WO2020099035A1

WO2020099035A1 - Mixed flow fan that can be variably combined with different nozzles

Info

Publication number: WO2020099035A1
Application number: PCT/EP2019/077418
Authority: WO
Inventors: Thomas Heli; Eugen Kleinhanß; Ann-Kathrin Löber
Original assignee: Ebm-Papst Mulfingen Gmbh & Co. Kg
Priority date: 2018-11-16
Filing date: 2019-10-09
Publication date: 2020-05-22
Also published as: DE102018128811A1; CN210033892U

Abstract

The invention relates to a mixed flow fan comprising an electric motor, a housing and a mixed flow impeller which is accommodated within the housing and can be driven by the electric motor, wherein the mixed flow generated during the operation thereof is deflected in an axial flow direction by an inner wall of the housing, wherein, at the air inlet thereof, the housing is designed to securely receive an inlet nozzle, and wherein the housing has at least two axial securing planes for securing a heat exchanger to the housing in two different axial positions, wherein a first securing plane is formed by a flange on an outer casing surface of the housing and a second securing plane is formed by a fixing device for the inlet nozzle on the air inlet.

Description

Diagonal fan that can be combined with different nozzles

Description:

The invention relates to a diagonal fan that can be variably combined with different nozzles.

Diagonal fans and their use are generally known from the prior art, for example from DE 10 2014 210 373 A1.

Diagonal fans are used in applications with high air performance requirements with higher back pressure and a small installation space, for example in cooling technology or extractor hoods. Due to the large motor diameter of diagonal fans in relation to the installation space of the axially central motor, the blow-out area at the blow-out opening is relatively small, which leads to high outlet losses in the flow due to high dynamic pressure at the outlet of the diagonal fan.

Axial fans are usually used to achieve long throwing distances, but they require a not inconsiderable axial installation space. Diagonal fans are cheap for the compact design. In addition, they have a larger area of application for higher back pressures with higher efficiency.

The invention solves the problem of being able to replace axial fans with diagonal fans when used with heat exchangers without increasing the overall axial length of the overall system.

This object is achieved by the combination of features according to claim 1.

According to the invention, a diagonal fan with an electric motor, a housing and a diagonal impeller which is accommodated within the housing and can be driven by the electric motor is proposed. The diagonal flow generated by the diagonal impeller during operation is deflected by an inner wall of the housing in an axial flow direction. The housing is designed at its air inlet to receive an inlet nozzle. Furthermore, the housing has at least two axial fastening planes for fastening a heat exchanger to the housing in two different axial positions, a first fastening plane being formed by a flange on an outer circumferential surface of the housing and a second fastening plane being formed by a fixing device for the inlet nozzle on the air inlet.

With the solution according to the invention, the heat exchanger can either be attached to the outside of the housing via the flange, so that parts of the slide gonalventilator are arranged within the heat exchanger and therefore the axial length is small. In this case, a separate inlet nozzle is attached to the air inlet. Alternatively, the heat exchanger itself can form a nozzle, which is led into the diagonal fan at the air inlet and influences the intake flow. For this purpose, the same fixing device on the air inlet is used, which is otherwise used for fastening the inlet nozzle. In such an embodiment, the heat exchanger extends axially into the diagonal fan, so that the overall axial length of the overall system is also small.

In an advantageous embodiment, the diagonal fan is characterized in that the flange is positioned on the housing at a distance M from the air inlet and at a distance N from an axial air outlet of the diagonal fan, a ratio IWN being established, that is 0.70 < M / N <1, 3, a ratio of 0.5, ie. Is particularly preferred a central arrangement of the flange on the housing.

The flange is preferably annular.

Furthermore, in the case of the diagonal fan, the inlet nozzle can be detachably attached to the housing as a separate component.

Furthermore, an embodiment is favorable in which the fixing device for the inlet nozzle is designed in such a way that both the inlet nozzle and, alternatively, the heat exchanger can be fastened. For this purpose, for example, holes can be provided in the material of the housing, the position and size of which are matched to both the inlet nozzle and the heat exchanger.

In a further development, the diagonal fan provides that the housing has a flattened portion at the air inlet, which has an edge dimension

Housing diameter is approximated at the air outlet, so that when the diagonal fan is immersed in a cross-sectionally rectangular heat exchanger space-saving assembly is made possible. In addition, the overall height of the heat exchanger can be minimized.

