• Journal of Welding and Joining
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• v.28 no.2
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• pp.27-31
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• 2010

Generally, angle pieces at the corners of cargo tank of membrane type LNG carrier ship are manually welded, due to their various shapes and positions. In this study, a GTA welding robot system was developed in order to improve productivity, which consists of a 7-axis manipulator, a system controller, a GTA welding power source, and peripheral devices. The welding system is characterized by capabilities of welding corrugated work pieces as well as 90/135 degree linear work pieces, and controlling the entire weld cycle automatically. The developed system was field tested on actual work pieces and its performance was proven to be successful.

• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.51-58
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• 2013

Recently, there has been an increase in the demand for natural gas as a source of clean energy, which has increased the demand for LNG carriers. However, LNG carriers require a capital investment to obtain equipment for the regasification process, which prevents fires and explosions. Thus, on account of NIMBY, a CNG carrier is suggested that eliminates the need for regasification equipment. Meanwhile, carbon dioxide emissions are more and more regulated by international conventions such as the Kyoto Protocol. Because of this, $CO_2$ carriers have also received international attention as a methodology to transport and store $CO_2$ cargoes. Several vessels or tanks to transport and store $CO_2$ gas have been studied in various countries. This paper proposes a conceptual design for a 20ft container shaped tank to effectively transport small cargoes of $CO_2$ and CNG. The proposed pressure vessel or tank will be carried by a conventional containership or special cargo ship. The influences of the design parameters for proposed pressure vessel or tank. Including the materials, scantlings, and shape of the pressure vessel, are studied theoretically and computationally.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.89-97
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• 2020

Container vessels continue to grow in size, led by global shipowner. Large ships can be loaded more cargo at a time, reducing the cost of transportation per teu. this eventually leads to economies of sale, in which the production cost per unit decreases with increasing output. in accordance with the 70th Convention of the Marine Environment Protection Committee of the International Maritime Organization, as of January 1, 2020, MARPOL Annex VI Regulation 14.1.3 will be effective. All vessels must be meet these criteria to reduce Sox emissions and reduce NOx emissions by reducing the content of manned sulfur oxides from 3.5% to less than 0.5%, otherwise IACS Member States Entry to the port is denied. in order to do that need to LNG storage tank. in this study characteristic of the material after line heating (600℃,700℃,800℃,900℃) of 9% Ni steel used in the manufacture of LNG fuel tank of ship were verified using by mechanical test. In the heating method by line heating. The initial properties of steel are changed by variables such as temperature, time, speed. The experimental data of line heating presented in this paper confirmed that the initial change of 9% Ni steel could be minimized.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.16-28
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• 2008

Recent growth in LNG market has led dramatic increase in new buildings of LNG carriers and several large LNG carriers are now being constructed by shipbuilders in Korea. Large size LNG carriers has brought keen concerns on the issue regarding safety of cargo containment systems and sloshing impact load which is the critical source of loads on the membrane type containment systems. Up to the present, the best way to properly assess sloshing impact pressures on surrounding walls is a model testing for wide-ranged excitation conditions. These impact pressures obtained from model tests sometimes need to be interpreted to full-scale values and in the near future this necessity will be strengthened for more rigorous and direct safety assessment of LNG cargo containment system. In this paper, a basic experimental study is carried out with two different sized, 2D identically shaped model tanks excited in simple translational motions. Relationships between pressures of different sized model tanks are investigated Model tanks are filled with fresh water and equipped with same sized pressure sensors.

• Journal of Welding and Joining
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• v.27 no.5
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• pp.74-80
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• 2009

The membrane of the LNG carriers consists of thin strips of INVAR(Fe-36%Ni) steel plates, and the junction between INVAR strips is fabricated by welding. Thousands of the raised edge joints, regularly spaced, are located around all the side of the tank corner near the transverse bulkhead, and TIG welding is manually made on the top of the raised edges. Since the thickness of all the laminated edge plies is extremely thin and the weld position is under a bad accessibility, highly skilled workers are required to perform welding relatively for a long welding time. An alternative scheme for the corner membrane fabrication is proposed in the study to improve the installation workability and thus productivity. The scheme replaces the welded edges with the preformed corrugation ones. A panel strip with regularly-spaced corrugations is installed at the corner instead of the individual flat strip of which edge is vertically raised to be welded with the adjacent strip. In the study, a series of the evaluation on the corrugated edge members was performed to assess the applicability to the real LNG carrier fabrication. Opening displacement at the raised edge was experimentally examined. Elastic stiffness regressed from the displacement was nearly same in both edge types. Edge displacement and local stresses were calculated under hydrostatic pressure and temperature change due to liquefied cargo. Fatigue test was performed on both corrugated and welded edge specimens consisting of two or five plies of invar strips. Fatigue strength of the corrugated specimens was not less than that of the welded specimens.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.3
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• pp.269-274
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• 2009

