Ultra low temperature cryogenic equipment is usually used for experimental or industrial applications in low-temperature environments, especially in the storage and transportation of liquefied gases and low-temperature materials. Their manufacturing methods mainly include the following:
1. Gas liquefaction method
Gas liquefaction is a common method in ultra-low temperature cryogenic equipment. By compressing gas and liquefying it under controlled temperature and pressure. For example, air liquefaction equipment compresses air and then liquefies it through expansion and cooling, mainly used to produce gases such as liquid oxygen, liquid nitrogen, and liquid argon.
Refrigeration principle: utilizing principles such as gas expansion for cooling and heat exchange.
Application: Liquefied natural gas (LNG) or other industrial gases.
2. Mechanical refrigeration method
Mechanical refrigeration method is to achieve low-temperature environment through mechanical equipment such as compressors, expansion valves, etc. It is commonly used in places that require stable temperature control, and the equipment contains different refrigerants (such as Freon, ammonia, etc.).
Principle: By circulating the refrigerant through processes such as compression, expansion, evaporation, and condensation, the temperature inside the system is reducedtolow-level.
Application: Laboratory equipment, cold chain transportation and storage.
3. Liquid nitrogen cooling method
Liquid nitrogen is a commonly used ultra-low temperature cooling medium with a temperature of -196 ° C. The low temperature of liquid nitrogen can be cooled by direct contact with the target substance, making it suitable for applications that require rapid cooling.
Applications: such as superconductor research, low-temperature physics experiments, medical freezing technology, etc.
4. Stirling refrigeration method
Stirling refrigeration technology utilizes the Stirling cycle to achieve low temperatures through gas compression and expansion. This technology has also been widely used in equipment that requires ultra-low temperature operation.
Principle: Low temperature is obtained through heat exchange between the piston and gas movement.
Application: Suitable for small cooling equipment, laser cooling, cryogenic storage, etc.
5. Cold storage method
The cold storage method usually stores low-temperature substances (such as liquid nitrogen or liquid helium) in well insulated containers, and then adjusts the temperature by refrigerating or releasing the stored cold.
Principle: Use the phase transition process of liquid or solid to store cold energy.
Application: Auxiliary cooling for medical equipment and cryogenic equipment.
6. Heat exchange method
The heat exchange method utilizes the temperature difference between two fluids to transfer heat through a heat transfer plate or pipeline. This method is usually used in combination with other refrigeration methods in ultra-low temperature equipment to ensure that the temperature remains within a predetermined range.
Application: Temperature control in cooling systems, such as cryogenic storage systems, aerospace equipment, etc.
Summary:
The process methods of ultra-low temperature cryogenic equipment include gas liquefaction, mechanical refrigeration, liquid nitrogen cooling, Stirling refrigeration, cold storage method, and heat exchange method. These methods select appropriate technologies and equipment based on the different applications. According to the actual needs of the equipment, multiple cooling technologies may be combined to achieve the best results.