Heat pipe-a must-know LED cooling technology

  Car owners in the market demand safe light patterns, fast signal switching, high-brightness lighting effects, and high cost performance. In the design of LED car lights, cooling solution is the core problem of high-brightness LED car lights. The heat concentration of high-brightness chips is also an inevitable topic in the design process of LED car lights.

  There are three ways of heat transfer: conduction, convection and radiation. Any heatsink design is a comprehensive application of these methods. At present, there are three main cooling methods for LED car lights: natural heat dissipation, forced convection cooling, and heat pipe cooling

Natural heat dissipation is represented by copper heat sink strips,

Forced convection cooling is represented by a fan,

I believe everyone is quite familiar with the above two cooling methods.

But the cooling of heat pipes should be less understood?

Heat pipe cooling is the most stable heat conduction device in the industry at present, and its heat conduction speed is tens to hundreds of times higher than that of pure copper substrates. It is commonly used in computer CPU heat dissipation. It can quickly transfer the heat generated by the LED chip in the fastest way, faster and more effective than other heatsink materials, so what is the principle of the heat pipe?

  The heat pipe is a passive heat transfer element that uses phase change heat transfer technology to transfer heat by relying on the phase change of the working fluid (the transition between the liquid phase and the vapor phase). A typical heat pipe consists of a shell, a wick and a working fluid. When one end of the heat pipe absorbs heat, the liquid working fluid at the heat absorption end vaporizes into steam. Under the action of the pressure difference inside the heat pipe, the steam moves to the other end at a high speed. The wick structure returns.

As shown in the figure below, the area where the working fluid is heated and evaporates is called the evaporation section, and the area where the steam is cold and liquefied is called the condensation section. Between the evaporation section and the condensation section, since the heat exchange between the heat pipe and the outside is little, it is called Adiabatic section.