Recently, the construction of Liquefied Natural Gas Carriers(LNGC) is being promoted larger and larger depending on long voyage. In 1950 years, $5,000m^3$ class of LNGC had been changed to $71,500m^3$ class in 1973. and to $210,000-266,000m^3$ class in 2007. Especially, the system of main engines and cargo control, Re-liquefaction of natural gases have become possible in LNGC. This research deals with the LNG projects, world markets of energy and developing tendency of liquefied natural gas carriers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.225-231
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• 2013

Liquefied gas carriers generally transport cargoes of flammable or toxic nature. Since these cargoes may cause an explosion, fire or human casualty, the accommodation spaces, service spaces and control stations of liquefied gas carriers should be so located as to avoid ingress of gas. For this reason, the paragraph 8.2.9 of IGC Code in IMO requires that the height of vent exits should be not less than B/3 or 6 m whichever is greater, above the weather deck and 6 m above the working area and the fore and aft gangway to prevent any concentration of cargo vapor or gas at such spaces. Besides as known, the LNG market has been growing continually, which has led to LNG carriers becoming larger in size. Under this trend, the height of a vent will have to be raised considerably since the height of a vent pipe is generally decided by a breadth of a corresponding vessel. Accordingly, we have initiated an examination to find an alternative method which can be used to determine the safe height of vent masts, instead of the current rule requirement. This paper describes the dispersion characteristics of boil-off gas spouted from a vent mast under cargo tank cool-down conditions in the membrane type LNG carriers.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.2
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• pp.103-108
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• 2019

A new state-of-the-art sloshing research equipment has developed to perform the model test of LNG tanks for the safer design of LNG cargo containment system in violent sloshing phenomena. This sloshing test system has developed by the Samsung Ship Model Basin (SSMB) and thoroughly verified. The accuracy of the motion of hexapods equipment for the excitation of a model tank has been verified. The maximum displacement in six degrees of freedom, harmonic motions of various frequencies, and irregular motions in wave conditions are measured and compared with input signals. In order to confirm the reliability of the post-processing program for measured impact pressure, the post-processed results were compared with those of the reference institute. A benchmarking sloshing test using 1/50 scale model of 160K LNGC tank was conducted for the verification of the whole testing system. The partial filing levels were considered. As a result of the experiment, it is confirmed that the results are in good agreement with those of the reference institute.

• Land and Housing Review
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• v.6 no.2
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• pp.61-66
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• 2015

This study is the realization of natural gas as ways to advance the South and the continental railway linking basic research was conducted on railway transport. Summary data on the Status of North Korean railway which was to have reviewed the case of LNG railway transportation in Japan and China is becoming an LNG tank containers by rail transportation is done. In the case of Korea, the stability of railway transportation through the development of LNG tank containers and rail transportation pilot project was tested. It was set up and the basic directions of freight trains transport routes and methods for rail transport 7.5 million tons of natural gas per year. TKR ~ TSR between the LNG transportation business is an existing railway south. North. Russia gas pipeline (PNG) instead of a separate project to replace the business SRX (Silk Road Express) is a symbolic project for the early realization of the Eurasian railway linking policy. This study may give greater meaning to secure the iconic railway transport route for continental transport of containers and bulk cargo (coal, ores, etc.).

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.48-56
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• 2007

Wash primer was applied to cargo tank of Membrane-LNG Carrier (M-LNGC) for corrosion resistance and high bond-strength with the mastic. However, a lack of bond-strength verification at high thickness wash primer coating resulted in strict coating thickness control. Therefore wash primer was controlled below DFT(Dry Film Thickness) $30{\mu}m$. In order to develop the wash primer satisfying GTT (GAZ TRANSPORTAION TECHNIGAZ) standard even at high thickness, we evaluated coating properties such as wash primer/mastic bond-strength, corrosion resistance, as well as workability for the newly formulated wash primer materials. The newly formulated wash primer had high bonding-strength to mastic even at high thickness and had proper corrosion resistance and workability suitable to yard condition.