Issues regarding large LNG full-volume tanks
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I am a senior about to graduate, currently working on my graduation project as mentioned in the title. Regarding the selection of storage tanks, there are mainly two types: those with metal exteriors and those with concrete exteriors. However, my teacher said that for large LNG storage tanks, carbon steel exteriors are commonly used, while my design is already based on a concrete exterior. What are the advantages of concrete outer tanks and metal outer tanks respectively? ? Is it necessary to change it back? ? Thank you all
Outside of LNG, negative pressure adiabatic treatment is required. Is it possible to have an outer tank made of concrete?
Currently, concrete outer tanks are the standard choice; this is not merely a matter of technical and economic considerations, but also relates to security against terrorism.
For insulation, there’s foam glass wool between the tank roof and the tank walls, as well as glass bricks at the tank bottom. As for negative pressure, I’ve managed to achieve a negative pressure of -1.5 kPa. The teacher didn’t provide specific figures.
The issue of terrorism and security is fairly okay. . . .
Basically, it reaches a vacuum level close to absolute zero, -0.098
Senior, may I ask how the thickness of the insulation layer for this LNG storage tank is designed?
The reason why concrete structures cannot be used for exterior walls is that concrete lacks toughness and also has poor sealing properties. LNG storage tanks have a layered structure, and vacuum insulation is required within these layers; therefore, their sealing properties do not meet the necessary standards.
The outer shell of large LNG full-volume tanks (such as 160,000 cubic meter LNG storage tanks) is made of concrete, without a carbon steel shell structure.
Generally, the outer wall of a single-volume tank is made of carbon steel, while the outer walls of double-volume and full-volume tanks are constructed from stainless steel or concrete.