Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Design of Portable Welded-Nitrogen Vessel (11 kg, 10 L and 50 bar) for Shipbuilding

선박용 휴대형 질소용기(11 kg, 10 L 및 50 bar)의 두께 및 외형 설계

  • Seong, Hansaem (Mechanical Convergence Technology, Pusan Nat'l Univ.) ;
  • Kim, Jaeyeol (Wonkwang Valve Co., LTD.) ;
  • Eom, Taejin (Wonkwang Valve Co., LTD.) ;
  • Kawk, Hyo Seo (Research Institute of Mechanical Technology, Pusan Nat'l Univ.) ;
  • Lee, Kwang O (Research Institute of Mechanical Technology, Pusan Nat'l Univ.) ;
  • Kim, Chul (School of Mechanical Engineering, Pusan Nat'l Univ.)
  • Received : 2016.07.12
  • Accepted : 2017.01.02
  • Published : 2017.04.01
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Abstract

The shipbuilding industry uses large stationary tanks to store low-pressure air, which is used to open and close large shut-off valves. However, when supplying air from the tank to a distant valve, there are problems related to the need for supplementary pipes and the pressure drop during transportation. In this study, a portable welded vessel for storing high-pressure nitrogen (11 kg, 10 L, and 50 bar) was designed to prevent air leakage and improve the convenience of workers. This pressure vessel was elliptical to reduce the number of welded parts, which are structurally weak. The thickness and ratio of the major and minor axes of the pressure vessel were calculated to verify its structure stability at the working pressure (50 bar), and that the proposed weight and capacity were satisfactory. The residual stress caused by the welding process was calculated by performing a transient thermal-structural coupled field analysis using the ANSYS parametric design language (APDL), and the fatigue life of the vessel was verified based on the Goodman criterion.

조선소에서 사용되는 대형 셧오프 밸브의 개폐를 위한 용기의 경우, 저압의 고정식 대형 공기탱크가 사용되고 있는데, 이는 먼 거리에 있는 밸브에 공압을 공급해야 할 경우, 추가 배관이 필요하며 수송도중 압력 강하가 발생하는 문제점이 있다. 이에 본 논문에서는 작업자들의 편의성을 증대시키고, 공기누설로 인한 폭발 방지를 위하여 고압의 휴대형 용접식 질소용기(11 kg, 10 L 및 50 bar)의 설계를 수행하였다. 구조적으로 취약한 용접부를 최소화하기 위하여 용기의 외형을 타원형으로 설계하였으며, 기준 무게 및 용적 충족과 사용압력에 대한 구조안전성을 확립하기 위하여 용기의 두께와 장단축 비를 설계하였다. 또한 용접 잔류응력 예측을 위해 APDL(ANSYS Parametric Design Language)을 이용하여 과도 열-구조 연성해석을 수행하였으며, 내압에 의한 구조안전 및 피로수명을 검증하였다.

Keywords

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