Led tunnel light is a kind of tunnel light. It is applied to large-area floodlighting in tunnels, workshops, large warehouses, venues, metallurgy and various plant areas, engineering constructions, etc. It is very suitable for urban landscapes, billboards and buildings. The face is landscaping.
Advantages of led tunnel lights:
Led and traditional tunnel illumination source contrast LED is a solid-state semiconductor device, which can directly convert electricity into light, compared with traditional road tunnel illumination source (sodium lamp, metal halide lamp, etc.), led light source has the following advantages:
(1) Low light decay: If the heat dissipation condition is good, the 10000h before the LED is positive light decay, the first 10000h light decay is 3% to 10%, and the first 50000h is basically 30%, which is far lower than the ordinary road illumination source. The light is more stable.
(2) High color rendering: Generally, the color rendering of led is about 70 to 80, which is higher if using three primary color phosphors; the general high pressure sodium lamp is 20 to 35, and the low pressure sodium lamp is lower, so even the brightness of the conventional light source Higher than led, but the visual effect is worse than led, "not very bright, but very clear" This should be a direction of the development of led point light source applications.
(3) Lifespan: The life of led is higher than that of general road tunnel illumination sources, and is now generally higher than 50000H.
(4) Price: Although the current price of led lamp is higher than that of traditional lighting, with the maturity of manufacturing technology, its price is currently falling sharply. The price of high and low pressure sodium lamp is generally around 2,000 yuan, and its cable is auxiliary. The price of the piece is higher than the cost of the LED cable.
In addition, led also has the advantages of high maintenance coefficient, good safety performance, no stroboscopic and energy saving and environmental protection.
Foreground challenge
At present, among the light sources used in tunnel lighting applications, high-pressure sodium lamps have been used for large-scale applications because of their high visual light efficiency (up to 120 lm/w), but high-pressure sodium lamps still have some difficulties in tunnel illumination. The problem is mainly poor color rendering and limited choice of light source power (usually only 250W and 400W), especially in the internal segment illumination, the high-pressure sodium lamp has no smaller power on the one hand, on the other hand, the point is strong. The glare and stroboscopic light caused by the light source are more serious. In some long tunnels, straight tube fluorescent lamps have also been used for their good visual inductivity due to their high color rendering and linear illumination. However, due to the short life of fluorescent lamps, they are usually only about 8,000 hours, so they often need to be replaced. , greatly increasing the maintenance cost of the tunnel. In addition, the power of the fluorescent lamp is small, and it is impossible to meet the requirements in areas such as the inlet section, the transition section, and the exit section where higher illumination is required. In recent years, with the maturity of the electrodeless lamp technology, due to the elimination of the influence of the electrode factor, the electrodeless fluorescent lamp has a longer life than the conventional fluorescent lamp, and can also achieve greater power, which makes the electrodeless lamp embodied in the tunnel lighting occasion. The advantage. However, the luminous surface of the electrodeless lamp is large, and the optical efficiency of the entire lamp is low when the optical design is performed.
Although there are still many difficulties and challenges in the large-scale application of led tunnel lights, such as the imperfect standard of led lighting products, the negative impact of some inferior products on market promotion, the initial purchase cost of led tunnel lights is relatively high. These all put pressure on the large-scale market application of led tunnel lighting products, but these pressures are inevitably encountered in the early stage of any new technology and new products. However, with the further development of high-power white light LED technology, LED tunnel thermal power system technology continues to mature, people's energy conservation and environmental awareness are further enhanced, led technology will create a new future in the semiconductor lighting industry in tunnel lighting applications. Applicable environment
The LED tunnel lamp housing is made of high-strength and tough alloy environmentally friendly materials. The transparent parts are tempered glass, dustproof, waterproof, corrosion-resistant and rust-proof. It has strong anti-strong collision and impact ability; multi-channel anti-vibration structure and high-tech surface spraying treatment, all kinds of close-range high-intensity high-frequency vibration can not affect the lamps, and can vibrate and wet in the workshop, roadbed, rails, etc. Long-term stable work in high temperature environment. Good electromagnetic compatibility will not cause interference to the transmission network.
Installation method
The led tunnel light has a variety of installation methods such as ceiling type, boom type, seat type and wall hanging type, and the operation is more convenient. Adapt to the needs of different work site lighting. The integrated design of the lamp and the electrical box has strong overall reliability, low failure rate, and safer and more convenient use and maintenance. The led tunnel light can adopt intelligent control technology to realize its own dimming control and save energy. The basic situation of led tunnel lighting is long. The tunnel is arranged according to the double-hole one-way driving mode. The tunnel lighting is divided into the entrance section, the transition 1, 2, 3, the basic section and the exit section; the lighting function is divided into three types: enhanced light, full day light and emergency light. . Double side lighting, the installation height of the lamp is 5.5 meters.
