Flow grid for a ventilation device and ventilation device

Abstract

The invention relates to a flow grille 100 for fastening to a fan housing of a ventilation device, wherein the flow grille 100 has an outer region 120 and a central region 130, wherein the outer region surrounds the central region, wherein the flow grille in the outer region comprises a plurality of radial guide vanes 160 which run radially towards the central region of the flow grille, and a plurality of centric guide vanes 170 which run at least partially centrically around the central region of the flow grille, wherein the outer region comprises at least a first partial section 140 and a further partial section 150, wherein at least one of the plurality of centric guide vanes is interrupted at least in the first partial section of the outer region and wherein fewer radial guide vanes are arranged in the first partial section of the outer region than in the further partial section.This enables an increase in the efficiency of the ventilation unit while simultaneously reducing the sound power level.

Description

[0001] The present invention relates to the field of ventilation devices and, in particular, to a flow grille for use in a ventilation device.

[0002] Ventilation systems are increasingly being used in private homes. This requires continuous optimization of ventilation systems, particularly by increasing their efficiency and minimizing sound power levels.

[0003] The sound power level, or noise level, of a ventilation unit depends significantly on the airflow through the unit. This begins at the air inlet, where the inlet is usually covered by a flow grille.

[0004] Here it is desired to improve the flow behavior of the air to the impeller (fan) through the geometry of the flow grille in order to increase the efficiency of the fan or ventilation unit while reducing the sound power level.

[0005] An object underlying the present invention is to improve an electrical efficiency of the ventilation device and / or to reduce a sound power level without impairing or even improving the electrical efficiency of the ventilation device.

[0006] It is therefore desired to present a solution that addresses the above problems.

[0007] According to a first aspect of the invention, a flow grille is proposed as defined in claim 1, namely a flow grille for attachment to a fan housing of a ventilation device, wherein the flow grille has an outer region and a central region, wherein the outer region surrounds the central region, wherein the flow grille in the outer region comprises a plurality of radial guide vanes which run radially towards the central region of the flow grille, and a plurality of centric guide vanes which run at least partially centrically around the central region of the flow grille, wherein the outer region comprises at least a first partial section and a further partial section,wherein at least one of the plurality of centric guide vanes is interrupted at least in the first subsection of the outer region, and wherein fewer radial guide vanes are arranged in the first subsection of the outer region than in the further subsection, in particular per unit area.

[0008] The flow grille according to the invention enables an increase in the electrical efficiency of the ventilation unit and a simultaneous reduction in the sound power level of the ventilation unit.

[0009] The flow grille is designed and configured for attachment to a fan housing of a ventilation unit. In particular, the flow grille is designed and configured for attachment to a differential pressure nozzle, which can be considered part of a fan housing.

[0010] The airflow grille has an outer region and a central region, with the outer region surrounding the central region. In particular, the outer region and the central region correspond to regions of the airflow grille, viewed from a front side of the airflow grille when properly attached to the fan housing of the ventilation unit. The central region can be understood as essentially round, with sections of the outer region then being understood as sections of a circular ring.

[0011] The flow grid is at least partially circular, where "partially circular" means that an outer contour of the flow grid can be defined by a circle or a circular arc.

[0012] The flow grid comprises a plurality of radial guide vanes in the outer region, which converge radially toward the central region of the flow grid. In particular, the plurality of radial guide vanes extend from the outer edge of the flow grid to the central region, preferably not extending into the central region. The outer edge of the flow grid is defined by the radial guide vanes. The radial guide vanes preferably converge toward a center point of the central region or of the flow grid.

[0013] The flow grid further comprises a plurality of centric guide vanes that extend at least partially centrically around the central region of the flow grid. "At least partially centrically" here means that the centric guide vanes extend at least partially centrically around the central region of the flow grid.

[0014] The flow grid according to the invention is characterized in particular by the fact that at least one of the plurality of inner centric guide vanes is interrupted at least in a first partial section. "Interrupted" means that the at least one of the plurality of centric guide vanes does not extend centrally around the center point over its entire circumference, but rather partially.

[0015] In other words, the flow grid comprises at least one partial section (at least the first partial section) in which no centric guide vanes are provided.

