Tunnel lighting source selection has been a focus of attention. Today, lighting manufacturers will analyze the usage of various light sources in tunnels.
High-pressure sodium lamps have been widely applied due to their high luminous efficacy (up to 120lm/W). However, they have some insurmountable issues in tunnel lighting, mainly reflected in poor color rendering and a limited range of power selection (typically only 250W and 400W). Especially in internal segments, high-pressure sodium lamps present serious glare and flicker caused by the small power outputs combined with point-like strong light sources.
In some long tunnels, straight-tube fluorescent lamps have found applications due to their high color rendering and linear lighting, providing good visual guidance. However, the short lifespan of fluorescent lamps, typically around 8000 hours, necessitates frequent replacements, significantly increasing maintenance costs. Additionally, the low power of fluorescent lamps does not meet the lighting requirements in areas like entrance, transition, and exit sections that require higher illumination.
In recent years, as the technology of induction lamps has matured, their advantages over traditional fluorescent lamps, such as longer lifespans and the ability to achieve higher power outputs due to the elimination of electrode factors, are increasingly evident. However, because induction lamps have a larger light-emitting surface, their optical efficiency during design is relatively low.
LED tunnel lights can be described as an integration of the advantages of high-pressure sodium lamps, straight-tube fluorescent lamps, and induction lamps, making them an ideal light source for tunnel lighting applications. Their advantages include:
1) High luminous efficacy: Currently, mass-produced single-chip 1W LEDs can achieve luminous efficacy of over 100lm/W. Additionally, since the light is emitted on one side, the entire optical system can achieve high fixture efficiency.
2) Long lifespan: Under reasonable heat dissipation design and power driver conditions, LEDs can last up to 50,000 to 70,000 hours. This significantly reduces maintenance costs for 24-hour tunnel lighting applications.
3) Easy light distribution: Due to the small size of LED light sources and their strong directionality, they can conveniently be paired with lenses or reflectors for optimal light distribution. This not only improves the overall efficiency of the fixture but also ensures good uniformity.
4) Flexible fixture design: LED tunnel lights can flexibly adjust power by using around 1W LED devices, allowing the number of LEDs in the light source to be varied according to actual illumination requirements, achieving energy-saving effects. Additionally, due to their small size, the design of the fixtures is also very versatile, accommodating linear fixtures for good visual guidance or rectangular fixtures for higher illumination needs in entrance, transition, and exit segments.
5) Intelligent dimming control: LED technology allows for infinite dimming of fixtures, combined with entrance brightness, to dynamically adjust the brightness of tunnel lighting. This fully utilizes the technical characteristics of LED tunnel lighting fixtures, further enhancing energy efficiency and achieving smart tunnel lighting.
Currently, the market offers intelligent LED tunnel lights that can achieve functions such as computer dimming, temperature control, automatic inspection, and adjustable tilt and horizontal angles. The light efficiency is 80lm/W, with a 70% energy-saving rate. While there are still many challenges to large-scale applications of LED tunnel lights, such as the lack of complete standards for LED lighting products and the negative impacts of inferior products on the market, the initial purchase cost of LED tunnel lights is relatively high. These challenges inevitably pressure the market for large-scale applications of LED tunnel lighting products. However, with the further development of high-power white LED technology and the continuous maturation of the overall light-heat-electric system technology of LED tunnel lights, along with the enhanced awareness of energy saving and environmental protection, LED technology will surely create a new future for the semiconductor lighting industry in tunnel lighting applications.
