Centrifugal fan operation principle and turbine compressor basic same, just because the gas low velocity and pressure change is not big, generally need not consider gas hematocrit of change, namely the gas as incompressible fluid handling. Centrifugal fan can be made into a right-lateral and left-lateral two types. From motor side face, impeller, clockwise, called right rotation fan, spinning counter-clockwise, called a left-lateral.

Centrifugal fan is based on the principle of kinetic energy transfer as potential energy, using high-speed rotating impeller gas acceleration, then deceleration, change flow direction, make kinetic energy converts potential energy (pressure). In a single stage centrifugal fan, gas from the axial gas flows into the impeller, impeller when change into radial diffuser, and then entered. FengJiChang in lingnan diffuser, gases changed direction of flow caused by slowing down, such a slowdown role at converting kinetic energy into stress can. Pressure occur predominantly in the impeller, secondly occurred in rise pressure process. In multi-stage centrifugal fan, use reflux device which the breath is round, produce higher under pressure.

Centrifugal fan is essentially a variable flow speed constant pressure device. When certain centrifugal fan of pressure-flow curve theory should be a line. Due to internal loss, lingnan FengJiChang actual characteristic curve is curved. Centrifugal fan in the pressure produced by the inlet temperature or density change moretremendous influence. For a given the subsystem, the highest temperature (air density lowest) when the pressure generated for a given minimum. The pressure and flow characteristic curve, there was a power and the flow characteristic curve. When blower with constant speed operation, for a given flow, the power needed with the reduction of the inlet temperature rise.