심해저 채광시스템의 설치를 위한 수치해석 연구

Abstract

Because of depletion of the land mineral resources, interest in deep-seabed mineral resources is increasing. KRISO has developed a deep-seabed integrated mining system for collecting manganese nodules. The deep-seabed integrated mining system, which consists of mining vessel, vertical lifting pipe, lifting pumps, buffer, flexible riser, umbilical cable and self-propelled mining robot, is presented in Figure 1. Manganese nodules collected by the mining robot are transferred to the buffer and then lifted up to the vessel by lifting pumps. In general, it cost many time and much money in deep-sea test. Therefore, numerical simulation for prediction of dynamic behaviors has to be performed before deep-sea test. Dynamic analysis of such a system is a challenging task because lifting pipe and flexible riser are very long systems. Also, it is need to consider ocean environment such as current, wave and so on. The launching operation is divided into four critical phases: (1) deployment of mining robot and flexible conduit, (2) deployment of lifting pipe, flexible conduit and mining robot, (3) touch-down of mining robot, (4) final launching. this paper concerns about coupled dynamics analysis of the deep-seabed integrated mining system in launching operation according to the changing periods of motion by ship’s RAO and wave spectrum at mining vessel in water depth 5000 meter. The dynamic responses of subsystems are dive