Spatial migration and distribution of suspended particles in saturated sand layer under the impact of temperature

The migration, deposition and detachment of suspended particles in saturated sands are used in many fields. Temperature is an important influencing factor in the transport and deposition process of particles in porous media, and it plays an important role in ground-water heat pump (GWHP) projects. This article discusses the independent development of a three-dimensional percolation sandbox test device and the design of a particle migration test based on the Reynolds number in the context of the backfilling process of GWHP systems as the experimental background. The effects of various temperatures (10, 25, and 40 degrees C) on the movement of suspended particles in porous media were studied. The experimental results showed that as the temperature rose, more particles were deposited in the sand layer, the uneven flow of particles in the sand layer accelerated, and the particles spread out in the direction opposite to the non-percolation direction with a wider distribution range in the sandbox. Increased temperature also promoted the percolation of smaller particles, causing the diffusion zone to terminate sooner and the deposition zone to last longer, resulting in the capture of more particles on the surface and in the pore channels of the sand layer.