When the diagonal fan is seen in a further embodiment in the axial flow direction of the diagonal impeller a Nachleit device with a plurality of circumferentially distributed guide vanes is arranged, which uniformizes an air flow generated by the diagonal impeller.

In the case of the diagonal fan, an advantageous embodiment provides that the after-guiding device is formed in one piece with the housing. The number of parts and assembly steps can thus be reduced. A seal between the components can also be dispensed with.

In a further development, the follow-up device has a protective grille that extends over a blow-out section of the diagonal fan. The axial length of the protective grille is less than 50% of the maximum axial length of the guide device.

A variant of the diagonal fan in which the secondary guide device, the housing and the protective grille are formed in one piece is also favorable.

In an advantageous embodiment, the protective grille also has a multiplicity of ring webs arranged coaxially to one another, each of which forms web surfaces that run parallel and opposite to the axial flow direction. The flow thus runs in parallel along the web surfaces over the entire axial length of the protective grille.

In a further development of the diagonal fan, the ring webs in the area of the guide vanes are formed axially in relation to a leading edge of the respective guide vanes. The guide vanes can thus also be formed in part by the projecting section of the ring webs, so that the web surfaces formed by the ring webs in the region of the guide vanes are axially enlarged. In addition, the axially projecting sections of the ring webs can serve as stiffening of the guide vanes.

The guide vanes of the guide device can have different shapes and cross sections. In an advantageous embodiment, the guide vanes are curved in the shape of an arc as seen in the axial cross section and are additionally or alternatively profiled. A wing shape, e.g. a convex shape. The different inflow angles of the diagonal impeller used in each case can therefore be taken into account. A straight radial extension of the guide vanes is also possible.

In addition to the forward or backward curved design seen in axial cross section, in a further alternative embodiment the guide vanes of the after-guide device can be designed to be three-dimensionally curved, i.e. the curvature is also axial.

A favorable design of the diagonal fan also provides that the guide vanes of the secondary guide pass directly into the protective grille and thus interact directly in terms of flow.

In addition to the guide device, the diagonal impeller also includes a hub with impeller blades attached or formed thereon. The two hubs or hub areas are preferably dimensioned such that a maximum diameter G of the hub area of the guide device is larger than a maximum diameter F of a hub of the diagonal impeller, so that the hub area of the guide device covers the hub of the diagonal wheel as seen in axial projection.

A further advantageous solution for the axially compact design of the diagonal fan is characterized in that the follow-up device has a motor mount for the electric motor in the hub area. For this purpose, the hub area of the guide device can also be designed to be axially retracted are seen, so that motor components and follow-up device overlap as seen in radial section.

An advantageous embodiment of the diagonal fan also provides that the diagonal impeller has a centrifugal ring which surrounds impeller blades distributed in the circumferential direction. The centrifugal ring enables a precisely adjustable outflow angle and a flow line at a predetermined angle with respect to the axis of rotation of the diagonal impeller.

Another advantageous aspect is to design the electric motor as an external rotor motor in the case of the diagonal fan. This allows the diagonal impeller to enclose the motor and the axial space requirement is minimized.

A further development of the diagonal fan also provides that the inlet nozzle preferably extends axially into the centrifugal ring, so that the inlet nozzle and the centrifugal ring overlap in sections as seen in radial section.

Other advantageous developments of the invention are characterized in the subclaims or are presented below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

1 is an exploded perspective view of a diagonal fan with a view of the inlet side,

Figure 2 is an exploded perspective view of the diagonal valve from Figure 1 with a view of the outlet side.

3 shows a view in radial section of the diagonal fan from FIG. 1;

Fig. 4 is a perspective sectional view of the diagonal fan

Figure 1.

In the figures 1 to 4 is an embodiment of an inventive Diagonal fan 1 shown.

In the exploded views according to FIGS. 1 and 2, the components of the housing 2 can be seen with the stationary guide device 3 formed thereon in one piece, the diagonal impeller 4, the electric motor 5 designed as an external rotor motor and the inlet nozzle 6 which can be inserted into the housing 2.

