Device and method for detecting leakage of seal chamber by infrared imaging technology

Abstract

The invention provides a device for detecting leakage of a seal chamber by infrared imaging technology. The device comprises a gas source, a filter, a pressure regulating valve, an electromagnetic valve, a pressure sensor, a temperature sensor, a thermal infrared imager and a control system, wherein the pressure sensor, the temperature sensor and the thermal infrared imager are connected with the control system through lead wires respectively. A method for detecting the leakage of the seal chamber by the device comprises the following steps that a device to be detected reaches a thermodynamical equilibrium state after inflation, namely heat of a material around a vent released to airflow in unit time is equal to that of the material absorbed from atmosphere around the vent, and a leakage point can be determined through the position with reduced temperature detected by the thermal infrared imager; and the leakage amount can be determined through calculation of a computer in the control system. The device and the method have the advantages that the detecting device has simple structure, easy operation and low cost; the detecting method is practical, has small detection error, and can quickly and accurately detect the leakage point and the leakage amount of a chamber to be detected; and the detecting device and the method have strong applicability and wide application prospect.

Description

(1) Technical field [0001] The invention relates to a method for detecting gas leakage in a sealed cavity, in particular to a device and method for detecting the leakage of a sealed cavity using infrared imaging technology. (2) Background technology [0002] There are many ways to detect the leakage of the sealed cavity. For example, filling the measured cavity with a certain pressure of gas (using air as the medium), and then observing the pressure drop through the pressure gauge to check whether there is leakage. The advantage is that the method is simple, but Due to the use of direct pressure to detect the pressure drop, the resolution is low, and it is difficult to detect when the leakage is small, and the detection results are greatly affected by the ambient temperature and the specific location of the leakage point cannot be determined. There is also a differential pressure leak detection method, that is, two identical measured cavities (one of which has no leakage) ar...

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Problems solved by technology

[0002] There are many ways to detect the leakage of the sealed cavity. For example, filling the measured cavity with a certain pressure of gas (using air as the medium), and then observing the pressure drop through the pressure gauge to check whether there is leakage. The advantage is that the method is simple, but Due to the use of direct pressure to detect the pressure drop, the resolution is low, and it is difficult to detect when the leakage is small, and the detection results are greatly affected by the ambient temperature and the specific location of the leakage point cannot be determined

There is also a differential pressure leak detection method, that is, two identical measured cavities (one of which has no leakage) are connected to both ends of the differential pressure manometer, and then a certain pressure of gas is filled into the two measured cavities at the same time. , to observe the pressure difference change at both ends of the differential pressure manometer. Its advantage is that it can offset the influence of the ambient temperature on the measured cavity, but it needs a test object without leakage, and the specific location of the leak point cannot be determined at the same time.

Another method is to immerse the measured cavity in water and check whether there is any leakage by observing the air bubbles. The advantage is that the method is relatively simple and the specific location of the leakage point can be known, but it is not easy to accurately calculate the leakage amount.

Other detection methods include helium mass spectrometry leak detection and hydrogen leak detection, that is, by filling helium or hydrogen into the measured cavity at a certain pressure, and then using a sensitive device for helium or hydrogen to detect whether there is helium or hydrogen Leaking out of the measured cavity has the advantage of high detection accuracy, but it needs to be filled with special gas and the cost is high and the process is complicated

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