Effect of pipe orientation on erosion of π-shaped pipelines

Abstract

Erosion of particles in elbows mounted in series is a detriment in the course of natural gas transmission. The flow and erosion characteristics of π-shaped pipelines were investigated via coupling the computational fluid dynamics (CFD) and the discrete phase model (DPM) method. The effect of pipe orientation on particle erosion was mainly studied. Spiral and asymmetrical trajectories of particles were observed from the second elbow to the downstream straight pipe of the fourth elbow in the non-coplanar π-shaped pipelines. The integral erosion rate of the first elbow increased by 0.35%, and it grew by 72.49% and 87.48% in the second and fourth elbows in non-coplanar structures, respectively, while the integral erosion rate of the third elbow reduced by 32.94%. In the actual transportation of natural gas, it is necessary to make local thickening treatment of the second and fourth elbow of the non-coplanar π-shaped pipelines. • A swirling effect was discovered in non-coplanar structures. • Spiral and asymmetrical particle trajectories were generated. • Integral erosion degree of fourth elbow increased by 87.48% due to swirling effect. • The erosion rate increased exponentially with the increase of velocity.