LED cooling technology and cooling materials
Heat dissipation is a major factor affecting the intensity of LED lighting. Heat sink can solve the problem of heat dissipation of low illumination LED lamps. A heat sink can not solve the 75W or 100W LED lighting cooling problem.
In order to achieve the desired illumination intensity, active cooling technology must be used to solve the heat by LED lamp assembly. Some active cooling solutions as LED lamps. In order to provide a practical active cooling solution for high brightness LED lamps, the heat dissipation technology must be low energy consumption; and can be applied to small lamps; its life is similar to or higher than the light source.
Generally speaking, in accordance with the way from the radiator to take away the heat, the radiator can be divided into active cooling and passive cooling. The so-called passive heat, is through the heat sink of heat source LED light source naturally distributed to the air, the cooling effect is proportional to the size of the heat sink, the effect of course greatly reduced heat , often used in the space of the heat dissipation, such as some popular motherboards in the North Bridge also take a passive cooling, the vast majority of take the initiative to heat, active cooling is through the fan and other cooling equipment forced The heat will be out of the heat sink, which is characterized by high thermal efficiency, and equipment, small size.
Active cooling, subdivided from the way heat can be divided into air-cooled heat, cooling heat, heat pipe cooling, semiconductor refrigeration, chemical refrigeration and so on.
Air-cooled air cooling is the most common way of cooling, in comparison, is also cheaper way. Air cooling is essentially a fan that takes away the heat absorbed by the radiator. With the price is relatively low, easy installation and so on. But the environmental dependence is relatively high, as the temperature rise and overclocking its thermal performance will be greatly affected.
Liquid cooling heat is driven by the liquid in the pump driven by the heat to take away the radiator, compared with the air-cooled, with a quiet, cooling stability, the advantages of small dependence on the environment and so on. The price of liquid cooling is relatively high, and the installation is also relatively cumbersome. At the same time as installed in instructions to install the instructions in order to get the best cooling effect. For cost and ease of use considerations, liquid cooling is commonly used as a heat-conducting liquid, so liquid-cooled radiators are often referred to as water-cooled radiators.
The heat pipe is a kind of heat transfer element which makes full use of the heat conduction principle and the rapid heat transfer property of the refrigerant. It conveys heat by evaporation and condensation of the liquid in the fully enclosed vacuum tube, has extremely high thermal conductivity, good isothermal The heat transfer area on both sides of the hot and cold can be arbitrarily changed, can be a long distance heat transfer, can control the temperature and a series of advantages, and heat pipe composed of heat exchanger with high heat transfer efficiency, compact structure, advantage. Its thermal conductivity has far exceeded the thermal conductivity of any known metal.
Semiconductor refrigeration is the use of a special semiconductor cooling film in the electricity generated as the high temperature side of the heat can be also distributed, the low temperature side is constantly cooling. A temperature difference is generated on each part of the semiconductor particles, and a cooling sheet is formed by the concatenating dozens of such particles as the form of temperature difference on both surfaces of the cooling sheet. The use of this temperature phenomenon, with the air-cooled / water-cooled high-temperature side of the cooling, can get excellent cooling effect. Semiconductor cooling has the advantages of low cooling temperature and high reliability. The cold surface temperature can reach below 10, but the cost is too high, and the process of semiconductor refrigeration is not mature enough practical.
The so-called chemical refrigeration, the use of some ultra-low temperature chemical substances, the use of them in the melting time to absorb a lot of heat to reduce the temperature. It is more common to use dry ice and liquid nitrogen. Such as the use of dry ice can be reduced to below 20? temperature, there are some more ‘abnormal’ player