LED street lights have low luminous efficiency

As with LED lights to replace the high pressure sodium lamp, also there are some different views, for example, compared to high pressure sodium, low luminous efficiency LED lights, the illumination is poor; illuminated LED light is too concentrated, relatively poor uniformity of illumination; LED lamp light attenuation rate is large, life is far unable to reach the theoretical lifetime. In fact, these ideas can be illustrated by the following analysis.

The first is called "luminous efficiency" problem, in the current technical conditions, the luminous efficiency of LED lamp is indeed not as high pressure sodium lamp, it is an indisputable fact, but high pressure sodium lamp spectrum concentrated in the yellow area, the lower the color temperature Only 2000-2500K, while an LED color temperature is relatively high, LED street light, neutral white warm up to 4000-5000K, LED cold white temperature of 5000-8000k. At the same time, compared to high pressure sodium lamp, LED lamps have a high color rendering index, close to natural light in the actual lighting, can bring people comfort.

Followed by "illumination uniformity" problem, although the LED lamp illumination is relatively concentrated, but by the second design of its optical path, so that the lamp can light showing the ideal state, to achieve a reasonable distribution curve adjustment, control of light distribution, in order to achieve uniformity of the illumination.

Then "bad light" problem, in practical application process, because the long-term work in high temperature environments, LED lamp life will be affected accordingly. As can be seen, if the junction temperature increased from 115 ℃ to 135 ℃, the LED lamp life will be reduced from 50,000 hours 20,000 hours theory.

In the current technical conditions, in order to enhance short in luminous efficiency LED lights is basically impossible, it can only be extended LED lamp life by way enhance heat dissipation. Currently, Taiwan light a torch Ltd. (LightTorch Technology), the use of loop heat pipe (LHP) cooling technology, heat dissipation of the LED lights work, and achieved good results, the ability to reduce the LED junction temperature to 65 ℃, at this temperature, if the lights work 12 hours a day, its light fades less than 3%.