Backward centrifugal fan and air conditioner

Abstract

The invention provides a backward centrifugal fan and an air conditioner, the backward centrifugal fan comprises an upper cover plate, a lower cover plate and a plurality of groups of backward blades, the upper cover plate and the lower cover plate are oppositely arranged, the backward blades are uniformly connected between the upper cover plate and the lower cover plate at intervals, and the outer edge, close to the edge of the backward centrifugal fan, of each group of backward blades is inclined in an S shape. According to the backward centrifugal fan, the front edge line of any blade of the blade group is kept unchanged, and the rear edge of each blade is reversely inclined in the rotating direction to form an S shape, so that the volume flow rate of the fan is ensured, air flow in a blade channel is optimized, meanwhile, tip vortexes at the front edges of the blades are eliminated, and falling vortexes at the rear edges are reduced; for broadband noise generated by interaction of the trailing edge and boundary layer turbulence, the phase difference between blade trailing edge noise sources is increased through the double-S-shaped mutually-connected inclined trailing edge blade groups, and the pressure pulsation intensity of trailing edge falling vortexes is reduced; and according to the backward centrifugal fan and the air conditioner, the broadband and BPF noise of the fan are reduced, and the efficiency of the fan can be improved.

Description

technical field [0001] The invention belongs to the technical field of refrigeration, and more specifically relates to a backward centrifugal fan and an air conditioner using the same. Background technique [0002] At present, the common backward-facing centrifugal fans (also known as backward-inclining fans) on the market are generally made of circular arc plates (such as figure 1 shown) or integrally twisted and inclined blades, front (upper) cover and rear (lower) cover. When the backward-facing centrifugal fan is actually in operation, this type of blade is prone to generate various noises, and the noise generated mainly includes broadband noise and BPF noise. Among them, broadband noise can be divided into five noise sources: boundary layer vortex shedding (separation), trailing edge blunt vortex shedding, (leading edge) tip vortex, turbulent flow separation, and turbulent boundary layer trailing edge noise, namely The tip vortex acts on the leading edge, the boundary...

AI Technical Summary

Problems solved by technology

[0005] The present invention proposes a backward centrifugal fan and its application in order to solve the technical problem of overall noise reduction at the leading edge and trailing edge of the blade that cannot be realized by the existing backward centrifugal fan and at the same time ensure sufficient volume flow in the blade passage. air conditioner

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