In Figures 3 to 4, the diagonal fan 1 is shown in the assembled state and has an overall taxi length E. The diagonal impeller 4 comprises a plurality of impeller blades 9 which extend radially outward from the axially open hub 8 and which are surrounded by the slinger 14. The centrifugal ring 14 has a flow cross section which widens radially outward in the axial flow direction and faces the inner wall of the housing 2. The electric motor 5 is inserted into the axially open hub 8 of the diagonal impeller 4 and is completely enclosed by it. In the axial direction, i.e. along the axis of rotation, the electric motor 5 extends into the central depression 11, so that it can be positioned closer to the diagonal impeller 4. The diagonal impeller 4 driven by the electric motor 5 is arranged within the housing 2 forming a flow channel and has an axial length D. The inlet nozzle 6 is arranged on the inlet side and extends with its end section of the smallest flow cross section (diameter A) into the region of the diagonal impeller 4, so that the slinger ring 14 and the end section of the inlet nozzle 6 overlap.

The housing defines two axial fastening planes X, Y for fastening a heat exchanger 200, 200 'to the housing 2 in two different axial positions. The first axial position is on the fastening plane X, which runs through the flange 25 on the outer lateral surface of the housing 2.

The second axial position and the corresponding fastening plane are designed by the fixing device as screw holes for screwing the inlet nozzle 6 to the air inlet 21. FIGS. 5-8 show the diagonal fan 1 in different installation situations with a heat exchanger 200, 200 '. The heat exchanger 200 according to FIG. 5 comprises a nozzle 201, which replaces the inlet nozzle 6 of the diagonal fan 1. With its contact surface 205 facing the diagonal fan 1, the heat exchanger 200 is fixed on the fastening plane Y at the screw holes for the inlet nozzle 6. The nozzle 201 extends into the diagonal impeller 4 and forms an overlap region comparable to the inlet nozzle 6.

In the embodiment according to FIG. 6, the diagonal fan 1 is equipped with the inlet nozzle 6, the heat exchanger 200 ′ with the inlet nozzle 6 being fastened to its contact surface 205 facing the diagonal fan 1, but not requiring a nozzle, as in the exemplary embodiment according to FIG. 5.

The exemplary embodiment according to FIG. 7 also uses the diagonal fan 1 with the inlet nozzle 6, but the contact surface 205 facing the diagonal fan 1 is carried out radially further outside, so that the fastening is carried out by screws on the annular flange 25 and the diagonal fan 1 is thus half its axial extent is positioned within the heat exchanger 200 '. Figure 8 shows an embodiment identical to Figure 7, but with a diagonal fan 1 installed in a pushing manner, i.e. the air exits into the heat exchanger 200 '.

Now again referring primarily to FIG. 3. In operation, the diagonal fan 1 sucks in air in the axial direction via the diagonal impeller 4 and conveys this diagonally, i.e. with respect to the axis of rotation in a pre-determined outflow angle in the direction of the inner wall of the housing 2. In the embodiment shown, the outflow angle is determined obliquely radially outward via the slinger 14. On the inner wall of the housing 2, the flow is then deflected again in an axial flow direction and conveyed to the after-guiding device 3.

The air outlet of the diagonal fan 1 has a predetermined exhaust diameter B, the ratio of total axial length E to blow-out diameter B in the exemplary embodiment shown being 0.38. The ratio can be increased to 0.6 or reduced to 0.3. In the air inlet 21 formed by the inlet nozzle 6 (in the area of the smallest flow cross section of the inlet nozzle), the diagonal fan 1 has an intake diameter A that is 0.87 times smaller than the outlet diameter B. The ratio can be adjusted in a range of 0 , 70-0.95. The required redirection of the flow in the radially outer area is thus small.

Seen in the axial flow direction of the diagonal impeller 4, the after-guide device 3 is then arranged with a plurality of guide vanes 7 distributed in the circumferential direction. The follow-up device 3 further comprises an integral protective grille 17 with a plurality of ring webs 13 arranged coaxially to one another, each of which form web surfaces 19 that run parallel and opposite to the axial flow direction. The axial length of the protective grille 17 corresponds to half the axial length C of the guide device 3. The maximum flow cross-section of the guide device (diameter B) is on the exhaust side in the area of the ring webs 13. The guide device 3 evens out the flow by means of the guide vanes 7 and the protective grid 17. The guide vanes 7 extend in the axial direction through the protective grid 17 and thus break through the ring webs 13 as a kind of arcuate radial webs, as can be seen clearly in FIG. 2.

