Thermal and Mechanical Coupled Analysis of Marine Composite Cryogenic Pipeline

2019 ◽  
Author(s):  
Haitao Hu ◽  
Jun Yan ◽  
Baoshun Zhou ◽  
Zhixun Yang ◽  
Liang Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Natural Gas ◽  
Extreme Temperature ◽  
Liquefied Natural Gas ◽  
Coupled Analysis ◽  
Temperature Load ◽  
Structural Responses ◽  
Bending Loads ◽  
Marine Composite ◽  
Cryogenic Pipeline

Abstract Marine composite cryogenic pipeline is one of the key equipment for offshore gas explorations, which is mainly used in the transmission of liquefied natural gas. Due to the harsh marine environment and extreme temperature of transmission medium, the marine composite cryogenic pipeline needs to bear both the tensile and bending loads caused by marine environments and the ultra-low temperature load caused by transmission medium. Due to the extremely low temperature of liquefied natural gas, about −163 °C, the structure and the composed material of cryogenic pipelines will be faced greatly challenges. Previous studies have considered mechanical properties or temperature loading separately. In this research, the structural performance of the marine composite cryogenic pipeline under the combined action of mechanical loads and thermo-load is studied with numerical methods. The framework of the coupled mechanical and thermo-analysis for the structure of composite cryogenic pipeline is established. The numerical results show that the temperature distribution has great impacts on the structural responses of the cryogenic pipeline. The coupled mechanical and thermo analysis of the cryogenic pipeline is proved to be necessary. The established method and framework provide a reference for the engineering design and application of the marine composite cryogenic pipeline.

Investigation of fatigue performance of low temperature alloys for liquefied natural gas storage tanks

2015 ◽  
Vol 229 (7) ◽  
pp. 1300-1314 ◽  
Author(s):  
Dong-Jin Oh ◽  
Jae-Myung Lee ◽  
Byeong-Jae Noh ◽  
Wha-Soo Kim ◽  
Ryuichi-Ando ◽  
...  
Keyword(s):  
Low Temperature ◽  
Natural Gas ◽  
Structural Integrity ◽  
Liquefied Natural Gas ◽  
Operating Conditions ◽  
Production Costs ◽  
Fatigue Performance ◽  
Nickel Steel ◽  
Storage Tanks ◽  
Operating Life

One of the most important issues associated with liquefied natural gas (LNG) storage tanks, such as LNG carrier cargo tanks and land LNG tanks, is their structural integrity. In order to ensure the operating life and safety of LNG storage tanks used under operating conditions such as thermal and cyclic loadings, the securing of safety evaluations for fatigue performance is considered to be of particular importance. There have been various efforts to reduce the production costs of LNG storage tanks, such as the optimum selection of materials and the development of new low temperature materials. This, the motivation of this study is to evaluate new material candidates for LNG storage tanks. This study begins with a comprehensive review of the characteristics of low temperature alloys such as SUS 304L, Invar, A5083 and 9% Ni steel that are widely used for LNG storage tanks. Then, the fatigue characteristics of a newly developed low temperature material, 7% nickel steel are investigated. Finally, the fatigue performance of 7% nickel steel is compared with that of 9% nickel steel.

HFI Welded Steel Pipes for Low Temperature Pipelines

2016 ◽  
Author(s):  
Holger Brauer ◽  
Manfred Veit ◽  
Michael Stiller ◽  
Lutz Grube ◽  
Frank Meyer
Keyword(s):  
Low Temperature ◽  
Natural Gas ◽  
Alternative Energy ◽  
Liquefied Natural Gas ◽  
Austenitic Steels ◽  
Energy Sources ◽  
Hydrogen Energy ◽  
Pipe Material ◽  
Line Pipe ◽  
Pipe System

Due to an ever increasing endeavor for the reduction of greenhouse gas emissions over the next few decades, with a gradually increasing demand for energy world-wide and despite a society which is becoming more and more civilized and industrialized, the actual challenge in handling this problem is intensified by decreasing sources of energy, a global economic recession as well as energy market instabilities. Replacing fossil energy sources such as oil with alternative energy concepts is at best difficult because of the high initial investment costs needed installing alternative energy concepts. As an answer to the problems faced, the industry offers several solutions ranging from advanced technologies with a high efficiency ratio such as fuel cell and hydrogen energy, up to and including alternative new or renewable energy sources such as solar, hydro and wind power. One of the major solutions for the transitional period to economical and reliable renewable energies is considered to be the use of Liquefied Natural Gas (LNG). To accommodate for these requirements, Salzgitter Mannesmann Line Pipe has continuously developed highly sophisticated materials in the form of bainitic pipes for the transportation of gaseous or liquefied medium at ultra-low temperatures. In the first part of this presentation paper the process route as well as the material and pipe properties will be shown and explained. In cooperation with our construction partner Fernwaerme-Technik (FW), the bainitic pipes were used to construct a special multi-pipe system for the conveyance of liquefied natural gas (LNG) at a temperature of −162 °C. The pipe system as well as results from the field testing is presented below and tests have been conducted on this system for three years using liquid nitrogen. It can be shown, that not only the low temperature pipe material requirements for transportation of LNG are fulfilled, moreover it offers further potential as an alternative for the replacement of expensive austenitic steels applied at temperatures down to −196°C.

A Comparison of Fracture Toughness and Fatigue Crack Propagation Characteristics of High Manganese and Nickel Steels

2018 ◽  
Author(s):  
Jeong-Yeol Park ◽  
Myung-Hyun Kim
Keyword(s):  
Fracture Toughness ◽  
Fatigue Crack ◽  
Low Temperature ◽  
Natural Gas ◽  
Structural Integrity ◽  
Liquefied Natural Gas ◽  
Manganese Steel ◽  
Nickel Steel ◽  
High Manganese ◽  
High Manganese Steel

Recently, demands for liquefied natural gas (LNG) are increased by developing countries such as China, India and Middle East area. In addition, the International Maritime Organization (IMO) reinforced regulations to avoid the serious environmental pollution. This trend has led to manufacturing and operating various LNG vessels such as liquefied natural gas carrier (LNGC), floating liquefied natural gas (FLNG) and very large gas carrier (VLGC). In the design of LNG vessels, the structural integrity of LNG storage tank is of significant importance to satisfy the service conditions. In order to secure structural integrity, LNG storage tank is fabricated with low temperature materials. In general, low temperature materials such as SUS304L, Invar alloy, Al 5083-O, nickel alloy steel and high manganese steel exhibit excellent fatigue and fracture performances at cryogenic temperature. In particular, high manganese steel has attracted interest because they are potentially less expensive than the competing other low temperature materials. This study compares the fracture toughness and fatigue crack growth characteristics of high manganese steel with those of nickel steels. In addition, fracture toughness and fatigue crack growth rate tests for various nickel steels are conducted according to BS 7448 and ASTM E647, respectively. In order to obtain less conservative design values, the results of high manganese steel and various nickel steels were compared to those of BS7910. As a result, the CTOD value of high manganese steel is higher than that of 9% nickel steel at cryogenic temperature. In case of FCGR, the high manganese steel and 9% nickel steel are found to be similar to each other.

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