Chemical Industry and Engineering Progress ›› 2022, Vol. 41 ›› Issue (S1): 81-90.DOI: 10.16085/j.issn.1000-6613.2022-1289

• Chemical processes and equipment • Previous Articles     Next Articles

Erosion investigation of liquid-solid flows in narrow rectangular channel

REN Libo1(), HE Hailan1, ZHANG Manli1, LU Hao2()   

  1. 1.Shanghai Heat Transfer Equipment Co. , Ltd. , Shanghai 201508, China
    2.School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2022-07-08 Revised:2022-08-16 Online:2022-11-10 Published:2022-10-20
  • Contact: LU Hao

狭窄矩形通道内液固两相磨蚀特性

任立波1(), 何海澜1, 张曼丽1, 卢浩2()   

  1. 1.上海板换机械设备有限公司,上海 201508
    2.华东理工大学机械与动力工程学院,上海 200237
  • 通讯作者: 卢浩
  • 作者简介:任立波(1983—),博士,高级工程师。研究方向为化工过程多相流与强化传热。E-mail:by101010@163.com
  • 基金资助:
    国家自然科学基金(52000072)

Abstract:

Extensive research on the liquid-solid two-phase erosion in round tubes and jet flow conditions has been conducted, but the liquid-solid two-phase erosion investigation in narrow rectangular channels, such as in plate heat exchanger, is rarely reported. The technique for computational fluid dynamics-discrete phase method-erosion model was developed in the framework of secondary development of Fluent software. The characteristics of liquid-solid two-phase flow and wall erosion in a narrow rectangular channel with cylinder were studied, and the interaction mechanism between the wall and solid particles was explored. Simulation results showed that the presence of cylinder significantly changed the erosion rate of the wall. The erosion rate increased with the increase of liquid-solid velocity and wall roughness, and low inlet flow rates and wall roughness were critical to extend equipment life. The erosion rate increased first and then decreased with the increase of particle size, and reached the maximum value at about 60μm. Shape factor of non-spherical particles had little effect on wall erosion behavior. By means of a dimensionless particle size, the reason that the particles were trapped within the liquid viscous sublayer was explained. Compared with the smooth wall condition, the particles impacted the rough wall with higher energy and high frequency, resulting in faster erosion of the wall. The liquid-solid two-phase impinged on the wall at a lower angle and velocity, and the wall material removal mechanism was mainly micro-cutting.

Key words: liquid-solid, erosion, narrow rectangular channel

摘要:

液固两相磨蚀研究主要集中于圆管弯头和射流工况,板式换热器等狭窄矩形通道内液固两相磨蚀特性的研究鲜见报道。在Fluent软件及其二次开发框架内构建了描述稀疏颗粒液固两相磨蚀特性的CFD-DPM-磨蚀耦合数学模型框架,研究了存在圆柱体阻挡物的狭窄矩形通道内两相流动特性和壁面磨蚀特性,揭示了壁面和固体颗粒的相互作用机制。研究结果表明:阻挡物的存在显著改变了狭窄矩形通道壁面的磨蚀行为;磨蚀速率随液固流速和壁面粗糙度的增加而增加,因此,保证设备较低的入口流速和壁面粗糙度对延长设备寿命至关重要;磨蚀速率随颗粒粒径的增加先增加后降低,在60μm左右时达到极大值;球形度系数对磨蚀行为影响较小。引入量纲为1颗粒尺寸,阐述了液相边界层束缚颗粒运动的作用机制;与光滑壁面工况相比,颗粒以较大能量高频撞击粗糙壁面,导致了壁面磨蚀较快。液固两相以较低的角度和速度撞击壁面,壁面材料去除机理以微切削为主。

关键词: 液固, 磨蚀, 狭窄矩形通道

CLC Number: 

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