EP3228873A1 - Centrifugal fan in a duct, with an obstructing device placed downstream of the fan and concentric with the fan - Google Patents

Abstract

The invention relates to a component for a room ventilation ventilation system comprising a channel-shaped housing (1), which preferably has a rectangular, square or round cross-section, and at least one arranged on a cross-sectional plane in the housing (1) radial fan (2) or more on a cross-sectional plane in the housing (1) arranged radial fans (2). In order to provide a component in which the outflow of the centrifugal fan is improved, as a result, the efficiency is increased due to a lower pressure loss, should in the flow direction (4) seen at a distance which is smaller than the diameter of the centrifugal fan (2), preferably smaller than half the diameter of the centrifugal fan (2), particularly preferably less than a quarter of the diameter of the centrifugal fan (2), behind at least one radial fan (2) is a device (3) with an orthogonal to the general flow direction (4) aligned fluidically be closed end face (13) to be arranged, each device (3) in its cross-sectional plane is surrounded on all sides by a circumferential space (12) for flowing the gas, so that each device (3) on all sides by the flowing gas can flow around, wherein the housing cross-section one of the number of in an area of the housing cross section 3) corresponds to a number of theoretical housing cross-sectional subareas I and II or III and IV, respectively, wherein each device (3) has between 50% and 75%, preferably 50% and 75%, relative to its associated housing cross-sectional subareas I and II or III and IV, respectively between 55% and 70% of the theoretically free flow cross-section of the housing cross-sectional portion I or II or III or IV blocked.

Description

The invention relates to a component for a room ventilation ventilation system comprising a channel-shaped housing, which preferably has a rectangular, square or round cross-section, and at least one arranged on a cross-sectional plane in the housing radial fan or more arranged on a cross-sectional plane in the housing radial fans.

Centrifugal fans include an impeller driven by a drive motor. The impeller generally has on its downstream side a cover plate, to which the impeller blades adjoin. The radial fan usually has no housing. The air is usually sucked parallel to the drive axis of the centrifugal fan and deflected by the rotation of the impeller by 90 °. Thus, the air is radially outward, d. H. blown in the direction of the wall of the channel-shaped housing. So that the air on the pressure side of the centrifugal fan, d. H. on the outflow side, flowing again in the main flow direction, the air flow must be redirected again by 90 °. This creates a pressure drop that reduces the overall efficiency of the centrifugal fan.

The object of the invention is to avoid the aforementioned disadvantages and to provide a component in which the outflow of the centrifugal fan is improved, so that as a result the efficiency is increased due to a lower pressure loss.

This object is achieved in that seen in the flow direction at a distance which is smaller than the diameter of the centrifugal fan, preferably less than half the diameter of the centrifugal fan, more preferably less than a quarter of the diameter of the centrifugal fan, behind at least one radial fan one Device is arranged with an orthogonal to the general flow direction aligned fluidically closed end face, each device is surrounded in its cross-sectional plane on all sides by a circumferential space for flowing the gas, so that each device can be flowed around on all sides by the flowing gas, wherein the housing cross-section one of the number the devices provided in a region of the housing cross-section corresponding number of theoretical housing cross-sectional portions I or II or III or IV, each device based on their zughörigen housing cross-section partial area I or II or III or IV between 50% and 75%, preferably between 55% and 70%, of the theoretically free flow cross-section of the housing cross-sectional portion I or II or III or IV blocked. The end face of at least one device may be formed completely closed. But it is also possible that the end face has an opening or a recess which is closed by another part, such as a drive motor or a part of a drive motor. In the case of the component according to the invention, the device is thus arranged, viewed in the flow direction, directly behind the associated radial fan.

Each device is made of a moisture-resistant material so that the gas flowing in the component can also be moist. Also, each device has such a material that withstands the usual, prevailing in an air conditioning temperatures and temperature fluctuations. Each device is intrinsically stable, d. H. she has a stable shape.

Each facility has an exclusively flow-improving effect. The arrangement of a device immediately behind the centrifugal fan, the ruling behind the radial fan fluidic dead zone is used. There is no flow in the dead area. The radially after Outside flowing gas is deflected by 90 ° and then flows through the circulating space. The inventive design, the flow is made uniform. Thus, the flowing air is swirl and turbulence, which leads to a reduction of the pressure loss. Due to the resulting lower pressure loss results in a higher efficiency.

