Inflatable "pot lid" 1,500 tons

In late September, the Huanggang LNG gas storage Facility project of 80,000 cubic meters of LNG prestressed concrete full capacity tank gas jacking ceremony was held, which marked the successful completion of the largest LNG prestressed concrete full capacity tank gas jacking operation in the inland area of China, and another solid step was taken to achieve the target of production on schedule.

Huanggang LNG Storage Facility Project takes the construction of national gas storage facility project as an opportunity, relying on the existing Huanggang LNG plant, to build a new LNG storage tank with a scale of 80,000 water cubic meters. This is a key LNG storage facility project in Hubei Province, and the first prestressed concrete LNG storage tank constructed in Hubei Province. It is also a pilot project for petrochina Kunlun Gas Company to carry out digital delivery of LNG storage tanks. After the completion of the project, it will realize the peak energy regulation in Huanggang City, Wuhan City and surrounding areas of Hubei Province, improve the energy structure of Hubei Province, help the rapid economic and social development of Hubei Province, ensure the safety of peak natural gas consumption in Hubei Province, and help China achieve the strategic goal of "carbon peak and carbon neutrality".

The 80,000 square meters LNG prestressed concrete full capacity tank is the core equipment of the project. The outer diameter of the storage tank is 60 meters, the inner tank is 58 meters, and the total height is more than 46 meters. The span of the vault structure is 59.62 meters, the height is 8.038 meters, the weight of the arch containing the card tool is more than 375 tons, and the height of the dome needs to be increased to nearly 36 meters.

Gas jacking is one of the most difficult, complicated and risky engineering nodes in the installation and construction of large LNG storage tanks. The vault structure is slowly lifted from the bottom of the tank to the predetermined position on the top of the tank by using the principle of closed space and external pressure difference.

Before the installation, the project department cooperated with the construction unit to compile a series of documents such as construction plan and emergency plan, and invited domestic experienced experts to strictly check the gas jacking plan and repeatedly discuss the gas jacking measures. In the preparation stage of gas jacking, coordinated the existing problems of each participating party according to the daily marketing items, carried out safety investigation on equipment and facilities and made full technical disclosure; In the construction process, the implementation of staff post responsibilities at the same time, sent experts stationed at the site to provide technical support, the whole implementation of supervision.

In this project, there is no previous internal construction experience for reference in the construction of pile and column integrated high cap concrete cast-in-place pile, LNG low-temperature concrete full capacity tank exterior wall construction, vault gas jacking, 06Ni9DR inner tank welding. The C50 (P8 F200) cryogenic concrete used in the outer tank of the storage tank is the first time to be used in Hubei Province. There are many special construction schemes, hoisting equipment, heavy lifting workload, special-shaped parts hoisting, high height work and high-risk cross work, and the installation and construction of steel mesh is difficult and the safety risk is high.

In order to ensure that the gas storage tank of jack-up construction goes well, the full capacity for prestressed concrete tank design and roof ascension is difficult, for the first time program design research team, in the design process using pile one time molding technology and finite element software Angle of prestressed concrete tank overall analysis and thermal protection analysis and design techniques, On the premise of meeting the safety and reliability of the storage tank, the construction period is shortened and the construction difficulty of the gas jacking is reduced.

The external tank project lasted for 132 days. During the construction, the high temperature weather, which was the worst in 60 years, was encountered, especially the impact of the epidemic. The project department carefully organized, scientifically deployed, strictly controlled the key links of safety control, quality control, high altitude operation and lifting operation, and carried out risk analysis, process control and measures for each high-risk operation.

Finally, with the cooperation of all the participating units, which lasted for 2 hours and 24 minutes, the vault accurately combined with the pressure bearing ring on the top of the tank, and was successfully jacked into place at one time. The overall external tank of concrete is of high quality, and the verticality and ellipticity are measured on site, which all meet the relevant specifications and standards.

Huanggang LNG gas storage facilities project LNG tank dome gas cap of 80000 litres of success, not only marks the project officially into the inner pot installation phase, the project period laid a solid foundation for security, but also marks the CPC engineering has fully mastered the technology of prestressed concrete LNG storage tanks, achieved in the field of LNG storage tank project and a major breakthrough.

In fact,

There are bigger and heavier ones that span 60 meters and weigh 375 tons,

100 meters in diameter and 1,500 tons in weight.

On May 17, a 270,000-cubic meter liquefied natural gas (LNG) storage tank at Sinopec Qingdao LNG receiving station was successfully raised by air pressure, marking the basic completion of the main structure of the outer tank. The storage tank is independently developed by Sinopec, with a diameter of 100.6 meters and a height of 55 meters, equivalent to the area of a football field and the height of a 20-story building. It is the fastest and largest LNG storage tank in China, marking a breakthrough in the research and construction technology of China's super-large volume LNG storage tank and entering the world's leading level. It is of great significance to accelerate the construction of China's natural gas production, supply, storage and marketing system and promote the high-quality development of energy.

Air pressure jacking operation, commonly known as gas jacking operation, is one of the key processes in the construction of LNG storage tanks, which uses the principle of closed space and external pressure difference to slowly lift the dome structure of storage tanks from the bottom to the predetermined position on the top of the tank.

The vault of 270,000 cubic meters LNG storage tank successfully lifted this time weighs about 1500 tons, 25% more than the previous largest domestic LNG storage tank of 220,000 cubic meters, and the span is increased by 6 meters. It requires very high stability in the process of lifting the roof.

The project team of Sinopec innovatively proposed the use of "new technology of dome stability analysis" for the first time. In the process of jacking, infrared self-measuring instrument and manual monitoring were used to accurately control the balance stress of 30 steel cables of the dome and ensure a smooth ascent. It took 107 minutes to lift the dome into place smoothly.

The project intensified technical research, developed 5 provincial and ministerial construction methods, and adopted 17 proprietary intellectual property patented technologies to solve construction problems. 270000 cubic meters of tank construction process is more complex, the assembly accuracy, higher gas branch Qingdao LNG receiving station and design units in China petrochemical engineering construction co., LTD. (SEI), the construction unit of sinopec tenth construction co., LTD., adhere to the concept of the new development, draw lessons from the past experience of 160000 cubic meters and 220000 cubic meters of LNG storage tank construction, To ensure the flatness of the foundation surface of the storage tank and prevent cracks in bulk concrete, etc.

At the same time, the overall construction period of the project is tight. Sinopec project team implemented the "single-layer electric heating floor construction", "low-temperature concrete internal heating and external thermal insulation construction", "9%Ni steel wall panel automatic welding process" for the first time in China, achieving technological breakthroughs, promoting the construction with high quality and efficiency, and realizing the progress ahead of the overall plan. It is the fastest 270,000 cubic meters full capacity LNG storage tank in China at present.

The safe and stable completion of gas jacking operation this time is the first 270,000 (vertical) square (meter) full-capacity LNG storage tank in China, and it is also the fastest and largest LNG storage tank in China. (The success of gas jacking operation) marks the basic completion of the main structure of the outer tank, and the construction of the inner tank is about to start.

This article is reproduced from China Petroleum Corporation