• Title/Summary/Keyword: Membrane-type LNG cargo hold

Search Result 3, Processing Time 0.022 seconds

Optimization of Sheet Arrangement of Membrane Panel in Korean LNG Cargo Containment System (한국형 LNG 화물창 멤브레인의 Sheet 배치 최적화)

  • Kim, Yeong-Su;Ham, Seung-Ho;Park, Kwang-Phil
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.59 no.2
    • /
    • pp.109-117
    • /
    • 2022
  • Membrane panels are installed in LNG cargo-hold in order to endure extremely low temperature LNG. Although there are several types of membranes around the world, Korean LNG cargo containment system is developing to accomplish technology independence from the other countries. The membrane panel of Korean LNG cargo containment system is composed of corrugation and flat sheets which are arranged asymmetrically. It is very important to reduce the number of the type of corrugation sheet because a mold is required as much as the type of the corrugation sheet. Therefore, we proposed an optimization method to minimize the type of the corrugation sheet. For this method, the number of pitches, which is the distance between the centers of two corrugation sheets should be minimized. We also developed optimized arrangement procedure of the flats simultaneously. Finally, the developed optimization program is applied to 174K LNG cargo hold, and the minimum pitch size is found.

Analysis of Thermomechanical Properties Considering the Thermal Expansion Anisotropy of Membrane-Type Fiber-Reinforced Composite Material (멤브레인 형 섬유강화 복합재료의 열팽창 이방성을 고려한 열 기계적 특성 분석)

  • Jeong, Yeon-Jae;Kim, Hee-Tae;Kim, Jeong-Dae;Oh, Hoon-Gyu;Kim, Yong-Tai;Park, Seong-Bo;Lee, Jae-Myung
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.58 no.1
    • /
    • pp.17-23
    • /
    • 2021
  • The membrane-type Liquefied Natural Gas (LNG) cargo tank is equipped with a double barrier to seal the LNG, of which the secondary barrier serves to prevent LNG leakage and mainly uses fiber-reinforced composite materials. However, the composite materials have thermal expansion anisotropy, which deteriorates shape distortion and mechanical performance due to repeated thermal loads caused by temperature changes between cryogenic and ambient during the unloading of LNG. Therefore, in this study, the longitudinal thermal expansion characteristics of the composite materials were obtained using a vertical thermo-mechanical analyzer, and the elastic modulus was obtained through the tensile test for each temperature to perform thermal load analysis for each direction. This is considered that it is useful to secure reliability from the viewpoint of the design of materials for a LNG cargo hold.

A Study on a New Concept for the Structural Strength Assessment to Development of Membrane LNG Cargo Container System under Static Load (멤브레인형 LNG 화물창 개발을 위한 정적 구조 안전성 평가 모델 연구)

  • Hwang, Se Yun;Kim, Yooil;Kang, Joong Kyoo;Lee, Jang Hyun
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.53 no.2
    • /
    • pp.162-169
    • /
    • 2016
  • A new concept of membrane type LNG CCS was proposed. Also, its static behavior was numerically analyzed considering the interaction between primary and secondary barrier together with securing device. Hull deflection was taken into account as an external load, together with temperature distribution across the barriers. The suggested numerical model considers both sliding and contact between the two mating surfaces of both the primary and secondary barrier, and anisotropic material behavior of plywood, R-PUF was also taken into account. Furthermore, detailed local strength was evaluated for the securing device, which is arranged between two barriers to hold the primary barrier. It was confirmed through the numerical analysis that the new concept of membrane type CCS was structurally safe under static loading condition and securing concept was structurally reliable.