In recent years, domestic LED lighting applications have developed rapidly. Many manufacturers have introduced high-power LED street lamps, and more and more energy-saving products are used in road lighting. At present, high-power LED street lamps can really replace traditional light sources (mainly High pressure sodium lamp)? Here are some views on the application of high-power LED street lights:
First, regarding the power-saving effect of LED street lamps, in many cases where practical LED street lamps replace high-pressure sodium lamps, power saving is an important factor, but actual LED street lamps are not more energy-efficient than high-pressure sodium lamps. From the comparison of luminous efficiency, the luminous efficiency (80lm/W) of high-power LED street lamps currently used in practice is much lower than that of high-pressure sodium lamps (100~138lm/W). Although LEDs are directional, the efficiency of lamps is higher than that of high-pressure sodium lamps. At the end of luminous efficiency, the comprehensive energy efficiency of LED street light lamps is still lower than that of high pressure sodium lamps.
In some cases where LED street lamps have been replaced by high-pressure sodium lamps to obtain power-saving effects, according to analysis, these cases are often caused by high power of the original street lamps (brightness exceeding the standard) or low efficiency of the lamps and severe attenuation of the light source. The basis of electricity is not scientific.
Second, the LED light color problem, the current high-power LED street light is basically using 5000K ~ 6000K color temperature white light, as a road lighting source, the visual feeling is too cold, while the eyesight observation ability will decline when farsighted, in this regard Some studies have proved that yellow light or warm white light below 3000K is more suitable for road lighting, so daylight-colored LED street lights are not suitable for street lamps.
Third, the current cost of LED street lamps is far more than high-pressure sodium lamps. The current price of an LED street lamp is 4,000 yuan to 8,000 yuan, or even higher. The price of a set of imported high-pressure sodium lamps (including lamps and complete sets of electrical appliances) does not exceed 1,500 yuan. The average price is less than a quarter of the LED street light.
Fourth, the service life comparison, LED street lamp nominal service life is more than 50,000 hours, this is the ideal life of the chip, chip packaging, lamp cooling and other factors may be light attenuation, as well as the drive circuit (mainly electronic components) The life expectancy is obviously not up to 50,000 hours. In some of the LED street lamps that have been tried, it is found that the attenuation of the lamps is very obvious after less than half a month.
The nominal life of high-pressure sodium lamps has now exceeded 28,000 hours. The actual application of 3-4 years is not a big problem. In contrast, the life of high-pressure sodium lamps and supporting electrical appliances is much more problematic.
For the maintenance of the light source, the high-pressure sodium lamp should be much easier, and the light source electric appliance can be directly replaced at the site, and the cost is also low. As for the LED street light, I think the manufacturer thinks it is maintenance-free, so the maintenance on site cannot be carried out.
5. The problem of light distribution of LED street lamps. At present, the light distribution technology of LED street lamps has been greatly developed. Some manufacturers have developed secondary light distribution systems, instead of relying solely on chip arrangement to distribute light, but comprehensively, The light distribution can not be completely reasonable. I have observed a light fixture. The light distribution on the road side is brighter and the uniformity also meets the requirements. However, the sidewalk side brightness is obviously insufficient, and the SR value obviously does not meet the requirements.
At present, there are not many products that have developed secondary light distribution systems, and there are not many good LED street lamps to choose from in the application.
Sixth, LED street lamps lack uniform technical standards in terms of product specifications. At present, there is no unified technical standard for LED street lamps production. Each manufacturer produces its own products according to its own standards. It is difficult to use them in common. In addition, LED street lamps and multiple chips are used. The characteristics of the assembly work make the chip and the luminaire bundled together, difficult to maintain, and the original product must be used for maintenance.
Due to the unification of technical standards, high-pressure sodium lamps have strong versatility in lamps, light sources and electrical appliances. Products between different manufacturers can be used interchangeably. From the perspective of maintenance, this is very important, and maintenance is for the street lamp management unit. It is the most important thing. Only in this way can the street lights be cleaned in time to ensure a high lighting rate (the most important part of the street lighting management assessment by the superior department), and greatly reduce maintenance costs.
It can be said that in the current development situation, LED street lights can not be maintained. In the event of a fault, only the entire luminaire can be replaced. In addition to the high cost, the maintenance time should be greatly extended. This is very important for the user. Adverse.
LED lighting is a technology that is developing. Its light efficiency is constantly improving and its cost is declining. However, it is not the time to replace traditional high-pressure sodium lamps as street lighting. Therefore, the “Eleventh Five-Year†city green issued by the Ministry of Construction The lighting project planning outline, the urban road lighting professional committee "implementing the "Eleventh Five-Year" urban green lighting project planning outline implementation rules" and other policy documents clearly that the street lamp energy-saving light source is still based on high-pressure sodium lamps, LED is recommended in urban landscape lighting Application.
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