[ Papers ]

Journal of the Korean Society of Manufacturing Technology Engineers - Vol. 27, No. 5, pp.430-438

ISSN: 2508-5107 (Online)

Print publication date 15 Oct 2018

Received 13 Sep 2018 Revised 18 Sep 2018 Accepted 01 Oct 2018

DOI: https://doi.org/10.7735/ksmte.2018.27.5.430

압축천연가스(CNG) 내압용기 결함에 따른 안전성 평가

장광수^a ; 홍민성^b^{, *}

Safety Evaluations for Defects in CNG Pressure Vessels

Kwang Su Jang^a ; Min Sung Hong^b^{, *}

aDepartment of Mechanical Engineering, Graduate School of Engineering, Ajou University, 206, Worldcup-ro, Yeongtong-gu, Suwon, Gyeonggi-do, 16499, Korea
bDepartment of Mechanical Engineering, Ajou University, 206, Worldcup-ro, Yeongtong-gu, Suwon, Gyeonggi-do, 16499, Korea

Correspondence to: ^*Tel.: +82-31-219-2526 Fax: +82-31-219-1611 E-mail address: mshong@ajou.ac.kr (Min Sung Hong).

Abstract

Based on four types of CNG cylinders, the features, causes of failure, risks, different pressure vessel inspection systems, and safety management techniques were analyzed and organized. Expected fatigue lifetime and burst pressure through external defect test were measured and finite element analysis was conducted for manufacturing process and inspection standard. External defect tests were conducted for three levels of artificial defects on the outer walls of cylinders, and all tests exceeded the pressure-proof test pressures. For the test with the most severe defects, the burst pressure was 431 bar, which was below the pressure test limit, and service life was shortened using finite element analysis. Thus, if internal pressure removal test is introduced to identify defects from the outside of cylinders through precision tests, and heat treatment defects that are the major cause of blowout accidents are found, the safety and security of CNG pressure vessels can be ensured.

Keywords:

Compressed natural gas (CNG), Finite element analysis, Safety evaluation, Pressure vessel

References

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Ministry of Land, Infrastructure, and Transport, 2018, Regulation for Safety of CNG Pressure Vessel, Ministry of Land, Infrastructure, and Transport No. 2018-176 1-5.