LED single watt lumen output is to determine whether the LED tunnel light has practical value of the basic indicators, according to the requirements, LED tunnel light used by the single watt lumen number should reach 80 lumens or more, after nearly three years of rapid development of LED luminous efficiency, At this stage, the LED light efficiency that can be supplied in large quantities has reached more than 90lm/W, and the brightness is still improving. Table 2 provides the main technical parameters of high-power 1W white leds that have been mass-produced by several major manufacturers at the forefront of the world. OSRAM manufacturer LUWW5AM can be used as the design light source, the use of LED light source has a variety of different color temperature to choose from the characteristics, choose with sunlight similar color temperature 4000~6000K LED light source, can effectively reduce the “bright hole” and “black hole” effect.

Light distribution design

According to the tunnel lighting requirements, different lighting lamps are used according to different lighting segments, according to the optical principle and the characteristics of high directivity of the LED light source, the use of reasonable light distribution, in the case of meeting the brightness or illumination requirements, reduce the power of the lamp to achieve the purpose of energy saving.

(1) The introduction section, adaptation section, transition section and exit section of the tunnel entrance section use asymmetric lighting distribution (backlight lighting), under the same illuminance conditions, compared with ordinary lighting, can improve the brightness of the road surface 121%, at the same time, the advantage of high directivity, strictly control the light intensity of the large Angle direction, eliminate most of the glare.

(2) In the basic section of the tunnel, the current common light distribution types are concentrated light distribution, side beam light distribution, Lambertian light distribution and so on. Different applications are suitable for different light distribution forms, such as: bat wing type light distribution should be used for road lighting, spotlights should be used for concentrating type light distribution. Due to the particularity of tunnel lighting, the arrangement density of lamps in tunnel lighting is very high, so the secondary light distribution form of lamps in tunnel lighting is different from that of general road lighting. In tunnel lighting, bat-wing light distribution and Lambert-type light distribution can meet the requirements of illuminance uniformity, which is mainly due to the relatively small lamp distance in tunnel lighting. Figure 1 shows the C0 direction light distribution diagram of the two LED tunnel lights. The left side is the road lighting and the bat-wing light distribution commonly used in tunnel lighting, and the right side is the Lambert-type light distribution. Using bat-wing light distribution, that is, wide-band symmetrical lighting light distribution, under the same illumination conditions, compared with ordinary lighting, it can increase the brightness of the road surface by 64% and improve the brightness uniformity of the road surface.