Flow-Accelerated Corrosion in Pipe Wall Downstream of Orifice for Water and Air-Water Bubble Flows
Flow-Accelerated Corrosion in Pipe Wall Downstream of Orifice for Water and Air-Water Bubble Flows作者机构:Graduate School of Engineering Mie University Tsu-shi Japan
出 版 物:《Journal of Flow Control, Measurement & Visualization》 (流量控制、测量及可视化(英文))
年 卷 期:2016年第4卷第3期
页 面:93-103页
学科分类:080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学(可授工学、理学学位)]
主 题:Flow-Accelerated Corrosion (FAC) Wall Thinning Rate (TR) Orifice Gas-Liquid Bubble Flow Turbulent Kinetic Energy Pressure Fluctuation (p’) Estimation of p’ or TR Suppression of p’ or TR
摘 要:An orifice is used widely as a flow meter or a contraction device in pipeline systems in hydro-power plants, thermal power plants, and chemical plants because of its simple construction, high reliability, and low cost. However, it is well known that flow-accelerated corrosion (FAC) occurs on the pipe wall downstream of the orifice. Some of the authors have examined FAC through experimental and numerical analyses and have reported that one of the major governing parameters of FAC for single-phase water flow is the pressure fluctuation p’ on the pipe wall, and also that pipe wall thinning rate TR can be estimated by p’. In addition, they have presented the effects of the ori-fice geometry on p’ or TR, and have described a method for suppressing p’ or TR. In the present study, FAC for a two-phase air-water bubble flow is examined and compared with the single-phase water flow experimentally. Further, it is shown that because p’ is also considered a governing parameter of FAC for a two-phase air-water bubble flow, TR can be estimated using p’. It is also indicated that, by using a downstream pipe with a smaller diameter than that of the upstream pipe, p’ or TR can be suppressed.