Design and Construction of LNG Storage Tanks E-Book

Josef Rötzer

• Herausgeber: Wiley-VCH
• Kategorie: Wissenschaft und neue Technologien
• Serie: Beton-Kalender Series
• Sprache: Englisch
• Veröffentlichungsjahr: 2019

Seitenzahl: 201

Beschreibung

Weltweit wird die Nutzung von Erdgas als Primärenergieträger noch über Jahrzehnte unverzichtbar bleiben. Dies gilt sowohl für Industrie- und Schwellenländer als auch für Entwicklungsländer. Bedingt durch die geringen Verunreinigungen gilt Erdgas unter den fossilen Brennstoffen als ein klimaschonender, da CO2-Emissionen armer, aber auch als ein bezahlbarer Energieträger. Um den Transport über weite Strecken wie auch über Ozeane zu ermöglichen - und damit eine wirtschaftliche und politische Alternative zu Pipelines zu erzeugen - wird das Gas unter erheblicher Volumenreduktion verflüssigt und mit Schiffen transportiert. An den Export- und Importhäfen sind Flüssiggastanks zur temporären Lagerung und zur weiteren Nutzung erforderlich. Die Tendenz zu kleineren Verflüssigungs- bzw. Verdampfungsanlagen mit den zugehörigen Lagertanks für die Nutzung als Schiffstreibstoff hat neue Marktteilnehmer hervorgebracht, die oftmals noch nicht über die erforderliche Erfahrung und technische Kompetenz verfügen. Der Verweis auf alle vorhandenen Normen reicht nicht aus, um widerspruchsfreie und dem Stand der Technik entsprechende Vorgaben und Anforderungen zu definieren. Durch die Umstellung auf europäische Normung wurden die Überarbeitung und Anpassung der vorhandenen nationalen Normen auf einen europäischen Standard unumgänglich. Komitees und Normenausschüsse auf nationaler und internationaler Ebene haben die Arbeit aufgenommen, um die Normenreihe EN 14620 zu aktualisieren und zu ergänzen. Aber auch in den USA werden die entsprechenden Vorschriften aktualisiert. Die Überarbeitung der 2011 erstmals erschienenen amerikanischen Vorschrift des American Concrete Institute ACI 376 "Requirements for Design and Construction of Concrete Structures for the Containment of Refrigerated Liquefied Gases" wird im Frühjahr 2019 abgeschlossen und die Vorschrift mit detaillierten Angaben zu Planung und Ausführung im Herbst veröffentlicht. Das vorliegende Buch gibt einen Überblick über den Stand der Technik hinsichtlich Planung und Ausführung von Flüssigerdgastanks (LNG-Tanks). Da die Thematik sehr umfangreich und vielschichtig ist, wird hier eine Einführung in die einzelnen Bereiche gegeben, wie zum Beispiel Anforderungen und Auslegung im Betriebszustand, thermische Auslegung, Flüssigkeits- und Gasdruckprüfung, Untersuchung des Baugrunds und zulässige Setzungen, Berechnung und Modellierung der Betonstruktur sowie die besonderen Einwirkungen aus Feuer, Explosion und Impact. Auch die dynamische Berechnung mit der Theorie der schwappenden Flüssigkeit wird dargestellt.

