scholarly journals A Study on Cross-Shaped Structure of Invar Material Using Cold Wire Laser Fillet Welding (PART I: Feasibility Study for Weldability)

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1385 ◽  
Author(s):  
Du-Song Kim ◽  
Changmin Pyo ◽  
Jaewoong Kim ◽  
Jisun Kim ◽  
Hee-Keun Lee
Keyword(s):  
Natural Gas ◽  
Fiber Laser ◽  
Feasibility Study ◽  
Coefficient Of Thermal Expansion ◽  
Welding Distortion ◽  
Fillet Welding ◽  
Manufacturing Method ◽  
Welding Part ◽  
Increasing Demand ◽  
Trial And Error Method

With the need for eco-friendly energy increasing rapidly due to global environmental issues, there is a rapidly increasing demand for liquefied natural gas (LNG). LNG is liquefied at minus 163 degrees Celsius, and its volume decreases to 1/600, giving it a relatively higher storage and transport efficiency than gaseous natural gas (NG). The material for the tanks that store cryogenic LNG must be a material with high impact toughness at cryogenic temperatures. Invar, which contains 36% nickel and has a very low coefficient of thermal expansion, is used for the membranes and corner structures of LNG cargo holds. The cross-shaped Invar structure used in an LNG cargo hold is manufactured through manual tungsten inert gas (TIG) fillet welding, which causes welding distortion and weldability problems. This study is a feasibility study that aims to reduce welding distortion, increase weldability with welding speed, and reduce the steps in an existing process by half by replacing the existing manufacturing method with automatic fiber laser fillet welding. Laser welding using fiber laser parameters are controlled for 1.5 and 3.0 mm thick Invar materials and weldability is secured through cross-section observation. Then, the optimal welding conditions with top and back beads secured are derived through a trial and error method.

scholarly journals A Study on Lap Joint Welding of Thin Plate ASTM F1684 Using Fiber Laser Welding

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 428
Author(s):  
Jaewoong Kim ◽  
Younghyun Kim ◽  
Jisun Kim ◽  
Yongtai Kim ◽  
Dongwoo Kim ◽  
...  
Keyword(s):  
Shear Strength ◽  
Laser Welding ◽  
Fiber Laser ◽  
High Speed ◽  
Coefficient Of Thermal Expansion ◽  
Lap Joint ◽  
Fiber Laser Welding ◽  
Cross Sectional ◽  
Shear Strength Test ◽  
Welding Part

The International Maritime Organization (IMO) has developed stricter regulations on emission standards for sulfur oxides, etc., and the demand for Liquefied Natural Gas (LNG) is increasing as an alternative to satisfy these standards. This study relates to fiber laser welding, an approach which offers high-speed welding and low welding deformation for ASTM F1684, which has a low coefficient of thermal expansion (CTE) even in a cryogenic environment. In this study, through three preliminary experiments using 0.25 mm thick Invar, the conditions required to secure sufficient penetration depth and back bead were identified. Through the cross-sectional observation analysis, the welding conditions without defects were identified and the trend of penetration shape according to increasing welding speed was identified. Following a lap joint laser welding experiment under the secured conditions, the mechanical properties were evaluated through the shear strength test and the heat influence range of a fiber laser was identified through the temperature measurement of a welding part. As a result, it was confirmed that the shear strength of the lap joint laser welding part was 86.8% that of the base metal.

scholarly journals ON THE CONSTRUCTION OF HSIN-TA LNG TERMINAL IN TAIWAN

1986 ◽  
Vol 1 (20) ◽  
pp. 189
Author(s):  
Shih-sheng Paul Lai ◽  
Cheng-shiun Lee
Keyword(s):  
Natural Gas ◽  
Feasibility Study ◽  
Land Reclamation ◽  
Soil Improvement ◽  
Liquefied Natural Gas ◽  
Increasing Demand ◽  
Under Construction

Since 1984 Hsin-Ta LNG Terminal has been under construction for the purpose of importing liquefied natural gas because of increasing demand and possible depletion of natural gas in Taiwan. Several alternatives were taken into account during the feasibility study. The Terminal is built with only a southern breakwater due to its good natural coastal conditions. Each construction item has been coordinated closely in order to advance the schedule. The first phase of land reclamation was finished by 1986. Three tanks have been under construction since soil improvement was finished. The entire project will be completed in 1989.

