CN217682470U

CN217682470U - Current collector for centrifugal fan, centrifugal fan and range hood

Info

Publication number: CN217682470U
Application number: CN202221350993.1U
Authority: CN
Inventors: 雷改; 何立博
Original assignee: Ningbo Fotile Kitchen Ware Co Ltd
Current assignee: Ningbo Fotile Kitchen Ware Co Ltd
Priority date: 2022-05-27
Filing date: 2022-05-27
Publication date: 2022-10-28
Anticipated expiration: 2032-05-27

Abstract

The utility model relates to a collector, centrifugal fan and range hood for centrifugal fan, collector are used for installing in centrifugal fan's air intake department, include: the inner circumference of the guide ring is provided with an axial guide part extending along the axial direction; the axial flow guide part is at least partially axially reduced along the circumferential direction of the flow guide ring in the circumferential direction. The utility model has the advantages that: because the axial height of the axial flow guide part of the current collector is gradually reduced along the circumferential direction of the flow guide ring, the flow guide part can be better matched with the motion rule of a flow field in the volute after being assembled at the air inlet of the volute of the centrifugal fan, particularly, the difference between the air pressure and the speed of two sides of the volute tongue of the volute can be better met, the backflow between the air inlet of the current collector and the end surface of the impeller is effectively reduced, and the air volume at the same rotating speed is increased.

Description

Current collector for centrifugal fan, centrifugal fan and range hood

Technical Field

The utility model relates to a centrifugal fan technical field especially relates to a collector, centrifugal fan and range hood for centrifugal fan.

Background

The range hood has become one of the indispensable kitchen household electrical appliances in modern families. The range hood works by utilizing the fluid dynamics principle, sucks and exhausts oil smoke through a centrifugal fan arranged in the range hood, and filters partial grease particles by using a filter screen.

The fan system of the existing range hood mostly adopts a multi-wing centrifugal fan system with small volume, large flow and high pressure, the multi-wing centrifugal fan comprises a volute, an impeller arranged in the volute and a motor driving the impeller to rotate, and an air inlet ring (collector) is arranged at an air inlet of the volute. In order to adapt to the working condition of the same width of a public flue, the gap between a current collector and an impeller is generally selected to be a fixed proper value within a certain range, actually, the impeller outlets of the multi-wing centrifugal fan of the traditional range hood are different in distribution of air flow speed along the axis, the air flow speed is highest in the area close to a central disc, the air flow speed near front and rear end rings is smaller, the pressure at the inlet of the current collector is small, the pressure in a volute is higher, and pressure difference exists among the air inlet of the current collector, the interior of the volute and an impeller end disc, so that larger backflow leakage exists between the current collector and the impeller end disc, the larger resistance is, the more obvious pressure difference is, the more serious leakage is caused, the integral efficiency is reduced, and the noise is increased.

Therefore, the application number is CN202121425480.8 (the authorized publication number is CN 215521332U), and an air inlet ring assembly, a fan system and a range hood are disclosed, wherein the air inlet ring assembly comprises an air inlet ring, the air inlet ring comprises a radial flow guide part and an axial flow guide part which axially extends from the inner periphery of the radial flow guide part, and the air inlet ring assembly further comprises a height adjusting mechanism, and the height adjusting mechanism can exceed the end part of the axial flow guide part far away from the radial flow guide part, so that the heights of the whole body formed by the height adjusting mechanism and the axial flow guide part in the axial direction are not completely equal. Through making the whole design that is not the same height of air inlet circle subassembly, can adapt to the air admission and the backward flow of different angles, reach the effect that reduces high back pressure environment, reduction backward flow, increase wind pressure, promote and prevent the refluence ability, strengthen whole efficiency.