At least one device may be arranged in the housing so that the device has a distance at least in the region S to the adjacent wall of the housing, each between 5% to 15%, preferably between 9% to 13%, of the corresponding internal dimension of the housing is. If the housing and the device are of square design, this means that the gap forming in the four regions S due to the free space has the same width. The area S is the area resulting from a projection of the outer surface of the device on the respectively adjacent wall of the housing. In the area of the four corners, however, the distance is slightly larger, provided that the housing is not rounded in the area of the four corners. In a round configuration of housing and device, the region S extends over the entire length, so that in the central arrangement of the device, the circumferential gap has the same width over its entire length. If the housing and the device are rectangular and the longitudinal sides of the housing are parallel to the longitudinal sides of the device, the resulting gap in area S between the longitudinal sides of the housing and the device is narrower than the resulting gap in area S between the short sides of the housing and the device. In the area of the four corners, the distance is different, unless the housing is rounded in the area of the four corners.

At least one device can be arranged in the housing such that the device is at least in the region S at a distance from the boundaries G of its housing cross-sectional portion I or II or III or IV, each between 5% to 15%, preferably between 9 % to 13%, the corresponding dimension of the housing cross-sectional portion I or II or III or IV. If the component has only one device corresponds the housing cross-section portion of the housing cross-section. Then, the walls of the housing, the boundaries G represent. In an embodiment with, for example, four devices a total of four theoretical housing cross-sectional portions are provided. The four boundaries of each housing cross-sectional portion are formed by two walls of the housing and by the two virtual theoretical limits G.

At least one device can be designed as a plate. The plate may be, for example, a thin sheet metal plate.

At least one device can be designed as a flow body. Thus, the device also has along the wall of the housing or along the adjacent boundary G of its housing cross-sectional portion extending outer surface (s). The flow is applied to the outer surface (s) of the device, which are parallel to the adjacent wall of the housing or parallel to the adjacent boundary G of its housing cross-sectional portion. As a result of the configuration according to the invention, the flow through the device is made uniform, so that the flowing air is swirl and turbulence-reduced, which leads to a reduction in the pressure loss. The mentioned in claim 1 cross-sectional plane is seen at each point of the device in the longitudinal extent of the device.

The dimensions can be seen constant in at least one device in the flow direction and thus the width of the free space in the flow direction to be constant.

Alternatively, the dimensions in at least one device can be seen to decrease at least in a partial region, preferably along the entire length, in the flow direction, and thus the width of the free space in the flow direction can increase. The reduction of the dimensions of the device seen in the flow direction can be continuous or discontinuous. In the decreasing area, the device is thus designed as a kind of diffuser. The flow relaxes in the increasing in the flow direction circumferential free space. This is the dynamic Proportion of total pressure converted into a usable static pressure. This results in a lower pressure loss, resulting in a higher efficiency.

It is advisable if, in the case of at least one device, the dimensions are continuously reduced at least in a partial region, preferably over the entire length, in the flow direction.

In at least one device, the outer surface of the downstream-reducing portion may be inclined to the flow-direction central axis of the device at an angle α between 4 ° and 10 °, preferably 7.5 °. Thus, the device is the design in the manner of a diffuser, so that the conversion of the dynamic pressure is additionally favored in the static pressure.

At least one device may have a quadrangular, in particular rectangular, cross-section. Of course, other cross-sectional shapes, such as round, are possible.

The outer contour of at least one device can be adapted to the inner contour of the housing. If the inner contour of the housing is round, offers a device with a round shape. If the inner contour of the housing is rectangular, offers a rectangular device and in a square inner contour of the housing, the device is advantageously also square.

At least one device can be arranged centrally relative to the housing cross-section or to the theoretical housing cross-sectional portion.

At least one device may have a recess for receiving a part of the radial fan and / or at least part of the drive motor of the centrifugal fan in the area of the end face facing the radial fan. By such a configuration, the distance between Centrifugal fan and device and thus the overall length even further reduced.

At least one radial fan, upstream of a radial fan, can be arranged a diaphragm which has at least one opening for the passage of the flowing gas to the intake region of the centrifugal fan. Between the diaphragm and the radial fan and a connection piece may be provided.

In the housing at least two juxtaposed and / or stacked arrangements comprising a radial fan and a device may be provided. In such an arrangement, each centrifugal fan is centered with respect to its associated device.

At least one device can be made of steel, in particular sheet steel, wood, plastic or the like, at least in the region of its outer surface (s), which is in contact with the flowing gas, preferably the device completely. Thus, the device in question consists of a non-sound-absorbing material. Due to the material, the device in question obtains a stable shape, even with the turbulence prevailing after an impeller of a centrifugal fan. The property of the device, at least in the region of its outer surface (s) in contact with the flowing gas, is therefore such that the outer surface concerned does not oscillate or resonate when the gas flows along.

Fig. 1 - 8

Seitenansichten auf unterschiedliche Ausgestaltungen einer erfindungsgemäßen Komponente,

Fig. 9

eine erfindungsgemäße Komponente mit vier nebeneinander angeordneten Anordnungen jeweils umfassend einen Radialventilator und eine Einrichtung entgegen die Strömungsrichtung gesehen,

Fig. 10

das Detail "X" aus Fig. 9 und

Fig. 11

eine erfindungsgemäße Komponente mit einem runden Gehäuse und einer runden Einrichtung entgegen die Strömungsrichtung gesehen.

