Application Of LED Street Lamp In Road lighting
2022-05-18
VIEW "3297
Due to the advantages of energy-saving, environmental protection, long service life, resistant to vibration, flexible control, fast response etc,LED light source has been widely used in many fields such as traffic signs, emergency lighting, advertising signs, large display screen, auto brake lights and urban night scene lighting engineering,so LED light source is known as a new generation of light source in the 21st century.The lighting blog post focuses on the lighting effect in practical use of LED street lamp compared with high- pressure sodium lamps on basis of some key indexes such as luminous efficiency distribution curve and luminaire lifetime.
Comparison of key indicators of two kinds of road lighting sources and lamps
Luminous efficiency
Luminous efficiency refers to the ability of an electric source to convert electrical energy into light energy,which is defined as the ratio of the luminous flux emitted by the lamp to the electrical power ,consumed in lm/W.
At present, the luminous efficiency of LED light source of the United States and Japan is about 75lm/W,the luminous efficiency of LED produced by China is about 65lm/W.The luminescence efficiency of high-pressure sodium light source is about 100lm/W 25 ~ 35lm/W higher than LED.The luminescence efficiency of 400W high pressure sodium lamp is 120 lm/W.
The average life span
Average life refers to the number of hours from the ignition point of a batch of light source to 50% of the total amount of damage,unit is h.
The average life of LED light source is greater than 5000h.However, in practical application, there are many factors affecting the life of LED light source. In addition to the material, manufacturing process and technology of LED device itself,LED particle combination, lamp design, components supporting the control circuit, heat dissipation, waterproof,dustproof and other factors will affect the life of LED light source.So the life is greater than 5000h can only refer to the theoretical life of LED light source at present.The average life of high pressure sodium lamp is more than 24000h,and the high pressure sodium lamp is a very mature product,the life of its supporting energy-saving inductance ballast is more than 5000h,sodium lamp ballast can still be used after the end of life.
Luminaire utilization factor
Luminaire utilization coefficient refers to the utilization efficiency of secondary distribution and emission of light flux emitted by luminaire through luminaire emitter.Urban road lighting design standards stipulate that the utilization coefficient of lamps is 70%.
LED single power is small,single 1W is considered to be high power.In addition, the light beam emission angle of LED light source is small,the light source has strong directivity. In a luminaire, the combination of hundreds of LED can replace the high-pressure sodium lamp,which brings the matching problem of LED combined light source and LED lamps.
Now common LED lamps some simply LED tiled on the reflector and folded into an Angle to increase the irradiation surface; Some combine several high-power LED together to enlarge the irradiation angle by convex lens refraction, and , but the utilization coefficient of lamps is low.
High pressure sodium lamp light source is line, column type light source,that is, in the whole space is omnidirectional radiation can better through the refraction of the lamp reflector for light secondary distribution , so the utilization coefficient is high.
Light distribution curve of LED lamp
The lamps must have bat-shaped light distribution performance, because the distance between the longitudinal two lamps on the road is generally about 40m,the lighting lamp must illuminate the light to more than 20m to form the light cross between the two lamps to avoid the dark area between the two lamps.
LED lamps are limited by the direction of the light source and the light source is too small and numerous to meet the requirements of the ideal bat-wing light distribution.Its maximum light intensity is within 15°, and most of the light is directed to the road at the bottom of the lamp, which cannot cover the dark area between the two lamps. As shown Figure 1.
The source of high pressure sodium lamp is not restricted by directionality,through the secondary distribution of light to form bat wing shape.Its maximum light intensity value is about 60° ~ 65°, and it can shine light in a further direction to cover the dark area between the two lights. As Shown Figure 2.
Protection grade of LED lamp
The protection grade of LED lamps is represented by IP, that is, the sealing degree of dustproof and waterproof lamps and lanterns.In general, the protection grade of LED lamps is required in IP55 ~ IP65,two kinds light source of lamps and lanterns can meet this requirement.
The application example of LED street lamp
Case 1
This road lighting project is located in Beihai Road, a certain city, Shandong province.Road type and conditions are: main road,two-way six lanes,total width 60m, 8m of middle divider,12m of both sides of the motor vehicle lane, 3m of both sides of the motor vehicle divider, 7m of both sides of non motor lane, 4m of both sides of the sidewalk.The street lamps are installed in the center of the 3m wide separation belt on both sides,arranged symmetrically,and the length of the lamp arm is 2∙5m.Originally, 400W high-pressure sodium lamp was installed on the side of the motorway, and 250W high-pressure sodium lamp was installed on the side of the slow lane, totaling 364 sets.After the implementation of lighting energy saving transformation,110W LED street lamps were refit on the side of motor vehicle lane, and 80W LED lamps on the side of non-motor vehicle lane.LED street lamps are provided by a Shenzhen company of EXC Streetlight.After 8 months of operation,the editorial board of City Lighting was commissioned by the street lamp management department of the city to conduct another test,the test is described as follows:
Figures 3 to 6 and Table 1 are charts and data of field tests.Seeing FIG. 3 and FIG. 4 for the installation diagram and the lighting test area of LED street lamps on Beihai Road.
Case 2
City lighting management office of New north district, Changzhou implement lighting projects in the 3 new roads of Minjiang river road, plum flower road of clock tower development zone and Xingke road of new north district. Choosing different light distribution scheme to test and install high-power LED street light.And respectively tested the illuminance of 3 roads at the beginning of the installation and after 55 days of installation and half years of installation.The test results are as shown in table 2.