Substation (distribution room) SF6 online monitoring system

I. Sulfur hexafluoride online monitoring system

1、According to SF6 safety regulations

（1）Powerful ventilation devices must be installed in distribution equipment rooms and SF6 gas laboratories equipped with SF6 equipment. The air outlet should be set at the bottom of the room.

（2）Indoors, when the equipment is filled with SF6 gas, the relative humidity of the surrounding environment should be less than 80%, and the ventilation system must be opened at the same time, and the leakage of SF6 gas into the working area must be avoided. The SF6 gas content in the air of the working area shall not exceed 1000ppm.

（3）Staff entering the SF6 distribution device room must first ventilate for 15 minutes and measure the SF6 gas content with a leak detector, try to avoid one person entering the SF6 distribution device room for inspection, and forbid one person to enter for overhaul work.

（4）Staff entering the low area of SF6 distribution unit room or cable trench for work should first monitor whether the oxygen content (not less than 18%) and SF6 gas content are qualified.

（5）Oxygen meter and SF6 gas leakage alarm are installed in the low area of SF6 distribution unit room which can alarm.

（6）In the event of an emergency, all ventilation systems should be opened immediately for ventilation.

2、Sulfur hexafluoride online monitoring system flow chart and equipment layout diagram

Sulfur hexafluoride online monitoring system flow chart

Sulfur hexafluoride online monitoring system equipment layout

3、Device Function

3.1 SF6 gas concentration exceeds the standard detection

The SF6 gas content at each gas sensor is displayed, and when the SF6 gas concentration exceeds 800ppm, the content exceeds the standard.

3.2 Oxygen concentration detection

Displays the oxygen concentration value of each gas sensor in the switching chamber.

3.3Temperature, humidity detection

The system can measure and display the current temperature and humidity values in the switching room.

3.4Shows when the fan was last started and stopped

Staff can use this information to determine if forced ventilation is required before entering the switch room.

3.5Infrared detection function

The system can detect staff who want to enter the switch room.

3.6Forced ventilation

When the fan is stopped, the system can be forced to ventilate for 15 minutes by pressing the forced button.

3.7Hypoxia alarm

When the oxygen concentration is lower than 18%, output contact alarm signal and live voice alarm.

3.8Fan control time

When the SF6 gas content exceeds the standard (≥800ppm) or the oxygen concentration is too low (≤18%), control the fan to start ventilation, and each ventilation time is at least 15 minutes.

3.9Timed ventilation

The system can set the fan to start and stop at regular times each day to ensure that the switch room is ventilated at least once a day.

3.10Voice function

The system can voice prompt ventilation and broadcast the current oxygen concentration and SF6 gas content status in the switch room after ventilation is completed to remind staff whether it is safe to enter the switch room.