Several heat transfer methods of low noise DC cooling fan
by:TOCH
2021-02-26
How many heat transfer methods do you know about low-noise DC fans? Let me share with you
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u003cbru003e Air pressure and air volume of low-noise DC fans are two relative concepts. Generally speaking, in consideration of cost-saving by manufacturers, DC cooling fans have to sacrifice some air pressure if they want to design a fan with a large air volume. If the fan can drive a large amount of air flow, but the wind pressure is small, the wind cannot blow to the bottom of the radiator (this is why some fans have high speed and large air volume, but the heat dissipation effect is not good). On the contrary, High wind pressure often means that the air volume is small, and there is not enough cold air to exchange heat with the heat sink, which will also cause poor heat dissipation. Tongchi cooling fan manufacturers welcome you to buy low noise DC fans!
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u003cbru003e Any type of radiator is basically inseparable from the following three heat transfer methods, but the focus is different.
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u003cbru003e 1.
u003cbru003eHeat conduction, heat convection and heat radiation. The material itself or when the material contacts the material, the transfer of energy is called heat conduction, which is the most common way of heat transfer. For example, the direct contact between the base of the radiating fan and the radiating fan to take away heat is heat conduction.
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u003cbru003e 2. Thermal convection: refers to the heat transfer method in which the flowing fluid (gas or liquid) moves the heat away. In the heat dissipation system of the car chassis, the 'forced heat convection' that the cooling fan drives the gas flow is more common. the way.
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u003cbru003e 3.
u003cbru003eHeat radiation: refers to the transfer of heat by radiation. The most common thing in daily life is solar radiation. These three heat dissipation methods are not isolated. In daily heat transfer, these three heat dissipation methods all occur simultaneously and work together.
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u003cbru003e For example, a common cooling fan, an air-cooled cooling fan, the cooling fan heat sink is in direct contact with the surface of the cooling fan, and the heat on the surface of the cooling fan is transferred to the cooling fan heat sink through heat conduction; the DC cooling fan generates airflow and heats the cooling fan through thermal convection The heat on the surface of the sheet is taken away; and the flow of air in the chassis is also through thermal convection.
u003cbru003eCooling fan The heat of the air around the heat sink is carried away to the outside of the chassis; at the same time, all parts with high temperature will radiate heat from the parts with low surrounding temperature.
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u003cbru003e The heat dissipation efficiency of the radiator is related to the thermal conductivity of the radiator material, the heat capacity of the radiator material and the heat dissipation medium, and the effective heat dissipation area of u200bu200bthe radiator.
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u003cbru003e What are the inherent defects of DC cooling fans?
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u003cbru003e The most widespread form is to use an axial fan (that is, the most common kind of fan) to blow downwards. The reason why it is so popular is because of its good overall effect and low cost. If the direction of the axial fan is reversed, it becomes an upward draft, which is used in some special models of radiators. The difference between the two types of air supply is the difference in air flow. When blowing air, it produces turbulent flow, and the wind pressure is high, but it is susceptible to resistance loss; when it is exhausted, it produces laminar flow, with low wind pressure but air flow.
u003cbru003eStable. In theory, the heat dissipation efficiency of turbulent flow is much greater than that of laminar flow, so it has become the mainstream design form. Although axial fans are widely used, they also have inherent defects. The axial flow fan is blocked by the position of the motor, and the airflow cannot flow smoothly
u003cbru003eAcross the middle of the blast area, this is called the 'dead zone'
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