Leseprobe

Table of Contents

Cover

Editorial

About the Author

1 Introduction

Reference

2 History of Natural Gas Liquefaction

2.1 Industrialisation and Energy Demand

2.2 The Beginnings of Gas Liquefaction

2.3 The First Steps Towards Transport in Ships

2.4 Algeria Becomes the First Exporter

2.5 Further Development with Peak‐Shaving Plants

2.6 The First German LNG Tank in Stuttgart

2.7 Wilhelmshaven – the Attempt to Establish a German Receiving Terminal

2.8 The Liquefaction of Gas in Australia

2.9 Pollutant Emissions Limits in the EU

References

3 Regulations and their Scope of Applicability

3.1 History of the Regulations

3.2 EEMUA Publication No. 147 and BS 7777

3.3 LNG Installations and Equipment – EN 1473

3.4 Design and Construction of LNG Tanks – EN 14620

3.5 API 620 – the American Standard for Steel Tanks

3.6 API 625 – Combining Concrete and Steel

3.7 ACI 376 – the American Standard for Concrete Tanks

References

4 Definitions of the Different Tank Types

4.1 Definitions and Development of the Different Types of Tank

4.2 Single Containment Tank System

4.3 Double Containment Tank System

4.4 Full Containment Tank System

4.5 Membrane Tank System

References

5 Performance Requirements and Design

5.1 Performance Requirements for Normal Operation

5.2 Thermal Design

5.3 Hydrostatic and Pneumatic Tests

5.4 Soil Survey, Soil Parameters and Permissible Settlement

5.5 Susceptibility to Soil Liquefaction

References

6 Tank Analysis

6.1 Requirements for the Analysis of the Concrete Structure

6.2 Requirements for the Model of the Concrete Structure

6.3 Strut‐and‐Tie Models for Discontinuity Regions

6.4 Liquid Spill

6.5 Fire Load Cases

6.6 Explosion and Impact

References

7 Dynamic Analysis

7.1 Theory of Sloshing Fluid

7.2 Housner's Method

7.3 Veletsos' Method

7.4 Provisions in EN 1998‐4, Annex A

7.5 Seismic Design of LNG Tanks

References

8 Construction

8.1 Construction Phases and Procedures

8.2 Wall Formwork

8.3 Reinforcement

8.4 Prestressing

8.5 Tank Equipment (Inclinometers, Heating)

8.6 Construction Joints

8.7 Curing of Concrete Surfaces

References

9 Summary

Index

End User License Agreement

List of Tables

Chapter 2

Table 2.1 Conversion of units of measurement for energy.

Table 2.2. LNG export terminals in Australia in operation as of 2012.

Table 2.3. CSG LNG export terminals planned as of 2012.

Table 2.4. LNG export terminals planned in Australia.

Chapter 3

Table 3.1 Physical properties of gases according to EN 14620‐1.

Table 3.2 Type of steel depending on stored product and type of tank.

Chapter 4

Table 4.1. Definitions of the tank types in the regulations.

Chapter 5

Table 5.1 Partial load factors for abnormal actions.

Table 5.2 Hydrostatic tests for different tank types.

Table 5.3 Permissible settlement according to ACI 376 and BS 7777.

Table 5.4 Soil surveys required by ACI 376.

Chapter 6

Table 6.1 Mechanical properties of cryogenic reinforcement.

Chapter 7

Table 7.1 Tables of

C

i

coefficients for rigid impulsive pressure.

Table 7.2 Tables of

C

c

coefficients for convective pressure.

Table 7.3 Definitions of various design earthquakes.

Table 7.4 Equivalent spring constants.

Table 7.5 Damping ratios.

List of Illustrations

Chapter 1

Fig. 1.1 Development of energy demand [1].

Fig. 1.2[[dot]] Gas price developments since 2000 [1].

Fig. 1.3[[dot]] Regional distribution of natural gas potential [1].

Chapter 2

Fig. 2.1[[dot]] The scene of the Cleveland accident with tanks 1 and 2 still i...

Fig. 2.2[[dot]] The

Methane Pioneer

after its conversion.

Fig. 2.3[[dot]] Canvey Island receiving terminal.

Fig. 2.4[[dot]] Peak‐shaving plant in Stuttgart, Germany.

Fig. 2.5[[dot]] Section through the 80 000 m

3

LNG tank in Wilhelmshaven, Germa...

Fig. 2.6[[dot]] Australian LNG projects.

Fig. 2.7 Gas deposits.

Fig. 2.8 Emission control areas (ECAs).

Fig. 2.9 Development of the maximum permissible sulphur content.

Chapter 4

Fig. 4.1 Single containment tanks.

Fig. 4.2 Double containment tanks.

Fig. 4.3 Full containment tanks.

Fig. 4.4 Detail of thermal corner protection (TCP).

Fig. 4.5 Membrane tank system.

Fig. 4.6 Designations of individual membrane tank components.

Fig. 4.7 Membrane plate with different corrugations.

