Soft metal blanket with optional anti-sloshing conceptual designs to improve pressure control for floating and land-based liquefied natural gas tanks

Abstract

A conceptual design for an additional in-tank system in liquefied natural gas (LNG) tanks (in offshore or land-based plants) is proposed for efficient control of tank pressure. This system involves simple supplementary components to standard boil-off handling systems. The design concept builds upon the recently recognised duality in tank pressure behaviour in large LNG tanks. Such behaviour is exploited to promote conditions where tank pressure naturally trends to lower levels and limits the significant and abrupt pressure increases that would otherwise occur from time to time during routine operations. The concept involves a soft floating metal blanket, which involves simple low-cost components, requires no additional power to run, is easily retrofitted to and removed from existing tanks. The construction modifications for tanks required are minor and could be beneficial to both land-based and offshore plants. In offshore plants this system is suitable for sheltered locations where LNG cargo sloshing is not an issue. The design concept can though be modified as a more complex and connected structure (an anti-sloshing floating soft metal blanket) to provide combined anti-sloshing and pressure-control capabilities for offshore applications. Both concepts provide their greatest potential benefits to offshore floating storage and regasification units and floating storage units with tanks constrained by tank strength design limits, typically those converted from LNG carriers. Additionally, the solutions presented have direct relevance to shore-based LNG tanks due to their simpler geometry and sloshing-free status.

Cited as: Kulitsa, M., Wood, D.A. Soft metal blanket with optional anti-sloshing conceptual designs to improve pressure control for floating and land-based liquefied natural gas tanks. Advances in Geo-Energy Research, 2019, 3(4): 424-447, doi: 10.26804/ager.2019.04.09

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