Although the air inlet ring assembly in the above patent application adopts a design with unequal heights to reduce backflow to a certain extent and achieve the effect of increasing air pressure, no more reasonable design is provided according to the distribution rule of the flow field in the volute, for example, in the distribution of the flow field in the volute, the pressure and speed difference on two sides of the volute tongue is large, wherein the volute tongue is close to the outlet side, the air flow pressure is small, and the speed is large; the volute tongue is far away from the outlet side, the airflow pressure is high, the speed is low, if the air inlet ring of the axial flow guide part with different heights is singly adopted, the vortex cannot be reduced to the maximum degree on the whole, and the flow of the centrifugal fan at the same rotating speed cannot be maximized.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the first technical problem that will solve is to prior art's current situation, provides one kind and can accord with the interior flow field law of motion of spiral case better, makes the whole air current motion vortex of centrifugal fan less, with the bigger current collector for centrifugal fan of flow under the rotational speed.

The utility model discloses the second technical problem that solve is the current situation to prior art, and it is less to provide an air current motion vortex, with the bigger centrifugal fan of flow under the rotational speed.

The utility model discloses the third technical problem that will solve is to prior art's current situation, provides a range hood of using above-mentioned centrifugal fan.

The utility model provides a technical scheme that above-mentioned first technical problem adopted is: a current collector for a centrifugal fan for mounting at an air inlet of the centrifugal fan, comprising:

the inner circumference of the guide ring is provided with an axial guide part extending along the axial direction;

the axial flow guide part at least partially reduces the axial height along the circumferential direction of the flow guide ring in the circumferential direction.

The axial flow guiding portion may be a whole (i.e. a complete circle) whose axial height gradually decreases along the circumferential direction of the flow guiding ring, or may be a section of the axial flow guiding portion in the circumferential direction, whose axial height gradually decreases along the circumferential direction of the flow guiding ring.

The axial height of the axial flow guide part is reasonably arranged according to the actual size of the volute and the size of the inner impeller, preferably, the maximum axial height h1 and the minimum axial height of the axial flow guide part are h2, wherein N = h1-h2, and N is more than or equal to 1mm and less than or equal to 10mm.

In order to further reduce the backflow between the current collector and the front end of the impeller of the centrifugal fan, the whole flow guide ring is oval.

The distances between the traditional current collector and the impeller end disc in the circumferential direction are equal, the air flow is uniform when entering the inner cavity of the volute from the air inlet after passing through the impeller blades, and the uniform air flow is easy to overflow at the impeller end disc close to the air inlet to cause a backflow phenomenon. The distance between the air inlet of the oval current collector and the impeller end disc in the circumferential direction is gradually changed, and the speed and the pressure of airflow entering the inner cavity of the volute after passing through the impeller blades from the air inlet are gradually changed. The gradual change airflow has relative motion along the circumferential direction, and the overflow of the airflow is reduced, so that the backflow is reduced, and the noise is reduced. Therefore, compared with the traditional circular collector, the oval collector changes the gap distribution between the collector and the impeller end disc, influences the pressure distribution and trend of airflow, weakens the reflux in the gap between the oval collector and the impeller and the volute, improves the flow field condition in the multi-wing centrifugal fan system, and improves the air inlet speed of the collector.

In order not to influence the air quantity entering the volute, the deformation degree of the elliptical guide ring is not too large compared with that of a conventional circular guide ring, and preferably, the long axis of the guide ring is L1, and the short axis of the guide ring is L2, wherein M = L1-L2, and M < L1/10 is more than 0.

The utility model provides a technical scheme that above-mentioned second technical problem adopted does: a centrifugal fan characterized by comprising: the volute is provided with an air inlet, and the current collector is arranged at the air inlet.

In order to better accord with the flow field motion rule in the volute, the volute is provided with a volute tongue, the position with the maximum axial height of the axial flow guide part of the flow guide ring corresponds to the volute tongue of the volute, and the direction of the reduction of the axial height of the axial flow guide part is consistent with the flow direction of the airflow in the volute.

