Numerical analysis on the wall-thinning rate of a bent pipe by liquid droplet impingement erosion

• Numerical analysis of deep erosion from liquid droplet impingement (LDI)
• Evaluation of LDI erosion for bent pipe of Onagawa power plant
• Comparison with predictions by existing erosion models
• The liquid film and erosion depth are influential factors in LDI analysis.

This paper presents a numerical analysis of liquid droplet impingement (LDI) erosion in the pipeline of nuclear/fossil power plants. The numerical method is based on combining a Eulerian/Lagrangian computational fluid dynamics (CFD) model with an erosion model to consider various aspects of LDI erosion, such as the influence of the droplet velocity, diameter, number density, impingement angle, material hardness, liquid-film thickness, and erosion depth on the wall-thinning rate. A numerical analysis of the erosion depth distribution was carried out for the LDI erosion of a bent pipe downstream of an orifice at the Onagawa power plant incident in 2007. The results were compared with existing erosion models, and the variations in the peak erosion depths were examined. The present model results showed reasonable agreement with the prototype results at the location and the erosion depth distribution of the bent pipe. The comparison showed the importance of the liquid film and erosion depth to predicting the LDI erosion characteristics.