Fig. 4.8 Make‐up of inner container with insulation.

Chapter 5

Fig. 5.1 The temperature gradient in a tank wall during a fire.

Fig. 5.2 Arrangement of boreholes/SPTs and CPTs.

Fig. 5.3 Susceptibility to soil liquefaction and percentage of fine particles.

Chapter 6

Fig. 6.1 A 3D model of a concrete outer container.

Fig. 6.2 The roof platform.

Fig. 6.3 Bernoulli regions (B‐regions) and discontinuity regions (D‐regions).

Fig. 6.4 Strut‐and‐tie models for change of depth in base slab.

Fig. 6.5 Strut‐and‐tie model of buttress during stressing: a) layout of tendon...

Fig. 6.6 Fixing of thermal corner protection (TCP).

Fig. 6.7 Temperature gradient in concrete wall, development over time.

Fig. 6.8 Bending moments for different liquid levels.

Fig. 6.9 Isotherms around TCP.

Fig. 6.10 Idealised heat radiation scenario.

Fig. 6.11 Upper and lower bounds of thermal conductivity.

Fig. 6.12 Relationship between specific heat and temperature.

Fig. 6.13 Temperature gradient in tank roof due to heat radiation.

Fig. 6.14 Example of hoop reinforcement in outside face of tank wall.

Fig. 6.15 Temperature gradient in roof after 1 h and 2 h.

Fig. 6.16 Example of a blast pressure wave development.

Fig. 6.17 Comparison of results obtained with CEB 187 and ACI 349.

Fig. 6.18 Comparison of results obtained with CEB 187 and ACI 376.

Chapter 7

Fig. 7.1 Qualitative presentation of rigid impulsive, flexible impulsive and c...

Fig. 7.2 Veletsos' deformation assumptions.

Fig. 7.3 Model of impulsive hydrodynamic pressure after Housner.

Fig. 7.4 Model of convective hydrodynamic pressure after Housner.

Fig. 7.5 Veletsos' model and designations.

Fig. 7.6 Rigid impulsive pressure component acting on tank wall and base slab.

Fig. 7.7 Convective pressure component acting on tank wall and base slab.

Fig. 7.8 Flexible impulsive pressure component acting on tank wall.

Fig. 7.9 Graphic presentation of impulsive and convective mass components acco...

Fig. 7.10 Graphic presentation of impulsive and convective lever arms accordin...

Fig. 7.11 Dynamic system for horizontal excitation.

Chapter 8

Fig. 8.1 Concrete pours for a tank base slab.

Fig. 8.2 A pre‐assembled reinforcement cage being installed.

Fig. 8.3 Installing the compression ring.

Fig. 8.4 Steel roof during construction – view from above.

Fig. 8.5 Steel roof during construction – view from below.

Fig. 8.6 “Roof air raising”.

Fig. 8.7 Concreting the roof in circumferential rings.

Fig. 8.8 Temporary opening.

Fig. 8.9 Idealised construction phases.

Fig. 8.10 Preparing the wall formwork elements.

Fig. 8.11 Climbing formwork being repositioned for next lift.

Fig. 8.12Fig. 8.12 Climbing formwork showing working platforms.

Fig. 8.13 Tank wall formwork.

Fig. 8.14 Orthogonal reinforcement layout in middle of base slab.

Fig. 8.15 Radial base slab reinforcement for a smaller tank.

Fig. 8.16 Large reinforcement mesh suspended from a crane spreader beam.

Fig. 8.17 Pre‐assembled reinforcement cages.

Fig. 8.18 Fixing buttress reinforcement.

Fig. 8.19 Storage of prestressing strands.

Fig. 8.20 Redirecting the vertical prestress in the base slab.

Fig. 8.21 Installing vertical tendons.

Fig. 8.22 Stressing the vertical strands.

Fig. 8.23 Working platform for horizontal stressing.

Fig. 8.24 Cable conduits for heating cables in middle of base slab.

Fig. 8.25 Laying cable conduits for heating cables around the perimeter.

Fig. 8.26 Inclinometer casing in base slab.

Fig. 8.27 Taking inclinometer readings.

