In the shipping sector, liquefied natural gas (LNG) has firmly established itself as the fuel of choice for the future, according to a wide range of participants. Despite this upbeat outlook, one of the most significant barriers to switching to natural gas is the expensive initial investment required for LNG storage facilities. Supplier is continuing to investigate innovative ways of integrating technology in order to provide cost-effective storage solutions for gas-fueled boats of any size and LNG installed volume, regardless of their fuel source.
Shipping is a truly global business with fierce competition on an ongoing basis. Increased public pressure to reduce the sector’s environmental effect only serves to increase customers’ desire to lower their expenses. In order to save money and stay one step ahead of the competition, it may be necessary to implement innovative new solutions or repurpose existing technology from other industries. The latter method is often less complicated, involves less risks, and results in a shorter time to market. The evaluation of current technologies and their cost drivers, as a consequence, may aid in the creation of strategies for overcoming implementation roadblocks. Of course, each Supplier solution takes into account the unique needs of each customer, but this research outlines a few of the ways in which Supplier may help more customers in realizing the environmental and economic benefits of LNG.
Installations and equipment for liquefied natural gas – EN 1473
Cryogenic Liquid Vacuum Storage Tank
Euronorm It is the European standard EN 1473 Installation and equipment for liquefied natural gas, which serves as the overarching document for the design, building, and operation of all onshore LNG facilities. It includes installations for liquefaction and regasification, as well as storage facilities, which are often referred to as tanks in the industry. Environment compatibility, safety needs, risk assessments, and safety engineering are all addressed in detail in EN 1473, which specifies terminology and imposes standards to be taken into consideration throughout the design process. These LNG facilities are specified in detail in the standard and in Annex G: – LNG export terminal; – LNG receiving terminal; – LNG peak-shaving plants; and – LNG satellite plants.
Some parts of this standard have a direct impact on the design and construction of concrete tanks, while others have a less direct impact. This includes suggestions on how to evaluate safety and environmental compatibility, which are included in Chapter 4, for example. A thorough environmental impact assessment (EIA) must be carried out after the site has been determined. It is necessary to do this evaluation in order to determine the total amount of solids, liquids, and gases released by the facility during both regular operation and accidents. It is essential that plants be built in such a manner that gas is not constantly flared or vented, but is instead recovered to the greatest extent feasible, and that hazards to persons and property both within and outside the facility are minimized to a level that is widely considered acceptable. The study of the site may provide load scenarios that are important for the design, such as tsunamis or blast pressure waves,amongst other possibilities. It is necessary to include information on the existence of karst, gypsum and swelling clays in geological and tectonic soil surveys, as well as the susceptibility of the soil to liquefaction, the physical formation process, and the possibility for seismic activity in the future.
When constructing an LNG plant, it is necessary to do a risk assessment. The guidance in Annexes I, J, and K (which are given only for informational reasons) pertains to establishing frequency ranges, classes of consequence, degrees of risk, and acceptance criteria, among other things. A risk category is given to the plant based on a study of frequency ranges and consequence classes, and the plant is assigned to one of three risk categories. If the risk is acceptable, it must be lowered to a level that is as low as reasonably practicable (ALARP), if it is unacceptable, it falls into one of the categories listed above. In the annexes, the values specified are minimum requirements that may be increased by national laws or project specifications.
When doing a hazard and operation study (HAZOP), risk assessment is often included, but other methods are also allowed, such as failure mode and effect analysis (FMEA), event tree method (ETM), and fault tree method (FTM). It is necessary to categorize plant systems and components based on their relevance to safety within the scope of the risk assessment. Here, there is a division into two categories: class A, which includes systems that are critical to plant safety or protection systems that must be kept operational to ensure a minimum level of safety; and class B, which includes systems that perform functions that are critical to plant operation or systems whose failure could result in a major impact on the environment or create an additional hazard.
Sections 6.3 and 6.4 are particularly important for the design of concrete storage tanks, respectively. Section 6.3 and Annex H include specifics and illustrations of the different tank types, information that is complemented by the more comprehensive requirements of EN 14620 Part 1 (European Standard for Pressure Vessels). Because it covers spherical tanks as well as concrete tanks with both the main and secondary containers constructed of prestressed concrete, EN 1473 goes farther than EN 14620 in terms of the information that it provides. 6.4 defines design principles, which include criteria for fluid-tightness, maximum and minimum pressures, tank connections, thermal insulation, instrumentation, heating, and liquid level restrictions, among other things. These principles allow for the development of design criteria for the architecture of the facility, the minimum distance between tanks, and the consideration of potential sources of danger such as fire or blast pressure wave, among other things.
Construction of LNG Tanks – EN 14620 The European Standard EN 14620, which specifies the design and manufacture of site-built vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures ranging from zero degrees Celsius to one hundred and sixty degrees Celsius, is divided into five parts:
Part 1: Overarching Concepts
Part 2: Components made of metal
Part 3: Components made of concrete
Part 4: Components of the insulation
Part 5: Testing, drying, purging, and cooling-down procedures.
Types of LNG Storage Tanks
Type of LNG tanks
Liquefied gas storage tanks are classified according to their kind and size according to a variety of standards and rules that vary in terms of when they were issued as well as the amount of information they provide. The two German standards, DIN EN 1473 and DIN EN 14620, are even diametrically opposed in terms of the language they use. This section will make use of either the terminology found in the British counterpart, BS EN 1473, or the terms found in API 625. BS EN 1473 is the British equivalent of API 625. From a practical standpoint, the term “containment tank system,” as used in API 625, seems to be the most suitable, since the many, but coordinated, components work together to form a cohesive system as a result of their interaction. According to the standards EEMUA, BS 7777, EN 1473, EN 14620- 1, NFPA 59A, and API 625, containment tank systems may be classified as single, double, or complete containment tank systems. There is one additional tank type that is described in more depth in the European standards EN 1473 and EN 14620, and that is the membrane tank.
Until the 1970s, the only kind of tank that was constructed was the single-wall tank. It was the hazard scenarios resulting from abnormal actions such as failure of the inner tank, fire, blast pressure wave, and impact that inspired the subsequent further development of the various types of tanks or tank systems, and the associated requirements placed on the materials and construction details. Because of the dangers that a tank failure poses to the surrounding regions, it is essential to choose the appropriate kind of tank system.
It will be shown, using the failure of the inner container, the consequences of such a failure on the tank as a whole and its surroundings for three widely used tank systems. It will also be discussed how these three tank systems have evolved over time.