Research on ice slurry pigging and exploration of optimal cleaning parameters based on CFD

To quantitatively investigate the volume distribution of ice slurry and the distribution of wall shear forces during the ice slurry pigging process， and explore the optimal process parameters， this study integrated the kinetic theory of granular flows （KTGF）， adopted the Euler-Euler method and the shear stress transport （SST） model to establish a computational fluid dynamics （CFD） model. The flow characteristics of the established model were verified using experimental data from relevant literature. After simulating 125 sets of different parameters for the ice slurry pigging process under common working conditions， the evaluation indicators were optimized， and the optimal flushing process parameters were determined. The results indicate that ice slurry with a high initial concentration can effectively clean both the upper and lower parts of the pipe wall， with the effective shear stress ratio of 60% concentration ice slurry reaching 77.39%. Ice slurry with larger particles exhibits significant upward movement behavior， and the non-uniformity of solid particle distribution increases with the increase in particle diameter. Flow velocity is the most critical factor affecting the shear stress exerted by ice slurry on the pipe wall； the cumulative shear stress increases and becomes more uniform with the increase in flow velocity， and the effective shear stress ratio at a flow velocity of 1.0 m/s is 83.16%. When the initial concentration of ice slurry is 50%， the particle size is 0.5 mm， and the flushing speed is 1.0 m/s， the average cumulative shear stress is 11.59 Pa·s， achieving the optimal flushing effect. This study can provide theoretical guidance for the operation of ice slurry pigging in water supply pipelines.