LNG저장탱크 코너프로텍션의 설계 최적화에 관한 연구

The full containment Liquefied Natural Gas(LNG) storage tank is based on a double liquid container concept: two separate containers, one within the other, are capable of containing the LNG. The outer concrete tank provides comer protection(secondary containment) to withstand and safely contain any spill from the inner tank. The comer protection is installed on inside comer surface of outer concrete tank. Because of high and complex stresses, comer protection is designed by ASME section VID Div. 2, Appendix 4 on behalf of API 620 which is main design code for LNG tank. Design guidelines to determine design factors such as liner thickness and knuckle radius are not well understood because Appendix 4 is the design method not based on equation but FEM. Recently, the volume of LNG tank shows a tendency to increase. So it is necessary to set up the design guidelines to cope with change of LNG tank capacity and height/diameter ratio. In this paper, optimum design of comer protection was performed and the design guidelines were suggested by the results of FEM for LNG tanks which have different capacities and height/diameter ratio.