AIR HANDLING UNIT WITH DIAGONAL FLOW FAN

Abstract

An air handling unit is disclosed, including a housing duct through which air is moved from an inlet to an outlet; a heat exchanger configured to facilitate a transfer of heat to and from the air moving through the housing duct; and a fan disposed inside the housing duct, configured for moving air within the housing duct. The fan includes a diagonal flow impeller having an axis of rotation arranged in-line with a direction of flow of air through the duct, wherein an air flow path through the impeller has a mean angle that is oriented along a direction divergent from the axis of rotation of the impeller. The fan further includes a set of axial outlet guide vanes disposed downstream of the impeller, configured to redirect a flow of air exiting the impeller to be substantially parallel to the axis of rotation of the impeller.

Description

TECHNICAL FIELD

This invention relates to an air handling unit and more particularly, to an air handling unit with a diagonal flow fan.

BACKGROUND

Conventional air conditioning systems may be sold as a single package unit including an air handling unit, or as a split package in which the air handling unit is installed within a premises. Conventional air handling units rely on blowers, such as a forward-curved blower, to circulate air through the air handling unit. Forward-curved blowers, however, have a limited static efficiency and may incur significant system losses depending on their installation due to excess turning required of the airstream.

SUMMARY

Disclosed herein is an air handling unit for use with an air conditioning system. The air handling unit includes a housing duct through which air is moved from an inlet to an outlet. The air handling unit further includes a heat exchanger configured to facilitate a transfer of heat to and from the air moving through the housing duct. The air handling unit further includes a fan disposed inside the housing duct, configured for moving air within the housing duct. The fan includes a diagonal flow impeller having a plurality of blades extending therefrom, and an axis of rotation arranged in-line with a direction of flow of air through the housing duct. An air flow path through the impeller has a mean angle that is oriented along a direction divergent from the axis of rotation of the impeller. The impeller is operable by a direct-drive motor. The fan further includes a fan inlet casing disposed circumferentially around the fan shroud, defining a clearance between the impeller inlet casing and the fan shroud, with upstream and downstream flow control clearances. The fan further includes a set of axial outlet guide vanes disposed downstream of the impeller. The set of axial outlet guide vanes includes a plurality of vanes extending radially from a stator hub towards a stator shroud, and configured to redirect a flow of air exiting the impeller such that the flow of air exiting the impeller is substantially parallel to the axis of rotation of the impeller.

In one or more embodiments, the fan further includes a rotating shroud extending circumferentially around the impeller. The rotating shroud is secured to the plurality of blades.

In one or more embodiments, the air handling unit includes a ducted fan coil.

In one or more embodiments, the air handling unit further includes a supplemental heating device.

In one or more embodiments, the supplemental heating device is located downstream of the fan with a radiation shield between the heating device and the fan.

In one or more embodiments, the air handling unit further includes a packaged rooftop indoor air management system.

In one or more embodiments, the fan is positioned downstream relative to the heat exchanger.

In one or more embodiments, the fan is positioned upstream relative to the heat exchanger.

In one or more embodiments, the heat exchanger is substantially V-shaped relative to the direction of flow of air through the housing duct.

In one or more embodiments, the heat exchanger is substantially A-shaped relative to the direction of flow of air through the housing duct.

In one or more embodiments, the heat exchanger includes a single slab heat exchanger.

In one or more embodiments, the heat exchanger includes a primary heat exchanger and other heat transfer devices.

In one or more embodiments, the heat exchanger is configured to cool the air moving through the housing duct.

In one or more embodiments, the heat exchanger is configured to heat the air moving through the housing duct.

In one or more embodiments, a rotor defines the air flow path through the impeller. The air flow path through the impeller has a mean angle oriented diagonally between about 30 degrees and about 80 degrees relative to the axis of rotation of the impeller.

In one or more embodiments, the impeller blade camber is between about −10 degrees and about −40 degrees.

In one or more embodiments, the impeller blade lean is between about 25 degrees and about 50 degrees.

In one or more embodiments, the number of impeller blades is between about 5 and about 11.

In one or more embodiments, the guide vanes have a circumferential sweep along at least a portion of the guide vane span.

In one or more embodiments, the circumferential sweep of the guide vanes at the stator hub end wall is between about 10 degrees and about 30 degrees.

In one or more embodiments, the circumferential sweep of the guide vanes at the stator shroud end wall is between about 10 degrees and about 30 degrees.

In one or more embodiments, the guide vanes are axially swept in a range of between about 0 degrees and about 30 degrees.

