What are the main factors affecting LED heat dissipation?
As we all know, LED headlights are very popular in recent years, and more and more people regard LED as their first choice. LED is not only environmentally friendly and energy efficient, it has a fast response, and it has a long life compared to HID. But LED is not without its shortcomings, the heat is not good, the price is expensive, and the LEDs on the market are uneven.
Today we will talk about LED cooling.
In the LED headlight industry, we usually divide the heat into two types: passive heat dissipation and active heat dissipation. Passive heat dissipation is mainly the heat dissipation on the structural material, and the metal material is connected to the heat-generating part of the lamp to achieve heat dissipation. There are three main types of historical iterations: the first generation of aluminum body heat dissipation, the disadvantage of which is that the heat dissipation area is small and the power cannot be improved, so the general brightness of such products is not high.
The advantage of active heat dissipation is that the heat dissipation efficiency is higher. Therefore, the fan type LED lamp will be brighter when the same lamp bead and the upper structure are the same.
To understand the LED heat dissipation problem, we also need to understand the three principles of heat transfer: heat conduction, heat radiation, and heat convection.
Heat conduction: the process of heat transfer from a high-temperature object to a low-temperature object. Use materials with good thermal conductivity: such as aluminum, copper.
Heat radiation: All objects with temperature generate heat radiation to dissipate heat in ways we can't see. Improve heat dissipation: Radiation heat dissipation coating. The coating of the nano-radiation coating is sprayed on the surface of the lamp body by using the coating to increase the thermal emissivity, thereby greatly improving the heat radiation capability of the surface of the lamp body.
Heat convection: The process in which heat convection occurs in liquids and gases is a cyclical flow that causes the temperature to become uniform.
The low-temperature air in a closed space of the lamp goes down, squeezing the high-temperature air, and the hot air staying in the cool place becomes cold and then forms a cycle.
Heat conduction is to transfer heat from the heat source to the surface of the heat sink as quickly as possible, while heat dissipation is to dissipate heat from the surface of the heat sink to the air. First of all, the fastest heat should be exported, and then effectively dispersed into the air. Regardless of the way in which heat is dissipated, only heat can be dissipated into the air. There are only two ways to dissipate heat: convection and radiation.
Therefore, when we choose LED headlights, we must consider not only the material of the LED, but also the heat dissipation structure of the LED.