ABSTRACT:

Numerical study on a lifting system developed for shallow sea test was performed by a CFD model. In this study, the flow behaviors in a lifting pump and flexible hoses is simulated by using FLUENT, a commercial CFD model. Two cases for avoiding the pump cavitation behavior were selected according to the hose length and the depth of lifting pump. From the numerical results, it is found that the calculated NPSH meet the minimum required by a lifting pump based on the shallow sea environments.

INTRODUCTION

The deep sea floor could be thought as the last treasury of mineral resources to be left for mankind. The advanced countries have already driven forward actively the development of deep sea mineral resources in preparation for the on-land mineral resource exhaustion since 1960"s. Especially, the successful development of deep sea manganese nodules requires developing exploration, mining and transfer technologies simultaneously, among which mining technology includes collecting and lifting technologies of the manganese nodules (Chung, 1994). Lifting system is crucial to achieve the success of the deep-sea mining project, by which manganese nodules are conveyed from the seafloor to the mining ship. Among the lifting methods, the hydraulic pump lifting system is situated between the buffer system and the lifting pipe that is connected to the mining ship. The lifting pump, one of the core parts in the hydraulic pump lifting system, need to be designed with multi-stages because it requires a high hydraulic head (Park et al, 2007). In Japan, an 8-stage lifting pump was developed for its offshore experiment (Chung, 1994). In this study, the simulations of the lifting pump and the connecting flexible hoses for shallow sea test have been conducted to guarantee the performance of the developed lifting pump using FLUENT, a commercial CFD model.

This content is only available via PDF.
You can access this article if you purchase or spend a download.