In one or more embodiments, the guide vanes have airfoil profiles with a maximum camber located at between about 25% and about 30% of the chord of the guide vanes.

In one or more embodiments, the number of guide vanes is between about 13 and about 27.

In one or more embodiments, the impeller and guide vane assemblies are manufactured using thermoplastics.

In one or more embodiments, the direct-drive motor is digitally communicating with HVAC controls and has continuous speed control.

In one or more embodiments, the axial position of the fan inlet plane is in a range of between −0.2 and about 1.0 times the fan inlet diameter of the coil outlet plane.

In one or more embodiments, the fan inlet casing includes a plurality of casing elements extending from a radially inboard surface of the fan inlet casing toward the shroud and defining a radial element gap.

In one or more embodiments, the fan inlet casing includes a plurality of casing elements extending axially forward of the inlet plane.

In one or more embodiments, the outlet guide vanes have a hub-to-tip ratio in a range of between about 60% and about 80%.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, features, and techniques of the invention will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the subject disclosure of this invention and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the subject disclosure and, together with the description, serve to explain the principles of the subject disclosure.

In the drawings, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

FIG. 1 is a schematic representation of an air handling unit, in accordance with one or more embodiments of the invention;

FIGS. 2A and 2B are detailed schematic perspective and sectional views, respectively, of a fan of the air handling unit of FIG. 1, in accordance with one or more embodiments of the invention;

FIG. 3 is a detailed schematic perspective view of an impeller of the fan of FIGS. 2A and 2B, in accordance with one or more embodiments of the invention;

FIG. 4A is a detailed schematic view of a portion of a set of guide vanes of the fan of FIGS. 2A and 2B, in accordance with one or more embodiments of the invention;

FIG. 4B is a schematic sectional view of a guide vane of the set of guide vanes of FIG. 4A, in accordance with one or more embodiments of the invention;

FIG. 5A is a schematic representation of another air handling unit, in accordance with one or more embodiments of the invention; and

FIG. 5B is a schematic representation of another air handling unit, in accordance with one or more embodiments of the invention.

DETAILED DESCRIPTION

The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject disclosure as defined by the appended claims.

Various terms are used herein. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the subject disclosure, the components of this invention described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” “first,” “second” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components.

The use of the term “about” with reference to a numerical value includes ±10% of the numerical value.

Referring to FIG. 1, a schematic sectional representation of an air handling unit (AHU) 100 for use with an air conditioning system (not shown in figure) is shown. The AHU 100 includes a housing duct 102 fluidically coupling an inlet 104 and an outlet 106. Air is moved through the housing duct 102 from the inlet 104 to the outlet 106 along a direction 190 of flow of air.

The AHU 100 further includes a heat exchanger 110. The heat exchanger 110 may be disposed within the housing duct 102 along a direction 190 of flow of the air, such that the air flowing through the housing duct 102 further flows through the heat exchanger 110. The heat exchanger 110 is configured to facilitate transfer of heat to and from the air moving through the housing duct 102. In some embodiments, the heat exchanger 110 may be configured to cool the air moving through the housing duct 102. In some other embodiments, the heat exchanger 110 may be configured to heat the air moving through the housing duct 102. In some embodiments, the heat exchanger 110 includes a primary heat exchanger and other heat transfer devices (not shown). In some embodiments, the heat exchanger 110 may be a ducted fan coil unit (FCU) (as shown in the embodiment of FIG. 1). In some embodiments, the heat exchanger 110 may further be coupled with a humidifier to facilitate the air passing through the heat exchanger 110 to include predefined levels of moisture.

In some embodiments, the AHU 100 further includes a supplemental heating device 112. In some embodiments, the supplemental heating device 112 may be disposed within the housing duct 102, along the direction 190 of flow of the air, such that the air flowing through the housing duct 102 flows through the supplemental heating device 112, as shown in FIG. 1. Further, in one or more embodiments, the supplemental heating device 112 may be located downstream of the fan 120 with a radiation shield between the heating device 112 and the fan 120. The supplemental heating device 112 may be configured to heat up the air passing through the housing duct 102. In some embodiments, the supplemental heating device 112 and the heat exchanger 110 may together be configured to heat up the air and regulate the heated air temperature, respectively, that is flowing through the housing duct 102.

