An Assessment of Structure Safety for Basic Insulation Panel of KC-1 LNG Cargo Containment system under Sloshing Load

Abstract

요 약 한국형 LNG선 화물창(KC-1)의 개발은 LNG선의 핵심기술인 화물창시스템의 원천기술을 확보하여 외화절감 및 조선 산업의 경쟁력을 높이는데 그 목적이 있다. 화물창 내부의 액체가 선박의 모션에 의해 생기는 슬로싱 충격 하중에 대한 LNG선의 화물창의 구조 안전성 평가는 중요한 설계 요소가 되었다. 슬로싱 현상에 의한 구조 안전성 을 평가하는 가장 이상적인 방법은 유체 영역과 화물창 구조의 상호 작용을 완벽하게 구현하는 것이다. 그러나 유 체-구조 연성해석은 방대한 계산 시간과 결과의 정확성을 보장하기 어렵기 때문에 불규칙적인 슬로싱 압력을 삼 각파의 형태로 이상화하여 구조 안전성을 평가하였다. 따라서 본 연구에서는 슬로싱 압력은 15/1000초 동안에 최 대 10bar의 압력으로 가정한 삼각파로 고려하였고, 해석 결과 한국형 LNG선 화물창(KC-1)의 보냉 판넬은 슬로싱 하중에 대해 구조적으로 건전한 것으로 평가되었다.Abstract -The purpose of the development of KC-1 LNG cargo containment system is reduction in royalty and increase in competitiveness of shipbuilding industry. An assessment of structure safety for LNG cargo containment system under sloshing load due to ship motion has become an important design element. The ideal way is to implement fully interaction of the fluid domain and the cargo containment system. However the irregular sloshing pressure were idealized in the form of a triangular wave for safety assessment because the fluid-structure interaction analysis is taken the extensive computation time and difficult to ensure the accuracy of the results. In this study, the sloshing load was assumed to be a triangular wave with a maximum pressure of 10 bar during 15/1000 seconds. In the analytic results, the basic insulation panel of KC-1 LNG cargo containment system was assessed to be structurally safe for sloshing load.

Calculation of Boil-Off Gas (BOG) Generation of KC-1 Membrane LNG Tank with High Density Rigid Polyurethane Foam by Numerical Analysis

“…Unlike the double insulation structures of Mark-III and GT96, KC-1 insulation is composed of a single insulation structure that includes a high density rigid polyurethane foam (H-PUF) layer with a blowing agent in its cells [14,15]. The purpose of such design is to simplify geometry of the insulation structure to facilitate easier construction and maintenance while meeting the insulation performance of a double insulation structure [16]. To account for the thermal expansion and contraction phenomenon of LNG, a double-stainless steel-membrane layer, composed of primary and secondary membrane layers, constitutes the inner surface of the tank.…”

“…3, is constructed as a layer to support for the gap between the plywood and the inner hull. Mastic of mastic/air layer is assumed to be of fiberglass/G10 epoxy, and the mastic/air layer is assumed to be a unified layer of a single material that has a composition of 1:3 volume averaged ratio of the epoxy and air [16]. The thermal conductivities of the unified mastic/air layer along with the other insulation materials as a function of temperature is shown in Table 1 [19,20].…”