A radiator is a device used to dissipate heat. Some devices generate a lot of heat when they are working, and this excess heat cannot be dissipated quickly and accumulates to generate high temperatures, which may damage the working equipment. At this time, a radiator is needed. A radiator is a layer of good heat-conducting medium attached to the heating device, playing the role of a middleman. Sometimes, fans and other things are added on the basis of the heat-conducting medium to speed up the heat dissipation effect. But sometimes the radiator also plays the role of a robber, such as the radiator of a refrigerator, which forcibly extracts heat to achieve a temperature lower than room temperature.
Working principle
The working principle of the radiator is that heat is generated from the heating device and transferred to the radiator and then to the air and other substances, where the heat is transferred through heat transfer in thermodynamics. The main ways of heat transfer are heat conduction, heat convection and heat radiation. For example, when substances come into contact with each other, as long as there is a temperature difference, heat transfer will occur until the temperature is the same everywhere. The radiator takes advantage of this point, such as using good thermal conductive materials, thin and large fin-like structures to increase the contact area and heat conduction speed from the heating device to the radiator to the air and other substances.
Uses
Computer
The CPU, graphics card, etc. in the computer will emit waste heat when running. The radiator can help remove the waste heat continuously emitted by the computer to prevent the computer from overheating and damaging the electronic components inside. The radiator used for computer heat dissipation usually uses fans or water cooling. [1] In addition, some overclocking enthusiasts will use liquid nitrogen to help the computer dissipate a large amount of waste heat, allowing the processor to operate at a higher frequency.
Refrigerator
The basic function of a refrigerator is to cool to preserve food, so the room temperature in the box must be removed and kept at a suitable low temperature. The refrigeration system is generally composed of four basic components: compressor, condenser, capillary tube or thermal expansion valve, and evaporator. Refrigerant is a liquid that can boil at low temperature under low pressure. It absorbs heat when boiling. The refrigerant circulates continuously in the refrigeration system. The compressor increases the gas pressure of the refrigerant to create liquefaction conditions. When passing through the condenser, it condenses and liquefies to release heat, then reduces the pressure and temperature when passing through the capillary tube, and then boils and vaporizes to absorb heat when passing through the evaporator. In addition, the development and use of refrigeration diodes nowadays have no complex mechanical devices, but the efficiency is poor and is used in small refrigerators.
Classification
Air cooling, heat dissipation is the most common and very simple, that is, using a fan to take away the heat absorbed by the radiator. The price is relatively low and the installation is simple, but it is highly dependent on the environment. For example, the heat dissipation performance will be greatly affected when the temperature rises.
Heat pipe is a heat transfer element with extremely high thermal conductivity. It transfers heat by evaporating and condensing the liquid in a fully enclosed vacuum tube. It uses fluid principles such as capillary absorption to achieve a similar effect as refrigerator compressor refrigeration. It has a series of advantages such as high thermal conductivity, excellent isothermal properties, heat flux density variability, reversibility of heat flow direction, long-distance heat transfer, constant temperature characteristics (controllable heat pipes), thermal diodes and thermal switch performance, and the heat exchanger composed of heat pipes has the advantages of high heat transfer efficiency, compact structure, and low fluid resistance. Due to its special heat transfer characteristics, the temperature of the pipe wall can be controlled to avoid dew point corrosion. But the price is relatively high.
Liquid cooling uses liquid to circulate under the drive of a pump to take away the heat of the radiator. Compared with air cooling, it has the advantages of quietness, stable cooling, and low dependence on the environment. But the price of liquid cooling is also relatively high, and the installation is relatively troublesome.
Semiconductor refrigeration uses a piece of N-type semiconductor material and a piece of P-type semiconductor material to connect into an electric couple. When a DC current is connected in this circuit, energy transfer can be generated. The current flows from the N-type element to the joint of the P-type element to absorb heat and become the cold end. The current flows from the P-type element to the joint of the N-type element to release heat and become the hot end, thereby generating a heat conduction effect. [2]
Compressor refrigeration, inhaling low-temperature and low-pressure refrigerant gas from the suction pipe, compressing it through the compressor, and then discharging high-temperature and high-pressure refrigerant gas to the exhaust pipe, providing power for the refrigeration cycle, thereby realizing the refrigeration cycle of compression → condensation → expansion → evaporation (heat absorption). Such as air conditioners and refrigerators.
Of course, most of the above heat dissipation types cannot be separated from air cooling in the end.