The AHU 100 further includes a fan 120 disposed inside the housing duct 102. The fan 120 is configured to move the air through the housing duct 102, from the inlet 104 to the outlet 106. In some embodiments, the fan 120 is operable by a motor 122. The motor 122 may be a direct-drive motor. The motor 122 may be operable with a continuous speed control. The motor 122 may be communicably coupled to HVAC controls of the air conditioning unit. As the fan 120 rotates, it may pull in air through the inlet 104 and blows the air through the fan 120 and towards the outlet 106 through the housing duct 102. The fan 120 may have an axis of rotation 192 that is in-line with the direction 190 of flow of the air through the housing duct 102.

In some embodiments, the fan 120 may be positioned upstream relative to the heat exchanger 110. In some other embodiments, the fan 120 may be positioned downstream relative to the heat exchanger 110. In the illustrated embodiment of FIG. 1, the fan 120 is positioned downstream relative to the heat exchanger 110. Further, in the illustrated embodiment of FIG. 1, the fan 120 is positioned upstream relative to the supplemental heating device 112. Furthermore, in the illustrated embodiment of FIG. 1, the heat exchanger 110 is substantially V-shaped relative to the direction 190 of flow of the air through the housing duct 102.

In some embodiments, the AHU 100 may be configured with flow directional changes such that air entry and exit are configured for upflow and downflow, as applicable to packaged rooftop units. The AHU 100 may further include a packaged rooftop air management system 150 that is communicably coupled to the different components of the AHU 100, including, without limitations, the heat exchanger 110, the supplemental heating device 112, the fan 120, and the motor 122. The system 150 may be implemented by a controller 152 configured to control operations of the different components of the AHU 100. In some embodiments, the system 150 may be a part of the HVAC controls of the air conditioning system.

Referring to FIGS. 2A and 2B, detailed schematic perspective and sectional views, respectively, of the fan 120 are shown. Referring now to FIGS. 1 to 2B, the fan 120 includes a diagonal flow impeller 202. The impeller 202 includes a plurality of blades 204 extending therefrom. In some embodiments, the number of impeller blades 204 is between about 5 and about 11. Referring now to FIGS. 1 to 2B, in some embodiments, the blades 204 may extend from a hub 206 of the impeller 202. Specifically, the impeller 202 may have the axis of rotation 192 that is arranged in-line with the direction 190 of flow of the air through the housing duct 102. In some embodiments, the impeller 202 assembly may be manufactured using thermoplastics.

The fan 120 further includes a fan shroud 210 extending circumferentially around the impeller 202. The fan shroud 210 is further secured to the plurality of blades 204. The fan 120 further includes a fan inlet casing 212. The fan inlet casing 212 is disposed circumferentially around the fan shroud 210. The fan inlet casing 212 defines a clearance between the fan inlet casing 212 and the fan shroud 210. The clearance may have appropriate upstream and downstream flow control clearances. In some embodiments, the fan inlet casing 212 includes a plurality of casing elements (not shown in figure) extending from a radially inboard surface of the fan inlet casing 212 towards the fan shroud 210, thereby defining a radial element gap. In some embodiments, the plurality of casing elements may extend axially forward of an inlet plane.

An air flow path through the impeller 202 has a mean angle 0 that is oriented along a direction divergent from the axis of rotation 192 of the impeller 202, establishing a diagonal air flow path. In some embodiments, the air flow path through the impeller 202 may be oriented diagonally at an angle of between about 30 degrees and about 80 degrees relative to the axis of rotation 192 of the impeller 202.

The fan 120 further includes a set of axial outlet guide vanes 220 disposed downstream of the impeller 202. The set of guide vanes 220 include a plurality of vanes 222 extending radially from a stator hub 224 towards a stator shroud 226. In some embodiments, the set of guide vanes 220 may include between about 13 and 27 guide vanes 222. In some embodiments, the guide vane assembly may be manufactured using thermoplastics. The set of guide vanes 220 is configured to redirect the flow of air exiting the impeller 202, such that the flow of air exiting the impeller 202 is substantially parallel to the axis of rotation 190 of the impeller 202. In one or more embodiments, the axial position of a fan inlet plane 194 is in a range of between −0.2 and about 1.0 times the fan inlet diameter of the coil outlet plane 196 (shown in FIG. 1).

Referring to FIG. 2B, a schematic perspective view of a guide vane 222 is shown. In some embodiments, the guide vanes 222 have an axial sweep 230 in a range of between about 0 degree and about 30 degrees.

FIG. 2B further shows the blade tip channel angle θs, the mean flow path angle θm, and the blade root channel angle θh. The blade tip channel angle θs of a blade 204 of the impeller 202 may be defined as an angle between the axis of rotation 192 of the impeller 202 and a line tangent to the fan shroud surface 210. The mean flow path angle θm may be defined as the mean meridional flow angle. The blade root channel angle θh may be defined as an angle between the axis of rotation 192 of the impeller 202 and a line tangent to the fan hub surface 206.

