High speed suction gun leak detection device and detection method for large transformer sealing element

Abstract

The invention provides a high speed suction gun leak detection device for a large transformer sealing element. The device is characterized by including a high speed suction gun (1), a sampling pipe (2), a filter (3), a high-power suction pump (4), a helium separator (5) and a helium mass spectrometer (6). The air carrier gas enters from a probe of the high speed suction gun (1), passes through a first branch (2-1) of the sampling pipe (2), and is pumped out by the high-power suction pump (4). The helium leaked from a leak in the detected large transformer sealing element enters the probe of the high speed suction gun (1), then passes through a second branch (2-2) of the sampling pipe (2) with the high speed air carrier gas provided by the high-power suction pump (4), enters a mass spectrum chamber of the helium mass spectrometer (6) through the helium separator (5) to be analyzed. Finally, a response leak rate signal is given. A high speed suction gun leak detection method for the large transformer sealing element is further provided.

Description

technical field [0001] The invention relates to leakage detection technology, in particular to a high-speed sniffing gun leakage detection device and detection method for large-scale transformer sealing components. Background technique [0002] Helium mass spectrometry leak detection is currently the most used leak detection method with high sensitivity. This method can usually be divided into evacuation method and pressurization method. The evacuation method is to connect the detected element or the suspected leaking part to the leak detection valve. Use the pumping system of the leak detector or a specially designed pumping system to evacuate the inner cavity of the tested component, and then apply helium to the external weld of the tested component by blowing or helium cover method, generally at an atmospheric pressure Under the action of the pressure difference, helium enters the inner cavity of the detected element through the leak hole and is sent to the leak detector,...

AI Technical Summary

Problems solved by technology

[0004] Standard suction guns are divided into capillary type, film type, and needle valve type. However, with the rapid development of large thermal power plants, nuclear power plants, rockets, aircraft, and metallurgical industries, more and more special sealed containers are used in large transformers. The standard 2-5m sniffing gun can no longer meet the requirements of use. If the capillary type is lengthened and needs to be slender to maintain a pressure difference of at least four orders of magnitude inside and outside the sniffing gun, it will inevitably cause excessive flow resistance and shorten the reaction time. Too long, the helium elimination time is long, and the sensitivity is extremely low, and the needle valve type sniffing gun faces these special sealed containers, and the tightness, adjustability, repeatability and overall service life of the structure are questioned and challenged , and the most common thin-film type at present, if the length of the sniffing gun is lengthened, even if the penetration of helium gas by the quartz thin-film is not affected, the detection time will be prolonged

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