Road tunnel lighting has its own characteristics, which are not the same as ordinary road lighting. In design, you need to consider the following points:
1. The road surface should have a certain brightness level
2. The tunnel wall should have a certain brightness level
3. Designing factors such as speed, traffic volume, route alignment, etc.
4. Comprehensively determine the level of lighting from aspects such as driving safety and comfort
5. Human visual adaptability, especially at the entrance and exit sections of the tunnel
6. Tunnels also require lighting during the day, and daytime lighting problems are more complicated than at night.
In order to save energy, improve lighting and ensure the safety and comfort of driving in tunnel lighting, it can usually be considered from the following aspects:
Brightness
Since the brightness outside the tunnel during the day is much higher than that in the tunnel, when the driver drives into the tunnel, the vision needs to have a certain adaptation time, and then the inside of the tunnel can be seen. This phenomenon is called “adapted hysteresis”. "If there is no proper transition, a black hole will occur, causing the driver to temporarily lose normal visual function, which will bring certain security risks." The black hole phenomenon is a visual problem that occurs before entering the tunnel and is also an important issue in tunnel lighting. Tunnel lighting for this purpose is usually divided into entrance lighting, interior lighting and exit lighting. The brightness of the daytime tunnel entrance illumination is determined by the brightness outside the tunnel, the speed of the vehicle, the field of view at the entrance, and the length of the tunnel. The threshold segment is to eliminate the "black hole" phenomenon, and the illumination level of the transition segment is further gradually decreased, thereby providing the driver with time for visual dark adaptation.
2. Brightness uniformity
Good visual function requires not only a better average brightness, but also an average difference between the average brightness and brightness on the road surface. If the difference in brightness in the field of view is too large, the bright part will form a glare source, and the change of light and dark will bring about a certain stroboscopic effect, which will affect the vision, and the visual effect of the human eye will be significantly worse, and the vision Fatigue will also increase.
The overall brightness uniformity U0 refers to the ratio of the brightness on the road surface of the tunnel to the average brightness. The longitudinal uniformity U1 refers to the ratio of the brightness of the small road surface to the brightness of the large road surface on the lane axis. If the bright and dark bands appear on the road surface continuously and repeatedly, that is, the "zebra effect", it will be very annoying for the road users who are traveling in this lane. This problem involves people's psychology, but it also jeopardizes road safety. Vertical uniformity is mainly used to evaluate the size of the "zebra effect."
3. Glare
The formation of glare is due to the presence of extremely high brightness or brightness contrast in the field of view, which causes the visual function to drop or the eyes to feel uncomfortable. Glare in tunnel lighting can come from oncoming vehicle headlights, tunnel lighting, and high brightness outside the tunnel exit. Glare can reduce the ability of people to recognize obstacles and endanger the safety of driving. Tunnel lighting fixtures should adopt a cut-off type, adopting special technical measures to eliminate direct and reflected glare, forming diffuse reflection, so that the light enters the human eye very softly. The International Commission on Illumination uses a relative threshold increment (TI) to account for the decline in visual function due to glare, a measure of disability glare. In the tunnel lighting standard of the European Standards Committee (CR 14380:2003E), the provisions for disability glare are as follows: the tunnel threshold segment and the inner segment during the day and the entire tunnel at night, the relative threshold increment (TI) must be less than 15% .
4. Strobe effect
Stroboscopic means that in a long tunnel, due to the discontinuity of the arrangement of the illuminators, the driver is constantly disturbed by the stimulation of light and dark changes. It is related to the brightness change of light and dark, the frequency of light and dark changes, and the total time of stroboscopic. These three are related to the optical characteristics of the luminaire used, the traveling speed of the vehicle, the illuminator installation pitch, and the tunnel length. In general, stroboscopic phenomena caused by stroboscopic frequencies less than 2.5 and greater than 15 Hz are acceptable.
If the vehicle's speed is 60km / h or 16.6m / s, the installation spacing of the luminaire is 4, so the frequency of the strobe is about 4.2Hz. When designing, should consider, choose the appropriate illuminator installation spacing. If the frequency of the strobe is between 4 Hz and 11 Hz and lasts longer than 20 s, it will cause significant discomfort to the driver.
5. Lighting control
The advanced lighting control method is an important skill for reasonable energy saving in the case of ensuring visual conditions and meeting the tunnel lighting requirements. The purpose of lighting control is to change the lighting level of the tunnel at any time. Due to the cloudy, rainy or dusk time, the brightness outside the tunnel is much smaller than usual. Therefore, appropriate measures should be taken to reduce the level of illumination in the entrance section to reduce unnecessary energy waste. In the tunnel illumination, the illumination of the tunnel illumination environment or the opening and closing of the lamp can be adjusted and controlled by various dimming devices or control devices according to factors such as daytime, nighttime and traffic volume. At present, most of the foreign countries use photosensitive devices and dimmable electronic rectifiers to form an intelligent lighting system, which reduces the overall brightness of the lamps in the tunnel and reduces the energy consumption. At the same time, the uniformity of the tunnel brightness is guaranteed.