At the beginning of 2018, CEDINSA, within its Energy Optimization and Safety Improvement Plan of the facilities that it has under concession by the Generalitat de Catalunya, proposed the use of LED technology for lighting in the existing tunnels to along the C-16, C-25 and C-17 motorways. A first action was to study the lighting in one of the tunnels to verify that both the technology and the energy savings obtained of this action were ready to justify the investment.
In the middle of 2019, a through an exhaustive study was performed, it concluded that using the LED technology to illuminate a tunnel during day and night, and considering the operating hours, installed power and regulation possibilities offered by LED technology, provides energy savings that causes the investment to be repaid in a reasonable period of time.
This project also gave the opportunity to improve the lighting quality, changing from HID technology, and given the dimensions and geometry, using LED technology in the fixtures the light distribution was significantly improved.
The tunnel chosen was Joanet Tunnel located on the C-25 highway and, the one-way tunnel in the direction of a town call Vic. The tunnel is 1,394 m long and has 3 lanes of circulation with a total width of 10.8 m, with hard-shoulders on both sides of 0.5 m and pavements on both sides of 1 m. In addition, the tunnel fixtures are located on a single side (fast lane), mounted on a cable tray in unilateral distribution, located within the track at 1.4 m from the start of it and at 5.65 m in height. At the light level, the challenge in this tunnel was to improve the lighting conditions of the slow lane (the one furthest from the installation point of the fixtures), especially when that lane, the slow one, supports the vast majority of the traffic of heavy and large tonnage vehicles.
We decided to opt to develop the solution that concentrated on three main points: optimization of total installed power, improvement of uniformity conditions, especially in the slow lane, minimizing possible glare, and reliable, long-lasting LED technology with the ability to be integrated into the management and regulation system that the tunnel already had at that moment. Ultimately, Tungsram's solution was the winner and therefore the chosen one.
Tungsram, with its fixtures of the TLBT and TMBT range, not only offered the most optimized solution but also managed to provide excellent lighting conditions for the slow lane. With this, we refer to the uniformity and the illumination not only of the horizontal plane but also of the vertical plane that defines the vehicle as it passes through the lane this, minimizing the impact of possible glare since, thanks to the reflective type technology used by these fixtures in their optical system. The light source (the LEDs) is set back (hidden) with respect to the plane that defines the glass that protects the fixture and it is with a polished and anodized aluminium reflector that the desired photometry is obtained, thus avoiding direct vision and a wide range of LED viewing angles.
The solution that made possible to provide the tunnel with day and night lighting, according to current regulations, with 95 cd / m2 in the access zone and with 2.55 cd / m2 inside, was designed based on the installation of:
12 units TMBT / 3 / F / AC / 302w / 40 / AMP / SP / C1 / N / B, double bracket
74 pcs TMBT / 3 / F / AC / 260w / 40 / AMP / SP / C1 / N / B, double bracket
28 pcs TMBT / 3 / F / AC / 130w / 40 / AMP / SP / C1 / N / B2
18 pcs TLBT / 3 / F / C / 89 / 40w / AMP / SP / C1 / N / B2
107 pcs TLBT / 3 / F / C / 65 / 40w / AMP / SP / C1 / N / B2 for interior lighting
The new energy consumption of the executed solution is 35.7kw. It optimizes the power to be consumed by approximately 38%, considering an alternative based on the old HID technology based on 400, 250 and 150w projectors. Furthermore, the used devices are equipped with drivers with the ability to interpret a regulation order through a variation in the supply voltage, a DALI signal, so we not only provide to the new installation the ability to be integrated and be compatible with the existing headend regulators system in this tunnel, but also, and for the future, we enable them to work under a system that works with DALI.
The solution implemented not only meets the initial objectives set by the property, but, as Tungsram defends in different forums, the technology that these projector models use in their optical system, provides minimal glare and high visual comfort.
