Gas-Underground Chamber Combustible Gas Monitoring Solution

## Deployment Mode (Key Innovation)

### NB-IoT Wireless Detector (Mainstream Solution)

– Equipment: CH4 + communication integration, battery-powered (high-density lithium-ion ER34615) with a battery life of 5-8 years
– Installation: Magnetic attraction / bolt fixation on the inner wall of the manhole cover, **completing 1 manhole chamber in 5 minutes** (compared to 1-2 days for traditional wired excavation)
– Communication: NB-IoT (full coverage of operator base stations, stronger signal penetration than LoRa — underground well chambers are 1-2m deep)
– Reporting frequency: Regular heartbeat reporting every hour + immediate alarm reporting (with a delay of < 30 seconds)

### Explosion-proof + Protection Parameters

– Explosion-proof: Ex d IIC T4 (highest gas category level)
– Protection: IP68 (for long-term submersion in well chambers)
– Operating temperature: -40℃ ~ +70℃ (winter in the north + heat in the south)
– CH4 measurement range: 0-100% LEL
– Alarm: Low alarm at 25% LEL (automatic SMS) + High alarm at 50% LEL (automatic notification to emergency response team)

## Applicable Well Chamber Types

1. **Gas pressure regulating station well**: pressure regulator + valve + flowmeter well, with the highest probability of leakage
2. **Gas pipeline branch well / valve well**: intersection of pipeline network, with high frequency of operation and maintenance
3. **Gate shaft / Drainage shaft**: Long-term enclosed, prone to CH4 accumulation
4. **Secondary/Tertiary Pressure Regulating Box Outdoor Well**: Located along the street/in the commercial area, with a wide influence range
5. **Monitoring wells within the boundary walls of gas metering stations/pressure regulating stations**: Dual protection at the station boundary

## Implementation Key Points

1. **Operator Cooperation**: Select the NB-IoT signal with the most stable connection (China Telecom/China Mobile Shenzhen has already established a private network in key areas), and implement city-by-city access in batches
2. **Joint operation by multiple gas companies**: platforms such as Hong Kong and China Gas, Shenzhen Gas, China Gas, and ENN can be shared, with **city-wide supervision**
3. **Integrated Emergency Response**: Abnormal Concentration → Automatically dispatch the nearest emergency vehicle (GPS positioning) + Send SMS notification to surrounding businesses for evacuation
4. **Data Compliance**: Real-time data is reported to the supervision platform of the Housing and Urban-Rural Development Bureau/Emergency Management Bureau, in compliance with Article 30 of the Regulations on the Administration of Urban Gas
5. **Lifecycle Management**: Automatic alarm for battery remaining capacity, with batch replacement after 5 years

## Regulatory Basis

– Regulations on the Administration of Urban Gas (Decree No. 583 of the State Council)
– CJJ 51-2016 "Technical Regulations for Operation, Maintenance, and Emergency Repair of Urban Gas Facilities"
– GB 50493-2019 Design Standard for Detection and Alarm Systems
– GB 50028-2006 "Code for Design of City Gas Engineering"
– GB 12358-2006 "General Technical Requirements for Fixed Environmental Gas Detection and Alarm Instruments in Workplaces"
– Guiding Opinions on Strengthening Urban Gas Safety Work issued by the Office of the Work Safety Commission of the State Council (2023)

## Applicable Customers

Municipal gas companies (Towngas / China Gas / ENN / China Resources / Beijing Gas / Shanghai Gas / Shenzhen Gas / Kunlun Energy); LPG operators; pipeline network construction companies (PetroChina Pipeline / Sinopec Pipeline); gas safety regulators (Housing and Urban-Rural Development Bureau / Emergency Management Bureau); industrial park gas distributed systems.