Preliminary investigation of dynamic characteristics of leaching strings for solution mining of salt cavern storage

摘要

During leaching for salt cavern underground energy storage, leaching string accidents for solution mining, excessive bending or breakage, etc., often occur. They seriously affect project progress and shape control of the cavern construction. Preliminary theoretical and experimental researches on the dynamic characteristics of leaching strings were carried out. It is shown that the main reason why the overbending or breakage of leaching strings occurs is self-excited fluid-structure coupling vibration of leaching strings in confined space, well. The critical flow velocity expression of leaching strings is obtained under idealized condition, revealing that leaching bending stiffness of leaching strings, overhang length and overflowing area are the main influence factors of tubing dynamic stability. The phenomena of water hammer, static buckling and chaotic motion were observed in the model experiment, accounting for the main influence factors. Finally, some research advices on the overall analysis of dynamic characteristics of the leaching string are proposed.