Modeling the Consequences of Methane Gas Expansion in a CNG Fuel Stations of Isfahan Province

Introduction: Assessment of the consequences of hazards such as fire and explosion is one of the most urgent and important steps to improve the level of safety in the current stations and those that are in the design process. The purpose of this study was to review the model of CNG Compressed Natural Gas releases and the range of damages to individuals and equipment. Moreover, we examined the observance of safe distance of this station to its surroundings. Materials and Methods: In this study, modeling the effects of fire and explosion on the CNG fuel station in Isfahan province was performed using ALOHA software. In this model, six scenarios were designed to create a hole with a diameter of 0.03m and a gap of 0.2m and width of 0.2 m in a pressure vessel. Results: It was observed that the toxic atmosphere was within the distance of 55 meters at a concentration of 65000 ppm. In the case of a gap, the toxic vapor cloud range could increase to 66 meters. The flammable superpower range was 89meters for the hole but 107 meters for the gap. The thermal radiation from the jet fire to the distance of 25meters was 10 kw/sqm for the hole, but the thermal radiation was 10 kw/sqm for the gap to 35meters. Conclusion: The most dangerous scenario was the Jet Fire, which involved not only the CNG station, but also the municipal parking area. Furthermore, the thermal radiation produced by the gap was greater than the hole with regard to the involved range.

Download Full-text

USE OF COMPRESSED NATURAL GAS ENERGY AT SMALL REDUCING POINTS OF GAS GRID USING ADJUSTABLE POSITIVE DISPLACEMENT GAS EXPANSION MACHINE

MINING INFORMATIONAL AND ANALYTICAL BULLETIN ◽

10.25018/0236-1493-2017-9-0-18-26 ◽

2017 ◽

Vol 9 ◽

pp. 18-26

Author(s):

A.E. Belousov ◽

◽

O.V. Kabanov ◽

G.Kh. Samigullin ◽

I.I. Filatova ◽

...

Keyword(s):

Natural Gas ◽

Compressed Natural Gas ◽

Positive Displacement ◽

Gas Expansion

Download Full-text

A Model for Intact and Damage Stability Evaluation of CNG Ships during the Concept Design Stage

Journal of Marine Science and Engineering ◽

10.3390/jmse7120450 ◽

2019 ◽

Vol 7 (12) ◽

pp. 450 ◽

Cited By ~ 1

Author(s):

Francesco Mauro ◽

Luca Braidotti ◽

Giorgio Trincas

Keyword(s):

Natural Gas ◽

Design Process ◽

Design Stage ◽

Concept Design ◽

Compressed Natural Gas ◽

Hull Form ◽

Intact Stability ◽

Damage Stability ◽

Marine Engineering ◽

Feasible Solutions

To face the design of a new ship concept, the evaluation of multiple feasible solutions concerning several aspects of naval architecture and marine engineering is necessary. Compressed natural gas technologies are in continuous development; therefore, there are no available databases for existing ships to use as a basis for the design process of a new unit. In this sense, the adoption of a modern multi-attribute decision-based method can help the designer for the study of a completely new ship prototype. A database of compressed natural gas ships was generated starting from a baseline hull, varying six hull-form parameters by means of the design of experiment technique. Between the attributes involved in the concept design process, stability is for sure one of the most relevant topics, both for intact and damaged cases. This work describes two approaches to identify the compliance of a ship with the intact stability regulations based on the ship main geometrical quantities. Moreover, a metamodel based on the maximum floodable length concept (damage stability) allows determining the main internal subdivision of the ship. The metamodel outcomes were compared with results from direct calculations on a ship external to the database, highlighting the adequate accuracy given by the developed methods.

Download Full-text

Development of ASME Section X Code for High Pressure Vessels

ASME/USCG 2010 2nd Workshop on Marine Technology and Standards ◽

10.1115/mts2010-0209 ◽

2010 ◽

Author(s):

Norman L. Newhouse ◽

George B. Rawls

Keyword(s):

High Pressure ◽

Natural Gas ◽

Pressure Vessel ◽

Load Sharing ◽

Pressure Vessels ◽

Operating Conditions ◽

Compressed Natural Gas ◽

Qualification Testing ◽

Industry Needs ◽

Pressure Hydrogen

ASME has a project to meet industry needs for pressure vessel Code updates to address storage of high pressure hydrogen. This has resulted in updates to existing B&PV Code, new Code Cases, and new Code requirements. One of the tasks was to develop requirements for high pressure composite reinforced vessels with non-load sharing liners. Originally developed as a Code Case, the requirements have been approved as mandatory Appendix 8 of ASME Section X of the B&PV Code, to be published in July 2010. The allowed pressures of this new Code are from 0.7 MPa (3,000 psi) to 103.4 MPa (15,000 psi). Qualification testing addresses expected operating conditions. Inspection requirements are being developed in cooperation with NBIC. Pressure vessels are being developed that meet the new ASME requirements. Efforts will be made to include additional gases, including compressed natural gas, and additional operational requirements in future revisions. Paper published with permission.

Download Full-text

Design of Compressed Natural Gas Pressure Vessel (Type II) to Improve Storage Efficiency and Structural Reliability

Journal of Pressure Vessel Technology ◽

10.1115/1.4045027 ◽

2019 ◽

Vol 142 (1) ◽

Author(s):

Hyo Seo Kwak ◽

Gun Young Park ◽

Chul Kim

Keyword(s):

High Pressure ◽

Natural Gas ◽

Pressure Vessel ◽

Structural Reliability ◽

Structural Safety ◽

Thickness Variation ◽

Type Ii ◽

Uniform Thickness ◽

Compressed Natural Gas ◽

Metallic Liner

Abstract Type II storage vessel, which consists of a metallic liner hoop wrapped with a carbon fiber-resin composite to work at high pressure, has been widely adopted as the fuel container for compressed natural gas (CNG) vehicles. The general vessel, manufactured by welding enclosures to an open-end cylinder, shows uniform thickness throughout the whole liner, while the high pressure vessel, fabricated by the deep drawing and ironing (D.D.I) and spinning processes, has the integral junction part of cylinder with increased end thickness along the meridian direction. This study established a design method for improvement of failure resistance and inner capacity of the seamless CNG pressure vessel (Type II) through finite element analysis with consideration of thickness variation. Autofrettage pressure is used to enhance fracture performance and fatigue life of the vessel, and variations of stress behaviors in the liner and composite were analyzed during the autofrettage process. The influence of the composite on generation of compressive residual stress was investigated. In order to verify advantages of the D. D. I. and the spinning processes for structural safety at the end closure, the stress distribution considering thickness variation was compared with that with uniform thickness, and the maximum inner capacity objective satisfying structural reliability was obtained. The inner capacity of the proposed model with the ratio of major axis to minor axis, 2.2, was expanded by 4.5. Theoretical equivalent stresses were compared with those from the simulations, and the technique of FEM was verified.

Download Full-text