May 20, 2022
The safety and well-being of tunnel users depend on excellent ventilation. With its compact electric drives, ABB helps designers and operators of major infrastructures to meet the major technical challenges.
Ventilate better to protect better
Ventilation systems in tunnels first intend to protect their users’ health and safety. Under normal circumstances, ventilation limits the concentration of pollutant emissions from motor vehicles and ensures good visibility. However, ventilation is part of the extinguishing system when a dangerous condition occurs, such as a fire. It removes smoke and heat from the tunnel, maintains escape routes and allows emergency services to access the incident site.
In 1999, a truck accident in the Mont Blanc tunnel caused a major fire. One of the leading causes was an insufficient smoke ventilation system. This unfortunate incident prompted France to inspect all its tunnels over 300 meters and review its safety standards, and many countries followed suit.
ABB meets ventilation challenges in Montreal and Toronto
In Canada, ABB proudly contributes to the safety of the Louis-Hippolyte Lafontaine tunnels in Montreal and the Crosslinx project in Toronto by installing its ACS880-17 and ACS880-37 series drives.
Reliability, an essential ally
Tunnels are critical infrastructures that provide essential transport connections for the local, national, and even international economy. Therefore, they must be safe and available, always. Controlling operational risks, such as ventilation failure in an emergency, must be supported by reliable facilities.
The technical challenges of ventilation
The tunnel ventilation system presents numerous technical challenges, including rapid braking and reversing direction in an emergency. ABB drives, such as our ACS880-17 ultra-low harmonic and regenerative drives, can stop and restart fans in less than 10 seconds feeding braking energy back to the grid – a blazing speed. Furthermore, these compact drives are ideal for tight spaces, which is often the case in tunnel infrastructure.
Global guidelines and standards for tunnel fans specify the time and temperature at which they must operate under extreme conditions. Particular attention is paid to acceleration and braking times. For example, motors must be tested in accordance with EN 12101-3, which is considered the most demanding standard for smoke extraction.
Promoting energy efficiency
Ventilation systems in tunnels can be incredibly energy-intensive and expensive. Ensuring the energy efficiency of such projects is a priority. Adjusting the speed of a fan according to demand is a sensible use of energy. ABB drives, equipped with high-efficiency motors (up to IE5), control the fans’ speed according to the tunnel’s air pollution.
Our variable speed drives can generally reduce energy consumption by 20 to 60% compared to fans operating at nominal speed.
They are also equipped with temperature monitoring, overload, overcurrent, under/overvoltage and other protections and warnings to prevent control failures in ventilation systems. In addition to these features, the drive contains a fire override mode, which promotes safe evacuation in the event of a fire, and a real-time clock, which indicates the incidence of events by tracking failures. Our ACS880-37 ultra-low harmonics (ULH) drives guarantee the quality of power supply on the tunnel network, ensuring the reliability of the electrical system and equipment – the electrical harmonics are taken to a minimum of 3%, and voltage drops over long tunnel cables are compensated with a drive-based voltage boost feature, so ventilation runs smoothly 24/7.
Security and efficiency
ABB’s variable speed drives combined with accessible customer service help designers and operators of large infrastructure projects to ensure the safety and well-being of their users while improving the energy efficiency of their infrastructure.