As an important container for storing liquefied natural gas, the rigor of its structural design is very important. These close institutions are not successful in one step, but developed through continuous exploration and improvement. So what about the discovery of cryogenic storage tanks?

LNG is stored in cryogenic storage tanks. Early storage tanks were in the form of single wall. The top cover and bottom of single wall storage tank adopt block insulation, but there are many disadvantages, such as no moisture-proof layer, vulnerable to wind disaster, etc. In order to eliminate these shortcomings, a double wall and double roof storage tank was proposed later. It is to fill the dry pure gas into the annular insulating space between the two walls to maintain positive pressure to prevent inhalation of humid air. However, with the increase of storage tank capacity, the cost of supplying dry pure gas increases significantly. In addition, since liquefied gas is stored close to its normal boiling point, it is easy to produce steam, resulting in overpressure in the tank. This prompted the development of suspended roof technology, and finally formed a double wall single roof storage tank. This tank cancels the pure gas system and replaces the top cover of the inner container with a suspended insulated ceiling to form an independent roof space. The double wall single top open tank makes the top of the inner container open so that LNG steam can enter the annular space. This not only prevents the entry of humid air, but also depressurizes the inner container. Another form of double wall single roof low-temperature storage tank is to use the outer wall with air tightness to prevent the entry of humid air, and use the roof space to contain LNG steam for decompression, which can also reduce the self weight burden of the tank top.