Submerged Cargo Pump의 진동평가와 공진 회피 설계

Abstract

Cargo Pump (CP) is a vertical and submerged pump which operates at a speed of 1000~2000 rpm. This speed is lower than the speed of horizontal pump. Due to the low rotating speed, measuring and analyzing the natural frequency of CP is of necessity for safe behavior. However, CP systems manufactured in domestic companies have not been still applied the natural frequency analysis and vibration evaluation. Therefore, the purpose of this study is to use the ANSI/HI 11.6-2001standard for analyzing the vibration of CP system. In order to carry out this analysis, an impact testing is firstly performed on the main pipe of CP system. The testing results are then compared with the results obtained from the simulation using MSC. Nastran. The rotating frequency in both testing and simulating process is close to the resonance regions of the 2nd mode. In order to avoid these regions in design, the upper and lower clamps are adjusted in the modal analysis simulating process. This enables to 20% of the error ratio in design to avoid the resonance region.