Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
  • F04D17/16—Centrifugal pumps for displacing without appreciable compression
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/06—Helico-centrifugal pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D25/00—Pumping installations or systems
  • F04D25/02—Units comprising pumps and their driving means
  • F04D25/08—Units comprising pumps and their driving means the working fluid being air, e.g. for ventilation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
  • F04D29/281—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for fans or blowers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
  • F04D29/288—Part of the wheel having an ejecting effect, e.g. being bladeless diffuser
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/40—Casings; Connections of working fluid
  • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
  • F04D29/4206—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
  • F04D29/4226—Fan casings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/40—Casings; Connections of working fluid
  • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
  • F04D29/44—Fluid-guiding means, e.g. diffusers
  • F04D29/441—Fluid-guiding means, e.g. diffusers especially adapted for elastic fluid pumps

Definitions

• the invention relates to a fan, in particular a radial or diagonal fan.
• the fan includes a motor, an impeller driven to rotate by the motor, an inlet nozzle, and a nozzle plate extending around the inlet nozzle.
• the impeller essentially consists of a base disk, a cover disk and several blades extending in between.
• fans of the type in question should have high - identical - efficiencies both when installed and on the test bench. This requirement seems trivial. However, it had to be determined that impellers optimized for a specific installation situation and thus corresponding fans can have a rather disadvantageous behavior on the test bench.
• impellers of radial and diagonal design have been developed, which have very high efficiencies under test bench conditions, but do not have these efficiencies in concrete installation situations.
• impellers of radial and diagonal design which have very high efficiencies under installation conditions on the pressure side, but come up with lower efficiencies under test bench conditions. This situation is problematic, especially since the test bench and thus the test bench conditions are intended to provide information about the performance of the fan in the specific application.
• the invention is therefore based on the object of designing and developing the generic fan in such a way that it has the highest possible efficiency both in the pressure-side installation situation and under test bench conditions Has. At the very least, any differences between the two situations should be as small as possible.
• the nozzle plate has an edge that is folded over towards the pressure side, while the outer edge of the cover plate is rounded towards the suction side.
• the edge of the nozzle plate and the rounding of the shroud are shaped and dimensioned in such a way that the outflow from the impeller close to the shroud interacts with the edge of the nozzle plate.
• a special nozzle plate with a special cover plate, the nozzle plate having a folded or beveled edge on the pressure side and the cover plate being rounded off on the suction side, namely having a curvature.
• the tangential extension of the inner cover disk contour facing the blades at its radially outer edge is the nozzle plate, including its edge seen, intersects over at least 90%, preferably over 100% of the circumferential positions.
• the rounding of the cover disk is advantageously a strong curvature on the outer edge of the cover disk, which can be seen in combination with the beveled edge of the nozzle plate.
• the inner (blade-side) contour of the rounding and thus the outer edge of the cover disk at the outer end of the cover disk in the area of the impeller outlet gives the air flow an exit direction that can be defined by a straight, tangential extension of the cover disk.
• the overcurvature gives the air a particular exit direction, and the structural design of the overcurvature can be designed in such a way that the air exit direction is constant or variable over the circumference of the cover disk. Any or different influences over the circumference of the cover plate can be implemented.
• the air exit direction can be backwards with respect to the main flow direction, towards the nozzle plate.
