Views: 14 Author: Site Editor Publish Time: 2018-11-23 Origin: Site
Generally speaking, according to the way of taking heat away from the heat sink, the heat sink can be divided into active heat dissipation and passive heat dissipation. So-called passive cooling, refers to through the heat sink to heat source, the LED light source as natural heat into the air, the heat dissipation effect is proportional to the size of heat sink, but because it is a natural send out quantity of heat, the effect of course, is often used in those without the requirements of the equipment to the space, or used to heat cooling small parts, such as part of the affordable motherboard also take passive cooling on north bridge, the vast majority of taking active cooling type, active cooling is through the fan cooling device, such as compulsive to heat away from the heat sink, its characteristic is high cooling efficiency, small volume and equipment.
Active heat dissipation can be divided into wind cooling, liquid cooling, heat pipe cooling, semiconductor refrigeration and chemical refrigeration.
Air cooling is the most common way of heat dissipation, and relatively speaking, it is also a cheaper way. Air cooling and heat dissipation are essentially the heat absorbed by using a fan to take away the heat sink. It has the advantages of relatively low price, convenient installation and so on. However, environmental dependence is high, such as rising temperatures and the heat dissipation performance of over clocking can be greatly affected.
Liquid cooling is the heat that the liquid circulates to take away from the heat sinkunder the drive of the pump. Compared with air cooling, it has the advantages of being quiet, stable in cooling, little dependence on the environment and so on. The price of liquid cooling is relatively high, and the installation is relatively troublesome. At the same time, try to follow the instructions to install the method to obtain the best cooling effect. For the consideration of cost and easiness of use, liquid cooling and heat dissipation usually adopts water as heat conducting liquid. Therefore, liquid cooling heat sink is often called water cooling heat sink.
Heat pipe belongs to a kind of heat transfer element, it makes full use of the heat transfer principle and rapid heat transfer properties of cooling medium, through the liquid evaporation and condensation in the vacuum tube to transmit heat, with a high thermal conductivity, good isothermal, heat transfer area on both sides of the hot and cold can be arbitrarily changed, can be long-distance heat transfer, controllable temperature and a series of advantages, and composed of a heat pipe heat exchanger has high heat transfer efficiency, compact structure, small fluid resistance loss, etc. Its thermal conductivity has far exceeded that of any known metal.
Semiconductor refrigeration is to use a special semiconductor refrigeration chip to produce temperature difference when electrified. As long as the heat of the high-temperature end can be effectively distributed, the low-temperature end will be continuously cooled. A temperature difference is produced on each semiconductor particle, and a cooling sheet is made up of dozens of such particles in series, thus forming a temperature difference on two surfaces of the cooling sheet. By using this temperature difference phenomenon and cooling the high temperature end with air cooling/water cooling to cool the high temperature end, can get excellent heat dissipation effect. Semiconductor refrigeration has the advantages of low refrigeration temperature and high reliability, cold temperatures can below minus 10 ℃, but the cost is too high, and may cause short circuit caused by low temperature, and a process of semiconductor refrigeration is not mature now, not practical enough.
Chemical refrigeration is the use of ultra-low temperature chemicals that use them to absorb large amounts of heat as they melt to lower the temperature. The use of dry ice and liquid nitrogen is common. Such as the use of dry ice temperature can be reduced to below minus 20 ℃, there are some of the more "abnormal" players using liquid nitrogen to CPU temperature has dropped below minus 100 ℃ (in theory), and, of course, due to the expensive and duration is too short, this method in laboratory or more extreme over clocking enthusiasts.