LED street lamp and high pressure sodium lamp in the application of road lighting

1. 1 luminous efficiency refers to the luminous efficiency electric light source's ability to convert electric energy into light energy, defined as the luminous flux of light and the ratio of the electric power consumption, unit for lm/W. The luminous efficiency of the LED light source, the United States, Japan, about 75 lm/W, domestic production of LED some 65 l

1. 1 luminous efficiency refers to the luminous efficiency electric light source's ability to convert electric energy into light energy, defined as the luminous flux of light and the ratio of the electric power consumption, unit for lm/W. The luminous efficiency of the LED light source, the United States, Japan, about 75 lm/W, domestic production of about 65 lm/W leds. High pressure sodium lamp light source of luminous efficiency is about 100 lm/W, higher than the LED 25 ~ 35 lm/W. 400 W high pressure sodium lamp luminous efficiency is as high as 120 lm/W. 1. 2 life expectancy life expectancy refers to a group of light flash point to have 50% of the total number of damaged when the number of hours, the unit for h. LED light source, the average life expectancy is greater than 50000 h, but in practice there are many factors which can affect its life, in addition to the LED device itself materials, manufacturing process, technology, the combination of LED particles, the design of lamps and lanterns, control circuit of form a complete set of components, heat dissipation, waterproof, dust and other factors will affect the service life of the LED light. So life is more than 50000 h, currently only refers to the theory of the life of LED light source. High pressure sodium lamp light source, the average life expectancy of more than 24000 h, and high pressure sodium lamp is already very mature product, its form a complete set of energy-saving inductance ballasts is more than 50000 h, the life of a sodium lamp light source after worshiped ballast can still use. 1. 3 using the coefficient of utilization coefficient refers to the light source of lamps and lanterns of lamps and lanterns of luminous flux through the light source of lamps and lanterns to secondary distribution of emission light utilization efficiency. Standard lamps and lanterns city road lighting design utilization coefficient of 70%. 1 w LED the single star power is small, the star has a high power. Other LED light beam emission Angle is small, light intensity, in a combination use of hundreds of thousands of star in the LED lamps and lanterns to instead of high pressure sodium lamp, the combination that leads to the LED light source and the matching problem of LED lamps and lanterns. Now common LED lamps and lanterns, some simple LED flat out on the reflector and fold into an Angle in order to increase exposure surface; There will be several high power leds together, using the convex lens refraction expand the irradiation Angle, but the utilization coefficient of lamps and lanterns is low. High pressure sodium lamp light source for line and column type of light source, that is, in the whole space is omni-directional radiation, can well through the reflectors of lamps and lanterns of refraction of light secondary distribution, so the utilization coefficient is higher. 1. 4 light distribution curve of the lamps and lanterns of lamps and lanterns must have a wing of the bat light distribution performance, because the road longitudinal distance between two light generally at about 40 m, lamps and lanterns must put light to more than 20 m, form a cross between two lamp light, avoid appear dark space between the two lights. LED lamps and lanterns is limited by the light source direction, as well as the light source is too small and numerous, difficult to achieve the ideal bat wing shape light distribution requirements, its maximum light intensity within 15 ° or so, most of the light point-blank lamp to lower the road, will not be able to cover the dark areas between the two lights, as shown in figure 1. High pressure sodium lamp light source is not restricted by direction, through secondary distribution of light forming a bat wings, its maximum light intensity around 60 ° ~ 65 °. To the direction of the light to further, cover the dark areas between the two lights, as shown in figure 2. 5 the protection grade of the degree of protection of lamps and lanterns of lamps and lanterns with IP, said the lamps and lanterns is dustproof and waterproof seal degree. General requirements in IP55 ~ IP65 lamps and lanterns, two kinds of light source of lamps and lanterns can meet this requirement.

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