A method for detecting leakage of trunk gas pipelines using the pressure drop rate at the shut-off valve

Abstract

The present application discloses a method for detecting the leakage of a trunk gas pipeline by using the pressure drop rate at a cut-off valve, which includes acquiring pressure data at the position of the cut-off valve at preset time intervals; when the pressure data is within a preset pressure range and decreases monotonically with time , calculate the current value of the voltage drop rate; compare the current value of the voltage drop rate with each voltage drop rate threshold in the predetermined sequence of voltage drop rate thresholds; compare the counter corresponding to the voltage drop rate threshold smaller than the current value of the voltage drop rate Add the preset time interval, and clear the counter corresponding to the pressure drop rate threshold greater than the current value of the pressure drop rate, and cycle in turn; when the counter corresponding to any pressure drop rate threshold reaches the alarm time threshold, the shut-off valve is controlled to close . The above method can make the shut-off valve more accurately and quickly respond to the leakage accident of the main gas transmission pipeline and shut it off in time, reduce economic losses and environmental safety impacts, and is suitable for judging more types of leakage situations.

Description

technical field [0001] The invention belongs to the technical field of gas transmission pipeline safety, and in particular relates to a method for detecting the leakage of a trunk gas transmission pipeline by using the pressure drop rate at a shut-off valve. Background technique [0002] In the prior art, when a large-diameter leak occurs in the trunk gas pipeline, the pressure along the line will drop sharply. When the decompression wave propagates from the leak point to the upstream and downstream valve chambers, the shut-off valve located upstream and downstream of the leak point will be controlled. The system is shut down urgently. Therefore, before deciding whether the shut-off valve needs to be shut down urgently, it is necessary to accurately judge whether the pipeline has leaked. This judgment process requires continuous processing of changes in the pressure of the pipeline. In the prior art, it is determined whether the pipeline leaks according to the fluctuation of...

AI Technical Summary

Problems solved by technology

At present, the threshold setting of the shut-off valve on the main trunk gas pipeline in China only takes a pair of fixed values, such as [120s, 0.15MPa / min]. This existing method has the following disadvantages: , Mainline pipelines with different pressure levels and different leakage degrees only set a pair of fixed thresholds, which is not good enough in terms of economy and safety, and it is impossible to judge small and medium-sized leakage situations

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