Analysis Of Factors Affecting The Life Of LED Street Lights (II): Heat Dissipation Performance

For manufacturer, in order to prolong the service life of LED street lights, it is necessary to solve the heat dissipation problem of LED chip.In this way, can occupy the advantage in many LED street lighting products.

Generally speaking, (heat transfer) heat dissipation ways are mainly divided into heat conduction, heat convection and heat radiation.In popular terms, the heat generated by the LED chip passes through the LED package structure, circuit board and heat dissipation structure in the way of heat conduction.Finally, the heat is transmitted to the external environment in the way of thermal convection and thermal radiation, so as to reduce the accumulation of heat inside the lamp and reduce the impact of temperature on the energy saving effect and life of LED lamp.

At present,most of the LED street lights on the lighting market that use radiator made of aluminum, the heat dissipation only highlight the role of heat transfer.Due to various reasons such as technical limitations, there is no more optimization design in terms of thermal convection and thermal radiation.However, in the face of heat dissipation problem of LED street light, EXC Streetlight did not stagnate.

LED street lights that researched and developed by EXC Streetlight in the use of independent ceramic heat dissipation technology, but also fully consider these three basic (heat transfer) heat dissipation.In the study of the natural convection heat transfer mechanism of the heat dissipation structure, the "hollow structure" design was put forward after the in-depth study of the causes of fluid flow, fluid phase transformation, fluid flow state, fluid physical conditions and geometric factors of the heat transfer surface.

That is, while taking into account the use function and aesthetics of lighting fixture, the number of heat dissipation holes are opened on the cover and bottom plate of lamp.The heat inside the lamp is directly transferred to the radiator through heat conduction, and then dissipated into the air by natural convection (a type of convection).That is, taking use of the temperature difference between the inside and outside of the lamp, making the density of cold and hot air different.The density of hot air with high temperature is small, and it will rise inevitably.Cold air with a low temperature is dense and must fall.In this way, the circulating flow between hot air and cold air makes the temperature tend to be uniform, so as to realize the real-time heat dissipation, avoid the "heat island effect", reduce the PN junction temperature, improve the service life of lighting product.In addition, as a reliable passive heat dissipation mode, natural convection does not need other auxiliary spare parts and has low maintenance cost. It is an efficient and reliable heat dissipation mode.

So far,this "hollow-out" structure design has been widely used in LED street lights, solar LED street lights,smart street lights,LED tunnel lights and other road lighting products, effectively solve the heat dissipation of lighting fixture, improve the reliability and service life of lighting products.