Fig. 8.28 Construction joint being prepared with expanded metal.

Guide

Cover

Table of Contents

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Design and Construction of LNG Storage Tanks

Josef Rötzer

Copyright

Author

Dr. Josef Rötzer

TGE Gas Engineering GmbH

Leopoldstraße 175

80804 Munich

Germany

Cover: LNG tank with typical steel structure

Photo courtesy: Günther Sell, TGE Gas Engineering GmbH, Munich

Editors of Beton‐Kalender

Prof. Dipl.‐Ing. Dr.‐Ing. Konrad Bergmeister

Ingwien.at engineering GmbH

Rotenturmstr. 1

1010 Vienna

Austria

Prof. Dr.‐Ing. Frank Fingerloos

German Society for Concrete and Construction Technology

Kurfürstenstr. 129

10178 Berlin

Germany

Prof. Dr.‐Ing. Dr. h.c. mult. Johann‐Dietrich Wörner

ESA – European Space Agency

Headquarters

8‐10, rue Mario Nikis

75738 Paris cedex 15

France

English Translation: Philip Thrift, Hannover, Germany

All books published by Ernst & Sohn are carefully produced. Nevertheless, authors, editors, and publisher do not warrant the information contained in these books, including this book, to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate.

The original German text is published in Beton‐Kalender 2016, ISBN 978‐3‐433‐03074‐5, titled “Planung und Auslegung von Flüssigerdgastanks”. This book is the revised English translation of the mentioned contribution.

Library of Congress Card No.:

applied for

British Library Cataloguing‐in‐Publication Data A catalogue record for this book is available from the British Library.

Bibliographic information published by the Deutsche Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at <http://dnb.d‐nb.de>.

© 2020 Wilhelm Ernst & Sohn, Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Rotherstraße 21, 10245 Berlin, Germany

All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form – by photoprinting, microfilm, or any other means – nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law.

Print ISBN:  978‐3‐433‐03277‐0

ePDF ISBN:  978‐3‐433‐60997‐2

ePub ISBN:  978‐3‐433‐60996‐5

oBook ISBN: 978‐3‐433‐60998‐9

Cover Design: Hans Baltzer, Berlin, Germany

Editorial

The Concrete Yearbook is a very important source of information for engineers involved in the planning, design, analysis and construction of concrete structures. It is published on a yearly basis and offers chapters devoted to various, highly topical subjects. Every chapter provides extensive, up‐to‐date information written by renowned experts in the areas concerned. The subjects change every year and may return in later years for an updated treatment. This publication strategy guarantees that not only is the latest knowledge presented, but that the choice of topics itself meets readers' demands for up‐to‐date news.

For decades, the themes chosen have been treated in such a way that, on the one hand, the reader gets background information and, on the other, becomes familiar with the practical experience, methods and rules needed to put this knowledge into practice. For practising engineers, this is an optimum combination. In order to find adequate solutions for the wide scope of everyday or special problems, engineering practice requires knowledge of the rules and recommendations as well as an understanding of the theories or assumptions behind them.

During the history of the Concrete Yearbook, an interesting development has taken place. In the early editions, themes of interest were chosen on an ad hoc basis. Meanwhile, however, the building industry has gone through a remarkable evolution. Whereas in the past attention focused predominantly on matters concerning structural safety and serviceability, nowadays there is an increasing awareness of our responsibility with regard to society in a broader sense. This is reflected, for example, in the wish to avoid problems related to the limited durability of structures. Expensive repairs to structures have been, and unfortunately still are, necessary because in the past our awareness of the deterioration processes affecting concrete and reinforcing steel was inadequate. Therefore, structural design should now focus on building structures with sufficient reliability and serviceability for a specified period of time, without substantial maintenance costs. Moreover, we are confronted by a legacy of older structures that must be assessed with regard to their suitability to carry safely the increased loads often applied to them today. In this respect, several aspects of structural engineering have to be considered in an interrelated way, such as risk, functionality, serviceability, deterioration processes, strengthening techniques, monitoring, dismantlement, adaptability and recycling of structures and structural materials plus the introduction of modern high‐performance materials. The significance of sustainability has also been recognized. This must be added to the awareness that design should focus not just on individual structures and their service lives, but on their function in a wider context as well, i.e. harmony with their environment, acceptance by society, responsible use of resources, low energy consumption and economy. Construction processes must also become cleaner, cause less environmental impact and pollution.