When the current collector is assembled and matched with the volute, the position with the maximum axial height of the axial flow guiding part of the current collector corresponds to the volute tongue of the volute, the radial size of the volute is larger in one side area, close to the air outlet, of the volute along the flowing direction of airflow in the volute, the speed of the airflow in the volute is higher, the axial height of the axial flow guiding part of the current collector is relatively smaller, the airflow enters the volute from the current collector through the impeller blades, more axial airflow passes through the impeller blades, the utilization rate of axial work done by the blades is higher, the speed provided by the blades for the airflow is higher, and the discharged flow is increased. In the area of one side of the volute far away from the air outlet, the radial size of the volute is small, the pressure of airflow inside the volute is large, and the speed is small. In the area, gas shows a crowded condition, backflow is obvious between the current collector and the impeller end disc, the axial height of the axial flow guide part of the current collector is large at the position, the axial utilization rate of the blades is low, the transportation of the blades to airflow is reduced, backflow can be reduced, and noise is reduced.

As an improvement, the volute line takes the center of the air inlet as an original point O, a horizontal line passing through the original point O as an X axis, a vertical line passing through the original point O as a Y axis, and the position of the air outlet of the volute is located in a second quadrant along the counterclockwise direction;

the whole guide ring is oval, and the long axis of the guide ring is coincided with the X axis or the Y axis of the volute molded line.

The oval collector plate is superior to the circular collector plate in the flow of the internal flow field on the whole, and the backflow between the collector plate and the impeller end plate is reduced. When the long axis of the oval current collector is coincident with the X axis of the coordinate axis of the volute, the effect of reducing backflow is optimal overall, and then the long axis of the oval current collector is coincident with the Y axis of the coordinate axis of the volute, and the effect is slightly weakened but still better than that of a round current collector in other placing modes.

The utility model provides a technical scheme that above-mentioned third technical problem adopted does: a range hood, comprising: the centrifugal fan comprises a casing and a centrifugal fan arranged in the casing, wherein the centrifugal fan is the centrifugal fan.

Compared with the prior art, the utility model has the advantages that: the axial height of the axial flow guide part of the current collector is gradually reduced along the circumferential direction of the flow guide ring, so that the flow guide part can be better matched with the motion law of a flow field in the volute after being assembled at the air inlet of the volute of the centrifugal fan, particularly the difference between the air pressure and the speed of two sides of the volute tongue of the volute can be better met, the backflow between the air inlet of the current collector and the end surface of the impeller is effectively reduced, and the air volume under the same rotating speed is increased.

Drawings

Fig. 1 is a schematic perspective view of a current collector according to an embodiment of the present invention;

fig. 2 is a top view of a current collector according to an embodiment of the present invention;

fig. 3 is a left side view of a current collector of an embodiment of the present invention;

fig. 4 is a front view of a current collector of an embodiment of the present invention;

fig. 5 is a front view of a centrifugal fan according to an embodiment of the present invention (showing a coordinate system where a volute profile is located).

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

Terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", and the like, are used in the specification and claims of the present invention to describe various example structural parts and elements of the present invention, but these terms are used herein only for convenience of description and are determined based on example orientations shown in the drawings. Because the disclosed embodiments may be arranged in different orientations, these directional terms are for illustrative purposes only and should not be construed as limiting, and for example, "upper" and "lower" are not necessarily limited to orientations opposite or consistent with the direction of gravity.

Referring to fig. 1-4, a collector for a centrifugal fan is provided for being installed at an air inlet 22 of the centrifugal fan to guide an air flow from the air inlet 22 of the centrifugal fan into an interior of a volute 20 more smoothly.

The collector comprises a flow guiding ring 11 and an axial flow guiding part 12 extending from the inner circumference of the flow guiding ring 11 in the axial direction. The guide ring 11 may be connected to a periphery of an air inlet 22 of the centrifugal fan volute 20. After the collector is in place, the axial flow guide 12 extends toward the air inlet 22 of the volute 20.