[0016] The outer region can be divided into various subsections; in particular, the outer region comprises at least a first subsection and a further subsection. The plurality of radial guide vanes and the plurality of centric guide vanes are arranged in the subsections. A subsection of the outer region corresponds to a subsection of a circular ring defined by the outer region.

[0017] Fewer radial guide vanes are arranged in the first subsection of the outer region than in the further subsection. In particular, the space that the first subsection provides for radial guide vanes preferably corresponds to at least 20% and a maximum of 60%, for example 20 to 40% of the outer region. The further subsection comprises in particular a third subsection and a fourth subsection (see below), wherein the space that the first subsection has for radial guide vanes is preferably substantially the same size as the space that the third subsection and the fourth subsection each have for radial guide vanes. It is preferred that no radial guide vanes or one radial guide vane is arranged in the first subsection. It should already be noted here that not every subsection must comprise guide vanes; in particular, the first subsection may also not have any guide vanes (i.e.no radial guide vanes and no centric guide vanes).

[0018] The outer region preferably comprises four subsections, wherein two opposing subsections are more preferably designed identically, ie, comprise an equal number of radial guide vanes and centric guide vanes, which are particularly preferably arranged identically.

[0019] In an advantageous embodiment of one aspect of the invention, the flow grid comprises a circular ring arranged around the central region. The circular ring is thus arranged between the central region and the outer region. The circular ring extends along an air flow direction through the flow grid, i.e., it projects into the flow grid. The circular ring defines a substantially circular opening. Preferably, no central guide vanes or radial guide vanes are arranged in the circular opening.

[0020] In a preferred variant of the above embodiment, the circular ring has at least one further opening, preferably two further openings, along the direction of air flow through the flow grille. In particular, the one further opening or the two further openings are rectangular and / or arranged next to the first subsection and / or the first subsection and a second subsection (see below), i.e., next to a subsection in which at least one of the plurality of central guide vanes is interrupted and in which fewer radial guide vanes are arranged than in the further subsection.

[0021] In a further preferred variant of the above embodiment, the annulus is funnel-shaped along the direction of air flow through the flow grille. The flow grille has an outer opening and an inner opening of the annulus, wherein the outer opening, when used as intended, is arranged outward, i.e., away from the ventilation unit, and the inner opening is arranged inward, i.e., toward the ventilation unit. An inner diameter of an outer opening of the annulus is larger than an inner diameter of the inner opening of the annulus. The annulus preferably has at least three different inner diameters.

[0022] In a further preferred embodiment, at least one of the plurality of centric guide vanes is interrupted in a second subsection of the outer region opposite the first subsection of the outer region. This means that the flow grid preferably has a first subsection of the outer region and a second subsection of the outer region, which are opposite one another and in which at least one of the plurality of centric guide vanes is interrupted. In particular, it is then preferred that fewer radial guide vanes are arranged in the first subsection of the outer region and in the second subsection of the outer region than in the further subsection. The above-mentioned preferred features of the first subsection also preferably apply to the second subsection.

[0023] In particular, it is preferred that the further subsection of the outdoor area comprises a third subsection of the outdoor area, which is arranged between the first subsection of the outdoor area and the second subsection of the outdoor area, and a fourth subsection of the outdoor area opposite the third subsection of the outdoor area, which is arranged between the first subsection of the outdoor area and the second subsection of the outdoor area.

[0024] It is particularly preferred that the plurality of centric guide vanes be arranged in the third subsection and the fourth subsection and be interrupted in the first subsection and the second subsection. Additionally or alternatively, fewer radial guide vanes are arranged in the first subsection and the second subsection of the outer region than in the third subsection and the fourth subsection, respectively.

[0025] In a further embodiment of the invention, at least one of the plurality of radial guide vanes is provided with a pre-swirl. "Provided with a pre-swirl" means that the at least one of the plurality of radial guide vanes generates a pre-swirl, e.g., through a curved surface (curvature), an angle oblique to the direction of air flow through the flow grille (tilt), etc. In particular, it is preferred that all of the plurality of radial guide vanes, particularly preferably all of the plurality of radial guide vanes arranged in the further subsection, are provided with a pre-swirl.