• such a configuration is not mandatory.
• the air outlet direction at the outer end of the cover disk i.e. at its overcurved area, has an angle of more than 35°, preferably more than 45°, to the radial direction.
• the imaginary extension of the cover plate intersects with the nozzle plate or its edge, preferably over the entire circumference or at least over a large area of the circumference of more than 95%. This ensures that the air flowing out of the impeller interacts with the nozzle plate or the outer edge.
• the ratio of the air outlet diameter DD of the inlet nozzle to the air outlet diameter DL of the impeller at the outer edge of the cover plate is greater than/equal to 70%, preferably greater than/equal to 75%.
• the ratio of the axial overall height c of the inlet nozzle to the air outlet diameter DL of the impeller is less than or equal to 12% at the outer edge of the shroud.
• the nozzle plate of the fan according to the invention can have any shape, for example it can have a rectangular, preferably square, outer contour.
• the cover disk can advantageously have a larger outer diameter than the base disk in order to promote the flow conditions in this respect as well.
• such an embodiment is particularly suitable for an installation condition in which the flow continues to flow more axially downstream of the fan, ie in an installation situation that limits radially on the pressure side.
• the ratio of the outside diameter of the base disk to the outside diameter of the cover disk should advantageously be between 85% and 95%.
• FIG. 1 a perspective view from the outflow side of a fan with an impeller with a heavily curved cover disk, a motor, a suspension and a nozzle plate with a nozzle,
• Fig. 2 in a section on a plane through the axis of the fan
• FIG. 3 shows an enlarged representation of a partial area from FIG. 2, with dimensions also shown schematically,
• FIG. 5 shows the fan according to FIGS. 1, 2, 4 and 5 in a view from the outflow side
• FIG. 6 shows a perspective view of a schematic representation of a partial area on the outflow side of a flow pattern, calculated by simulation, of a fan according to the invention at a first operating point
• FIG. 7 is a perspective view of a schematic representation of an outflow-side partial area of a flow pattern, in a Similar representation as in Fig. 6, a fan according to the invention in a second operating point.
• Fig. 1 shows a perspective view of a fan 1 seen from the outflow side, with a radially outer overcurved area 7 of the cover plate 8.
• the fan 1 is a backward-curved centrifugal fan with an impeller 3, consisting of a cover plate 8, a bottom disk 10 and blades 9 extending in between.
• the impeller 3 is driven by a motor 4, here an external rotor motor with an electronics pot 21 integrated in the stator 12, with the rotor 11 (not visible here) of the impeller 3 being non-rotatably connected.
• an inflow nozzle 5 is attached with fastening provisions 14 to a nozzle plate 2 , which is connected to the motor 4 on the stator side via a suspension 13 consisting essentially of support struts 19 and a motor support plate 20 .
• the cover disk 8 of the impeller 3 has an inner opening into which the inflow nozzle 5 protrudes.
• the nozzle plate 2 has an approximately rectangular, here square, outer contour, and a folded edge 6 is formed on the radially outer edge, which is directed toward the outflow side, ie toward the impeller 3 .
• fastening provisions 30 are formed on the nozzle plate 2 for fastening the nozzle plate 2 or the entire fan 1 to a higher-level system, for example an air-conditioning unit, a ventilation system or a cooling device.
• FIG. 2 shows the fan 1 according to FIG. 1 in a section on a plane through the fan axis, seen from the side, the motor 4 with the stator 12 and rotor 11 not being shown in section.
• the curved outer area 7 of the cover disk 8 of the impeller 3 is clearly visible, as is the edging 6 in the outer area of the nozzle plate 2.
• the support struts 19 of the suspension 13 are attached to the nozzle plate 2 by means of attachments 27, advantageously screwed.
• the support plate 20 of the suspension 13 is attached to the stator 12 of the motor 4 with fasteners 15, advantageously also screwed.
• the impeller 3 is rotatably connected to fasteners 16, advantageously screwed.
• the inlet nozzle 5 is attached to the nozzle plate 2 with fasteners 14 . In other embodiments, it can also be manufactured integrally as one component with the nozzle plate 2. The inflow nozzle 5 protrudes into an inner opening which the cover plate 8 of the impeller 3 has.
