天然气水合物浆体分解对其在垂直管中流动特性影响的研究

针对天然气水合物浆体开采提升过程中水合物分解的问题,采用Euler多相流模型以及Finite-Rate/Eddy-Dissipation模型对天然气水合物浆体垂直管输的固-液两相流动以及气-液-固三相流流动特性进行研究。结果表明,受天然气水合物分解产生的气体影响,天然气水合物颗粒的速度分布、体积浓度分布均随高度的变化呈现出波动-均匀-波动的规律;水合物分解对浆体管道运输具有减阻作用,并提出天然气水合物浆体分解工况下,其流动速度不应低于3m·s~(-1);通过对管道的阻力特性分析,拟合出水合物分解下的水力提升阻力损失与流速的关系式,为天然气水合物浆体管道的经济提升参数提供指导。

Study on Flow Characteristics of Natural Gas Hydrate Slurry with Decomposition in Vertical Tube

The Euler multiphase flow model and the Finite-Rate / Eddy-Dissipation model were used to study the flow characteristics of solid-liquid two-phase flow and the gas-liquid-solid flow in the vertical pipeline. The results showed that the velocity distribution and the volume distribution of hydrate both exhibit a fluctuation-uniform-fluctuation law with the change of height effected by gas from decomposition of hydrate slurry. Besides, it was found that the gas producing from hydrate dissociation on the slurry transportation has a drag reduction effect, and it can be proposed that natural gas hydrate three-phase flow slurry flow rate should not be less than 3.0 m/s. Finally, the relationship between the loss of the hydraulic lift and the flow rate of the hydrate slurry was fitted through the analysis of the resistance characteristics of the pipeline, which will provide guidance on the economic upgrading of gas hydrate slurry pipelines.