In the power system,SF6The online monitoring and alarm system for gas concentration is a key defense line to ensure the safe operation of equipment and the health of personnel. To ensure the long-term stable operation of the system, it is necessary to establish a scientific maintenance and management system. This article will analyze the maintenance points of the system from five dimensions: daily inspection, regular calibration, component maintenance, data management, and emergency response.

1、 Daily inspection: basic support, prevention and control

Appearance and connection inspection

Daily inspection of the appearance integrity of monitoring hosts, sensors, sound and light alarms, and other equipment, with a focus on checking for loose wiring terminals and aging and cracking of sampling pipelines. For example, a certain substation once experienced air leakage due to loose sampling pipeline joints. Through daily inspections, the pipeline was promptly discovered and replaced to avoid data distortion.

Environmental adaptability verification

Confirm that there is no strong electromagnetic interference source at the installation location of the equipment, and that the surrounding temperature and humidity meet the requirements for sensor operation (usually-20℃~50℃, humidity≤95%RH）. For installation inGISThe monitoring host at the entrance of the room should be securely mounted on the wall to avoid displacement caused by vibration.

Preliminary functional testing

Through the user interface or mobile phoneAPPCheck if the system self-test function is normal, including sound and light alarms, voice prompts, fan linkage, etc. For example, a certain system supports“One-click test”Function, can quickly verify the response speed of alarm signal transmission and fan start stop.

2、 Regular calibration: accuracy assurance, reliable data

Calibration cycle and standards

According to the Guidelines for Operation and Maintenance of Online Monitoring and Alarm Devices for Sulfur Hexafluoride Gas Leakage, the system needs to undergo professional calibration once a year, and the calibration error should meet the requirementsSF6concentration≤±5%Oxygen concentration≤±1%Calibration requires the use of standard gases (such as1000ppm SF6+20.9%O2Mixed gas and dedicated calibration device.

Sensor performance verification

For those who use the principle of infrared spectroscopySF6The sensor needs to be checked for its dual wavelength compensation function to avoid zero drift caused by aging of the light source. For example, a certain model of sensor can automatically eliminate environmental temperature and humidity interference through a reference channel design, and the calibration cycle can be extended to18A month.

Historical data comparison

Compare the monitoring data before and after calibration with the standard values and analyze the error trend. If data fluctuations exceed the threshold during a certain period of time, it is necessary to investigate sensor contamination or sampling pipeline blockage issues.

3、 Component maintenance: precise replacement, extended lifespan

Sensor lifespan management

infraredSF6The lifespan of sensors is usually5-10The lifespan of the electrochemical oxygen sensor is2-3Year. A component ledger needs to be established to record replacement time, model, and calibration records. For example, a certain substation adopts“Sensor rotation”Strategy: Regularly exchange spare sensors with in use sensors to extend the overall lifespan.

Cleaning of sampling system

Blow the sampling pipeline with compressed air every quarter to prevent dust blockage. For diffusion sensors, it is necessary to clean the metal mesh of the air inlet with a soft bristled brush to avoid slow response caused by dust accumulation.

Maintenance of fans and exhaust systems

Check the operation status of the fan every month and clean the dust accumulation on the filter screen. For example, a certain system determines the load situation by monitoring the fan current, and prompts the replacement of bearings or lubricants when the current rises abnormally.

4、 Data management: in-depth analysis, optimization of operations and maintenance

Historical data backup

Regularly export alarm events, ventilation equipment operation logs, and other data to a dedicated server for storage. For example, a certain system supports multi-dimensional queries by device, time, alarm type, etc., to help analyze the correlation between high leakage periods and devices.

Trend prediction and warning

Establish through big data analysis toolsSF6The correlation model between concentration, equipment pressure, and temperature. When a device is detectedSF6When the concentration continues to rise and the pressure drops, the system can provide early warning of the risk of seal aging.

Remote upgrade and firmware maintenance

For support4G/LoRaThe communication system needs to regularly check the firmware version and upgrade it in a timely manner to fix vulnerabilities. For example, a certain manufacturer remotely pushes update packages to adjust the system alarm response time from3Shorten seconds to1.5In seconds.

5、 Emergency response: rapid response, reducing risks

Alarm grading response mechanism

Establish a first level（SF6Concentration>1000ppmorO2＜18%）Level 2（SF6concentration500-1000ppm）Alarm handling process. The first level alarm requires immediate evacuation of personnel and activation of strong ventilation, while the second level alarm requires increased inspection frequency.

Guidelines for troubleshooting false alarms

When the system reports a false alarm, it is necessary to check in sequence whether the alarm value setting has been modified, whether the equipment pressure is normal, whether there is water accumulation in the sampling pipeline, and whether the sensor is affected by alcohol/CO2Interference. For example, a certain substation was once affected by the volatilization of cleaning agentsSF6Sensor false alarm, recovered after isolating the pollution source.

Emergency drills and training

Organize once every six monthsSF6Leakage emergency drill, simulating scenarios such as alarm triggering, personnel evacuation, and equipment isolation. At the same time, special training will be provided to operation and maintenance personnel on the use of gas masks and the operation of positive pressure air respirators.

Conclusion

SF6The maintenance of the online monitoring and alarm system for gas concentration requires the construction of“prevention-monitor-analyze-response”The full chain management system. Through standardized inspections, precise calibration, and intelligent data analysis, system reliability can be significantly improved and equipment failure rates can be reduced40%Above, personnel safety risks have been reduced70%With the development of IoT technology, future system maintenance will shift towards“Self diagnosis and self repair”The direction evolution provides a more solid guarantee for the safety production of the power industry.