Blades, centrifugal fan impellers, centrifugal fans and range hoods

Abstract

The invention discloses a blade, a centrifugal fan impeller, a centrifugal fan and a range hood. The blade comprises a plate-shaped blade body for extending in the longitudinal direction; the cross section of the blade body is arched; the blade body is provided with a first side edge and a second side edge opposite to the first side edge in the transverse direction; the blade body is provided with penetration grooves for extending in the longitudinal direction and communicating with the inner and outer sides of the arched blade body; and the penetration grooves are near the first side edge of the blade body. The penetration grooves are formed in the blade body, so that one part of air currents are attached on the inner side surface of the blade body for flowing, the other part of air currents are attached on the outer side surface of the blade body for flowing through the penetration grooves, the flowing separation of the air currents is reduced, the generation of eddy currents generated between adjacent blades is prevented, the air performance of the impeller is improved, the noise level is lowered, the performance of the centrifugal fan is improved, and the optimization cost of the centrifugal fan is reduced.

Description

technical field [0001] The invention relates to exhaust equipment, in particular to a blade, a centrifugal fan impeller, a centrifugal fan and a range hood. Background technique [0002] Most of the fans used in range hoods are centrifugal fans, which are suitable for the requirements of range hoods because they provide relatively high wind pressure, compact structure, high pressure coefficient and flow coefficient. Among them, the impeller is the core component of the centrifugal fan, and its performance directly affects the air performance and noise of the range hood, and the blades assembled on the impeller are the key components that determine the performance of the centrifugal fan impeller. Generally, the impeller rotates so that the airflow enters the center of the impeller and flows from the leading edge 13' of the blade to the trailing edge 14' of the blade to discharge the airflow. [0003] However, the centrifugal fans of smoke absorbers in the prior art are mostl...

AI Technical Summary

Problems solved by technology

[0003] However, the centrifugal fans of smoke absorbers in the prior art are mostly made of sheet metal materials, and the blades are usually designed as circular arc plate structures. For details, see figure 1 and figure 2 , the blade path of this arc-shaped blade is usually short, and in order to obtain an accelerated blade path to improve the efficiency of the impeller, the blade is usually designed to have a larger inlet airflow angle, which makes the leading edge 13' of the blade form a shorter With a large reverse pressure gradient, the airflow is prone to flow separation at the leading edge 13' of the blades, and vortices will be generated between adjacent blades

For details, see image 3 The simulation results of the blade flow field in the prior art are shown. Due to the excessive curvature of the arc-shaped blade, the inlet airflow angle is also relatively large, so that a large reverse pressure is formed between the inner surface and the outer surface of the arc-shaped blade. The gradient causes the flow separation of the airflow at the leading edge 13' of the blade, and because the curvature of the arc-shaped blade is too large, when the airflow adheres to the inner surface of the arc-shaped blade and flows close to the trailing edge 14', this part of the airflow is due to inertia And the centrifugal force flows back towards the blade leading edge 13' to generate vortex flow between adjacent blades, so that the air flow is not discharged smoothly, resulting in a decrease in the air performance of the impeller and an increase in noise

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