电熔镁烟气袋式除尘器温度控制

发布时间：2018-01-05 00:12

本文关键词：电熔镁烟气袋式除尘器温度控制　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：大气污染严重,主要表现粉尘特征。国内电熔镁生产工艺落后,粉尘大量排放,因此采用袋式除尘器对电熔镁粉尘进行收集。通过对电熔镁生产新工艺过程进行分析,粉尘温度高对袋式除尘器的影响最大,为此提出温度控制的问题。本文采用冷却风扇强化散热与混风阀混入冷风的方式对电熔镁粉尘进行温度控制。运用流体力学确定粉尘的流态,粉尘与管道壁面之间的主要换热形式为对流换热,依据传热学相似第一定理和相似第二定理,运用雷诺准则、格拉夫晓准则、普朗特准则和努塞尔特准则确定影响电熔镁粉尘热传递的主要因素,并运用经验公式对其进行量化。采用冷却风扇扰动的办法去改变粉尘热传递的影响因素,使其散热能力加强,并针对粉尘的实际情况对风扇几何参数和物理参数进行设计、定型。混风阀控制粉尘温度是根据混风阀不同开度来向粉尘混入不同流量冷风的方式达到对粉尘温度控制的目的,运用参数自整定模糊PID控制混风阀的开度,参数自整定模糊PID控制策略结合了模糊控制和PID控制二者的优点,对粉尘这种难于建模、时变、非线性的复杂温度系统进行精确控制使用Smith控制算法对参数自整定模糊PID控制过程进行优化,削弱延迟环节对粉尘温度控制的负面影响。运用Matlab软件对控制过程进行模拟仿真,运用Fluent软件对管道内混合流体的温度分布进行模拟分析。结果显示雷诺数对粉尘对流换热量影响最大,通过理论推导得出雷诺数与粉尘流体对流换热系数成正比例关系,风扇扰动使雷诺数增大,对流换热量增加。Matlab软件的仿真结果显示三角分布的隶属度函数最适合用于粉尘温度控制,参数自整定模糊PID温度控制比单纯PID温度控制达到设定值所需时间短,波动性更小,运用Smith控制算法对控制系统优化使温度系统达到设定值的时间更短,且调节过程无波动性。运用Fluent软件模拟仿真得出对应7种温度的混风流量,且得出冷风温度增加,混风阀流量呈指数递增的结论。
[Abstract]:Serious air pollution, mainly domestic dust features. Fused magnesium production process backward, dust emissions, so the use of bag type dust collecting electric melting magnesium dust. The fused magnesium production process analysis, high temperature dust bag dust influence, proposed temperature control the problem. This paper uses the way of cooling fan and enhanced cooling air mixing valve mixed with air to control the temperature of the electric melting magnesium dust. Flow of fluid mechanics is used to determine the dust, dust and the main forms of heat transfer between the pipe wall for convective heat transfer, based on heat transfer is similar to the first theorem and second similarity theorem, using Reynolds criterion Graff, Xiao criterion, determine the Prandtl criterion and Sert criterion. The main influence factors of electric melting magnesium dust heat transfer, and the use of empirical formula to quantify the cooling fan disturbance. To change the effect of dust heat transfer factor, the radiation ability strengthens, and in view of the actual situation of dust parameters and physical parameters of the fan geometry design, setting. Mixed air valve control dust temperature mixing valve according to the different opening to dust with different cold wind flow way to control the temperature of dust to use parameter self-tuning fuzzy PID control of wind mixing valve, parameter self-tuning fuzzy PID control strategy combines the advantages of fuzzy control and PID control of the two, on the dust is difficult to model, time-varying, nonlinear and complex temperature system for precise control of the Smith control algorithm is used for parameter fuzzy PID the control process of setting optimization, weaken the negative influence on the dust temperature control delay link. Using Matlab software to simulate the control process, using Fluent software to the pipeline in mixed fluid temperature Simulation analysis is carried out. The results show that the Reynolds number of the distribution of dust convection heat transfer effect, through theoretical derivation Reynolds and dust fluid convection heat transfer coefficient is proportional to Reynolds number increases, the fan disturbance, convection heat transfer increases the simulation results of.Matlab software show the membership function of the triangular distribution is most suitable for dust temperature control, parameter self-tuning fuzzy control compared with PID control of temperature reaches the set value required for a short time PID temperature fluctuation is small, the use of Smith control algorithm of the temperature control system optimization system to achieve a shorter setting time, and the adjustment process without volatility. Simulation draw mixed air flow corresponding to the 7 kinds of temperature the use of Fluent software, and the cold air temperature increase, air mixing valve flow exponential conclusion.

【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X758

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