How is the centrifugal fan designed?

Many people know how the centrifugal fan is used. We have also popularized the troubleshooting and reasons of the centrifugal fan before and how to extend its life. So today, Ruiapple will introduce how it is designed.

step one:

The design of a centrifugal fan first measures the relationship between its air volume and air pressure. It is very difficult to measure the characteristics of air flow. Currently, there are two methods for measuring static pressure and air volume, one is wind tunnel test, and the other is double box method. The air volume and static pressure characteristics are measured in a double-box method. The double-box variable exhaust system is used to extract air to adjust the air density. Opening the nozzle instantly will cause an instant change in static pressure and air volume, and then read each static pressure Pressure reading on the gauge.

Under the conditions of standard atmosphere and fixed operating voltage and frequency, static pressure is expressed as a function of air volume. The static efficiency of a centrifugal fan is equal to the volume of the air volume multiplied by the static pressure and divided by the input electrical energy. A centrifugal fan includes a motor, a fan blade and an outer frame, so its efficiency includes the motor efficiency of the motor and the air flow efficiency of the fan blade and the outer frame.

Step two:

The entire system impedance/system characteristic curve of the centrifugal fan. When the air flows, the airflow will encounter the obstruction of the internal parts of the system in its flow path, and its impedance will restrict the free circulation of air. The change in pressure is the measured static pressure, expressed in inches of water column. In order to confirm the cooling wattage of each slot row, the system designer or manufacturer must not only have the effective fan characteristic curve of the centrifugal fan to determine its maximum air volume, but also know the wind resistance curve of the system. The parts inside the system will cause the loss of wind pressure. This loss varies with the air volume, the so-called system impedance.

In addition, the intersection of the system operating point of the centrifugal fan and the characteristic curve of the fan is called the system operating point, which is the optimal operating point of the centrifugal fan. At the operating point, the change slope of the silent fan is the smallest, and the change rate of the system characteristic curve is the smallest. Note that the static efficiency of the centrifugal fan (air volume × air pressure ÷ power consumption) is optimized at this time.

Shenzhen Ruiapple Electronics Co., Ltd. is a professional fan manufacturer with 20 years of R&D, production and sales experience. Main business: Cooling fan, DC fan, AC fan, silent fan, centrifugal fan, blower and other full range of cooling and ventilation products as an integrity enterprise, the series of cooling fan products have obtained UL, CUL, CE, CCC, ROHS, etc. International Certification.