2014 年 9 巻 3 号 p. JFST0036
In the piping system such as power plants, the pipe wall thinning caused by flow accelerated corrosion (FAC), liquid droplet impingement (LDI) erosion, and cavitation erosion (C/E), are very serious problems because they lead to serious damage and destruction of the piping system. In this study, the pipe wall thinning caused by FAC in the downstream of an orifice (flow meter) was examined. Experimental and numerical analyses were carried out to clarify the characteristics of FAC, generation mechanism, and to propose of a new governing parameter for the prediction of the thinning and a reduction method. The corrosion pattern on the pipe wall was also examined by an experimental analysis. This clarified that the occurrence of thinning mainly depends on the amount of the pressure fluctuation p' on the pipe wall. It was also found that the wall thinning rate TR can be estimated by p' and that the suppression of p' or TR can be realized by replacing the orifice with a tapered one having an angle to the upstream or by using a downstream pipe with a smaller diameter than that of the upstream of the orifice.
