|Abstract||When operating an LNG carrier, maintaining the internal temperature of LNG tanks is one of the most important factors. In order to transport cryogenic LNG, insulation panels are installed on the inner walls of the LNG tanks. Meanwhile, during the production process of the LNG tanks, the inner walls of the LNG tanks are not flat and can have flexion. If the insulation panels to be installed on the inner walls of the LNG tanks are not flat and their slopes are large, the insulation efficiency may decrease, and dynamic fatigue may increase. Therefore, wedges to support the insulation panels are installed on the inner walls of the LNG tanks. |
In addition, mastic ropes are installed under the insulation panels to fill the gap between the inner walls and the insulation panels. In this process, if the mastic ropes are excessively used, the unnecessary cost is incurred. On the other hand, if the usage of the mastic ropes decreases, the insulation panels may be inclined, and the insulation efficiency may decrease. Therefore, in this study, we proposed an optimization method to minimize the total amount of mastic ropes used in the membrane-type LNG tanks while satisfying the flatness of the insulation panels within the allowable criteria. To verify the effectiveness of the proposed method, it was applied to the examples and the result was compared with the manual design. As a result, it was confirmed that the proposed method could reduce the usage of the mastic ropes by about 30% as compared with the manual design.