Liquefied Natural Gas for Superconducting Energy Pipelines: A Feasibility Study on Electrical Insulation

2021 ◽  
Author(s):  
Chuansheng Zhang ◽  
Chengyan Ren ◽  
Shuai Zhang ◽  
Hanwen Xue ◽  
Yanxing Zhao ◽  
...  
Keyword(s):  
Natural Gas ◽  
Feasibility Study ◽  
Liquefied Natural Gas ◽  
Electrical Insulation

scholarly journals Assessing Natural Gas Versus CO2 Potential Underground Storage Sites in Greece: A Pragmatic Approach †

2022 ◽  
Vol 5 (1) ◽  
pp. 98
Author(s):  
Vagia Ioanna Makri ◽  
Spyridon Bellas ◽  
Vasilis Gaganis
Keyword(s):  
Natural Gas ◽  
Co2 Storage ◽  
Sedimentary Basins ◽  
Hydrocarbon Exploration ◽  
Greenhouse Gas Mitigation ◽  
Underground Storage ◽  
Pragmatic Approach ◽  
Increasing Demand ◽  
Salt Caverns

Although subsurface traps have been regularly explored for hydrocarbon exploration, natural gas and CO2 storage has drawn industrial attention over the past few decades, thanks to the increasing demand for energy resources and the need for greenhouse gas mitigation. With only one depleted hydrocarbon field in Greece, saline aquifers, salt caverns and sedimentary basins ought to be evaluated in furtherance of the latter. Within this study the potential of the Greek subsurface for underground storage is discussed. An overview and re-evaluation of the so-far studied areas is implemented based on the available data. Lastly, a pragmatic approach for the storage potential in Greece was created, delineating gaps and risks in the already proposed sites. Based on the above details, a case study for CO2 storage is presented, which is relevant to the West Katakolo field saline aquifer.

scholarly journals A Study on Welding Deformation in Fiber Laser Welding of 9% Nickel Steel through Finite Element Analysis Part I: Implementation of Welding Heat Source Model

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2188
Author(s):  
Changmin Pyo ◽  
Jaewoong Kim ◽  
Du-Song Kim
Keyword(s):  
Natural Gas ◽  
Heat Source ◽  
Laser Welding ◽  
Fiber Laser ◽  
Source Model ◽  
Heat Transfer Analysis ◽  
Welding Deformation ◽  
Nickel Steel ◽  
Fiber Laser Welding ◽  
Heat Source Model

Due to various environmental regulations, the demand for natural gas, i.e., a clean energy, is expected to increase continuously. In terms of efficient storage and transportation of natural gas, liquefied natural gas has an advantageous volume of 1/600 compared to natural gas, but the materials that can be used at a cryogenic temperature of −163 °C are limited. A 9% nickel steel is a material recommended by IMO through IGC. It has excellent mechanical properties compared to other cryogenic materials, but its use has been limited due to its disadvantages in arc welding. Therefore, the main topic of this study is the automatic welding of 9% nickel steel using fiber laser and its purpose is to predict the welding deformation during fiber laser welding. First, an investigation was conducted to find the fiber laser welding heat source. A model that can cover all the models in prior studies such as curve, exponential, conical, conical-conical combination, and conical-cylinder combination models was proposed and the heat source model was constructed in a multi-layer format. Heat transfer analysis was performed using the ratio of a heat source radius and heat energy of each layer as a variable and the pass or failure of a heat source was determined by comparing the analysis results to the experimental results. By changing the variables in conjunction with the optimization algorithm, the main parameters of a passed heat source model were verified in a short period of time. In addition, the tendency of parameters according to the welding speed was checked.

Investment Analysis of New Port Development Project As a Solution to Overload Problems in Long Ports

2019 ◽  
Vol 19 (2) ◽  
pp. 61-70
Author(s):  
Pandi Aditiya ◽  
Ahmad Herison ◽  
Ika Kustiani ◽  
Amril Ma’ruf Siregar
Keyword(s):  
Feasibility Study ◽  
Net Present Value ◽  
Payback Period ◽  
Development Project ◽  
Cost Ratio ◽  
Present Value ◽  
Port Development ◽  
Benefit Cost Ratio ◽  
Increasing Demand ◽  
Benefit Cost

The increasing demand for port services at the Panjang port causes high levels of ship queues. The solution to overcome this problem is to build a new port. However, this new port construction project has not yet conducted a feasibility study. The purpose of this study is to assess the feasibility of port development in the Panjang district of Bandar Lampung in terms of investment or financial aspects. The methods are Benefit-Cost Ratio, Net Present Value, Payback Period, and Internal Rate of Return. The results of the feasibility study of the most profitable investment are in the seventh scenario, the Net Present Value (NPV) of Rp. 463,292,122,605.34, the BCR result of 1.2959, the IRR yield of 12.11% and the Payback Period (PP) occur in the year to thirty-seventh with an economic age of 60 years. The conclusion is that the construction of a new port can be a solution to overcome the overload of Panjang port.

Feasibility study on pressure swing sorption for removing H2S from natural gas

2004 ◽  
Vol 59 (12) ◽  
pp. 2401-2406 ◽  
Author(s):  
Li Zhou ◽  
Miao Yu ◽  
Limei Zhong ◽  
Yaping Zhou
Keyword(s):  
Natural Gas ◽  
Feasibility Study ◽  
Pressure Swing
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