Numerical Simulation of the Rotating Water Jet Flushing the Insoluble Particles in the Salt Cavern Underground Gas Storage Based on DPM Model

The construction of underground gas storage is currently an important method for global natural gas storage and peak shaving. Underground salt cavern gas storage has the advantages of convenient cavity construction and low cost, and has become a type of gas storage with a wide range of applications. In the process of making the cavity of the salt cavern gas storage, insoluble particles will be generated and eventually deposited on the bottom of the cavity. However, there are few reports on effective methods for cleaning insoluble particles at the bottom of salt cavern gas storage. This paper presents the application of a novel technique, known as a flushing method in the insoluble particles. This paper proposes a set of rotating jet cleaning tool, which is composed of a filter, a controller and a rotating nozzle. The rotating nozzle includes four side nozzles, two 45° lateral nozzlesand one bottom nozzles. The rotating jet generated by the nozzle cleans the insoluble particles deposited on the bottom of the cavity. Based on the mathematical model of the solid-liquid two-phase flow, the DPM model in Fluent is used to simulate the particle movement under the action of the rotating jet.The particle migration trajectory and the number of particles escaped from the annulus under different planes and different particle sizes were studied and the laws of influence of hydraulic parameters such as cavity diameter and displacement and rotational speed on flushing efficiency were analyzed. Finally the research indicates: Insoluble particles deposited on the upper portion of the bottom of the cavity are more easily flushed into the annulus. within a certain particle size range, the cleaning efficiency of the particles increases as the particle size increases and 1.0 mm insoluble particles have the highest simulated flushing efficiency. The flushing efficiency is basically consistent with the simulation conclusion of the previous mathematical model of the solid-liquid two-phase flow. The development of this research can provide a theoretical basis for the flushing of insoluble particles by the rotating jet in practical engineering applications.