CN213419479U - Fan current collector with tail end diffusion current collecting structure - Google Patents

Abstract

The utility model discloses a fan collector with terminal diffusion mass flow structure, including the collector body, its export end is outside open flaring. The utility model discloses can strengthen the air current to getting into the impeller and carry out the diffusion guide effect, improve fan air-out efficiency, reduce the fan noise.

Description

Fan current collector with tail end diffusion current collecting structure

Technical Field

The utility model relates to a fan parts makes technical field, especially relates to a fan collector with terminal diffusion mass flow structure.

Background

The centrifugal fan accelerates gas by using an impeller rotating at a high speed according to the principle that kinetic energy is converted into potential energy, and then decelerates and changes the flow direction so as to convert the kinetic energy into the potential energy (pressure). In a single stage centrifugal fan, the gas enters the impeller from an axial direction, changes to a radial direction as it flows through the impeller, and then enters the diffuser. In diffusers, the gas changes flow direction causing a deceleration which converts kinetic energy into pressure energy. The pressure increase occurs primarily in the impeller and secondarily in the diffusion process. In a multistage centrifugal fan, a flow reverser is used to direct the air flow to the next impeller, creating a higher pressure.

The centrifugal fan is essentially a variable flow constant pressure device, the pressure-flow theoretical curve of the centrifugal fan should be a straight line when the speed is constant, the actual characteristic curve is curved due to internal losses, the pressure generated in the centrifugal fan is greatly affected by changes in the inlet air temperature or density, the pressure generated at the highest inlet air temperature (lowest air density) is lowest for a given inlet air quantity, for a given pressure and flow characteristic curve, there is a power and flow characteristic curve, and the power required increases with decreasing inlet air temperature for a given flow when the fan is operated at constant speed.

The loss of the centrifugal fan is mainly divided into three parts: volume losses, mechanical losses and flow losses. At present, most of domestic and foreign researches on centrifugal fans are focused on structures and flow field characteristics of an impeller and a volute, the flow field characteristics of a space region among a current collector, the volute and a front disc of the impeller and the volume loss of the fan are not concerned much, and the volume loss is caused by that part of gas flowing out of the impeller flows back to a low-pressure region at an inlet of the impeller through a gap between the current collector and the inlet of the impeller, so that the outlet flow of the fan is smaller than the inlet flow, and the noise of the fan is increased.

In order to ensure the safe operation of the fan, the radial clearance between the current collector and the impeller is controlled to be 5-8 mm in the prior art, and the current collector extends into the impeller by 20-30 mm. In the prior art, the outlet of a current collector generally adopts a necking structure, as shown in fig. 1 and fig. 2; or a straight opening structure is adopted, as shown in fig. 3 and 4. No matter the outlet of the current collector adopts a necking structure or a straight structure, the gap between the current collector and the inlet of the impeller is controlled to be larger, and the diffusion of the entering air flow is not guided, so that the air outlet efficiency of the fan is lower and cannot reach the design value.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art, the utility model provides a technical problem how strengthen the guide effect to the diffusion air current that gets into the impeller, improve fan air-out efficiency, reduce fan noise.

In order to solve the technical problem, the utility model provides a technical scheme is a fan collector with terminal diffusion mass flow structure, including the collector body, its export end is outside open flaring.

The angle between the flaring edge and the shaft centerline is in the range of 10 to 20 degrees. Preferably, the included angle is 15 degrees.

Further, as the utility model discloses an improve, the flaring makes the drainage effect better for convex outwards opening.

Compared with the prior art, adopt the technical scheme of the utility model, can strengthen the air current to getting into the impeller and carry out the diffusion guide effect, improve fan air-out efficiency, reduce the fan noise.

Drawings

FIG. 1 is a schematic view of a prior art necking structure current collector;

FIG. 2 is an enlarged view of a portion of a prior art reduced structure current collector structure area A;

FIG. 3 is a schematic view of a current collector with a prior art straight port structure;

FIG. 4 is an enlarged view of a portion of a current collector structure B of a prior art straight port structure;

FIG. 5 is a schematic structural view of the present invention;

fig. 6 is a partial enlarged view of the structure C region of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings, but the present invention is not limited thereto.

Fig. 1 and 2 show a structure schematic of a current collector with a necking structure in the prior art, wherein an outlet end of a current collector body 1a is of an inward necking structure and is provided with an inward-necking flaring 11 a.

Fig. 3 and 4 show the structural schematic of the current collector with a straight port structure in the prior art, and the outlet end of the current collector body 1b is in a straight port structure and is provided with a vertical flaring 11 b.

Fig. 5 and 6 show a fan collector with a diffusion-end collector structure, and the outlet end of a collector body 1c is provided with a flared opening 11c which is flared outwards.

The angle between the edge of the flared end 11c and the shaft centerline is in the range of 10 to 20 degrees. Preferably, the included angle is 15 degrees.

Further, as the utility model discloses an improvement, the convex outwards opening of flaring 11c makes the drainage effect better.

The utility model discloses a theory of operation: when the collector body 1c works, airflow enters from the air inlet and flows out from the tail end outlet to enter the fan impeller, and the tail end outlet is provided with an outward expanding opening, so that the airflow can be enhanced and guided to uniformly diffuse into the impeller, the air outlet efficiency of the fan is improved, and the noise of the fan is reduced.

Compared with the prior art, adopt the technical scheme of the utility model, can strengthen the air current to getting into the impeller and carry out the diffusion guide effect, improve fan air-out efficiency, reduce the fan noise.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention.

Claims (2)

1. A fan current collector with a tail end diffusion current collecting structure is characterized by comprising a current collector body, wherein the tail end of an outlet of the current collector body is an outward flared opening; the included angle range of the flaring edge and the shaft center line is 10-20 degrees; the flaring is arc-shaped and opens outwards.

2. The fan collector with a terminal diffusion collector structure according to claim 1, wherein said included angle is 15 degrees.

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