Abstract: The cold insulation effect of LNG terminal is directly related to safe and stable production. In order to evaluate the present cold insulation situation of cryogenic pipelines, a study was carried out from two aspects. Firstly, the cold loss of pipeline was measured and calculated by using surface temperature and heat flow meter method; Secondly, taking long-span straight pipe as an example, its strength and limit load were analyzed by using finite element analysis method. Through on-site measurement and calculation, it was found that out of the 135 detection points the ratio of cold loss exceeding allowable range was as high as 71.9%, and the surface temperature of all pipelines was lower than the dew point temperature. This means that some measures should be taken to reduce the cold loss. In addition, through numerical simulation calculation, it was considered that the pipeline load was within the allowable range, and no obvious pipeline deformation was found in field verification.

Key words: LNG terminal, cold insulation, surface temperature, finite element analysis, dew point