EP2333348B1 - Radial ventilator housing - Google Patents

Description

The invention relates to a radial fan housing device having at least one radial fan receiving space and at least one Luftabführöffnung, wherein the at least one radial fan receiving space with the at least one Luftabführöffnung forms a housing tongue. The invention further relates to a radial fan with at least one radial fan. Moreover, the invention relates to a vehicle air conditioning system, in particular an automotive air conditioning system.

In many fields of technology, it is necessary to generate a gas flow - usually an air flow - targeted. Fans or blowers are used for this purpose. These convert mechanical energy, which is supplied for example by an electric motor, into a gas flow (usually an air flow).

Basically, different types of blowers or fans are known, which are also used in practice. Typical designs are, for example, axial fans or radial fans.

A technical field in which blowers or fans are used is the ventilation or air conditioning of substantially closed rooms, such as, for example, of building interiors or vehicle interiors. A particularly frequent field of use are interior spaces of motor vehicles.

Ventilation or air-conditioning of closed interiors generally requires a high level of comfort. With these comfort requirements, the lowest possible operating noise of the system is desired. For this reason, in the air conditioning of closed interiors mostly radial fans are used, since they have compared to axial fans usually a lower operating noise (even if axial fans, for example, in terms of size and / or the air flow rate radial fans are often superior).

Although radial fans have been successively improved over the years, they still produce a noticeable operating noise, especially at higher airflow rates. Especially low frequencies are particularly problematic because they are perceived by the vehicle occupants as particularly disturbing. The problem is the resulting operating noise especially in a recirculation mode in automotive air conditioning systems, since then the suction of the fan draws the air to a large extent directly from the vehicle interior and thereby operating noise of the vehicle air conditioning system can be radiated directly into the passenger compartment.

In order to reduce the resulting operating noise in centrifugal fans different measures have already been proposed. So was in DE 197 10 622 A1 For example, a radial fan with integrated control unit is proposed, in which the housing is in the form of a spiral housing containing a controlled by a control unit electric motor which drives a radial fan, which is intended to inject air into the volute, which in a predetermined range at least includes a baffle having a curvature. In this case, the control unit is arranged such that it is at least partially integrated in the deflection wall. In EP 0 501 198 A1 a radial fan is proposed, which has a spiral housing, which at least in the area the spiral inlet is formed metallic and in this region has on its inside parallel to the air flow extending cooling fins. The control or regulating electronics receiving housing is in thermal connection with the part containing the cooling fins of the spiral housing.

Other proposals for reducing the noise generated by radial fan housings operating noise consist in a special design of the tongue area. Such radial fan housing, for example, in US Pat. No. 6,821,088 A1 or DE 100 17 808 B4 described. The problem with such embodiments that the used there, specially trained housing tongues usually represent a displacement body in the spiral for the flow, so that in particular at high air flow rates results in a relatively poor efficiency.

The US 3,794,439 A discloses a radial fan housing device having a louver and a fan blade. The louver is arranged opposite the fan tongue.

There is therefore still a need for noise-reduced radial fans, which in particular have the lowest possible proportion of low-frequency operating noise.

The object of the invention is therefore to propose an improved radial fan housing device in comparison with radial ventilator housing devices known in the prior art.

The object is achieved with the features of claim 1.

For this purpose, it is proposed a radial fan housing device, the at least one radial fan receiving space and at least one Luftabführöffnung wherein the at least one radial fan receiving space with the at least one air discharge opening forms a housing tongue such that at least one air guiding device is arranged in the radial fan receiving space. The inventors have discovered to their own surprise that such an arrangement of louvers in the actual radial fan receiving space can cause a significant noise reduction, with a noise reduction can occur especially in the low frequency range. In particular, usually with relatively small louvers large noise reduction effects can be achieved. Just small louvers, however, can not only be made and / or assembled particularly simply and / or cost-effectively, but moreover, as a rule, only a relatively small air resistance for the conveyed air, which can have an advantageous effect on the efficiency of the complete radial fan , The guide elements are usually arranged in a region of the radial fan housing device, which is arranged between the actual, usually spirally formed housing wall of the radial fan receiving space and the area in which the radial fan is in the assembled state of the radial fan housing device.

