LNG receiving station wharf pipeline leakage monitoring and evaluating method

Abstract

The invention discloses an LNG receiving station wharf pipeline leakage monitoring and evaluating method. The method includes using a wireless sensor network node to quantitatively detect the flow of liquefied natural gas in a pipeline and the pressure of the liquefied natural gas on the pipeline; determining an initial confidence rule base expert system according to expert experience or domain knowledge; establishing a belief rule base expert system with an activation rate, and optimizing an initial belief rule base expert system; and evaluating the leakage condition of the pipeline at the wharf of the LNG receiving station through the optimized belief rule base expert system to obtain an evaluation report. The invention has the advantages that the concept of the activation rate is ingeniously used, and the rule of never activation or insufficient activation can be trimmed in the optimization process. Even if a complete data set exists and all rules are activated, the activation rate can also be used for the parallel optimization process of the BRB expert system, the problem of BRB combination explosion is effectively solved, quantitative data can be fully utilized on the premise that original interpretability provided by experts is not damaged, and the result credibility is improved.

Description

technical field [0001] The invention relates to the field of detection and evaluation of pipeline leakage, in particular to a method for monitoring and evaluation of pipeline leakage at a wharf of an LNG receiving station. Background technique [0002] LNG is the English abbreviation of Liquefied Natural Gas, which is mainly composed of 85% methane, 9% ethane, 3% propane, 2% nitrogen and 1% butane, and can be used as fuel. Its volume ratio to gas natural gas is about 1:600, but its weight is only about 45% of the same volume of water, so it is widely used in urban pipeline networks and dock long transportation (LNG is stored in super large LNG storage tanks, transport by sea), etc. In industrial production, combustible gas will be stored and transported after being liquefied. Large-scale storage tanks and receiving station facilities are the most important storage carriers for combustible gases in my country. Once a safety accident such as leakage occurs, it will cause ser...

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Problems solved by technology

[0004] In view of the above-mentioned existing problems, the technical problem to be solved by the present invention is that it can make full use of the quantitative data obtained by the wireless sensor network nodes in the detection and the prior knowledge of experts, and adopt the method based on the confidence rule base with activation rate, which can solve both When adding attributes and reference levels, BRB must face the problem of combinatorial explosion. On the premise of not destroying the original interpretation provided by experts, quantitative data can be fully used to improve the credibility of the results; It is used in the parallel optimization process of BRB, in which the training data set is divided into some sub-processes, a monitoring and evaluation method for pipeline leakage of LNG receiving station wharf

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