The editors of the Concrete Yearbook have clearly recognized these and other trends and now offer a selection of coherent subjects that reside under the common “umbrella” of a broader societal development of great relevance. In order to be able to cope with the corresponding challenges, the reader can find information on progress in technology, theoretical methods, new research findings, new ideas on design and construction, developments in production and assessment and conservation strategies. The current selection of topics and the way they are treated makes the Concrete Yearbook a splendid opportunity for engineers to find out about and stay abreast of developments in engineering knowledge, practical experience and concepts in the field of the design of concrete structures on an international level.

Prof. Dr. Ir. Dr.‐Ing. h. c. Joost Walraven, TU Delft

Honorary president of the international concrete federation fib

About the Author

Dr.‐Ing. Josef Rötzer (born in 1959) studied civil engineering at the Technical University of Munich and later obtained his PhD at the Bundeswehr University Munich. From 1995 onwards, he worked in the engineering head office of Dyckerhoff & Widmann (DYWIDAG) AG in Munich. His area of responsibility included the detailed design of industrial and power plant structures. The DYWIDAG LNG Technology competence area, focusing on the planning and worldwide construction of liquefied gas tanks, was integrated into STRABAG International in 2005.

Josef Rötzer is a member of the Working Group for Tanks for Cryogenic Liquefied Gases of the German Standards Committee and a member of the committee for the American code ACI 376.

1Introduction

The use of natural gas as an independent branch of the global energy supply sector began in the early 1960s. Prior to that, natural gas had only been regarded as a by‐product of crude oil production; there was no use for it and so it was either pumped back into the ground or flared. But all that has changed in the meantime – natural gas currently accounts for 22% of global energy supplies. Huge deposits in Australia are now being exploited and deposits in the USA will soon be coming online, which will increase that global share (Fig. 1.1). There are many reasons for this development – economic, political and ecological: Australia is close to the growing Asian economies, the USA is aiming to reduce its dependence on foreign oil and energy supplies by developing its own resources, and global efforts to replace fossil fuels by gas apply throughout the world.

Fig. 1.1 Development of energy demand [1].

The International Maritime Organisation (IMO), a specialised agency of the United Nations, has drawn up new rules that have been valid from 2015 and are particularly strict for the North Sea and Baltic Sea. Complying with emissions requirements is difficult when using diesel and heavy oil as marine fuel. But using liquefied natural gas (LNG) as a marine fuel results in – compared with diesel – about 90% less nitrogen oxide, up to 20% less carbon dioxide and the complete avoidance of sulphur dioxide and fine particles [1]. Det Norske Veritas (DNV), the Norwegian vessel classification body, therefore expects that there will be about 1000 new LNG‐powered ships by 2020, which amounts to almost 15% of predicted new vessel orders. This change is heavily influenced by the huge drop in the price of natural gas, which has been brought about by the global production of shale gas (Fig. 1.2, Fig. 1.3).

Fig. 1.2[[dot]] Gas price developments since 2000 [1].

Fig. 1.3[[dot]] Regional distribution of natural gas potential [1].

The use of natural gas involves transport and storage difficulties. Transport via pipelines is economic up to a distance of 4000–5000 km, depending on the boundary conditions. In the case of difficult geographic circumstances, such as supplies to islands, e.g. Japan and Taiwan, or where it is necessary to cross mountain ranges, supplying gas via a pipeline is much more difficult and costly. Therefore, the method of liquefying natural gas and then transporting it over great distances in ships had already become established by the mid‐20th century.

