An online repair method for LNG pipeline cold insulation structure

Abstract

The invention discloses an online repair method for a cold-preservation structure of an LNG pipeline. The online repair method includes the following steps: 1) evaluating the cold insulation performance of the cold insulation structure of the LNG pipeline; Replace the cold insulation structure with the help of repair tools; 4) After the repair work is completed, test and evaluate the cold insulation performance of the cold insulation structure at the repaired part. When the repairing method of the present invention is used to repair the cold insulation structure of the LNG pipeline, the whole repairing process can be realized without stopping. The repairing method of the present invention uses a special repairing tool to ensure that the surface of the pipeline is not frosted during the repairing process and will not cause frostbite to personnel, and the cold preservation effect is remarkable after repairing. The invention is not only applicable to LNG pipelines, but also to other low-temperature pipelines and devices, and can be popularized and used in other low-temperature cryogenic fields.

Description

technical field [0001] The invention relates to an online repair method for a cold-preservation structure of an LNG pipeline, belonging to the technical field of low-temperature cryogenics. Background technique [0002] my country's LNG cold insulation project is developing rapidly. Most of the projects use rigid polyurethane foam as the cold insulation structure. After long-term use, the cold insulation structure will crack, shrink and deform. The main manifestations are: the contact surface between the cold insulation layer and the metal pipe is dry at first, When there is a temperature difference between the low temperature medium and the external cold insulation structure, there will be moisture between the steel pipe and the cold insulation structure, and it will adhere to the surface of the metal piping system in the form of frost particles. During maintenance, the low-temperature system stops working, and the temperature of the piping system begins to rise. The frost p...

AI Technical Summary

Problems solved by technology

[0003] Especially in the low-temperature LNG industry, the cold insulation layer of LNG pipelines in many domestic LNG receiving stations that have been put into operation has been damaged to varying degrees. Increased energy consumption and increased corrosion of equipment and pipelines, urgently need to repair the cold insulation structure

At the same time, it is considered that the traditional parking repair will have a great impact on the production capacity and economic benefits of the receiving station

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