Technical analysis of LED light source application in tunnel lighting

LED (Light Emitting Diode) is a solid-state semiconductor device capable of converting electrical energy into visible light. The principle of LED illumination is to pass current through the compound semiconductor. Through the combination of electrons and holes, the excess energy will be released in the form of light to achieve the effect of luminescence.

Since the birth of the first commercial LED in the 1960s, LED light sources have been rapidly developed and applied. LEDs are mostly used as indicators, display panels, etc. With the advent of white LEDs, their application range has been greatly improved. Now in traffic signals, advertising signs, emergency lighting, LCD backlighting, automotive lighting systems, commercial lighting And a wide range of applications in many lighting fields, such as urban nightscape lighting projects. Therefore, the LED light source is called the fourth generation illumination source or green light source, and has become a new generation of light source in the 21st century.

In recent years, with the rapid development of LED lighting technology and the in-depth implementation of China's energy-saving emission reduction policies, LED light sources have also begun to be applied to road lighting and road tunnel lighting. According to statistics, there are already hundreds of road and tunnel lighting companies that develop and produce white LEDs as light sources. Tunnels using LEDs as illumination sources have also increased, such as the Shanghai Yangtze River Tunnel and the Beijing Deshengkou Tunnel. Any new thing must have a process of development and perfection. Therefore, in the initial stage of LED lighting application, we should understand and understand the advantages and disadvantages of LED light source in current tunnel lighting as soon as possible, and give full play to the advantages of LED light source. The shortcomings of existence. Therefore, it provides a reference for the correct use of LED light source in tunnel illumination, and points out the direction for the application and development of LED light source in tunnel illumination in the future.

1, the characteristics of LED light source

As a new generation of light source, LED light source is quite different from traditional heat radiation and gas discharge light sources such as incandescent lamps and high pressure sodium lamps. The current LED light source has the following advantages in lighting:

(1) small size

Compared with the traditional light source, the LED light source is small in size and light in weight, and can be fabricated into various shapes of devices, which is convenient for arrangement and design of various lamps and equipments, has strong adaptability and wide application range.

(2) Good environmental performance

Since the LED light source does not need to add metallic mercury in the production process, the LED will not cause mercury pollution after being discarded, and the waste can be almost completely recycled, which not only saves resources but also protects the environment.

(3) Safe and stable

The LED light source can be driven by low-voltage direct current. The general supply voltage is between 6~24V, so the safety performance is better, especially suitable for public places. In addition, under the conditions of better external environment, the LED light source has less light decay and longer life than the conventional light source, and even if it is frequently switched, it does not affect its service life.

(4) Good seismic and impact resistance

The basic structure of the LED light source is an electroluminescent semiconductor material placed on a leaded shelf and then sealed with epoxy resin. There is no glass casing on the structure, and it does not need to be inside the lamp like incandescent or fluorescent lamps. Drain or rush into a specific gas. Therefore, the LED light source has good seismic and impact resistance, which brings convenience to its production, transportation and use.

(5) strong directivity

Compared with the traditional light source, the light emitted by the LED light source is oriented, and most of the light emitted from the LED can be directly directed to the illuminated surface, and the utilization rate is much higher than that of the conventional light source.