Electric Heat Tracing and Frost Protection Project for the Tunnel Fire Protection System of the G85 Pengyang (Ninggan Boundary) to Pingliang to Daqiao Village (Ganshan Boundary) Section of the Yinchua

Oct 27, 2023

The Yinchuan Kunming Expressway (G85) starts from Yinchuan City, Ningxia and ends in Kunming City, Yunnan. It has a total length of 2322 kilometers and is one of the north-south longitudinal lines in the National Expressway Network Plan. The north-south route runs through the core hinterland of China, and has a significant radiating and driving effect on the economic and social development of the western inland region.

The Yinchuan Kunming Expressway (G85) Ningxia Taiyangshan Pengyang section project, with a total length of 236 kilometers, is the largest single investment project in transportation in Ningxia. Anhui Huanrui has undertaken the design, supply, and commissioning of the fire pipeline electric heating project for the Dazhaiyuan Tunnel Group, Shibaozi Tunnel Group, Xiling Tunnel, Ankou Tunnel, Shenyu Tunnel, and Shengli Tunnel in this project.

The climate conditions of the project location have an extreme minimum temperature of -30.2 ℃. The tunnel fire pipeline system is distributed throughout the entire tunnel system, and the entire pipeline is flushed with water. In winter, pipelines are prone to freezing, leading to pipeline explosions and affecting driving safety. In case of fire, firefighting operations cannot be carried out.

Anhui Huanrui Tunnel Fire Pipeline Electric Tracing System

According to the characteristics of the environmental temperature of the tunnel, the temperature inside the extra long tunnel is higher than that outside the tunnel, and as the distance from the tunnel entrance increases, the influence of the temperature inside the tunnel gradually weakens. In this project, our company recommends using a segmented laying method. The model RDC3-J3 three core series constant power tracing cable is laid in the pipeline outside the tunnel and within 1000m of the tunnel entrance, with lengths ranging from 800-1250m. This model of heat tracing belt is suitable for insulation and heat tracing of long-distance pipelines. A single power point has a long radiation distance, and the heating power of the heat tracing belt is constant and uniform, with a service life of over 20 years. It is the preferred heat tracing method for long-distance tunnel fire protection pipelines.

In this project, electric heat tracing control cabinets are installed in the substation inside and outside the tunnel, and the power is taken from the low-voltage distribution cabinet of the substation. Introduce constant power heat tracing cables from the electric heat tracing control cabinet to the fire protection pipeline network inside and outside the tunnel. Temperature sensors are installed on each circuit pipeline, and the electric heat tracing control cabinet uploads temperature signals and control signals to the tunnel monitoring room for unified management through the industrial Ethernet switch of the tunnel monitoring system.

This electric heat tracing remote control system can provide real-time temperature and high/low temperature alarms on site, and can remotely transmit thermometer alarm signals to the monitoring room. The monitoring room can operate the start and stop of the electric heat tracing system and modify temperature parameters.

The on-site control unit of electric heat tracing will transmit monitoring temperature and other data that can reflect the integrity of the electric heat tracing line to the tunnel management station fire room through the industrial Ethernet switch of the tunnel fire protection system.