Comparison of various parameters between LED Street Lighting and traditional high pressure sodium lamp
LED Street Lightings and traditional high-pressure sodium lamp is now the most street lamp source of the two options, below let us understand their data comparison:
1 luminous efficiency
Luminous efficiency refers to the ability of electric light source to convert electrical energy into energy, which is defined as the ratio of luminous flux emitted by the lamp to the power consumed, and the unit is LM. At present LED light source luminous efficiency, the United States, Japan about 75lm/w around, domestic production of LED about 65lm/w around. The luminous efficiency of the high pressure sodium light source is 100lm/w or so, which is higher than the LED 25~35lm/w. The luminous efficiency of 400W high pressure sodium lamp is up to 120lm/w.
2 Average life
The average life expectancy refers to the number of hours that a group of light sources ignite to a total number of 50% damage, and the unit is H. LED Street Lighting The average life of LED light source is greater than 000h, but in the actual application of the factors that affect its life, in addition to the LED device itself materials, manufacturing technology, technology, LED particle combination, lighting design, control circuit supporting components, heat, waterproof, dustproof and other factors will affect the life of LED light source. Therefore, the life expectancy is greater than 000h, at present can only refer to the theoretical life of LED light source. High-pressure sodium light source life expectancy is greater than 000h, and high-pressure sodium lamp is very mature products, its matching energy-saving inductance ballast life is greater than 000h, sodium lamp source complete After the ballast can still be used.
3 Lighting Utilization factor
Lamp use coefficient refers to the luminous flux emitted by the light source through the lamp light emitting device will be two times distribution of the use efficiency of the emission. The urban road illumination Design standard stipulates that the lamp utilization coefficient is 70%. Led single power is small, single 1W is already considered high-power. In addition, LED light beam emission angle is small, the direction of the light source is strong, in a combination of lights in the use of hundreds of LEDs to replace the high-pressure sodium lamp, which brings led combination light source and LED lighting matching problems. LED Street Lighting Is the common LED lamps and lanterns, some simple will be tiled on the reflector and folded into an angle to increase the irradiation surface; some will be combined with a few high-power led, using the convex lens refraction to enlarge the angle of illumination, but the utilization coefficient of the lamp is lower. High-pressure sodium light source for the line, column-type light-emitting source, that is, in the entire space is a full range of radiation, can be better through the refraction of the lamp reflector light distribution two times, so the utilization coefficient is higher.
Light distribution curve of 4 lamps
Lamps must have a bat wing-shaped light distribution, because the road longitudinal between the distance between the two lamps in general around 40m, lamps must be light to more than 20m, the formation of light between the two lights intersection, to avoid the dark zone between the two lights.
LED lamps are limited by the direction of the luminous source, as well as the light source is too small and numerous, it is difficult to achieve the ideal of the bat wing-like light requirements, its maximum light strength in the 15° around, LED Street Lighting most of the light directly to the lower side of the lamp surface, not able to cover two lights between the dark area, as shown in Figure 1.
The luminous source of the high pressure sodium lamp is not limited by the direction, and the bat Wing form is formed by two distribution of light, and its maximum light intensity is around 60°~65°. Can illuminate light to farther direction, cover the dark area between two lights.
5 Protection Grade of lamps
The protection level of lamps is expressed by IP, that is, the degree of dust-proof and waterproof sealing of lamps. LED Street Lighting General lighting requirements in the IP55~IP65, two light source lamps can meet this requirement.
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