Embodiments of the invention illustrated in the drawings are explained below. Show it:

Fig. 1 - 8

Side views of different embodiments of a component according to the invention,

Fig. 9

a component according to the invention with four juxtaposed arrangements each comprising a radial fan and a device seen opposite to the flow direction,

Fig. 10

the detail "X" off Fig. 9 and

Fig. 11

a component according to the invention with a round housing and a round device seen against the flow direction.

In all figures the same reference numerals are used for identical or similar components.

In the figures, different embodiments of a component according to the invention are shown. Each component comprises a channel-shaped housing 1 with a rectangular cross-section, in which a radial fan 2 and a device 3 having an inflow-side end face 13 are provided. As each in the Fig. 1 to 8 such as Fig. 11 component shown has only one device 3, the housing cross-sectional portion corresponds to the housing cross-section. Of course, other cross-sectional shapes of the housing 1 and the device 3, such as round, are possible.

As seen in the flow direction 4, the respective device 3 is arranged behind the centrifugal fan 2, which is driven by a drive motor 5 arranged on the outflow side of the centrifugal fan 2. About a shaft of the centrifugal fan 2 and the drive motor 5 are interconnected. The radial fan 2 comprises an impeller with impeller blades 6 and a cover plate 7, which is arranged on the side facing the drive motor 5 side.

In the flow direction 4 seen in front of the centrifugal fan 2, a diaphragm 8 is arranged, which has an opening 9 for the passage of the gas to the intake of the centrifugal fan 2. Between the opening 9 in the aperture 8 and the suction of the centrifugal fan 2, a connector can be provided be. Not shown in all figures, both the attachment of each centrifugal fan 2 and the attachment of each device. 3

According to the embodiment Fig. 1 the device 3 is formed as a thin plate, while the device formed as a plate 3 in Fig. 2 has a greater thickness. In the embodiments of the Fig. 3 to 8 Each device 3 is designed as a block-like trained flow body. Thus, the device has four along the wall 10 of the housing 1 and along the adjacent boundary G of its housing cross-sectional portion extending outer surfaces 11. Each device 3 is arranged in the housing 1, that on all sides there is a distance from the wall 10 of the housing 1. This creates a circumferential free space 12 for the flow of gas, which is possibly interrupted in the region of a support structure. In this way, the device 3 is surrounded on all sides by the flowing gas.

In the in the Fig. 3 to 5 illustrated embodiment, the dimensions of the device 3 seen in the flow direction 4 remain constant and thus the width of the free space 12 is seen in the flow direction 4 constant. In the in the Fig. 6 to 8 illustrated embodiments, the dimensions of the device 3 seen in the flow direction 4 decrease. While in the embodiment according to Fig. 6 the outer surfaces 11 seen along its entire length in the flow direction 4 to the pointing in the flow direction 4 center axis M of the device 3 at an angle α of about 7.5 ° are formed extending and thus the device 3 is continuously reduced, reduce the dimensions of the device 3 in the embodiments of the Fig. 7 and 8th only in the region of the end facing away from the flow direction 4.

While in the Fig. 1 to 4 and 6 to 8 the drive motor 5 is exposed and thus the end face 13 of the device 3 is formed closed over its entire surface, the device 3 in Fig. 5 on the radial fan 2 facing End face 13 a recess for receiving the drive motor 5 of the centrifugal fan 2.

In Fig. 9 a component is shown having a channel-shaped housing 1 with a rectangular cross-section. There Fig. 9 a view opposite to the flow direction 4, the upstream in the flow direction 4 of the respective device 3 radial fans 2 are not visible, but are covered by the respective device 3. In the housing 1 four arranged on a cross-sectional plane in the housing 1 radial fans 2 are arranged. Each centrifugal fan 2 is assigned a device 3. Since four devices 3 are arranged in the housing 1, the housing cross-section has four, theoretical housing cross-sectional portions I-IV.

Each of these four housing cross-sectional portions I-IV is formed in the present case by two adjacent walls 10 of the housing 1 and by two virtual boundaries G. The latter are therefore shown only by dashed lines. Each device 3 blocks relative to its associated housing cross-sectional portion I or II or III or IV in the illustrated case, approximately between 55% and 70% of the respective housing cross-sectional portion I or II or III and IV.

Each device 3 is arranged behind its associated radial fan 2 as seen in the flow direction 4. In the flow direction 4 seen in front of the four centrifugal fans 2, the diaphragm 8 is arranged, the four openings 9 for the passage of the gas to the intake of the respective centrifugal fan 2 has.