In the present embodiment, the axial height of the axial flow guiding portion 12 of the header is gradually reduced along the circumferential direction of the flow guiding ring 11, preferably, the axial height of the axial flow guiding portion 12 is gradually reduced along the complete circumference, thereby, the maximum axial height of the axial flow guiding portion 12 forms a step a at the lowest axial height, specifically, the maximum axial height h1 of the axial flow guiding portion 12, the lowest axial height is h2, N = h1-h2,1mm ≦ N ≦ 10mm.

Because the distances between the conventional collector and the impeller end disc in the circumferential direction are equal, the airflow is uniform when entering the inner cavity of the volute 20 after passing through the impeller blades from the air inlet 22, and the uniform airflow is easy to overflow at the impeller end disc close to the air inlet 22, which causes a backflow phenomenon. For this reason, the deflector ring 11 of the present embodiment is oval as a whole. Because the distance between the oval collector and the impeller end disc is gradually changed along the circumferential direction, the speed and the pressure of the airflow entering the inner cavity of the volute 20 after passing through the impeller blades from the air inlet 22 are gradually changed, and the gradually changed airflow has relative motion along the circumferential direction, so that the overflow of the airflow is reduced, the backflow is reduced, and the noise is reduced. Therefore, the elliptical current collector air inlet structure is adopted, compared with the traditional circular current collector, the elliptical current collector changes the gap distribution between the current collector and the impeller end disc, the pressure distribution and the trend of airflow are influenced, the backflow in the gap between the elliptical current collector and the impeller and the volute 20 is weakened, the flow field condition in the multi-wing centrifugal fan system is improved, and the air inlet speed of the current collector is improved.

In order not to affect the air volume entering the volute 20, the deformation degree of the elliptical flow guiding ring 11 is not too large compared with the conventional circular flow guiding ring 11, in this embodiment, the major axis of the flow guiding ring 11 is L1, and the minor axis thereof is L2, where M = L1-L2, and 0 < M < L1/10.

Referring to fig. 5, a centrifugal fan includes a volute 20, an impeller and a collector 10, wherein the impeller is disposed in the volute 20 and is driven by a motor to rotate to generate a negative pressure for sucking and discharging oil smoke. The front cover plate of the volute casing 20 is provided with an air inlet 22. The collector adopts the above-mentioned collector structure and is installed at the air inlet 22 of the volute 20.

The volute 20 has a volute tongue 21. In the present embodiment, the maximum axial height of the axial flow guide portion 12 of the flow guide ring 11 (which may also be considered as the joint position where the maximum axial height of the axial flow guide portion 12 is at the minimum axial height) corresponds to the volute tongue 21 of the volute casing 20, and the direction of the axial height of the axial flow guide portion 12 decreases coincides with the airflow flowing direction S in the volute casing 20.

When the collector and the volute 20 are assembled, the position where the axial height of the axial flow guiding part 12 of the collector is the largest corresponds to the volute tongue 21 of the volute 20, along the airflow flowing direction in the volute 20, the area of one side, close to the air outlet 23, of the volute 20 is larger in radial size, the airflow speed in the volute 20 is higher, the axial height of the axial flow guiding part 12 of the collector is relatively smaller, the airflow enters the volute 20 from the collector through the impeller blades, more axial airflow passes through the impeller blades, the utilization rate of the blades is higher in axial work doing, the speed provided by the blades to the airflow is higher, and the discharged flow is increased. In the area of the side of the volute 20 far away from the air outlet 23, the radial size of the volute 20 is smaller, and the pressure and the speed of the airflow inside the volute 20 are higher. In the area, gas shows a crowded condition, the backflow is obvious between the collector and the impeller end disc, the axial height of the axial flow guide part 12 of the collector is large, the axial utilization rate of the blades is low, the transportation of the blades to air flow is reduced, the backflow can be reduced, and the noise is reduced.

