Evaluation method for pipe wall thinning due to liquid droplet impingement

2013 ◽  
Vol 264 ◽  
pp. 195-202 ◽  
Author(s):  
M. Naitoh ◽  
H. Okada ◽  
S. Uchida ◽  
H. Yugo ◽  
S. Koshizuka
Keyword(s):  
Evaluation Method ◽  
Pipe Wall ◽  
Liquid Droplet ◽  
Droplet Impingement ◽  
Wall Thinning

Development of Pipe Wall Thinning Evaluation Method and Prediction Tool

2013 ◽  
Author(s):  
Kimitoshi Yoneda ◽  
Ryo Morita ◽  
Kazutoshi Fujiwara ◽  
Fumio Inada
Keyword(s):  
Power Plants ◽  
Evaluation Method ◽  
Pipe Wall ◽  
Liquid Droplet ◽  
Thickness Measurement ◽  
Management Tool ◽  
Plant Management ◽  
Piping System ◽  
Wall Thinning ◽  
Thinning Rate

Flow accelerated corrosion (FAC) and liquid droplet impingement erosion (LDI) are the main pipe wall thinning phenomena in piping system of power plants in Japan. Authors have promoted the development of prediction method to evaluate local thinning trend by FAC/LDI. To apply the method to pipe wall thinning management in power plants, it is required to be transformed into practical tools for easy usage. In Japan, discussion is being made to considerate the introduction of prediction tools into wall thinning management based on wall thickness measurement at present. Authors have simplified their FAC/LDI models to predict wall thinning trend one-dimensionally along piping layout, and applied to actual thinning data of power plants. With PWR’s FAC data and BWR’s LDI data, maximum thinning rate for each pipe elements were roughly predictable with considerable accuracy. Especially for high thinning rate data, which is important in plant management, the model was able to evaluate within the factor of 2. By installing this model, prediction software “FALSET” was developed, equipped with practical functions for the management. With the further verification and improvement of each function, there are prospects for this software to be utilized as a management tool in power plants.

Studies on Flow and Pipe Wall Thinning and the Reduction in the Downstream of Orifice Nozzle

2011 ◽  
Author(s):  
Toshihiko Shakouchi ◽  
Takayuki Suzuki ◽  
Hideki Yuya ◽  
Masaki Naruse ◽  
Koichi Tsujimoto ◽  
...  
Keyword(s):  
Cavitation Erosion ◽  
Pipe Wall ◽  
Liquid Droplet ◽  
Piping System ◽  
Droplet Impingement ◽  
Accelerated Corrosion ◽  
Wall Thinning ◽  
System 1 ◽  
Flow Accelerated Corrosion ◽  
Droplet Impingement Erosion

In a piping system of power plant, pipe wall thinning by Flow Accelerated Corrosion, FAC, Liquid Droplet Impingement Erosion, LDI, and Cavitation Erosion, C/E, are very serious problems because they give a damage and lead to the destructtion of the piping system[1]–[6]. In this study, the pipe wall thinning by FAC in the downstream of orifice nozzle, flow meter, is examined. Namely, the characteristics of FAC, generation mechanism, and prediction of the thinning and the reduction are made clear by experimental analysis. As a results, it was made clear that (1) the thinning is occurred mainly according to the size of the pressure fluctuation p′ on the pipe wall and the thinning can be estimated by it, and (2) the suppression of p′ can be realized by replacing the orifice to a taper shaped one having an angle to the upstream.

Prediction of Liquid Droplet Impingment Erosion (LDI) Trend in Actual NPP

2009 ◽  
Author(s):  
Taku Ohira ◽  
Ryo Morita ◽  
Kazuhiro Tanji ◽  
Shinji Akiba ◽  
Koichi Niiyama ◽  
...  
Keyword(s):  
Evaluation System ◽  
Pipe Wall ◽  
Liquid Droplet ◽  
Assessment Method ◽  
Life Assessment ◽  
Pipe Surface ◽  
Actual Measurement ◽  
Measurement Result ◽  
Wall Thinning ◽  
Remaining Life Assessment

Liquid droplet impediment erosion (LDI) is a pipe wall thinning phenomena that a droplet accelerated by steam flow attacks pipe surface. It is difficult to evaluate LDI behavior in the system of NPP. Therefore, in current pipe wall thinning management, the pipe element is replaced conservatively when it is recognized to become thinner by pipe wall thinning measurement result. If LDI behavior at each point of the system can be estimated, it is possible to measure the pipe wall thickness and replace the pipe element at an appropriate time, in accordance with reasonable pipe wall measurement schedule. CRIEPI has constructed the evaluation system for LDI by using flow dynamics. This paper is concerned with the following items: • the applicability of the LDI evaluation system by a comparative verification between pipe wall thinning rate calculated by LDI system and that by actual measurement result; • establishment of remaining life assessment method of pipe in LDI environment by using LDI model.

C213 Evaluation of Local Wall Thinning of Piping with A Model Based on Liquid Droplet Impingement Accelerated Corrosion

2010 ◽  
Vol 2010.15 (0) ◽  
pp. 351-354
Author(s):  
Hidetoshi Okada ◽  
Shunsuke UCHIDA ◽  
Masanori Naitoh ◽  
Yasushi Uehara ◽  
Seiichi Koshizuka
Keyword(s):  
Liquid Droplet ◽  
Droplet Impingement ◽  
Accelerated Corrosion ◽  
Model Based ◽  
Wall Thinning ◽  
Local Wall Thinning
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