The Importance of Monitoring SF6 Moisture Density

The humidity and density of SF6 gas, whether they are within the specified range, determine the effectiveness of its insulation and arc extinguishing properties. However, during the manufacturing and operation of SF6 high-voltage switchgear, several factors can lead to deviations in the humidity and density of SF6 gas. These factors include the presence of moisture in new SF6 gas, residual moisture in the chambers and valves due to leaks during equipment installation, maintenance, filling, and refilling processes, as well as sealing failures caused by errors in switchgear component processing and aforementioned operations. Leakage of SF6 gas allows external moisture, which has higher pressure than the moisture inside the chamber, to infiltrate in the opposite direction, resulting in a decrease in gas density and an increase in moisture content.

Therefore, it is necessary to regularly monitor the density and moisture content of SF6 gas before and during the operation of the equipment. Common on-site methods for measuring the moisture content of SF6 gas include electrolysis, condensation, and capacitive measurement. Currently, portable laser moisture analyzers are widely used for on-site detection.

Laser moisture detector for SF6 gas

When the moisture content of SF6 gas exceeds the standard, it can react with metal substances at 200°C or higher, leading to the generation of toxic substances such as hydrogen fluoride, SOF2, SO2F2, SF4, SOF4, and sulfur dioxide. The decomposition of SF6 gas not only corrodes insulating and metal components but also yields heat that increases the pressure, reduces the interruption capacity, and may cause explosions, resulting in electrical, environmental, and safety hazards. The recent development of SF6 online laser moisture detectors addresses these concerns and mitigates the environmental damage from SF6 discharge.

The development trend in the current power industry has led to the development of SF6 online laser water content detectors. This system is mainly used for the online monitoring and control of SF6 gas, which is one of the main equipment in the power industry, such as SF6 high-voltage circuit breakers. It enables real-time data collection, display, remote transmission of information, fault alarm, activation of interlock mechanisms, and background data display and analysis of the water content, density, and temperature of SF6 gas without emitting SF6 gas. It provides information and basis for power system production management and equipment condition maintenance.

Social and economic significance of SF6 laser moisture detectors

Contribute to Earth conservation

The application of SF6 gas laser moisture detectors effectively prevents the emission of a large amount of SF6 gas, which has significance for Earth conservation.

Ensure the health of power workers

SF6 gas, when subjected to corona, sparks, and arc discharge in electrical equipment, produces various toxic and corrosive gases. After emission, sulfur dioxide stimulates the upper and lower respiratory tracts and causes tearing. Hydrofluoric acid is a strong dehydrating agent, and excessive inhalation can seriously harm health. The application of SF6 gas laser moisture detectors greatly reduces the emission of SF6 gas, which is beneficial for ensuring the health of power workers.

Reduce outage time and accident losses, improve power supply reliability, and enhance the level of power equipment management

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