Application and Specific Solutions of Various Gas Sensors in Utility Tunnels
Utility tunnels can be described as a major integration hub that combines water supply and drainage, gas, electricity, cables, and all other pipelines. Their importance is self‑evident. For a city, utility tunnels serve as the lifeline and critical infrastructure ensuring people’s livelihood and normal urban operation. The application of sensors endows this huge lifeline with perceptual capabilities.
Utility tunnels are high‑risk environments, where oxygen concentration, toxic gas concentration, ambient temperature and humidity, gas concentration, pipeline flow rate and pressure can all pose hazards. All these indicators can be detected by sensors to achieve real‑time monitoring, judge their risk levels, and ensure the safety and efficient management of the entire tunnel system.
An integrated utility tunnel, also known as an underground urban pipeline corridor, is a tunnel space built underground to integrate various engineering pipelines such as electricity, communications, gas, heating, water supply and drainage. Equipped with dedicated access openings, hoisting ports and monitoring systems, it is planned, designed, constructed and managed in a unified manner, acting as key infrastructure and the “lifeline” for urban operation.
Hazards in Utility Tunnels
Due to poor ventilation and a long‑term semi‑closed state, the oxygen concentration in underground integrated utility tunnels is lower than in the atmosphere, exposing workers to the risk of oxygen deficiency.
In addition, welding, anti‑rust painting and various topcoat applications during pipeline installation can easily trigger fires of materials and power cables. Long‑term fermentation of urban sewage and water in the tunnel’s sump may generate hydrogen sulfide, methane and carbon monoxide, which can accumulate and form safety hazards (hydrogen sulfide can poison inspection personnel, while methane may form explosive mixtures and directly threaten the safety of the tunnel itself).
Underground integrated utility tunnels contain numerous pipelines, and their lighting, ventilation, flood control, maintenance, fire protection and monitoring systems are more complex than those above ground. Electrical fires and flammable gas explosions are highly likely to occur, and accidents tend to trigger a “chain reaction”, increasing the difficulty of emergency rescue and accident handling, and causing huge losses to people’s lives and property safety.
Based on national standards and the above analysis, it is clear that before inspection and maintenance, utility tunnels must be equipped with oxygen, hydrogen sulfide, ammonia, carbon monoxide and methane detectors to prevent dangers, the importance of which is self‑evident.
Utility tunnels are equipped with corresponding sensors and alarms. Monitoring signals are led to the ground through manholes and transmitted to the monitoring center via wireless communication (GPRS), where data is analyzed through supporting integrated management software.
The software continuously collects the geographical location, measured values and working status of each measuring point. In case of abnormality, the system automatically generates alarms (optional audible and visual alarms, SMS alarms, email alarms) to notify relevant personnel immediately, eliminating potential dangers at the early stage to avoid major economic losses and disruptions to normal tunnel operation.
Recommended Gas Sensors for Utility Tunnels
