Comparison of various detection methods
1. mass/volume balance method
→ Is the mass/volume balanced?
Advantages: convenient installation and maintenance, mature technology.
Disadvantages:
1. The instrument requires high precision, high price and high installation requirements.
2. Unable to achieve positioning
3. The sensitivity of leak detection is low, and the false alarm rate is high.
4. Early warning cannot be realized
2. Negative pressure wave leak detection method
→ Capture the pressure drop wave
Advantages: convenient installation, maintenance and positioning, low cost and mature technology.
Disadvantages:
1. has low sensitivity and many false positives and false negatives in leak detection.
2. The leakage signal is gentle and the positioning error is large.
3. Large leak detection aperture (low sensitivity)
4. The alarm time delay is large and the real-time performance is poor.
5. Early warning cannot be realized
3. Optical fiber leak detection method
→ Temperature change or vibration caused by leakage
Advantages: high sensitivity, positioning and early warning, high positioning accuracy, small leak detection aperture, no explosion protection and long monitoring distance.
disadvantaged
1. The system has a large amount of installation and construction and complicated maintenance.
2. High cost
3. The sensitivity is too high, resulting in many false positives and false negatives.
4. Technical products have not been popularized.
4. Acoustic leak detection
→ infrasound waves with different frequencies in the background
Advantages: convenient installation and maintenance, mature technology, high sensitivity, accurate positioning, moderate cost and long monitoring distance.
disadvantaged
1. Sensitivity is affected by working pressure.
2. Poor early warning ability
Application industry
Automobile transportation industry: automobile door and window sealing, automobile and train door and window glass sealing, automobile wind noise, door sealing, cab windproof, air conditioning system leakage, liquefied gas tank car, refrigerated truck, tank car, pneumatic braking system, cargo hold, welding seam, hatch, gasket, water leakage (quality inspection), bearing system, electric contact arc and corona, high-speed railway, catenary electric monitoring, bearing inspection and inspection.
Petrochemical industry: gas station, oil pipeline leakage detection, natural gas system, transport container leakage detection (nitrogen, air, methane-butane), gas storage system, leakage detection, high pressure valve fault detection.
Power and electrical industry: remote leak detection of air cooling island, high-pressure gas leakage, vacuum negative pressure leakage, remote detection of high-pressure discharge power failure, online detection of high-speed bearing failure, internal leakage detection of valves and pipelines, negative pressure leakage detection of air cooling system, internal leakage detection of high-pressure hot and cold valves, hydrogen leakage detection of generator sets, online detection of high-altitude high-temperature and high-pressure pipelines, and sealing detection of various boilers, storage tanks and pipelines during power plant maintenance. State detection of motor bearings under high noise and vibration, and on-line quality detection of high voltage switchgear (circuit breakers, disconnectors, etc.). ), transformer and high voltage transmission line joint state detection, air cooling island remote leakage detection, vacuum system pipeline leakage detection, steam turbine leakage detection, valve internal leakage detection, insulator fault detection and location, electrical equipment partial discharge detection, corona discharge detection, high voltage switch insulation detection, and various key bearing state detection. Sealing monitoring of various waste gas treatment systems, integrity testing of condensing equipment, integrity testing of high-voltage joints of main transformers, and online quality testing of various high-voltage switchgear (circuit breakers, disconnectors, etc.). ).
Through the above introduction, we have a general understanding of various leak detection methods and their application industries. It can be seen that there are many ways to detect leakage. There is no clear distinction between advantages and disadvantages, but each has its own advantages and disadvantages. Therefore, when you choose, you should consider your actual situation, not casually or follow the trend. There are electrical industries and transportation industries that need to detect leakage frequently, and these industries also have serious consequences. Other fields should also pay attention to leakage at any time.