Valve leak detection system and method based on three-dimensional temperature reconstruction

Abstract

The present invention provides a valve leakage detecting system and method based on three-dimensional temperature reconstruction, and belongs to the technical field of thermal power engineering. Technical problems such as difficulties in realization of middle and long distance leakage detection of valves, in realization of quantified leakage detection by infrared technology, and in temperature correction for valves with different surface materials or different roughness, and limits in measuring precision are solved. The system and method are characterized in that measurements of surface materials or roughness of the valves are not required for temperature correction, a three-dimensional temperature field reconstruction model is established, the spray cooling technology is applied to valve pressure tests to accurately determine leaking points, and leakage amount quantitative detection is realized through a relation curve between a leakage amount of the leaking points and a temperature gradient. With adoption of the system and method, middle and long distance valve leakage detection is realized, qualitative detection of leaking points and quantitative detection of leakage amount are realized by thermal infrared imagers, the difficulty that a material surface emissivity is required to be detected by the conventional infrared thermography inspection technology is solved, the detection precision is raised, and high security and feasibility are achieved.

Description

technical field [0001] The invention belongs to the field of thermal energy engineering, and uses temperature analysis and thermal imaging methods to check the delivery quality of metal valves and a supervisory inspection department to detect the quality of the valves. Background technique [0002] As a general-purpose pipeline software, valves have a wide range of applications. In addition to being used on pressure pipelines, they are also used in boilers and pressure vessels. They are called "pressure-bearing special equipment" cells. Due to the fact that the safety supervision and inspection work of pipeline components started later than boilers and pressure vessels, and the standards and specifications for their design, manufacture, installation, transformation, maintenance, supervision, etc. For example, in 2009, the flange burst accident of Xiaoyangshan LNG pipeline in Pudong New Area, in May 2007, the gray cast iron used for liquid ammonia valve material in Anhui caus...

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Problems solved by technology

[0004] During the pressure test, the leak detection methods mostly rely on subjective and crude methods such as human eyes and pressure gauges, which have poor safety, the leakage cannot be accurately quantified, and the efficiency is low; and relying on close observation by human eyes, it is easy to detect in high-pressure air seal tests. safety incident

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