列管反应器改进结构环形分布器内变质量流动的数值分析

摘要

环形分布器是实现载热体在列管式固定床反应器壳程均匀流动的重要部件。采用计算流体力学方法对丙烯氧化反应器壳程熔盐在改进结构型式(即椭圆扩张型进口,进口处两侧分别设置呈45°的导流挡板,挡板上均匀分布小孔,不均匀的开孔方式)的环形分布器内的变质量流动进行了模拟研究,分析了环形分布器内的速度及静压分布规律,并与传统型式环形分布器进行对比,并考察了出口分布孔数目及进口熔盐流量对均布效果的影响。通过计算发现,改进结构的分布器均布特性优于传统结构;优选24个分布孔能够满足流体均布的要求,且分布孔达到36,流体均布情况基本稳定;减小进口熔盐流速,进口区域速度及静压波动较小,减小了进口能量损耗,有利于流体均布。

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	姜斌
	薛尚龙
	董佳鑫
	郝丽

关键词：丙烯氧化反应器；熔盐环形分布器；变质量流动；计算流体力学(CFD)；流体均布

Abstract：

The circular distributor plays an important role in uniform distribution of the coolant in the shell side of multi-tubular fixed bed reactor. In this paper, a three-dimensional industrial scale circular distributor physical model was established and computational fluid dynamics (CFD) model was employed to simulate the variable mass flow inside the circular distributor in the shell-side of multi-tubular fixed-bed reactor. The improved model was adopted with uneven distributing holes, using ellipse form inlet and setting two 45° deflector baffles on both sides respectively. Velocity and static pressure distribution inside the circular distributor were investigated, which were also compared with those inside the traditional distributor. The effects of number of outlet distributed holes and inlet molten salt flow rate on the performance of molten salt uniform distribution in the shell-side were also researched. Compared with traditional distributor, the improved circular distributor had a better performance. The improved distributor with 24 distributed holes can meet the requirements of the uniform distribution of fluid. When the number of distributed holes was more than 36, the situation of fluid uniform distribution was basically stable. With the decrease of inlet molten salt flow rate, fluctuation of static pressure at the inlet was weakened, which reduced energy consumption and had a better performance on the uniform distribution of fluid.

Keywords： propylene oxidation reactor； circular distributor of molten salt； variable mass flow； computational fluid dynamics(CFD)； fluid distribution

Received 2014-04-08;

Corresponding Authors: 姜斌,E-mail:binjiang@tju.edu.cn。 Email: binjiang@tju.edu.cn

About author: 姜斌(1966-),男,博士,教授,研究方向为化工传质与分离工程、计算流体力学。

引用本文:

姜斌, 薛尚龙, 董佳鑫, 郝丽.列管反应器改进结构环形分布器内变质量流动的数值分析[J]. 化学工业与工程, 2016,33(3): 89-95

Jiang Bin, Xue Shanglong, Dong Jiaxin, Hao Li.Numerical Analysis of Variable Mass Flow Inside Improved Structure Circular Distributor in Tubular Reactor[J]. Chemcial Industry and Engineering, 2016,33(3): 89-95

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