Design and Application of Vacuum Test Bench for LNG Cryogenic Pipeline

In order to study the effect of temperature variation on the vacuum of liquefied natural gas (LNG) cryogenic vacuum pipeline, in this paper, a set of high-precision test benches was designed for measuring the vacuum of LNG cryogenic vacuum pipeline based on the surface temperature method and the temperature field principle. This cryogenic vacuum pipeline vacuum test bench uses high vacuum multilayer insulation as the insulation method, an insulation layer consisting of a multilayer reflective layer and heat insulation layer as the insulation material, austenitic stainless steel as the material of cryogenic insulation pipeline, 5A molecular sieve as the adsorbent for adsorbing residual gas, cryogenic liquid container, simulated service pipeline, cryogenic liquid buffer zone, vacuum and temperature test unit to simulate the actual vacuum degree of the vacuum pipeline can be obtained by measuring only the temperature of the outer wall of the vacuum pipeline and the corresponding ambient temperature. The LNG cryogenic vacuum pipeline vacuum test bench designed in this paper solves the problem of being unable to directly measure the pipeline vacuum degree in vacuum pipelines.