带盘管的搅拌釜内气含率、传热特性及其应用研究

发布时间：2018-06-18 13:29

本文选题：盘管 + 搅拌釜　；参考：《浙江大学》2017年硕士论文

【摘要】：许多强放热反应,若温度控制不当,容易引发反应体系中部分化合物分解产生气体,进而恶化相关反应过程,甚至引发事故。在生产过程中常采用内置螺旋盘管来增加换热面积,但这也带来了计算和设计上的复杂。因此对搅拌釜中气液两相流与浸没在其中的盘管外侧的对流传热系数进行研究变得尤为重要。本文以水和空气分别作为液相和气相,研究了带盘管的搅拌釜内的气含率和气液两相搅拌釜内盘管外侧的对流传热特性,在此基础上对某强放热反应釜进行了设计。主要内容如下:1.实验研究了推进桨(PRO)、四斜叶桨(PBT)、翼型桨(CBY)三种桨型、桨径(D/3、D/2)、表观气速(0.00393～0.0197m·s-1)和转速(150～300rpm)对带盘管的搅拌釜的气含率的影响,对实验数据进行关联和分析。结果表明在气含率方面,D/2推进桨(PRO_L)优于其它各桨,在通气量较小时,宜采用大桨径搅拌桨,而在通气量较大时,宜采用小桨径搅拌桨。2.实验研究了不通气和通气下盘管外侧的对流传热系数,着重考察了轴向桨作用下,桨型、桨径、转速和表观气速对传热的影响,将所得盘管外侧对流传热系数值与不通气情况下的值比较分析,并引入通气数(NA=QG/d3N)对216组实验数据进行拟合,为a N一些特殊强放热反应釜的设计以及操作提供了一定的理论依据。3.根据实验结论从气含率和传热系数两方面综合考虑,PRO_L具有优势,结合设计手册上的设计规范,设计了某含能化合物制备过程所需的某一 7000L强放热反应釜,反应釜已投入实际生产且运行良好。
[Abstract]:Many strong exothermic reactions, if the temperature is not properly controlled, will easily lead to the decomposition of some compounds in the reaction system to produce gas, and then worsen the related reaction process, and even lead to accidents. The inner spiral coil is often used to increase the heat transfer area in the production process, but it also leads to the complexity of calculation and design. Therefore, it is very important to study the convection heat transfer coefficient of gas-liquid two-phase flow and submerged coils in stirred kettle. In this paper, water and air are used as liquid phase and gas phase, respectively, to study the gas holdup in agitator with coil and convection heat transfer characteristics outside the inner coil of gas-liquid two-phase agitator. On the basis of this, a strong exothermic reactor is designed. The main content is as follows: 1. The effects of propeller proton, four oblique blade propeller (PBTT), wing propeller (CBY) on the gas holdup of agitator with coiled coil were studied. The experimental data were correlated and analyzed. The effects of propeller diameters D / 3 / D / 2, apparent gas velocity of 0.003930.0197ms-1 and rotational speed of 150 ~ 300rpm) on the gas holdup of agitator with coil were investigated. The results show that D- / 2 propeller props are superior to other propellers in air holdup. When the aeration volume is small, large diameter propeller should be used, and small diameter propeller. 2 when the aeration volume is large, the propeller with small diameter should be used. The convection heat transfer coefficient on the outside of the coil is studied experimentally, and the effects of propeller type, diameter, rotational speed and apparent gas velocity on heat transfer under axial propeller are investigated. The convection heat transfer coefficient on the outer side of the coil was compared with that in the case of no ventilation, and the ventilation number NAQG / d 3N was introduced to fit 216 experimental data. It provides a theoretical basis for the design and operation of some special strong exothermic reactors. According to the experimental results, considering the gas holdup and the heat transfer coefficient, a 7000L strong exothermic reactor for the preparation process of a certain energetic compound was designed, combining with the design specification in the design manual. The reactor has been put into actual production and running well.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.72;TK124

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