Of the electric equipment amount that is isolated from as SF6 gas with each passing day grow in quantity, and raise its to run reliability special job is begun in the development in power system, blemish and hidden trouble are made basically in production, routine test, have sex reach move safeguard in waiting for each link, be discovered and eliminate, thereby the heavy recrudesce that great rate prevented an accident is unripe, but the electric equipment that SF6 gas is isolated from is flat the phenomenon still is the common problem that avoid hard and puts an end to thoroughly.
The electric equipment that SF6 gas is isolated from produces the main reason of leak to include: Manufacturing technology is bad, there is sand holes on crust, sealed material quality owes beautiful; Field assembly quality is not high, sealing surface processing does not reach the designated position; Equipment runs medium happening oscillatory, if switch cent closes, transformer runs medium vibration, the reason such as sealed material ageing.
How to detect leak of gas of electric equipment SF6
Lathery law
Implement a method
Bit of daub suds is like in doubt, whether does observation generate bubble, whether is judgement put in SF6 gas leak accordingly.
Actor defect
Detect the method is simple, need not precious instrument, but detect precision is poor, detect have blindness, detect cycle grows not to suit general to measure.
Wrap up law
Implement a method
The dot is like to wrap up in doubt polybag, mensurable detector is used to detect after the time that quiet place provides wrap up the SF6 gas chroma of place will judge flat.
Actor defect
Can realize ration to detect, but get easily environmental temperature, baric, wrap up polybag bulk, testing instrument the influence that wait.
Vacuum law
Implement a method
To the electric equipment that the SF6 gas that has not aerate is isolated from, device each part vacuumize reachs make an appointment with 133Pa, 4h of quiet place reachs above, through detecting vacuum is spent drop differentiate is flat.
Actor defect
Apply to leave factory detect, cannot achieve electrified test, applied limitation is bigger.
Halide detects law
Implement a method
Use metallic platinum " haloid effect " differentiate test point is flat.
Actor defect
OK and mensurable computation gives the specific parameter such as chroma of the leak career that leak chooses, gas, measure precision not tall.
Ultrasonic law
Implement a method
In temperature, intensity of pressure same condition falls, beg wait for measure aeriform concentration but translate into seeks gas mixture the problem of average velocity of sound, use phasic difference law to measure velocity of sound, launching ultrasonic namely while begin pulse computation, until detect computation stops after the amplitude of echo signal exceeds fair threshold value, get supersonic transmission time with at one's convenience of computation cycle photograph again, fixed transmission distance is divided it is velocity of sound namely with this time.
Actor defect
Measure precision to suffer interference of oscillatory, noise and ultrasonic to be in aeriform medium the impact of attenuation is bigger.
Sound wave law
Implement a method
The transmission speed in SF6 gas is less than benefit vocally to undertake detecting in the characteristic of the transmission speed in atmosphere.
Actor defect
Detect the method is simple, dan Lingmin is spent very low, the place of gas of the SF6 in sufferring environment of be confined to holds proportion.
Gas quick semiconductor law
Implement a method
The change that the block after using adsorbed gas of gas quick semiconductor is worth will decide the sort of an adsorbed gas and chroma, thereby whether does differentiate produce leak.
Actor defect
Use history is longer, the technology matures quite relatively, detect sensitivity is passable.
Electrochemistry law
Implement a method
Use electrochemistry gas sensor to measure voltaic value, through indirect computation SF6 gas is in be realized by the environment is medium chroma near check place.
Actor defect
Measure precision tall, but sensor is incidental saturated, and zero shift can rise as what measure precision and increase.
Thermal conductivity detector law
Implement a method
After carrying different gas, the block of heat quick component is worth change to differ, detect the electric current in circuit also changes subsequently, according to electric current change is worth and thermal conductivity coefficient of gas can be calculated a SF6 gas chroma.
Actor defect
Detect the effect that suffers air current stability as a result is bigger, detect the result is not direct, need computational analysis, do not facilitate field application.
Show footprint way
Implement a method
The adsorption that uses SF6 gas is characteristic, join can be made label by the material of SF6 element adsorption, chroma of gas of indirect measurement SF6.
Actor defect
Detect precision is tall, need uses auxiliary gas, be confined to laboratory research, operate hard in the spot.
Shi Min sensor law
Implement a method
The feature that uses leakage point point to be able to produce temperature and humidity change and change and leak speed to show positive to close will determine leakage dot and leak speed and serious rate.
Actor defect
Tall to the sensitivity requirement of sensor of temperature, humidity, and without representative application case, be in theory to study level only.
Ultraviolet ionization law
Implement a method
The input that carries comparative testing instrument and output weaveform will judge whether to produce leak, the lag time that exports weaveform represents the SF6 amount of leak.
Actor defect
SF6 leak degree can pass undee and direct response, measure precision to still be waited for rise.
Laser is become like the law
Implement a method
To be being launched by check place laser, back-scattering laser enters laser cinematograph to become like the system, SF6 gas can draw laser energy, use what back-scattering laser difference causes to become will decide like difference whether to put in leak.
Actor defect
Belong to indirect and visual detect, detect result precision is tall, but laser cost is high and volume is huge, do not facilitate the spot detects.
Infra-red into resemble a law
Implement a method
Use SF6 gas to have stronger absorption to infrared ray of specific wave band than air ability this one character, use backward astigmatism is become undertake resembling like the technology. Put when SF6 gas when area be detectinged, because SF6 gas is right,the infra-red light of wave band of 10.3~10.7 μ M has intense absorption, right now so reflection arrives detect the infrared energy of equipment is quick because of absorption the ground is abate, SF6 gas shows the aerosol account that is black on the indication screen of the detector. Right now, detect personnel can locate convenient and intuitionisticly source of SF6 gas leak.
Actor defect
Blame contact is electrified test, can catch in real time to leak of minim SF6 gas, clarity is become picture, decide definitely.
Law of leak hunting of helium mass spectra
Implement a method
Use technology of leak hunting of helium mass spectra, use vacuum law to detect to be being undertaken by check workpiece leakage is led, undertake reclaiming using to helium gas. Be opposite above all the helium that constant intensity of pressure fills after be being managed to find time by check workpiece is angry, the check ventage of vacuum box and leak detector is conterminous, be like leak be havinged by check workpiece, leak to be enraged into the helium of vacuum box can measure through leak detector piece. With what be linked together by check workpiece it is to aerate reclaim device, realize what helium enrages to fill respectively in leak hunting around note and reclaim. Detect finally fill inside ending product note SF6.
Actor defect
Detect precision is highest, need uses auxiliary gas (helium is angry) , reliable model good, detect do not suffer the environmental effect such as temperature, humidity. Use automation device, do not need artificial interpose to be able to realize automation to produce, this method applies extensively at switch ark, aerate ark routine inspection test. Defect is equipment relatively costly, one-time investment is higher.