[0026] In a preferred variant of the above embodiment, the pre-swirl is 8° to 10°, with the pre-swirl preferably being provided by a curvature of the radial guide vanes of 8° to 10°. In addition, the pre-swirl is preferably mounted on the radial guide vanes counter to the direction of rotation of a fan of the ventilation unit.

[0027] In a further preferred embodiment of the invention, the flow grid is designed as a flow straightener.

[0028] In another advantageous embodiment of an aspect of the invention, the flow grille has a fastening means for attachment to the ventilation unit. The fastening means is preferably arranged on an outer edge of the flow grille. Furthermore, the fastening means preferably comprises openings, particularly preferably four openings, for fastening, in particular screwing, the flow grille to the fan housing or the differential pressure nozzle of the ventilation unit.

[0029] According to a further aspect of the invention, a ventilation device is proposed as defined in claim 10, namely a ventilation device with a differential pressure nozzle, wherein the ventilation device comprises a flow grille according to one of the above or below embodiments. The flow grille is arranged on a suction side of the ventilation device, in particular fastened, e.g., via the fastening means as described above. Particularly preferably, the flow grille is arranged on the differential pressure nozzle, in particular fastened, e.g., screwed.

[0030] Features of advantageous embodiments of the invention are defined in particular in the subclaims, wherein further advantageous features, embodiments and configurations can also be gathered by the person skilled in the art from the above explanations and the following discussion.

[0031] In the following, the present invention is further illustrated and explained with reference to exemplary embodiments shown in the figures. Fig. 1 is a schematic representation to illustrate a first embodiment of the ventilation device according to the invention from the front, Fig. 2 is a schematic representation to illustrate the first embodiment of the ventilation device according to the invention from an angle from the front, Fig. 3a is a schematic representation to illustrate a first embodiment of the flow grille according to the invention from the front, Fig. 3b is a schematic representation to illustrate the first embodiment of the flow grille according to the invention from the rear, Fig. 4a is a perspective representation to illustrate the first embodiment of the flow grille according to the invention from an angle from the front, Fig. 4b is a perspective representation to illustrate the first embodiment of the flow grille according to the invention from an angle from the rear, and Fig. 5 is a schematic representation to illustrate the first embodiment of the flow grille according to the invention in cross section.

[0032] In the accompanying drawings and the explanations to these drawings, corresponding or related elements are - where appropriate - identified by corresponding or similar reference numerals, even if they are found in different embodiments.

[0033] Fig. 1 shows a schematic representation to illustrate a first embodiment of the ventilation device according to the invention from the front and Fig. 2 shows a schematic representation to illustrate the first embodiment of the ventilation device according to the invention from an angle from the front.

[0034] The ventilation device 200 comprises a fan housing 210 and a flow grille 100. The ventilation device 200 also comprises a fan (not shown) which is arranged in Fig. 1 and Fig. 2 is arranged behind the flow grille 100. The ventilation unit 200 further comprises a differential pressure nozzle 220, which can be counted as part of the fan housing 210. A measuring tube 230 is arranged on the differential pressure nozzle 220.

[0035] The flow grille 100 is provided and configured for attachment to the fan housing 210. The flow grille 100 preferably comprises four openings (not shown) through which the flow grille 100 can be attached, in particular screwed, to the differential pressure nozzle 220.

[0036] The flow grid 100 is described in further detail using the following figures.

[0037] Fig. 3a shows a schematic representation to illustrate a first embodiment of the flow grid according to the invention from the front and Fig. 3b a schematic representation to illustrate the first embodiment of the flow grid according to the invention from behind.

[0038] The flow grid 100 has an outer region 120 and a central region 130, wherein the outer region 120 at least partially surrounds the central region 130.

[0039] The flow grid 100 comprises, in the outer region 120, a plurality of radial guide vanes 160 that extend radially toward the central region 130 of the flow grid 100. Furthermore, the flow grid 100 comprises a plurality of centric guide vanes 170 that extend at least partially centrically around the central region 130 of the flow grid 100.

[0040] In connection with Fig. 3a The subsections are now described, whereby in connection with Fig. 3b the circular ring is described.

