The application of electric heat tracing bands in the subway industry

In the deep underground spaces of cities, the subway system operates tirelessly like an urban artery day and night. When a cold wave strikes in winter, the chilly air invades the underground spaces through entrances, air ducts, and tunnel portals, posing a severe threat of freezing to fire hoses, domestic water pipelines, and drainage systems. Electric heat tracing bands, with their precise temperature control and flexible installation capabilities, demonstrate high applicability in such low-temperature vulnerable areas.

1. Reliable anti-freezing of fire fighting pipelines

The fire sprinkler system and fire hydrant pipelines densely distributed in subway stations are always in a state of readiness, requiring immediate deployment in case of a fire. However, these pipelines are mostly laid in the entrance and exit areas where the temperature is low and the wind speed is high. The stagnant water inside the pipelines is prone to freeze and expand, causing the pipelines to rupture and the fire protection system to fail. The electric heat tracing system, by laying heating cables closely on the outer wall of the pipelines, actively compensates for the heat loss of the pipelines, maintaining the pipeline temperature within a safe range of above 5℃, thereby fundamentally eliminating the possibility of freezing.

In the daily operation and maintenance of subways, the anti-freezing effect of electric heat tracing systems has been fully verified. As early as October, before the arrival of winter, Dalian Metro incorporated the maintenance of electric heat tracing equipment into its safeguard plan. Staff members went deep into areas such as air shafts and entrances/exits to conduct a comprehensive inspection of fire hoses, dressing them in "warm clothes". Similarly, Shenyang Metro also activated the electric heat tracing system in advance for pipelines such as fire-fighting and domestic water pipelines, ensuring that equipment would not freeze and block and operate without obstacles in low-temperature weather.

2. Advantages of laying complex pipelines

In underground stations with compact space and criss-crossing pipelines, traditional methods such as steam tracing are difficult to implement. Self-regulating electric tracing bands, with their soft texture, can be cut and overlapped freely along pipelines, flexibly adapting to complex routing with dense valves and elbows. This "shape-following" laying capability enables them to precisely fit irregular surfaces, eliminate tracing dead zones, and ensure uniform heat distribution.

On the subway water supply pipeline, the electric heat tracing band effectively prevents water from freezing and blocking in the pipeline, ensuring the normal supply of the water system. In the drainage system, it prevents sewage from freezing, ensuring the smoothness of the entire drainage system. In the underground tunnel's extensive pipelines, this material, which is soft and can be cut on-site as needed, significantly reduces the difficulty of construction in confined spaces, allowing the heat tracing system to cover every corner prone to freezing.

3. Technological Innovation

Modern subway electric heat tracing technology not only continuously optimizes heating efficiency but also achieves innovation in intelligent system integration. Against the backdrop of a complex and costly original system structure, the maintenance team of Shijiazhuang Metro independently developed a highly integrated new system. The original system required one power board and four logic boards to control four pipelines, with a single set costing up to 14,300 yuan and requiring cumbersome troubleshooting. Through technological breakthroughs, the new system adopts a single board to control four pipelines, fully retaining core functions such as low temperature, high temperature, leakage, cable break detection, and dual-circuit automatic switching. The cost of a single set has plummeted to 900 yuan, a reduction of up to 94%.

This innovation not only addresses the long-standing issues of "complex structure, high cost, and difficult maintenance" that have plagued subway operation and maintenance, but also reduces system failure points by reducing the number of components, thereby enhancing operational safety. The maintenance team has also compiled a "Quick Maintenance Manual for Electric Heat Tracing", which includes the causes of failures, handling methods, and precautions, providing valuable reference materials for future operation and maintenance personnel.

4. Comprehensive value

The application value of electric heat tracing bands in the subway industry is multi-dimensional. In terms of safety assurance, they serve as an invisible guardian for fire protection pipelines, ensuring that the "lifeline" is always ready for action. In terms of technical efficiency, self-regulating temperature products adapt to the complex underground pipeline environment with their flexible installation characteristics. In terms of economic cost, localized technological research and development have reduced system costs by over 90%, making the electric heat tracing solution more economically feasible.

Whether facing the continuous low temperatures of the northern winter or dealing with sudden cold waves, electric heat tracing bands have become one of the core technologies for ensuring the safe operation of subways in winter. They are not only the invisible guardians of fire-fighting pipelines, ensuring that the "lifeline" is always ready for action; they are also the technical guarantee for the smooth operation of water supply and drainage systems, preventing operational interruptions caused by freezing and blockage. Through precise temperature control and reliable installation, electric heat tracing bands provide solid technical support for ensuring the stable operation of urban rail transit in wind and snow.