Vacuum pipelines achieve ideal cooling performance due to extremely low cooling loss in the transmission medium. Together with the advantages of energy saving and environmental protection, they are often used in the process design of cryogenic equipment, such as all LNG and BOG pipelines in natural gas liquefaction plants. (Design temperature is -169 ° C). Due to the complex structure of this type of pipeline, it is only used in special occasions, so it has less on-site installation information. This article introduces the installation field technology of vacuum pipeline installation, and hopes to help the installation of this kind of project.
The low temperature vacuum pipe has the following characteristics:
(1) The structure is the main pipe for the main pipe, the vacuum medium is inside the interlayer, and the temperature difference between the inner and outer pipes is nearly 200 °C.
(2) Vacuum can greatly reduce the heat conduction and convection of the gas.
(3) The long and thin wall greatly reduces the heat conduction of the metal.
(4) The multilayer super-insulation layer greatly reduces radiation.
(5) They are mostly made of stainless steel 0Cr18Ni9.