Each device 3 is arranged in the housing 1, that on all sides there is a distance to the housing 1 and the adjacent device 3. This creates around each device 3 around a circumferential space 12 for flowing the gas. In this way, each device 3 is surrounded on all sides by the flowing gas. In the in Fig. 9 illustrated embodiment, the distance between two devices 3 corresponds approximately to twice the distance between a device 3 to the adjacent wall 10 of Housing 1. In Fig. 9 The dimensions of each device 3 seen in the flow direction 4 remain constant, so that so that the width of the free space 12 seen in the flow direction 4 is constant.

Like that Fig. 9 and 10 can be seen, in the areas E, which are located in a corner, the distance is slightly larger than in the area between two areas E S. Of course, in the area E, the distance may be identical to the distance in the area S, if, for example, the corners of the housing 1 are rounded.

In Fig. 11 a component according to the invention is shown, which has a round housing 1 and a round device 3. As a result, the clearance 12 has the same width at each location.

Claims (15)

Component for an air-conditioning ventilation system comprising a channel-shaped housing (1), which preferably has a rectangular, square or round cross section, and at least one on a cross-sectional plane in the housing (1) arranged radial fan (2) or more on a cross-sectional plane in the housing ( 1) arranged radial fans (2), characterized in that seen in the flow direction (4) at a distance which is smaller than the diameter of the centrifugal fan (2), preferably smaller than half the diameter of the centrifugal fan (2), particularly preferably smaller than one quarter of the diameter of the centrifugal fan (2), behind at least one radial fan (2) is arranged a device (3) with an orthogonal to the general flow direction (4) aligned fluidically closed end face (13), wherein each device (3) in their cross-sectional plane on all sides of a circumferential space (12) is surrounded to flow of the gas, so that each device (3) can be flowed around on all sides by the flowing gas, wherein the housing cross section corresponding to the number of provided in a region of the housing cross-section means (3) corresponding number of theoretical housing cross-sectional portions I and II or III or IV, wherein each device (3) based on their associated housing cross-sectional portion I or II or III or IV between 50% and 75%, preferably between 55% and 70%, of the theoretically free flow cross-section of the housing cross-sectional portion I or II or III or IV blocked. Component according to the preceding claim, characterized in that at least one device (3) is arranged in the housing (1) such that the device (3) is spaced apart at least in the region S. the adjacent wall (10) of the housing (1), which is in each case between 5% to 15%, preferably between 9% to 13%, of the corresponding internal dimension of the housing (1). Component according to one of the preceding claims, characterized in that at least one device (3) is arranged in the housing (1) in such a way that the device (3) is at least in the region S at a distance from the boundaries G of its housing cross-sectional partial region I or II or III or IV, which is in each case between 5% to 15%, preferably between 9% to 13%, of the corresponding dimension of the housing cross-sectional portion I or II or III or IV. Component according to one of the preceding claims, characterized in that at least one device (3) is designed as a plate. Component according to one of the preceding claims, characterized in that at least one device (3) is designed as a flow body. Component according to one of the preceding claims, characterized in that the dimensions in at least one device (3) in the flow direction (4) remain constant and thus the width of the free space (12) in the flow direction (4) is constant. Component according to one of the preceding claims, characterized in that the dimensions in at least one device (3) at least in a partial region, preferably along the entire length, in the flow direction (4) decrease and thus the width of the free space (12) in the flow direction ( 4) increases. Component according to the preceding claim, characterized in that the dimensions in at least one device (3) at least in a partial region, preferably on the entire length, in the flow direction (4) decrease continuously. Component according to claim 8, characterized in that in at least one device (3) the outer surface (11) of the decreasing in the flow direction (4) reducing area to the flow direction (4) facing center axis M of the device (3) at an angle α between 4 ° and 10 °, preferably of 7.5 °, extending. Component according to one of the preceding claims, characterized in that the outer contour of at least one device (3) is adapted to the inner contour of the housing (1). Component according to one of the preceding claims, characterized in that at least one device (3) is arranged centrally relative to the housing cross-section or to the theoretical housing cross-sectional portion. Component according to one of the preceding claims, characterized in that at least one device (3) in the region of the centrifugal fan (2) facing end face (13) has a recess for receiving a portion of the centrifugal fan (2) and / or at least a portion of the drive motor ( 5) of the centrifugal fan (2). Component according to one of the preceding claims, characterized in that at least one radial fan (2) in the flow direction (4) seen upstream of a diaphragm (8) is arranged, the at least one opening (9) for the passage of the flowing gas to the intake of the centrifugal fan ( 2). Component according to one of the preceding claims, characterized in that in the housing (1) at least two side by side and / or superposed arrangements comprising a radial fan (2) and a device (3) are provided. Component according to one of the preceding claims, characterized in that at least one device (3) at least in the area its outside surface (s) (11), which is in contact with the flowing gas, preferably, the device (3) completely, consists of steel, in particular sheet steel, wood, plastic or the like.

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