According to the invention, when at least one air guiding device is arranged directly downstream of the housing tongue when viewed in the air flow direction. Initial tests have shown that especially in this area a particularly large noise reduction can be achieved. In addition, especially in this area, the air guide elements can also be made particularly small, which among other things can also have particularly great advantages in terms of the efficiency of the finished radial fan.

Although the louvers along the height extent of the radial fan housing device basically arranged at any location can be (as for example at mid-height of the radial fan housing device), so have first tests revealed that usually result in particularly large noise reductions, if at least one louver on the motor side and / or frame side is arranged. In other words, it is advantageous if at least one air guiding device is arranged in the region of the bottom or the cover of the radial fan housing device.

Moreover, it is particularly advantageous if the radial fan housing device has a plurality of louvers, in particular two, three, four, five, six, seven, eight, nine or ten louvers. With such a number, a particularly good compromise between noise reduction, simple and inexpensive construction and the highest possible efficiency of the finished radial fan can be found in the rule. Moreover, it is particularly advantageous if an even number of air guiding devices is provided, which are particularly preferably arranged in pairs in the cover region or in the bottom region of the radial fan housing device.

Furthermore, it has proved to be particularly advantageous if in the radial fan housing device, the height of at least one louver only a part of the height of the radial fan receiving space and / or the Luftabführöffnung makes, and in particular only a small part of the height of the radial fan receiving space and / or the Luftabführöffnung makes. Also by such a design of the radial fan housing device can be a particularly good compromise between the greatest possible noise reduction, relatively simple and inexpensive construction and maximum efficiency can be found. The height of a spoiler can for example be between 0%, 1%, 2%, 3%, 4%, 5%, 7.5% or 10% and 2.5%, 5%, 7.5%, 10%, 15%, 20%, 25%, 30%, 40% and 50% respectively the height of the radial fan receiving space and / or the Luftabführöffnung amount.

According to the invention, it is advantageous if, in the case of the radial fan housing device, at least one air guiding device has a curvature at least in some areas, which curvature is bent inwards as seen in the air flow direction. Again, initial tests have shown that can result from such a configuration, a particularly good filling of the gap between the radial fan and housing wall of the radial fan receiving space. This in turn can result, for example, in a particularly high efficiency and a particularly large noise reduction.

In addition, it may be advantageous if, in the radial fan housing device, at least one air guiding device has a rectangular, triangular, quadrangular, trapezoidal, curved and / or wave-like shape as seen in the direction of air flow. Here, too, initial tests have shown that on the one hand such shapes can usually be achieved mechanically relatively easily and, on the other hand, a particularly high noise reduction can result.

A further preferred embodiment of the radial fan housing device can then result if at least one air guiding device is shaped thin-walled at least in regions and / or has a plastic material at least in regions. Such a design may prove to be simple to manufacture (for example, the air On the other hand can be achieved with the proposed training usually a particularly low air resistance and thus a high efficiency of the resulting radial fan on the other hand can be made integral with the radial fan housing device or parts thereof, by a plastic injection molding.

Furthermore, a radial fan is proposed which has at least one radial fan, and which has at least one radial fan housing device with the structure described above. A radial fan designed in this way has the properties and advantages already described in an analogous manner.

Furthermore, it is proposed to design a vehicle air conditioning system, in particular an automotive air conditioning system, such that it has at least one radial fan with the structure described above and / or at least one radial fan housing device with the previously described construction. The resulting vehicle air conditioning system can then likewise have the properties and advantages already described in an analogous manner. The vehicle (or motor vehicle) in which the vehicle air conditioning system (motor vehicle air conditioning system) is installed can in particular be a watercraft, a land vehicle (rail-bound / non-rail-bound), an aircraft or a spacecraft.

Fig. 1:

eine schematische Darstellung einer Radiallüfteranordnung in Draufsicht von oben;

Fig. 2:

einen schemafischen Querschnitt durch einen Teilbereich der in Fig. 1 dargestellten Radiallüfteranordnung;

Fig. 3:

das in Fig. 1 dargestellte Rsdiallüftergehäüse in perspektivischer Ansicht;

Fig. 4:

das Akustikspektrum unterschiedlicher Radiallüfteranordnungen.

