Zhuoyue LNG storage tank

The LNG industry chain mainly includes natural gas liquefaction, storage, transportation, reception, gasification, etc., among which LNG storage is a very important link. For LNG liquefaction plants and LNG receiving stations, LNG storage tanks are key core equipment. LNG storage tanks are low-temperature and atmospheric pressure containers for storing LNG, and the design temperature is generally around -165C. Because the use of large storage tanks has the advantages of low cost, less land occupation, and convenient management and operation, many countries in the world attach great importance to the design and construction of large atmospheric LNG storage tanks, especially with the large-scale development of LNG carriers ( The ship capacity has gradually developed from the conventional 14.5x104m3 to 21x104m3 and 26x104m3), and the storage tanks of the LNG receiving station are also gradually becoming larger (the effective storage volume of LNG is above 16x104m3).

Special requirements for LNG cryogenic storage tanks

1) Low temperature resistance.
The boiling point of liquefied natural gas at atmospheric pressure is -160C. LNG is stored at low temperature and normal pressure, which lowers the temperature of natural gas below the boiling point, so that the operating pressure of the liquid storage tank is slightly higher than normal pressure. Compared with the high pressure and normal temperature storage method, the thickness of the tank wall can be greatly reduced and the safety performance can be improved. Therefore, LNG requires the liquid storage tank to have good low temperature resistance and excellent cold insulation performance.

2) High safety requirements.
Because the tank stores low-temperature liquid, once an accident occurs in the storage tank, the refrigerated liquid will volatilize in large quantities, and the vaporization amount is about 300 times that of the original refrigerated state, forming an air mass that will automatically detonate in the atmosphere. Therefore, API, BS and other standards require storage tanks to adopt a double-wall structure. Using the sealing concept, when the first layer of tank leaks, the second layer of tank can completely block the leaking liquid and vapor to ensure storage Safety .

3) Special material
The inner tank wall requires low temperature resistance, and materials such as 9Ni steel or aluminum alloy are generally used, and the outer tank wall is prestressed reinforced concrete.

4) Strict insulation measures
Since the temperature difference between the inside and outside of the tank can reach up to 200°C, in order to keep the temperature inside the tank at -160°C, the tank body must have good cold insulation performance, and high-performance cold insulation materials are filled between the inner tank and the outer tank. The cold insulation material at the bottom of the tank must also have sufficient pressure-bearing performance.

5) Good shock resistance
The seismic requirement of general buildings is to crack and not collapse under the specified earthquake load. In order to ensure the safety of storage tanks under unexpected loads, storage tanks must have good seismic performance. For LNG storage tanks, it is required that they will not fall or crack under the specified seismic load. Therefore, the selected construction site should generally avoid the seismic fault zone, and the seismic test should be done on the storage tank before construction to analyze the structural performance of the storage tank under dynamic conditions to ensure that the tank body will not be damaged under a given seismic intensity.

6) Strict Construction requirements
Storage tank welds must be subjected to 100% magnetic particle testing (MT) and 100% vacuum airtight testing (VBT). Cold insulation materials must be strictly selected, and prescribed procedures should be followed during construction. In order to prevent cracks in the concrete, post-tensioning prestressing is used for construction, and the verticality of the tank wall is strictly controlled. The concrete outer tank top should have high compressive and tensile capabilities, and be able to resist the impact of general falling objects; because the concrete at the bottom of the tank is thicker, the hydration temperature should be controlled when pouring to prevent cracking due to temperature stress.

Zhuoyue LNG storage tank

Zhuoyue is one of the most popular brands in the gas industry in the North of China . Focusing on green energy special equipment, leading products include: LNG storage tanks, oxygen ammonia argon storage tanks, CO2 storage tanks and other vacuum insulation cryogenic pressure vessels and other high-end green energy equipment.