Cryogenic liquid storage and packaging technology

With the continuous development of science and technology in China, the demand for cryogenic liquids in the high-tech field is also becoming more and more extensive. Liquids like liquid hydrogen (H2), liquid oxygen (02), liquid helium (He), liquid argon (Ar) and other cryogenic liquids need to be stored and transported in containers. The packaging of these very cold liquids is a high Science and technology disciplines, must be fireproof, explosion-proof, anti-static safety packaging for cryogenic liquids with temperatures of tens to hundreds of degrees Celsius. At present, the commonly used packaging forms at home and abroad are high vacuum insulation, vacuum powder insulation, vacuum glass fiber insulation and high vacuum multilayer insulation. Most of the packaging containers used to store cryogenic liquids are made of stainless steel and carbon fiber composite materials. External cylinders coated with carbon steel or stainless steel are coated on the outside of the heat-insulating layer. According to national standards, the external cylinders coated with carbon steel or stainless steel are coated with corresponding colors and ribbons according to national standards. The surface color of the outer cylinder of the container is usually coated with a military color or camouflage color, and there are strict standards and regulations for the storage and packaging of cryogenic liquids. It is not allowed to manufacture without a license.

The cryogenic liquid must have excellent thermal insulation performance in the packaging container. Under this condition, only a very low evaporation rate is allowed. In order to meet the above conditions, the cryogenic liquid packaging container is made into a double-layer type with inner cylinder and outer cylinder. Barrel, in addition to cryogenic liquid C02 can also use low-temperature carbon steel (16MnCr), most of the use of stainless steel (such as 1Crl8Ni9Ti, 1Crl8Ni9, etc.) manufacturing, the outer cylinder using carbon steel or stainless steel processing. In the interlayer between the inner cylinder and outer simplification, the material with good thermal insulation properties, pearl sand, polyurethane, and polystyrene foam with small thermal conductivity is filled, and a certain thickness can also be wrapped on the outside of the inner cylinder. The thermal insulation materials such as glass fiber layer, polypropylene, polyethylene fiber layer, aluminum foil and double-sided aluminized polyester film layer, etc., set “heat radiation screen” for cryogenic liquid packaging containers to form an effective thermal barrier and prevent heat convection, Heat conduction and heat radiation to reduce the cold loss, but also to prevent the heat transferred to the cryogenic liquid from the outside world is reduced to a minimum. According to the requirements of the manufacturing process, the interlayer between the inner and outer cylinders must be evacuated to a certain degree of vacuum (1×10-2,~l×10-5 Pa). When used, it can be maintained for a certain period of time. The vacuum degree indicator can ensure that the cryogenic liquid medium is in a liquid state and will not be vaporized.

After storage and packaging, the cryogenic liquid storage tanks can be loaded and transported by automobiles, trains, aircrafts, ships, etc. The most commonly used tank trucks for installing cryogenic liquid container tanks on car girders and trailer-mounted, semi-trailer tanks are the most commonly used. car. Storage tanks for cryogenic liquid storage packaging can be classified into two types, mobile and fixed, depending on the engineering process and the nature of the department. If the rocket is launched, special cryogenic liquid hydrogen (H2) and oxygen (02) in the moving storage tank will be transported by a cryogenic liquid pump to the rocket fuel storage tank as a fuel for the oxyhydrogen engine. Promote rocket launch. Large-scale iron and steel plants, chemical fertilizer plants, and chemical plants can be used as raw materials to store cryogenic liquids in fixed storage tanks for vaporization, pressurization, transportation, and use at any time.

The storage tanks for packaging cryogenic liquids have been widely used in various sectors of industry, agriculture, military industry, and scientific research. In recent years, it has also been widely used in civilian applications, such as liquefied natural gas, liquid carbon dioxide (C02), liquid ammonia, and special gas liquids for packaging and transportation. After this method is adopted, it brings great convenience to users. Packing cryogenic liquid storage tanks, as long as the configuration of the carburetor, bottle pumps, pipelines, valves, can be filled with gas cylinders, with the car used to transport hundreds of bottles, thousands of bottles of cylinders to transport gases in terms of It reduces labor intensity and improves safety. It also significantly reduces costs and improves mobility, timeliness, and economic efficiency. Because it has the advantages of reducing labor intensity, improving safety, preventing pollution, and having great practical value, it has been widely used. The use of packaged food-grade liquid carbon dioxide (C02) storage tanks in industry facilitates, cleans, prevents contamination, and ensures the quality of beverages. Argon gas (Ar), which is widely used for welding, can also be obtained by the above method. After the packaging, the cryogenic liquid storage tank can provide liquid hydrogen, liquid oxygen, and gaseous oxygen in time to provide great mobility, concealment, and safety. At present, domestic and foreign countries have vigorously developed storage tanks for packaging cryogenic liquids. The volume of production has ranged from as little as several to as much as thousands of cubic meters. It should be pointed out in particular that the first manned experimental spacecraft in China has been safely lifted to the sky. "No." "After escorting", the packaged cryogenic liquid storage tank plays a very important role.

The packaging containers for storing cryogenic liquids are different from other commercial products in terms of structure, surface pattern, color, trademark and commercialized characteristic forms. Its characteristic is that its physical and chemical properties directly affect the physical and chemical properties of the packaged media. The packaging containers can be used repeatedly within the service life. The packaging of the cryogenic liquid containers also serves as a commodity. The packaging has a high technical content. Therefore, the manufacturing enterprise must also have a complete product quality assurance system to obtain the pressure container manufacturing license issued by the country. Certificate, ASME Boiler Pressure Vessel Authorization Certificate, U, U2 Specification Seal, IS09000 Series Quality System Certification, etc. Therefore, the packaging of cryogenic liquids has its universality and its particularity when it comes to packaging, and this particularity determines High-tech content is also a reflection of the overall level of technology.