LNG technology takes advantage of the physical material behaviour of natural gas, the main constituent of which is methane. At the transition from the gaseous to the liquid state, the volume is reduced to 1/600. However, this requires the temperature of the gas to be lowered to ‐162°C. Only this extreme reduction in volume makes transport in ships economically viable. The entirety of the elements required for transporting LNG in ships is known as the “LNG chain”, which consists of the liquefaction plant in the country supplying the gas, LNG tanks for intermediate storage of the liquefied gas, jetties as berths for the special LNG transport vessels, tanks for the intermediate storage at the receiving (i.e. import) terminal and a regasification plant in the country importing the gas.

It is common practice these days to build full containment tanks, which consist of an outer concrete secondary container surrounding an inner steel primary container. The prestressed concrete outer container serves to protect the thin‐wall steel inner container against external actions and also functions as a backup container in the event of the failure of the primary container. The outer container must prevent uncontrolled leakage of vapours into the environment and must also be able to contain the liquefied gas and withstand any overpressure.

The great hazard potential of LNG is the risk of fire. If LNG changes to its gaseous state and mixes with air, the result is a combustible gas that can explode, and certainly burns very fiercely. Safe transport and storage are the technical challenges of LNG. At these low temperatures, the materials normally used in the construction industry exhibit a distinctly brittle behaviour and fail abruptly. During normal operation, the steel inner container takes on the temperature of the liquefied gas and cools to ‐165°C. In order to guarantee sufficient ductility at this temperature, the inner container must be made from 9% nickel steel or stainless steel. Thermal insulation about 1 m thick is placed between the steel inner and concrete outer containers.

Between the underside of the steel inner tank and the base slab of the concrete outer tank, the thermal insulation consists of loadbearing cellular glass (often called foam glass). The annular space between the inner and outer containers is filled with perlite, and a layer of elastic material (resilient blanket) is installed to compensate for the horizontal thermal deformation of the inner container. The insulation on the aluminium roof of the inner container is made from glass fibre or perlite. What at first sight seem to be very generous dimensions are necessary in order to keep the boil‐off rate below 0.05% by vol. per day. Should the inner container fail, the inside face of the concrete outer container cools to ‐165°C, and that calls for the use of special reinforcement that can resist such low temperatures. The dynamic design for the seismic load case must take into account the action of the sloshing of the liquid and the interaction with the concrete outer container. The tank must be designed to withstand a so‐called operating basis earthquake (OBE), i.e. is not damaged and remains operable, and also for a so‐called safe shutdown earthquake (SSE).

Reference

1 Flüchtige Zukunft. Wirtschaftswoche, No. 32, 2012, pp. 58–65.

2History of Natural Gas Liquefaction

History shows us how the present circumstances have evolved; every new development builds on previous situations. The demand for gas has developed with the demand for energy in general. Technical progress led to the development of the liquefaction of gases, and after this process had been realised for various gases, so it became possible to liquefy natural gas, too. That was followed by the development of storage and transport methods for the liquefied natural gas (LNG), which in turn evolved into a global LNG market. The history of LNG outlined in sections 2.1 to 2.4 below is essentially based on the book by Matthias Heymann: Engineers, markets and visions – The turbulent history of natural‐gas liquefaction [1].

2.1 Industrialisation and Energy Demand

The process of the industrialisation of the production of energy, iron and steel, which began in England and reached the rest of Europe in the early 19th century, required a transition from wood‐fired ovens and waterwheels to coal and oil as the energy sources. The start of the 20th century saw another considerable rise in the demand for oil and gas; oil was used as a fuel for many different means of transport, as a fuel for heating and as a raw material for the petrochemicals industry. The widespread use of natural gas did not come about until pipeline technology had been established, which then led to an increase in gas consumption in the USA during the 1930s and in Europe after 1945.

At first, gas was used for lighting only. The destructive distillation of coal produced gas and coke. This synthetic gas was therefore known as coal gas or, indicating its usage, town gas. It gave off a much brighter light and brought about a considerable change to people's living and working conditions, as they were no longer reliant on daylight alone. The operation of gas lighting was, in many respects, unchartered territory. It called for a complex infrastructure that was linked with high costs, a restriction to just one supplier for a defined area, political approvals and also society's acceptance of this new form of energy. Economic operations required the signing of long‐term contracts so that the costly investments could be recouped. Municipal or national bodies were set up in order to prevent monopolies from being abused.