation results, the setting of the explosion relief valve of the dust collector is optimized, and the reliability of the wet electrostatic precipitator running under the conditions of high pressure, high velocity and high explosive extreme is verified, which provides the basis for the design and installation of the exploding device of the dust collector. According to the fluid dynamics software FLUENT, the flow state of blast furnace gas in the wet electrostatic precipitator is first simulated, and compared with the field experiment, the feasibility of the software simulation is verified. Then according to the vortex dissipation model of premixed gas combustion, the blast furnace gas explosion is simulated, the mechanism of blast furnace gas explosion is explored, and the concentration and initial pressure of the combustible CO are analyzed. Under the influence factors such as equivalent ratio and ignition position, the characteristics of flame development and flow field development of explosion are determined, and the influence of each factor on explosion development is determined. The number and position of the venting scheme are simulated, and the law of pressure drop during the process of discharging is obtained, and the optimized scheme of setting the explosion-relief valve on the dust collector is put forward. In the simulation of explosion intensity, the formation and development of explosion combustion temperature and pressure are analyzed. It is concluded that the equivalent ratio has the greatest influence, followed by CO concentration, initial pressure and igniting position. The maximum temperature growth rate is 1.9 脳 10 ~ (-6) K / s, and the maximum pressure development rate is 9 脳 10 ~ (5) KPA / s. The influence of the diameter, number and position of the vent valve on the discharge process of wet electrostatic precipitator was studied. The results show that increasing the diameter and quantity of the vent valve can improve the efficiency and shorten the discharge time. Considering the reproducibility of the relief valve in its original position, two diameter D=600mm valves were optimized and the pressure of the process was developed to meet the requirement of the limit pressure of the wet electrostatic precipitator (ESP).
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TF088

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