The function of the cooling fan is to make the airflow into the radiator at the rated speed through the diversion, and the heat exchange between the air and the radiator is generated to extract the heat, so as to achieve the purpose of heat convection. In the air supply mode of an industrial cooling fan, the axial fan is widely used and favored by the motor cooling fan supplier because of its good comprehensive cooling effect and low cost. The axial cooling fan generally adopts the air supply mode of downward blowing, and it also reverses the direction of the axial fan into the form of upward suction.
The difference between the two ways of air supply lies in the different forms of airflow. When blowing, turbulent flow is produced, and the air pressure is large while it is easy to suffer resistance loss; when exhausting, laminar flow is produced, and the air pressure is small while the airflow is stable. Theoretically, the heat transfer efficiency of turbulent flow is much higher than that of laminar flow, so it has become the mainstream design form of the industrial cooling fan. But the movement of airflow is also directly related to the radiator. For example, in some designs, because the fins are too tight, the airflow is greatly hindered by the fins. At this time, the extracting method will give a better effect.
Although an axial cooling fan is widely used in industrial cooling fan, it also has its inherent defects. Blocked by the position of the motor, so the airflow of the axial fan cannot smoothly pass through the middle of the blast area, which is called a "dead zone". In a typical radiator, the temperature of the middle fin is the highest. Because of this contradiction, when the axial fan is used, the heat dissipation effect of radiator is not enough.