your current location:Homepage > Solution > Refrigeration / heat dissipation >
Refrigeration and heat dissipation

Principle of refrigeration technology
The water condensed in the first and second auxiliary condensers flows into the drainage tank. Due to the low pressure in the evaporator and condenser, in order to make the condensate flow smoothly from the lower part of the container, each fresh-keeping cabinet equipment should be installed at a height of more than 10 meters. The control circuit of fresh-keeping cabinet and other equipment is commonly used. Thermoelectric refrigeration is also known as thermoelectric refrigeration or semiconductor refrigeration, which is a new refrigeration technology in the 1950s.

Heat dissipation mode
Active heat dissipation can be divided into air cooling heat dissipation, liquid cooling heat dissipation, heat pipe heat dissipation, semiconductor refrigeration, chemical refrigeration and so on.
Air cooling
Air cooling is the most common way of heat dissipation, which is also a cheaper way. In essence, air cooling is to use the fan to take away the heat absorbed by the radiator. The utility model has the advantages of relatively low price and convenient installation. However, it is highly dependent on the environment. For example, when the temperature rises and overclocking, its heat dissipation performance will be greatly affected.
Liquid cooling
Liquid cooling takes away the heat of the radiator through the forced circulation of liquid driven by the pump. Compared with air cooling, it has the advantages of quiet, stable cooling, less 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 install in accordance with the method guided by the manual in order to obtain the best heat dissipation effect.
In consideration of cost and ease of use, water is usually used as the heat conducting liquid for liquid cooling heat dissipation, so liquid cooling radiator is often called water-cooled radiator.
heat pipe
Heat pipe belongs to a kind of heat transfer element, which makes full use of the principle of heat conduction and the fast heat transfer property of refrigeration medium to transfer heat through the evaporation and condensation of liquid in the fully enclosed vacuum pipe. It has a series of advantages, such as high thermal conductivity, good isothermal, arbitrary change of heat transfer surface area on both sides of cold and heat, long-distance heat transfer, temperature control and so on. The heat exchanger composed of heat pipe has high heat transfer efficiency It has the advantages of compact structure and small fluid resistance loss. Its thermal conductivity has far exceeded that of any known metal.
Heat dissipation technology of vacuum cavity soaking plate
Vacuum cavity soaking plate technology is similar to heat pipe in principle, but it is different in conduction mode. The heat pipe is one-dimensional linear heat conduction, while the heat in the vacuum cavity soaking plate is conducted on a two-dimensional surface, so the efficiency is higher. Specifically, after absorbing the heat of the chip, the liquid at the bottom of the vacuum chamber evaporates and diffuses to the vacuum chamber, transmits the heat to the radiating fins, and then condenses into liquid and returns to the bottom. The evaporation and condensation process similar to that of refrigerator and air conditioner circulates rapidly in the vacuum chamber, realizing quite high heat dissipation efficiency. Sapphire vapor-x vacuum cavity soaking plate is a product that can be seen in the market. It has two types: GPU based and CPU based.
Dual piezoelectric cooling jet
Ge recently announced a breakthrough heat dissipation technology, which is as big as a credit card and can be used in the next generation of ultra-thin tablets and notebooks. This radiator is called dcj (dual piezoelectric cooling jets), which can be understood as a micro flow bellows that sprays high-speed air to electronic equipment. The turbulent air sent by dcj increases the heat exchange rate by 10 times compared with the conventional convective air. Compared with the existing heat dissipation equipment, the thickness of dcj radiator is only 4mm, which is reduced by 50%, and the power consumption is only half that of fan radiator. In addition, its simple architecture also has higher reliability and maintainability than traditional radiator.
Sandia radiator (air bearing heat exchanger)
This "Sandia cooler", also known as "air bearing heat exchanger", is characterized by high-speed rotation of stationary fins. The biggest heat exchange bottleneck in the traditional CPU radiator is the dead air boundary layer attached to the heat sink. In the Sandia radiator, the heat is efficiently transferred from the stationary base to the rotating heat sink structure through a narrow gap with a thickness of only 0.001 inch (25 microns). The air static boundary layer wrapped with heat sink has a strong centrifugal pump effect, which makes the boundary thickness only one tenth of that in ordinary cases, so as to significantly improve the heat dissipation efficiency in a smaller space. The high-speed rotating heat exchange heat sink basically does not have the problem of "hiding dirt" and will not accumulate a pile of dust that is difficult to remove over time like the traditional radiator. In addition, the way the heat sink cuts the air has also been redesigned, which greatly improves the aerodynamic efficiency and has very low noise.
Semiconductor refrigeration
Semiconductor refrigeration uses a special semiconductor refrigeration chip to generate temperature difference when powered on. As long as the heat at the high temperature end can be effectively dissipated, the low temperature end will be continuously cooled. There is a temperature difference on each semiconductor particle. A refrigeration sheet is composed of dozens of such particles in series, so a temperature difference is formed on the two surfaces of the refrigeration sheet. Using this temperature difference phenomenon, combined with air cooling / water cooling to cool the high-temperature end, excellent heat dissipation effect can be obtained.
Semiconductor refrigeration has the advantages of low refrigeration temperature and high reliability. The cold surface temperature can reach below minus 10 ℃, but the cost is too high, and the CPU may condense and cause short circuit due to low temperature. Moreover, the process of semiconductor refrigeration chip is not mature and practical enough.
Chemical refrigeration
The so-called chemical refrigeration is to use some ultra-low temperature chemicals to absorb a lot of heat when melting to reduce the temperature. In this regard, the use of dry ice and liquid nitrogen is more common. For example, using dry ice can reduce the temperature to below minus 20 ℃, and some more "abnormal" players use liquid nitrogen to reduce the CPU temperature to below minus 100 ℃ (in theory). Of course, due to the high price and short duration, this method is often seen in laboratories or extreme overclocking enthusiasts.
Improve the heat conduction capacity of the heat sink   no matter what kind of heat dissipation method is adopted, we must first solve the problem of how to efficiently transfer the heat from the heat source such as CPU to the heat dissipation body. For example, for air-cooled heat dissipation, it needs to transfer the heat generated by the CPU to the heat sink by heat conduction, and then the fan rotates at high speed to take most of the heat away by convection (including forced convection and natural convection); The same is true for liquid cooling. In this process, the heat directly emitted by radiation is very little, and the decisive step is to improve the efficiency of heat conduction and bring the heat away from the heat source.

relevant information