Referring to FIG. 3, the diagonal impeller extends over an axial impeller width D. The ratio of the axial extent C of the guide device to the impeller width D has a value of 0.5 in the embodiment shown, but can be in the range of 0.30-0.75. in particular between 0.4 - 0.5. The ratio of the maximum diameter G of the Nabenbe range of the Nachleiteinrichtung 3 and the maximum diameter F of the hub 8 of the diagonal impeller 4 is also shown, wherein G> F. FIGS. 1 and 3 also show that the ring webs 13 are in the area of the guide blades 7 are formed axially to the leading edge of the respective guide blades 7 in section 12 and thus ensure stiffening and support of the guide blades 7. The guide vanes 7 are curved in the shape of an arc as seen in the axial cross section and are curved radially outward in the radial section according to FIG. 3, so that a three-dimensional overall curvature results. In addition, the guide vanes 7 are profiled in a radial section according to FIG. 3 according to an aerofoil, their respective thicknesses initially increasing in the axial direction and then decreasing again.

Claims

1. diagonal fan comprising an electric motor (5), a housing (2) and a diagonal impeller (4) accommodated within the housing and drivable via the electric motor, the diagonal flow generated during operation being deflected by an inner wall of the housing in an axial flow direction, the Housing (2) on its air inlet (21) is designed to attach an inlet nozzle (6), and wherein the housing has at least two axial fastening planes for fastening a heat exchanger to the housing (2) in two different axial positions, a first Fixing level by a flange (25) on an outer surface of the housing (2) and a second mounting level by a fixing device for the inlet nozzle (6) is formed at the air inlet.

2. Diagonal fan according to claim 1, characterized in that the flange (25) relative to the air inlet (21) at a distance M and opposite an axial air outlet of the diagonal fan (1) is positioned at a distance N on the housing, a ratio M / N is determined that 0.70 <M / N <1, 3 applies.

3. Diagonal fan according to claim 1 or 2, characterized in that the inlet nozzle (6) is detachably attachable to the housing (2) as a separate component.

4. Diagonal fan according to one of the preceding claims, characterized in that the fixing device for the inlet nozzle (6) is designed to fasten both the inlet nozzle and alternatively the heat exchanger.

5. Diagonal fan according to one of the preceding claims, characterized in that the housing (2) has a flat at the air inlet, which has a housing diameter on the air outlet in the edge dimension let it be approximated, so that when the diagonal fan (1) is immersed in a heat exchanger with a rectangular cross section, space-saving installation is possible.

6. Diagonal fan according to one of the preceding claims, characterized in that seen in the axial flow direction of the diagonal impeller (4) is subsequently arranged a follow-up device (3) with a plurality of circumferentially distributed guide vanes (7), which is an air flow generated by the diagonal impeller evened out.

7. Diagonal fan according to claim 6, characterized in that the after-guide device (3) has a blow-out section of the diagonal fan (1) which extends over a protective grille (17) which has an axial length which is less than a total taxi length of the after-guide device (3).

8. Diagonal fan according to claim 7, characterized in that the guide device, the housing (2) and the protective grille (17) are integrally formed.

9. Diagonal fan according to claim 7 or 8, characterized in that the protective grille has a plurality of coaxially arranged ring webs, each forming parallel to the axial direction of flow and opposite web surfaces.

10. Diagonal fan according to the preceding claim, characterized in that the annular webs in the area of the guide vanes (7) are formed axially in relation to a leading edge of the respective guide vanes.

11. Diagonal fan according to one of the preceding claims, characterized in that the guide vanes (7) of the guide device (3) seen in axial cross-section in a plane are curved and / or profiled.

12. Diagonal fan according to one of the preceding claims, characterized in that a maximum diameter G of the hub area of the after-guiding device (3) is larger than a maximum diameter F of a hub (8) of the diagonal impeller (4), so that the hub area of the after-guiding device (3) covers the hub of the diagonal impeller seen in axial projection.

13. Diagonal fan according to one of the preceding claims, characterized in that the secondary guide (3) in the hub area has a motor mount for the electric motor (5).

14. Diagonal fan according to one of the preceding claims, characterized in that the diagonal impeller (4) has a centrifugal ring (14) which surrounds impeller blades (9) distributed in the circumferential direction and defines the outflow angle of the diagonal impeller.

15. Diagonal fan according to the preceding claim, characterized in that the inlet nozzle (6) is arranged on the suction side of the housing (2) and extends in the axial direction into the slinger (14).