[0041] The outer region 120 comprises at least a first section 140 (corresponding to the left or right section in Fig. 3a ) and another section 150 (corresponds to the upper and lower sections in Fig. 3a und 3b ).

[0042] At least one of the plurality of centric guide vanes 170 is interrupted in the first subsection 140 of the outer region 120. Furthermore, fewer (here, none) radial guide vanes 160 are arranged in the first subsection 140 of the outer region 120 than in the further subsection 150.

[0043] In the embodiment shown, at least one of the plurality of centric guide vanes 170, here two, is also interrupted in a second subsection 141 of the outer region 120 opposite the first subsection 140 of the outer region 120. Furthermore, the further subsection 150 of the outer region 120 comprises a third subsection 151 (bottom in Fig. 3a ), which is arranged between the first sub-section 140 and the second sub-section 141 and a fourth sub-section 152 of the external area 120 opposite the third sub-section 151 of the external area 120 (in Fig. 3a above), which is also arranged between the first subsection 140 and the second subsection 141.

[0044] The flow grid 100 can be divided into twelve subsections like a clock; in particular, the outer region 120 can be divided into twelve subsections. The 12 o'clock position corresponds to one-twelfth of the flow grid 100 or the outer region 120 that is directed upwards; the 3 o'clock position corresponds to one-twelfth of the flow grid 100 or the outer region 120 that is directed to the right, etc.

[0045] According to this definition, the first section corresponds to the 3 o'clock position and one half of the 2 o'clock position and the 4 o'clock position. The second section then corresponds to the 9 o'clock position and one half each of the 8 o'clock position and the 10 o'clock position. The third section corresponds to the 5 o'clock position, the 6 o'clock position, the 7 o'clock position and the other half each of the 5 o'clock position and the 8 o'clock position. The fourth section then corresponds to the 11 o'clock position, the 12 o'clock position, the 1 o'clock position and the other half each of the 10 o'clock position and the 2 o'clock position. The first section can also be swapped with the second section, and the third section with the fourth section.

[0046] Preferably, at least one, particularly preferably all, of the plurality of radial guide vanes 160 are provided with a pre-swirl. In particular, the pre-swirl is implemented by a curvature, particularly preferably an 8° to 10° curvature, of the radial guide vanes. Additionally or alternatively, the pre-swirl is preferably applied to the radial guide vanes 160 counter to a direction of rotation of a fan of the ventilation device 200.

[0047] The flow grid 100 comprises a circular ring 180 which is arranged around the central region 130 and extends along a flow direction of air through the flow grid 100 over a depth of the flow grid 100 (in Fig. 3b into the flow grid towards the viewer). The circular ring 180 defines a substantially circular opening, wherein in particular no radial guide vanes or centric guide vanes are arranged in the circular opening.

[0048] The circular ring 180 has at least one further opening, preferably two further openings 181, along the flow direction of air through the flow grid 100.

[0049] In particular, the circular ring 180 is funnel-shaped along the flow direction of air through the flow grid 100 and preferably has at least three different inner diameters.

[0050] The flow grid 100 is designed as a flow straightener.

[0051] Fig. 4a shows a perspective view to illustrate the first embodiment of the flow grid according to the invention from an angle from the front and Fig. 4b shows a further perspective view to illustrate the first embodiment of the flow grid according to the invention from an angle from behind.

[0052] Here, the arrangement and shape of the radial guide vanes 160 and the centric guide vanes 170 are particularly evident. It is also clear that the outer contour of the flow cascade is defined by the radial guide vanes. Therefore, the radial guide vanes can also be considered tangential guide vanes.

[0053] In the present case, the radial guide vanes 160 and the centric guide vanes 170 define an outer contour of the outer region 120 of the flow grid 100. In particular, the outer contour in the outer region 120 of the flow grid 100 is convex.

[0054] Fig. 5 shows a schematic representation to illustrate the first embodiment of the flow grid according to the invention in cross section.

[0055] Here, too, the outer contour of the flow grid 100 can be seen. Furthermore, the guide vanes, i.e., the plurality of radial guide vanes 160 and the plurality of central guide vanes 170, arranged in the outer region 120 of the flow grid 100, can be seen. Furthermore, the circular ring 180 can be seen in cross-section in the central region 130. The depth of the circular ring 180 corresponds to the depth of the entire flow grid 100.