In the following the invention will be explained in more detail by means of advantageous embodiments and with reference to the accompanying drawings. Show it:

Fig. 1:

a schematic representation of a radial fan assembly in plan view from above;

Fig. 2:

a schematic cross-section through a portion of the in Fig. 1 illustrated radial fan assembly;

3:

this in Fig. 1 shown Rsdiallüftergehäüse in perspective view;

4:

the acoustic spectrum of different radial fan arrangements.

In Fig. 1 is a possible embodiment of a radial fan 1 shown in a schematic plan view from above. The radial fan 1 essentially consists of a housing 2, in the interior of which a housing wall 3 bounded by a receiving space 4, a fan 5 is arranged. Between the fan 5 and the housing wall 3, a gap, the so-called air gap 14, can be seen, which increases seen in the air flow direction L spiral. The fan 5 consists of an annularly arranged plurality of Lüfterradlamellen (not shown in the figures.). On one side of the fan 5, this has a plate-like hub 6, in the middle of the drive shaft 7 of the fan 5 is provided. The drive shaft 7 is - as is common practice - also connected in the present embodiment shown with an electric motor, which can put the fan 5 in the direction of arrow A in rotation. On the side of the engine 8 (on which the motor is located together with the drive shaft 7) opposite frame side 9 is the frame 10, through which the air K flows into the radial fan 1 into it.

The air flow L conveyed by the fan wheel 5 leaves the housing 2 via an air discharge opening 11, which opens into an air discharge duct 12. On one side of the Luftabführkanals 12, the local wall of the Luftabführkanals 12 forms together with the housing wall 3 of the receiving space 4, the so-called tongue (fan tongue) 13.

How one Fig. 1 can be seen, seen in the air flow direction L downstream (corresponds to the direction of rotation A of the fan 5) in the presently illustrated embodiment, a total of four vanes 17 are shown. Since the guide elements 17 are arranged in pairs, namely on the cover 15 and on the bottom 16 of the housing 2 (see Fig. 2 ; at the in Fig. 1 View shown only the bottom 16 arranged vanes 17 can be seen), in the illustrated embodiment of the radial fan 1 a total of eight vanes 17 are provided. The guide elements 17 each have a view in Luftströmungsnchtung inside, the fan 5 pointing towards curvature. (Of course, it is also possible that the guide elements 17 are only partially curved, are curved in a different direction, are not curved at all, and / or in each case only partially curved.) Preferably, the arrangement of the guide elements 17 extends to an angular range ( starting from the top of the tongue 13) which is between 0 °, 5 °, 10 °, 15 ° or 20 ° and 10 °, 20 °, 30 °, 40 °, 50 ° or 60 °.

The shaping of the guide elements 17 along the vertical extent of the radial fan 1 is in particular in Fig. 2 clearly visible. Fig. 2 shows a partial cross section through a region which is in Fig. 1 designated AA. In Fig. 2 is particularly easy to see how both a pair of guide elements 17 is arranged both at the bottom 16, and on the cover 15 of the housing 2. The guide elements 17 in this case have a triangular height profile. Their height thus increases steadily and linearly, starting from the housing wall 3 in the direction of the fan wheel 5. The height of the guide elements 17 is relatively small and varies in the illustrated embodiment between 3% in the region of the housing wall 3 and 10% in the area of the fan 5. Although the guide elements 17 are formed on the cover 15 and the bottom 16 in the present embodiment, completely symmetrical to each other, it is also possible that they are asymmetrical, and in particular have a different height of the lid 15 and the bottom 16.

In first experiments, it has been found that the guiding elements 17 lead to the formation of secondary vortices 18, which in Fig. 2 by dashed Lines are indicated. How one Fig. 2 can be seen, the secondary vortex 18 generated by the guide elements 17 are opposite to each other in terms of their direction of rotation.