Furthermore, FIG. 2B depicts a stator hub-to-tip ratio (Rh/Rt). Rh is a radius of the stator hub 224 from the axis of rotation 192 of the impeller 202. Rt is a radius of the stator shroud 226 from the axis of rotation 192 of the impeller 202. In some embodiments, the guide vanes 222 have a hub-to-tip ratio in a range of between about 60% and about 80%.

Referring to FIG. 3, a detailed schematic perspective view of the impeller 202 and the plurality of blades 204 is shown. FIG. 3 depicts impeller blade camber 304. In some embodiments, the impeller blade camber 304 is between about −10 degrees and about −40 degrees.

FIG. 3 further shows the impeller blade lean. Each impeller blade 204 (e.g., impeller blade 204-1) may lean circumferentially and axially. In some embodiments, the impeller blade lean is between about 25 degrees and about 50 degrees.

Referring to FIG. 4A, a detailed schematic view of a portion of the set of guide vanes 220 is shown. The guide vanes 222 may be arranged to include a sweep along one or both of a circumferential and an axial direction. Each of the guide vanes 222 extends from the stator hub 224 to the stator shroud 226. The guide vanes 222 have a circumferential sweep along at least a portion of the guide vane span. In some embodiments, the circumferential sweep of the guide vanes 222 at stator hub 224 end wall is between about 10 degrees and about 30 degrees. In some embodiments, the circumferential sweep of the guide vane 222 at the stator shroud 226 end wall is between about 10 degrees and about 30 degrees.

Referring to FIG. 4B, a schematic sectional view of a guide vane 222 is shown. In some embodiments, the guide vane 222 has an airfoil profile. A maximum camber 452 is located on a camber line 454 of the airfoil profile, at between about 25% and about 30% of the chord 456 of the guide vane 222.

Referring to FIG. 5A, a schematic representation of an AHU 500 is shown. The AHU 500 of FIG. 5A is substantially similar to the AHU 100 of FIG. 1. Hence, common components between the AHU 500 of FIG. 5A and the AHU 100 of FIG. 1 are referenced using the same reference numerals. However, the AHU 500 includes a heat exchanger 510 that is substantially A-shaped relative to the direction 190 of flow of the air through the housing duct 102.

Referring to FIG. 5B, a schematic representation of an AHU 550 is shown. The AHU 550 of FIG. 5B is substantially similar to the AHU 100 of FIG. 1. Hence, common components between the AHU 550 of FIG. 5B and the AHU 100 of FIG. 1 are referenced using the same reference numerals. However, the AHU 550 includes a heat exchanger 560 that includes a single slab heat exchanger.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined by the appended claims. Modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention includes all embodiments falling within the scope of the invention as defined by the appended claims.

In interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

Without excluding further possible embodiments, certain example embodiments are summarized in the following clauses:

Clause 1: An air handling unit for use with an air conditioning system, the air handling unit comprising: a housing duct through which air is moved from an inlet to an outlet; a heat exchanger configured to facilitate a transfer of heat to and from the air moving through the housing duct; and a fan disposed inside the housing duct, configured for moving air within the housing duct, the fan comprising: a diagonal flow impeller having a plurality of blades extending therefrom, and an axis of rotation arranged in-line with a direction of flow of air through the housing duct, wherein an air flow path through the impeller has a mean angle that is oriented along a direction divergent from the axis of rotation of the impeller, and wherein the impeller is operable by a direct-drive motor; a fan inlet casing disposed circumferentially around the fan shroud, defining a clearance between the fan inlet casing and the fan shroud, with upstream and downstream flow control clearances; and a set of axial outlet guide vanes disposed downstream of the impeller, comprising a plurality of vanes extending radially from a stator hub towards a stator shroud, and configured to redirect a flow of air exiting the impeller such that the flow of air exiting the impeller is substantially parallel to the axis of rotation of the impellerClause 2: The air handling unit of the preceding clause, wherein the circumferential sweep of the guide vanes at the stator shroud end wall is between about 10 degrees and about 30 degrees.Clause 3: The air handling unit of any of the preceding clauses, wherein the guide vanes have an axial sweep in a range of between about 0 degrees and about 30 degrees.Clause 4: The air handling unit of any of the preceding clauses, wherein the guide vanes have airfoil profiles with a maximum camber located at between about 25% and about 30% of a chord of the guide vanes.Clause 5: The air handling unit of any of the preceding clauses, wherein the number of guide vanes is between about 13 and about 27.Clause 6: The air handling unit of any of the preceding clauses, wherein the impeller and guide vane assemblies are manufactured using thermoplastics.Clause 7: The air handling unit of any of the preceding clauses, wherein the direct-drive motor is digitally communicating with HVAC controls and has continuous speed control.Clause 8: The air handling unit of any of the preceding clauses, wherein the axial position of the fan inlet plane is in a range of between −0.2 and about 1.0 times the fan inlet diameter of the coil outlet plane.Clause 9: The air handling unit of any of the preceding clauses, wherein the fan inlet casing comprises a plurality of casing elements extending from a radially inboard surface of the fan inlet casing toward the shroud, and defining a radial element gap.Clause 10: The air handling unit of any of the preceding clauses, wherein the fan inlet casing comprises a plurality of casing elements extending axially forward of the inlet plane.Clause 11: The air handling unit of any of the preceding clauses, wherein the outlet guide vanes have a hub-to-tip ratio in a range of between about 60% and about 80%.