[0056] Even though various aspects or features of the invention are shown in combination in the figures, it will be apparent to a person skilled in the art - unless otherwise stated - that the combinations shown and discussed are not the only possible ones.

[0057] Further considerations regarding the invention follow.

[0058] A flow grid for a ventilation unit is proposed, which is preferably made of plastic and more preferably manufactured by injection molding. The ventilation unit preferably comprises a fan arranged in a spiral casing and a differential pressure nozzle. The flow grid is preferably mounted on the suction side of the fan. In a preferred embodiment, the flow grid is screwed to the front part of the spiral casing at designated fastening points located on the differential pressure nozzle of the ventilation unit.

[0059] The flow grille is preferably a flow straightener, which has the task of breaking the vortices of the air being sucked in in the nozzle area and of distributing the air entering the ventilation unit or fan evenly over the blades of the fan.

[0060] The use of the airflow grille significantly improves the airflow pattern toward the fan. This increases the fan's electrical efficiency at the same flow rate, thus reducing power consumption. At the same time, the improved airflow into the fan, which is due to the airflow grille, also reduces the sound power level. In our case, at the ventilation unit's maximum airflow, the sound power level was reduced by approximately 6 dB compared to measurements without the airflow grille.

[0061] Simulations have shown that optimizations can be made to better direct the air flow onto the impeller blades.

[0062] The simulation has shown that vortices occur primarily at the 12 o'clock and 6 o'clock positions, and only in the area close to the front surface of the differential pressure nozzle. Therefore, measures to break the vortices should preferably be taken only at these locations.

[0063] Therefore, a preferred embodiment of the flow grid has radial and tangential guide vanes in a third subsection comprising the 5 o'clock position, the 6 o'clock position and the 7 o'clock position, and a fourth subsection comprising the 11 o'clock position, the 12 o'clock position and the 1 o'clock position.

[0064] In a first subsection and a second subsection, preferably no radial or centric guide vanes are provided.

[0065] An outer edge of each of the tangential guide vanes, i.e., an outer region that defines the outer contour of the flow grid, is preferably radial or curved. Furthermore, at least two central guide vanes are preferably embedded between the tangential guide vanes in the third subsection and the fourth subsection.

[0066] The tangential guide vanes in the third and fourth sections can be designed with or without pre-swirl. Pre-swirl, especially pre-swirl against the direction of rotation of the impeller, offers the advantage of improving the flow to the impeller. If pre-swirl is provided, it is designed with a curvature of between 8 and 10°.

[0067] Furthermore, the central region of the flow grid is preferably open, i.e., no guide vanes are provided in the central region. A circular ring is preferably arranged around the central region. The circular ring, viewed across the depth of the flow grid (i.e., in the direction of the air flowing through the flow grid), is composed of at least three radii, which particularly preferably merge tangentially into one another.

[0068] The circular ring preferably has two openings across its depth, in particular from the 1 o'clock position to the 5 o'clock position and from the 7 o'clock position to the 11 o'clock position. In this area, there are preferably no tangential guide vanes or centric guide vanes.

[0069] For strength reasons, a preferred embodiment provides a tangential guide vane at the 3 o'clock position and a tangential guide vane at the 9 o'clock position. To stiffen these two tangential guide vanes, an additional circumferential central guide vane is provided.

[0070] Preferably, the flow grille has a fastening concept such that it fits into the provided recess of the differential pressure nozzle via a type of sleeve. In one example, the flow grille is screwed to a front part of the spiral casing using four screws.

[0071] By preferentially eliminating the tangential and centric guide vanes between the 1 o'clock position and the 5 o'clock position and the 7 o'clock position and the 11 o'clock position, the pressure drop caused by the flow grille can be reduced. This measure leads, among other things, to improved flow distribution on the impeller / fan, which increases electrical efficiency and thus reduces power consumption under the same initial conditions.

[0072] The cascade, as shown in the figures, is optimized so that tangential and centric guide vanes are present only where they are needed. This saves material and also improves efficiency.

