Air cooling

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In the air cooling the surface of heat generating objects by flowing past it is air cooled . In internal combustion engines , electric motors or electronic components of power electronics, overheating and destruction of the components should be avoided; In the case of cooling and air conditioning systems, it is imperative that the refrigerant's condensation temperature be below the temperature in order to function.

General

The air movement necessary for air cooling can be brought about either by convection , blowers or, in the case of vehicles, by the airstream . The object to be cooled is free or is channeled around it. Often the object to be cooled is also provided with cooling fins or a heat sink as a heat exchanger , which allow a greater heat dissipation due to a larger surface.

Air-cooled engines

Main article: Cooling (internal combustion engine)

Air duct in the VW Beetle
(blue - cold air, red - warm air)

In the past, internal combustion engines were either passively or actively air-cooled by means of a fan . In the field of motor vehicles , air-cooled internal combustion engines are still sometimes used in motorcycles . They are also for propeller - aircraft , in RC cars and small engines, such as for lawn mowers or chain saws used. In the field of cars and trucks, they have been completely displaced due to the predominant disadvantages compared to liquid cooling, with the exception of some trucks for extreme climatic conditions.

Electric motors are much more efficient than combustion engines and therefore require less cooling capacity. Smaller motors often get by with air cooling. Powerful electric motors for cars or electric locomotives , for example, are usually liquid-cooled.

Air cooling in personal computers

A tower cooler for main processors with a heat pipe: the direct air cooler below is only small and does not dissipate enough heat; the heat is dissipated via the heat pipes to the metal, lamellar stacked cooling plates with a large total surface

In relation to the size - especially with processors from the class Intel 486/66 - the commercially economically available technology is accompanied by a large amount of heat development. Powerful microchips , such as those used in current PCs , generate considerable heat loss, which is mainly dissipated by air cooling. The purpose is not to exceed the permissible crystal temperature of the semiconductors in the processor. Exceeding this means destruction of the transistor semiconductor crystals by melting or by alloying the doping, which can cause a short circuit on the chip.

Since the logic components of a computer do not do any work in the physical sense, all electrical energy consumed is ultimately converted into heat. Since with today's processors the heat can no longer be dissipated passively by radiation and passive heat sinks , the heat dissipation must be increased. For this purpose, heat sinks and active fans are installed on components with high power consumption, such as the CPU and graphics card . These dissipate the heat directly from the components into the air in the housing. In addition, almost all computers have case fans that ensure a constant flow of air through the case and thus release the heat into the room air.

Alternatively, the heat can be removed from the components using water cooling , which can then be released into the room via radiators.

Other uses

literature

  • Hans Jörg Leyhausen: The master craftsman's examination in the automotive trade part 1. 12 edition, Vogel Buchverlag, Würzburg, 1991, ISBN 3-8023-0857-3
  • Jan Drummans: The car and its technology. 1st edition, Motorbuchverlag, Stuttgart, 1992, ISBN 3-613-01288-X

See also

Web links