The location, arrangement and orientation, especially the guide elements 17, is additionally in Fig. 3 which shows a perspective view of essential parts of the radial fan 1. For reasons of clarity, only the bottom 16 arranged guide elements 17 are shown. In addition, only the hub 6 can be seen from the fan 5, otherwise the air conveyor blades of the fan 5, the guide elements 17 would cover. As can be seen, the guide elements 17 each extend essentially completely between the housing wall 3 and the fan wheel 5 (also in FIG Fig. 1 and Fig. 2 to recognize). As the air gap 14 becomes larger in a spiral, this means that the guide elements 17 become successively longer (the angle of attack relative to the air flow L always remains constant). In the illustrated embodiment, however, the height of the guide elements 17 both in the region of the housing wall 3, as well as in the region of the fan 5 each have the same height. The guide elements 17 therefore have a different pitch. Of course, it is also possible that the guide elements 17 have a different length and / or a different angle of attack relative to the air flow L.

In Fig. 4 the effect of the guide elements 17 for the noise emission behavior of the radial fan 1 is shown. In the two counts of Fig. 4 is in each case along the abscissa 19, the frequency plotted on a logarithmic scale, while along the ordinate 20 in each case the frequency-dependent summation pressure level in dB (A) are plotted. Fig. 4a shows the measured on the pressure side of the radial fan 1 (ie in the region of Luftabführkanals 12) noise spectrum while Fig. 4b on the suction side (ie in the region of the frame 10 measured) noise emission spectrum of the radial fan 1 shows. The curves 21 and 22 show the noise emission behavior in the Fig. 1 to 3 shown centrifugal fan 1 with guide elements 17, whereas the graphs 23 and 24 shows the noise emission behavior of a radial fan without air guide elements. The curves 21 and 23 show the frequency spectrum, whereas the curves 22 and 24 respectively represent the acoustic spectrum of the thirds. As can be seen, the guide elements 17 cause noise reduction in the range of 3 to 5 dB (A) per third and more, in particular in the low-frequency range.

LIST OF REFERENCE NUMBERS

1.

radial fans

Second

casing

Third

housing wall

4th

accommodation space

5th

fan

6th

hub

7th

drive axle

8th.

engine

9th

frame side

10th

frame

11th

Air discharge opening

12th

air discharge

13th

tongue

14th

air gap

15th

cover

16th

ground

17th

baffles

18th

secondary vortex

19th

abscissa

20th

ordinate

21st

Frequency spectrum (new fan)

22nd

Third (new fan)

23rd

Frequency spectrum (old fan)

24th

Third (old fan)

A

Direction of rotation fan wheel

K

Air flow (suction side)

L

Air flow (on the pressure side)

Claims (7)

1. A radial fan housing device (2), having at least one radial fan receiving space (4) and at least one air discharge opening (11), wherein the at least one radial fan receiving space (4) forms a housing tongue (13) together with the at least one air discharge opening (11), wherein at least one air duct arrangement (17) is arranged in the radial fan receiving space (4), characterised in that the at least one air duct arrangement (17), as seen in the air flow direction (L), is arranged directly behind the housing tongue (13) and the at least one air duct arrangement (17) has, at least in regions, a curvature which, as seen in the air flow direction (L), is curved inwards.
2. The radial fan housing device (2) according to claim 1, characterised in that at least one air duct arrangement (17) is arranged on the side of the engine (8) and/or on the side of the frame (9).
3. The radial fan housing device (2) according to one of the preceding claims, characterised by a plurality of air duct arrangements (17), in particular by two, three, four, five, six, seven, eight, nine or ten air duct arrangements (17).
4. The radial fan housing device (2) according to one of the preceding claims, characterised in that the height of at least one air duct arrangement (17) only accounts for a part of the height of the radial fan receiving space (4) and/or the air discharge opening (11).
5. The radial fan housing device (2) according to one of the preceding claims, characterised in that at least one air duct arrangement (17) has a plastic material at least in regions.
6. A radial fan (1), having at least one radial fan impeller (5), characterised by at least one radial fan housing device (2) according to one of claims 1 to 5.
7. A vehicle air-conditioning system, in particular a motor vehicle air-conditioning system, having at least one radial fan (1) according to claim 6 and/or at least one radial fan housing device (2) according to one of claims 1 to 5.

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