In this embodiment, the profile of the volute 20 takes the center of the air inlet 22 as an origin O, a horizontal line passing through the origin O as an X-axis, and a vertical line passing through the origin O as a Y-axis, and the position of the air outlet 23 of the volute 20 is located in the second quadrant along the counterclockwise direction. The oval collector in this embodiment is superior to the circular collector in the internal flow field flow as a whole, and can reduce the backflow between the collector and the impeller end disc. When the long axis of the oval current collector coincides with the X axis of the coordinate axis of the volute 20, the effect of reducing backflow is optimal overall, secondly, the long axis of the oval current collector coincides with the Y axis of the coordinate axis of the volute 20, and other placing modes have slightly weakened effect but are still better than the effect of the round current collector. One way in which the major axis of the elliptical deflector ring 11 is offset (i.e. non-coincident) with the X-axis or Y-axis of the profile of the volute 20 is shown in figure 5.

The embodiment also shows a range hood, which comprises a casing (not shown) and a centrifugal fan arranged in the casing, wherein the centrifugal fan adopts the centrifugal fan.

Because the axial height of the axial flow guiding part 12 of the current collector is gradually reduced along the circumferential direction of the flow guiding ring 11, after the axial flow guiding part is assembled at the air inlet 22 of the volute 20 of the centrifugal fan, the axial flow guiding part can be better matched with the motion law of the flow field in the volute 20, especially the difference between the air pressure and the speed at two sides of the volute tongue 21 of the volute 20 can be better met, the backflow between the air inlet 22 of the current collector and the end surface of the impeller is effectively reduced, and the air volume under the same rotating speed is increased.

Claims

1. A collector for a centrifugal fan, intended to be mounted at an air inlet (22) of a centrifugal fan, comprising:

a guide ring (11) having an axial guide portion (12) extending in the axial direction along the inner periphery thereof;

the method is characterized in that: the axial flow guide part (12) at least partially reduces the axial height along the circumferential direction of the flow guide ring (11) in the circumferential direction.

2. The collector for a centrifugal fan according to claim 1, wherein: the axial flow guide part (12) is characterized in that the maximum axial height h1 and the minimum axial height h2 are respectively arranged, wherein N = h1-h2, and N is more than or equal to 1mm and less than or equal to 10mm.

3. The collector for a centrifugal fan according to claim 1 or 2, wherein: the whole guide ring (11) is oval.

4. The collector for a centrifugal fan according to claim 1, wherein: the long axis of the guide ring (11) is L1, the short axis is L2, wherein M = L1-L2, and M is more than 0 and less than L1/10.

5. A centrifugal fan characterized by comprising: a volute (20) and a current collector according to any one of claims 1-4, wherein the volute (20) has an inlet opening (22) and the current collector is mounted at the inlet opening (22).

6. The centrifugal fan of claim 5, wherein: the volute (20) is provided with a volute tongue (21), the position where the axial height of the axial flow guiding part (12) of the flow guiding ring (11) is the largest corresponds to the volute tongue (21) of the volute (20), and the direction of the reduction of the axial height of the axial flow guiding part (12) is consistent with the airflow flowing direction in the volute (20).

7. The centrifugal fan of claim 6, wherein: the molded line of the volute (20) takes the center of the air inlet (22) as an original point O, a horizontal line passing through the original point O as an X axis, a vertical line passing through the original point O as a Y axis, and the position of the air outlet (23) of the volute (20) is positioned in a second quadrant along the counterclockwise direction;

the whole flow guide ring (11) is oval, and the long axis of the flow guide ring (11) is superposed with the X axis or the Y axis of the molded line of the volute (20).

8. A range hood, characterized by comprising: the centrifugal fan comprises a casing and a centrifugal fan arranged in the casing, wherein the centrifugal fan is the centrifugal fan as claimed in any one of claims 5 to 7.