Claims

1. An air handling unit for use with an air conditioning system, the air handling unit comprising: a housing duct through which air is moved from an inlet to an outlet;a heat exchanger configured to facilitate a transfer of heat to and from the air moving through the housing duct; anda fan disposed inside the housing duct, configured for moving air within the housing duct, the fan comprising: a diagonal flow impeller having a plurality of blades extending therefrom, and an axis of rotation arranged in-line with a direction of flow of air through the housing duct, wherein an air flow path through the impeller has a mean angle that is oriented along a direction divergent from the axis of rotation of the impeller, and wherein the impeller is operable by a direct-drive motor;a fan inlet casing disposed circumferentially around the fan shroud, defining a clearance between the fan inlet casing and the fan shroud, with upstream and downstream flow control clearances; anda set of axial outlet guide vanes disposed downstream of the impeller, comprising a plurality of vanes extending radially from a stator hub towards a stator shroud, and configured to redirect a flow of air exiting the impeller such that the flow of air exiting the impeller is substantially parallel to the axis of rotation of the impeller.

2. The air handling unit of claim 1, wherein the fan further comprises a rotating shroud extending circumferentially around the impeller, and wherein the rotating shroud is secured to the plurality of blades.

3. The air handling unit of claim 1, wherein the air handling unit comprises a ducted fan coil.

4. The air handling unit of claim 1, wherein the air handling unit further comprises a supplemental heating device.

5. The air handling unit of claim 4, wherein the supplemental heating device is located downstream of the fan with a radiation shield between the heating device and the fan.

6. The air handling unit of claim 1, wherein the air handling unit further comprises a packaged rooftop indoor air management system.

7. The air handling unit of claim 1, wherein the fan is positioned downstream relative to the heat exchanger.

8. The air handling unit of claim 1, wherein the fan is positioned upstream relative to the heat exchanger.

9. The air handling unit of claim 1, wherein the heat exchanger is substantially V-shaped relative to the direction of flow of air through the housing duct.

10. The air handling unit of claim 1, wherein the heat exchanger is substantially A-shaped relative to the direction of flow of air through the housing duct.

11. The air handling unit of claim 1, wherein the heat exchanger comprises a single slab heat exchanger.

12. The air handling unit of claim 1, wherein the heat exchanger comprises a primary heat exchanger and other heat transfer devices.

13. The air handling unit of claim 1, wherein the heat exchanger is configured to cool the air moving through the housing duct.

14. The air handling unit of claim 1, wherein the heat exchanger is configured to heat the air moving through the housing duct.

15. The air handling unit of claim 1, wherein a rotor defines the air flow path through the impeller, and wherein the air flow path through the impeller has a mean angle oriented diagonally between about 30 degrees and about 80 degrees relative to the axis of rotation of the impeller.

16. The air handling of claim 1, wherein the impeller blade camber is between about −10 degrees and about −40 degrees.

17. The air handling unit of claim 1, wherein the impeller blade lean is between about 25 degrees and about 50 degrees.

18. The air handling unit of claim 1, wherein the number of impeller blades is between about 5 and about 11.

19. The air handling unit of claim 1, wherein the guide vanes have a circumferential sweep along at least a portion of the guide vane span.

20. The air handling unit of claim 1, wherein the circumferential sweep of the guide vanes at a stator hub end wall is between about 10 degrees and about 30 degrees.