• the conveyed medium flows from the suction side, in the illustration according to FIG it flows away from the fan 1 at the outlet 29 of the impeller 3, which extends between the radially outer edges of the cover disk 8 and the base disk 10.
• a radial gap 28 is formed between the inlet nozzle 5 and the cover disk 8 of the impeller 3 in the overlapping area, through which a secondary flow enters the impeller 3, which originates from the outflow side of the impeller 3 and thus has the higher pressure level of the outflow side.
• This secondary flow is essential for high efficiencies and low sound levels of the fan, since it has a stabilizing effect on the flow conditions in the impeller 3.
• the outflowing flow close to the cover plate interacts with the nozzle plate 2, in particular on its edge 6, due to the heavily curved cover plate 8 in the region of curvature 7.
• Advantageous effects can thus be achieved in a targeted manner.
• the secondary flow itself is influenced, in particular its swirl is reduced, on the other hand, the behavior of the entire flow flowing out of the impeller 3 at the outlet 29 can be decisively influenced. That way you can, at least for a range of operating points of the fan, improvements in terms of efficiency and/or noise emission can be achieved.
• FIG. 3 shows an enlarged representation of a partial area from FIG. 2, with dimensions also shown schematically. This is the area that is essential to the invention near the edge 6 of the nozzle plate 2 and near the outer edge of the cover disk 8 of the impeller 3 with its overcurved area 7.
• the inner flow-guiding contour of the cover disk 8 facing the blades 9 has been seen in section according to FIG ,
• an exit direction 33 which, viewed in section, is straight, imaginary tangential extension to the cover disk.
• this exit direction 33 can be variable over the circumference of the cover plate, in which case an average exit direction is decisive.
• the outlet direction 33 on the cover disk 8 is advantageously inclined backwards in the exemplary embodiment, going well beyond the radial direction 32 and, seen in the outflow direction, points towards the nozzle plate 2, i.e. backwards, so to speak, with regard to the main flow direction of the impeller 3 from left to right in the view shown .
• this exit direction 33 at the outer end of the cover plate 8 or its overcurved area 7 has an angle a 26, measured to the radial direction 32, of more than 35°, advantageously more than 45°.
• the imaginary extension of the cover plate 8 or its overcurved area 7 in the form of the (central) outlet direction 33 intersects with the nozzle plate 2 or its outer edge 6.
• the central outlet direction 33 also advantageously intersects the nozzle plate 2 or its outer edge 6 over the entire, rather angular circumference of the nozzle plate 2, but at least over a large area of the circumference of more than 95%. This will make the advantageous interaction of the flow flowing out of the impeller 3 with the nozzle plate 2 or its outer edge 6 is ensured.
• Fig. 3 some characteristic axial extension dimensions for the fan are shown, such as the axial distance a 25 of the flow outlet on the cover plate 8 to the open end of the edge 6 of the nozzle plate 2, the axial height b 24 of the edge 6 of the nozzle plate 2 or the axial extension c 23 of the inflow nozzle 5.
• some characteristic dimensions are drawn in the radial direction, such as the outlet diameter DD 22 of the inflow nozzle 5, the outlet diameter DL 18 of the impeller 3 at the outer edge of the cover plate 8 and a width w 17 of the nozzle plate 2, which is intended to represent the smallest side length of a rather rectangular contour of the nozzle plate 2. The diameters are measured relative to the fan axis.
• a large nozzle ratio DD/DL>70%, advantageously>75%, is advantageous in order to achieve high volume flows and to enable the design of an axially compact inflow nozzle 5 with a very small axial extension c 23 .
• the axial overall height c 23 of the inlet nozzle 5 then has a ratio C/DL ⁇ 12% in relation to the outer diameter DL 18 . This is advantageous because then, in combination with a certain axial height b 24 of the edge 6 of the nozzle plate 2, a small axial distance a 24 of the outflow surface from the impeller 3 at the cover disk contour to the outside Edge of the lip 6 can be achieved to promote the desired flow interaction.
• a ratio a/Di_ of not more than 20% is advantageous.
• a ⁇ W-DL or a ⁇ (w-Di_) * tan(a) is also advantageous.
