Tunnel lights, as the name suggests, are used for lighting in highway tunnels. With the continuous progress of our social economy, the road traffic network is more and more developed, more and more tunnels, and the lighting in the tunnel is also more and more attention.
Tunnel lights, as the name suggests, are used for lighting in highway tunnels. With the continuous progress of our social economy, the road traffic network is more and more developed, more and more tunnels, and the lighting in the tunnel is also more and more attention.
Many people will take it for granted that tunnel
lighting should be similar to highway and street lighting. But in fact, tunnel as a kind of tubular semi-enclosed area, there are some particularities. For example, when the vehicle enters the tunnel during the day, due to the sudden drop in brightness, the human eye reaction lags behind, and it is difficult to distinguish the situation in front of it, forming the so-called "black hole effect"; On the contrary, when the vehicle drives out of the tunnel, it will form the so-called "white hole effect" because of the strong glare. Therefore, tunnel lighting and general street lighting there is a big difference:
First, there are some special requirements on brightness. The lighting in the tunnel is divided into near section, entrance section, transition section, middle section and exit section, and the lighting requirements of different sections are different. Generally, the brightness is required to gradually decrease first,
maintain a stable middle, and then increase the brightness at the exit.
Hong Kong-Zhuhai-Macao Bridge tunnel picture
The second is that the light should be uniform, the brightest and the darkest can not be too different, to avoid the "zebra effect" of continuous bright and dark on the road surface. In addition, the installation spacing of the lamps should also be adjusted, especially to avoid changes in light and shade between 2.5-15Hz, resulting in the so-called "strobe effect". Because whether it is the "zebra effect" or the "stroboscopic effect", it is easy to cause visual fatigue and psychological discomfort.
Third, lighting control also has special requirements. Different from ordinary road lighting, tunnel lighting requires 24 hours a day, and the light intensity during the day is stronger than at night, and the power consumption is higher. In order to achieve energy saving under the premise of effective and safe lighting, it is necessary to control the strength of lighting in a targeted way.
Before the emergence of LED tunnel lights, there were three main types of tunnel lights on the market, high-pressure sodium lamps, fluorescent lamps and
electrodeless lamps. However, each of these three lamps has some advantages, but there are also some obvious disadvantages.
The advantage of high-pressure sodium lamps is that the light efficiency is high (up to 120ml/W), and the energy saving is relatively high. The disadvantages are poor color rendering and limited power range. Because often can not find the right power, have to use high-power bulbs, not only power consumption, but also easy to cause glare and stroboscopic effect under strong light.
Fluorescent lamps have better color rendering, and because they are generally used as straight tube fluorescent lamps, they have a certain visual induction effect. However, the power of fluorescent lamps is small, and the use time in the tunnel entrance or exit section is often unable to meet the requirements. In addition, the service life of fluorescent lamps is short, generally only 8000 hours, and it needs to be replaced frequently, which greatly
increases the cost.
The electrodeless lamp has good color rendering, long service life and greater power than fluorescent lamp. However, its light efficiency is not outstanding (80ml/W), and the volume is large, the luminous surface is also large, and the lamp design is often limited.
LED tunnel lights concentrate all the advantages of the above three lights and abandon their shortcomings. Therefore, it quickly becomes the most ideal light source in tunnel lighting. So far, tunnel lighting has basically been LED lighting. Specifically, the advantages of LED tunnel lights mainly have the
following aspects.First, high light efficiency. Today, the light efficiency of LED has generally exceeded that of high-pressure sodium lamps, and there is still a lot of room for improvement in the future. Therefore, the energy saving effect is obvious.
Second, long life. The theoretical life of the LED lamp is up to 100,000 hours, and the actual product is also more than 30,000 hours, which can greatly reduce maintenance costs.
Third, the lighting design is flexible. LED is a point light source, small in size, and can be designed according to the requirements of different tunnels or different sections of the same tunnel to achieve the best lighting effect.
Four is can be no
pole dimming. As a semiconductor solid-state light source, the biggest feature of LED lights is that the dimming is extremely flexible. It can be combined with the brightness of the entrance, the number of vehicles or other parameters to dynamically change the brightness of the light in the tunnel, if supplemented by appropriate sensing and control systems, intelligent lighting can be achieved.
Of course, LED tunnel lights are not without difficulties in the application, one of the more typical problems is the light decay of LED lights. The light decay of LED lamps is mainly related to the p-n junction temperature (
junction temperature) of semiconductor diodes. As the junction temperature rises, the brightness of the lamp decreases continuously. The LED tunnel light is 24-hour continuous lighting, and the heat is larger, so the requirements for heat dissipation are relatively high. In addition, the environment in the tunnel is harsh, the air circulation is not good, and the humidity is high, which will also accelerate the aging of the lamps.
In order to solve these problems, researchers in the industry have thought of many ways. For example, Shanghai Si Photoelectric developed a ceramic LED tunnel light, the LED lamp bead directly welded to the alumina ceramic radiator, the use of alumina ceramic high insulation and high thermal conductivity, to achieve the purpose of rapid heat dissipation. At the same time, due to the
excellent chemical stability of alumina ceramics, they are not sensitive to acid, alkali, moisture, etc. in the air, and can be used in harsh environments for a long time, and supplemented by appropriate structural design, they can solve the problem of aging of lamps. At present, this ceramic LED tunnel light has been applied in a number of important tunnels in China (such as the Hong Kong-Zhuhai-Macao Bridge Undersea tunnel, Xiamen Haicang Tunnel, Dalian Bay Undersea Tunnel, Jinan Yellow River Tunnel, etc.), and has achieved good results.
