System and method for safe filling after liquid ethane pipeline overhauling

Abstract

The invention discloses a system and method for safe filling after liquid ethane pipeline overhauling. The system comprises a trunk system, a trunk valve chamber system, an ethane filling system and apipeline temperature and pressure detection system, the trunk valve chamber system is responsible for emptying and reopening of upstream and downstream pipelines of a valve chamber and also providesa channel for replacing of a trunk pipeline, and the ethane filling system is used for introducing ethane from an upstream trunk line, heating the ethane for temperature adjustment and then feeding the ethane into a to-be-opened downstream trunk line before the downstream trunk line is reopened. According to the functional demand of reopening of a liquid ethane pipeline after overhauling and releasing, on the basis of the characteristic that the liquid ethane is vaporized under the low pressure to cause the low temperature, by adopting the measures that an upstream pipe section provides a medium filling channel through a valve chamber bypass, an initial-stage filled medium is externally connected with equipment for vaporization heating, and middle-and-later-stage filling, boosting and liquidation are conducted, the problem of low temperature of the medium in the filling process of an isolated and overhauled section of the liquid ethane pipeline is effectively controlled, safe operationof the liquid ethane pipeline is guaranteed, and the effective guarantee is provided for safe operation of the liquid ethane pipeline.

Description

technical field [0001] The invention belongs to the technical field of putting into production after the maintenance of liquid ethane pipelines, and in particular relates to a safe filling system and filling method for liquid ethane pipelines after maintenance. Background technique [0002] With the development of natural gas processing technology and the development of high-efficiency natural gas utilization technology, the recovery capacity of ethane in natural gas has been continuously improved, and its long-distance transmission technology needs to be vigorously developed. Ethane product is a kind of light molar mass among the auxiliary products of natural gas, with high saturated vapor pressure, critical temperature of about 32°C, and critical pressure of about 4.5MPa, so it is possible to carry out single-phase transportation in gas or liquid state. Compared with gaseous ethane pipeline transportation, liquid transportation has the remarkable characteristics of small p...

AI Technical Summary

Problems solved by technology

In contrast, if the filling method of directly introducing ethane from the upstream is used, the liquid ethane must be violently vaporized at the initial stage of filling during the process of filling the empty pipe, and the temperature of the vaporization medium can be as low as -90°C, which is harmful to the pipeline. If the external nitrogen stamping method is used, there will be problems with the operation of the intermediate pump station, and high-pressure nitrogen at the end outlet will affect the operation of the liquid phase equipment. Physical isolation causes unstable operation; if external purified water stamping is used, it will be difficult for the system to perform further drying operations, which will cause hidden dangers to corrosion in the pipeline

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