The Technical Principle Of LED Street Lights

Traditional LED street lamp design mainly focuses on the number of lumens of the LED, while less attention is paid to heat dissipation. In fact, the lumens of LEDs are increasing rapidly. The number of lumens per watt of mass-produced LEDs in 2009 has reached 100 lumens, and this value is still growing rapidly. The corresponding theoretical system of heat transfer has been mature, and the heat transfer methods we can use are basically clear: conduction, convection, radiation and phase change heat transfer. Therefore, in terms of heat transfer or heat dissipation, the measures we can take are visible and limited.

The heat dissipation technology of LED street lamps generally uses a heat-conducting plate, which is a 5mm thick copper plate, which is actually a temperature equalizing plate, which equalizes the temperature of the heat source. There are also heat sinks to dissipate heat, but the weight is too large. Weight is very important in the street lamp system, because the street lamp is 9 meters high, if it is too heavy, the danger will increase, especially in the event of typhoons and earthquakes. Accidents may occur. Domestic manufacturers use the world’s first needle-shaped heat dissipation technology, needle-shaped radiator The heat dissipation efficiency of the radiator is greatly improved than that of the traditional fin-shaped radiator, which can make the LED junction temperature more than 15℃ lower than that of the ordinary radiator, and the waterproof performance is better than that of the ordinary aluminum radiator. At the same time, the weight and volume are also improved. . In addition, the graphite heat sink developed for high-power LED lamps also has good heat conduction and heat dissipation performance.

The main heat dissipation methods are: natural convection heat dissipation, additional fan forced heat dissipation, heat pipe and loop heat pipe heat dissipation, etc. The forced heat dissipation method of installing a fan has a complicated system and low reliability, and the heat dissipation method of heat pipe and loop heat pipe is costly. The street lamp has the advantages of outdoor use at night, the heat dissipation surface is located on the side, and the size is less restricted. It is beneficial to the natural convection and heat dissipation of the air. Therefore, it is recommended to choose the natural convection heat dissipation method as much as possible.

The problems in the heat dissipation design of LED street lights are: the area of the heat dissipation fins is set at will, the arrangement of the heat dissipation fins is unreasonable, and the arrangement of the heat dissipation fins of the lamps does not take into account the use of the lamps, which affects the effect of the fins, and emphasizes heat conduction. Although many manufacturers have considered various measures: heat pipes, loop heat pipes, adding thermal grease, etc., they did not realize that the heat will eventually be dissipated by the outer surface of the lamp. Ignore The balance of heat transfer, if the temperature distribution of the fins is severely uneven, it will cause some of the fins to have no effect or have a limited effect.

Heat-dissipating high-power LED street light fixtures. Its purpose is to solve the heat dissipation problem of high-power LED lamps and propose a high-power LED street lamp lamp with air convection heat dissipation, which includes a lamp head assembly, a lamp heat sink assembly and a lamp tail assembly. The lamp heat sink assembly is an arc-chord cylindrical shell. , Open at both ends, the two sides of the arc cylindrical surface are vertical surfaces, and the vertical surface is also provided with array of through holes. In the inner cavity of the arc-chord cylindrical shell, there are 4-10 axially arranged and aligned with the arc cylindrical surface and the chord cylindrical surface. The two vertical sides of the vertical rib heat conduction plate and the vertical rib heat conduction plate and the arc-chord cylindrical shell are also provided with array through holes. The vertical rib heat conduction plate and the two vertical ribs on both sides of the arc-chord cylindrical shell are also provided with array through holes. 5-11 heat dissipation channels through which hot air flows are formed in the radiator assembly of the lamp. The utility model has the advantages that there are multiple heat dissipation channels through which hot air flows in the internal cavity of the heat dissipation body, and the vertical rib heat conduction plate also serves as a heat dissipation surface, the heat exchange surface is increased, and the heat discharge efficiency is high.