A Study on the Internal Flow of the Mixed Flow Pump for Deep-Sea Mineral Lifting System by CFD

In order to develop the minerals on the seabeds a research project was organized by developed countries including the USA, France and Japan from the 1970's to the 1980's. The current situation such as the price increases of natural resources indicates that the technological development to procure stable supply lines are urgently needed in Korea, as they depend entirely on imports to secure mineral resources like nickel, copper, cobalt and manganese. Mineral resource development technology was lagging behind in Korea, but they have made it a priority to accelerate their efforts to develop deep seabeds. The development of lifting pumps that lift minerals to a mining vessel are one of the vital parts of the commercial mining process. The Lifting pump is a kind of special pump which has a wider passage way for minerals to flow. The performance of the mixed flow pumps which lift minerals have not been studied widely and there is scarce data on their performance. More research is therefore necessary. The purpose of this study is to investigate internal flow and its effect on the performance of the mixed flow pump for developing the pump's performance. A numerical analysis was performed by commercial code CFX-11 based on flow rate and length of flexible tube. The rated rotational speed of the impeller is 1750rpm. Turbulence model, k-ω SST was selected to guaranty a more accurate prediction of flow separation. The experimental results such as head, efficiency and the brake horse power of the mixed flow pump were compared with the numerical analysis results. The simulated results are in good agreement with the experimental results and showed that its efficiency and the head of the pump are related mainly to the flow rate and the length of flexible tube. A lesser flow rate caused more secondary flow through the guide vane passage. The length of flexible tube and flow rate exert much more influence on the pump's performance than the shape of the flexible tube.제 1 장 서 론 1.1 연구 배경 1 1.2 국·내외 연구현황 2 1.3 연구목적 3 제 2 장 수치해석기법 2.1 수치해석 기법 5 2.2 설계사양 11 2.3 형상모델링 15 2.4 계산격자 22 2.5 경계조건 및 계산조건 26 제 3 장 양광펌프의 성능특성 3.1 성능곡선 29 3.2 Streamline 31 3.3 압력분포 33 3.3.1 펌프내부에서의 압력분포 33 3.3.2 임펠러 내부에서의 압력분포 33 3.3.3 가이드베인 유로에서의 압력분포 42 3.3.4 펌프 각단에서의 속도 및 압력변화 53 3.4 속도벡터 61 3.5 유연관 형상에 따른 성능 66 제 4 장 결론 7