Method and device for measuring accumulated liquid of natural gas pipeline

Abstract

The invention discloses a method and a device for measuring accumulated liquid of a natural gas pipeline. The method comprises the following steps of: vertically transmitting high-frequency ultrasonic wave into the pipeline by an ultrasonic probe coupled to the outer wall of the measured pipeline, wherein the energy of reflection echo has great difference due to different properties of gas and liquid media; judging that the pipe inner wall is contacted with gas or liquid at the position of the probe according to the characteristic of echo received by the ultrasonic probe and reflected by the pipe inner wall; gradually adjusting the measurement position of the ultrasonic probe on the pipe outer wall along the circumferential direction; and recording a circumferential angle of the ultrasonic probe by a circumferential angle ruler when the echo has mutation, and further calculating the height of the accumulated liquid. The method is a non-intrusive accumulated liquid measurement method, does not change the structure of the conventional pipeline, has no medium leakage risk, does not affect the operation such as cleaning the pipeline and the like, meanwhile is not affected by the composition of gas and liquid phase media in the pipeline and parameters such as temperature, pressure and the like, overcomes the defect that the conventional ultrasonic technology needs complex sound velocity correction, and is particularly suitable for measuring the accumulated liquid inside the pipeline for conveying corrosive and toxic media.

Description

Technical field [0001] The invention belongs to the field of liquid level measurement, and mainly relates to a method and a device for measuring the liquid level in an airtight container, in particular to a method and a device for measuring the liquid height inside a natural gas pipeline. Background technique [0002] Under certain conditions, natural gas pipelines will produce liquid accumulation, which occupies a part of the pipeline cross-section, reducing the effective cross-sectional area of ​​gas transmission, resulting in a decrease in pipeline transportation efficiency, and may form hydrates under certain temperature conditions, resulting in ice blockage ACCIDENT. For gas gathering and transportation pipelines with high sulfur and carbon dioxide content, the existence of effusion will also accelerate pipeline corrosion, cause pipeline perforation, cause leakage, and even lead to poisoning accidents. Periodic pigging is an effective and commonly used method to reduce...

AI Technical Summary

Problems solved by technology

The disadvantage of the ray method is that the ray attenuates sharply in the steel pipe wall, and it is necessary to open holes in the pipeline to arrange the ray source chamber, and it cannot perform non-intrusive detection of the liquid volume of the built gathering and transportation pipeline. In addition, this type of There is also a risk of radiation

[0005] The pressure of natural gas pipeline is high, the transmission medium is flammable and explosive, and the high-sulfur natural gas is also highly toxic. In order to ensure safety and eliminate the hidden danger of medium leakage, it is required that the liquid accumulation measurement method used cannot change the existing pipeline structure, and can only be carried out on the outer wall of the pipe. non-intrusive measurement

To sum up, the existing pipeline effusion measurement technology is usually an intrusive measurement method, which requires the transformation of existing pipelines, and cannot meet the needs of liquid effusion detection in running natural gas pipelines.

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