关键词: 泥水盾构, 泥水环流系统, 固液两相流, 倾斜管路, 管道排渣, 渣石平均速度

Abstract:

To investigate the slagdischarge characteristics of the slurry shield circulation system in actual design and application, the solidliquid twophase flow simulation technology coupling with engineering discrete element method and Fluent is employed to study the movement law and distribution state of slag and mud in horizontaltilthorizontal continuous circulation pipeline. The results reveal the following: (1) Dense discrete phase model is more accurate in calculation and more suitable for the actual working conditions compared with discrete phase model. (2) In the initial horizontal slag stone suspension motion, stones gradually settle and move at the bottom of the pipeline since gravity. (3) When stone moves in the inclined pipe, obvious accumulation and velocity stratification appear. The stone distribution number and the maximum mud velocity in the inclined pipe section first increase and then decrease with the increase of the inclined pipe angle. Both of them reach the maximum at 45° and the minimum at 90° of inclined angle. (4) The average velocity of slag decreases first and then increases with the increase of the inclined pipe angle, reaching the minimum at 45° and the maximum at 90° of inclined angle. It demonstrates that slag accumulation is more serious when the inclined angle is about 45°, so the inclined angle with 45° should be avoided in the actual design.

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Key words:

 , slurry shield, slurry circulation system, solidfluid twophase flow, inclined pipe, slag discharge, average velocity of particles