[0073] The following advantages can be achieved by implementing one or more of the above features: Elimination of the centric and tangential guide vanes between the 1 o'clock to 5 o'clock position and between the 7 o'clock to 11 o'clock position (partially or completely) leads to better flow distribution and less pressure loss, open annulus with openings in the depth of the annulus (funnel) promotes and optimizes the flow behavior to the impeller, pre-swirl on the tangential guide vanes (in certain areas) to optimize the flow to the impeller, saving of material.

[0074] The invention relates to a flow grille for fastening to a fan housing of a ventilation device, wherein the flow grille has an outer region and a central region, wherein the outer region surrounds the central region, wherein the flow grille in the outer region comprises a plurality of radial guide vanes which run radially towards the central region of the flow grille, and a plurality of centric guide vanes which run at least partially centrically around the central region of the flow grille, wherein the outer region comprises at least a first partial section and a further partial section, wherein at least one of the plurality of centric guide vanes is interrupted at least in the first partial section of the outer region and wherein fewer radial guide vanes are arranged in the first partial section of the outer region than in the further partial section.This enables an increase in the efficiency of the ventilation unit while simultaneously reducing the sound power level.

Claims

1. A flow grille (100) for attachment to a fan housing (210) of a ventilation device (200), wherein the flow grille (100) has an outer region (120) and a central region (130), wherein the outer region (120) at least partially surrounds the central region (130), wherein the flow grille (100) comprises, in the outer region (120), a plurality of radial guide vanes (160) which run radially towards the central region (130) of the flow grille (100), and a plurality of centric guide vanes (170) which run at least partially centrically around the central region (130) of the flow grille (100), wherein the outer region (120) comprises at least a first partial section (140) and a further partial section (150),wherein at least one of the plurality of centric guide vanes (170) is interrupted at least in the first partial section (140) of the outer region (120), and wherein fewer radial guide vanes (160) are arranged in the first partial section (140) of the outer region (120) than in the further partial section (150).

2. Flow grid (100) according to claim 1, wherein the flow grid (100) comprises a circular ring (180) arranged around the central region (130) and extending along a flow direction of air through the flow grid (100), wherein a substantially round opening is defined by the circular ring (180).

3. Flow grid (100) according to claim 2, wherein the circular ring (180) has at least one further opening, preferably two further openings (181), along the flow direction of air through the flow grid (100).

4. Flow grid (100) according to one of claims 2 and 3, wherein the circular ring (180) is funnel-shaped along the flow direction of air through the flow grid (100) and preferably has at least three different inner diameters.

5. Flow grid (100) according to one of the preceding claims, wherein the at least one of the plurality of centric guide vanes (170) is interrupted in a second partial section (141) of the outer region (120) opposite the first partial section (140) of the outer region (120), wherein the further partial section (150) of the outer region (120) preferably comprises a third partial section (151) of the outer region (120) which is arranged between the first partial section (140) of the outer region (120) and the second partial section (141) of the outer region (120), and a fourth partial section (152) of the outer region (120) opposite the third partial section (151) of the outer region (120) which is arranged between the first partial section (140) and the second partial section (141).

6. Flow grid (100) according to one of the preceding claims, wherein at least one, preferably all, of the plurality of radial guide vanes (160) is provided with a pre-swirl.

7. Flow grille (100) according to claim 6, wherein the pre-swirl is provided by a curvature of 8° to 10° and is preferably provided against a direction of rotation of a fan of the ventilation device (200).

8. Flow grid (100) according to one of the preceding claims, wherein the flow grid (100) is designed as a flow straightener.

9. Flow grille (100) according to one of the preceding claims, wherein the flow grille (100) has a fastening means for fastening to the ventilation device (200), wherein the fastening means preferably comprises openings, particularly preferably four openings.

10. Ventilation device (200) with a differential pressure nozzle (220), wherein the ventilation device (200) comprises a flow grille (100) according to one of claims 1 to 9, wherein the flow grille (100) is arranged, in particular fastened, on a suction side of the ventilation device (200), wherein the flow grille (100) is preferably arranged, in particular fastened, on the differential pressure nozzle (220).

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