• FIG. 4 shows the fan 1 according to FIGS. 1, 2 and 4 in a view from the inflow side.
• the bottom disk 10 and parts of the vanes 9 and the rotor 11 of the motor 4, to which the impeller is fastened with fastenings 16, can be seen inside the inflow nozzle 5 of the impeller 3, the bottom disk 10 and parts of the vanes 9 and the rotor 11 of the motor 4, to which the impeller is fastened with fastenings 16, can be seen.
• the wings 9 have a three-dimensional shape and a large part of the concave suction side of the wings 9 can be seen in the view Edge 6 can be seen.
• both the fastenings 27, with which support struts (19) are fastened to the nozzle plate 2, and fastening provisions 30, with which the fan 1 can be fastened to a superordinate system, can be seen.
• FIG. 5 shows the fan 1 according to FIGS. 1 to 4 in a view from the outflow side.
• One can see the stator 12 of the motor 4 with the electronics pot 21 integrated therein.
• You can see the bottom disk 10 and the cover disk 8 of the impeller 3, since the latter has a larger outer diameter than the former.
• Such an embodiment is particularly suitable for an installation condition in which the flow continues to flow more axially downstream of the fan, that is to say in an installation situation that limits radially downstream of the fan impeller.
• the ratio of the outside diameter of the base disk 10 to the outside diameter of the cover disk 8 is advantageously between 85% and 95%. Areas near the rear edge of the 6 wings 9 in the exemplary embodiment can be seen. They stretch on the cover disk 8 up to at most a few millimeters almost or completely up to its outer diameter, whereby the flow guidance along the overcurved contour of the cover disk 8 on its overcurved outer area 7 is favored.
• the suspension 13 consists of support struts 19, which in the exemplary embodiment have a rather round cross section, and an engine support plate 20.
• Other types of engine suspension are also conceivable, for example consisting essentially of flat material.
• Fig. 6 is a schematic, perspective representation of a flow pattern calculated by simulation in the outlet area of a fan such as that from Figs. 1 to 5 at a first operating point, which is characterized by a rather low delivery volume flow in relation to speed, impeller diameter and outlet area.
• the cover disc 8 with the curved outer area 7 and a flow exit surface 29 can be seen from the impeller 3.
• the nozzle plate 2 with the inflow nozzle 5 and the edging 6 can also be seen.
• the fan is only partially shown.
• the main delivery volume flow exiting the impeller is inclined in its entirety towards the nozzle plate 2 or its imaginary radial extension.
• FIG. 7 is, comparable to FIG. 6, a schematic, perspective illustration of a flow pattern calculated by simulation in the outlet area of a fan such as that from FIGS. Impeller diameter and outlet area is marked.
• the cover disc 8 with the curved outer area 7 and a flow exit surface 29 can be seen from the impeller 3.
• the nozzle plate 2 with the inflow nozzle 5 and the edging 6 can also be seen.
• the main delivery volume flow emerging from the impeller is directed away from the nozzle plate 2 and, seen in section, flows in a direction obliquely away from the nozzle plate 2 or its imaginary radial extension.
• FIG. 7 is only intended to show by way of example how an interaction between the air flow emerging from an impeller 3 and the edging 6 of the nozzle plate 2 can take place due to the curved area. It is based on a simulation.
• the streamlines 31 shown are based on local velocity vectors which are projected onto the streamline plane shown.
• Axial distance a of the outer edge of the cover disk 8 to the edge 6 of the nozzle plate 2 Angle a between the exit of the inner flow contour of the shroud at the outer edge to a line parallel to the fan axis, seen in a section on a plane through the fan axis

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=81750538

Family Applications (1)

Country Status (6)

Family Cites Families (11)

• 2021
  • 2021-05-04 DE DE102021204491.3A patent/DE102021204491A1/de active Pending
• 2022
  • 2022-04-25 WO PCT/DE2022/200074 patent/WO2022233372A1/de active Application Filing
  • 2022-04-25 JP JP2023566783A patent/JP2024517441A/ja active Pending
  • 2022-04-25 EP EP22724636.0A patent/EP4314564A1/de active Pending
  • 2022-04-25 BR BR112023022311A patent/BR112023022311A2/pt unknown
  • 2022-04-25 CN CN202280032978.9A patent/CN117242265A/zh active Pending

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