Development and Engineering Application Research on Pipeline Wear Model of Slurry Shield with Large Particle Size Slag Erosion

Based on a self-developed gravel impact target test device, this study takes particles with a particle size of 10~30 mm as the research object to investigate the effects of particle velocity, incident angle, particle size, and shape on the erosion wear law of the target material. A wear model of the target material under the erosion action of large-size gravel is established, and the applicability and accuracy of the proposed erosion wear model are verified by combining the computational fluid dynamics-discrete element method (CFD-DEM) coupling approach with field measured data. The research results show that: (1) With the increase of gravel impact angle, the wear rate of the target material first increases and then decreases, and the wear rates of Q235 and Q355 steel targets reach the maximum when the erosion angle is 30°; the wear rate of the target material increases proportionally with the increase of impact velocity; as the particle size increases from 10 mm to 30 mm, the wear rate of the target material increases; the wear rate caused by spherical particles is the lowest, while the wear rates caused by flat particles and equilateral triangular prism particles are 1.4 times and 1.8 times that of spherical particles, respectively; (2) When the elbow angle of the slurry discharge pipeline of the slurry shield is 90° and 60°, the maximum error between the simulation prediction of elbow wear and the field measured results is 13.6% in the sand-gravel stratum and 30.5% in the fullface hard rock stratum. Based on this wear model, the pipeline wear characteristics and key flow field characteristics at the position of the flow divider are analyzed, and the wear-resistant optimization of the slurry flow divider structure is carried out.