Method for detecting leakage of trunk gas pipeline by using pressure drop rate at block valve

Abstract

The invention discloses a method for detecting leakage of a trunk gas pipeline by using a pressure drop rate at a block valve. The method comprises the following steps: acquiring pressure data of the block valve at a preset time interval; when the pressure data is in a preset pressure range and monotonically decreases along with time, calculating a current value of a pressure drop rate; comparing the current value of the voltage drop rate with each voltage drop rate threshold in a predetermined voltage drop rate threshold sequence; adding a preset time interval to the counter corresponding to the voltage drop rate threshold value smaller than the current value of the voltage drop rate, clearing the counter corresponding to the voltage drop rate threshold value larger than the current value of the voltage drop rate, and circulating in sequence; and when the counter corresponding to any one pressure drop rate threshold value reaches the alarm time threshold value, the cut-off valve is controlled to be closed. According to the method, the cut-off valve can respond to leakage accidents of the trunk gas pipeline more accurately and quickly and cut off in time, economic losses and environmental safety influences are reduced, and the method is suitable for judgment of more types of leakage conditions.

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 leakage of a trunk gas transmission pipeline by using a pressure drop rate at a shut-off valve. Background technique [0002] In the prior art, when a large-diameter leakage occurs in the trunk gas pipeline, the pressure along the line will drop sharply. When the decompression wave propagates from the leakage point to the upstream and downstream valve chambers, the shut-off valves installed upstream and downstream of the leakage point will be controlled. The system is shut down in an emergency. Therefore, before deciding whether the shut-off valve needs to be shut down in an emergency, it is necessary to accurately judge whether there is leakage in the pipeline. This judgment process requires continuous processing of the pipeline pressure change. In the prior art, it is judged whether the pipeline leaks according to the ...

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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