US20100154468A1

US20100154468A1 - Air flow around blower resistor and at evaporator

Info

Publication number: US20100154468A1
Application number: US12/317,697
Authority: US
Inventors: Silva Shaska; Lisa Graf; Simon Kehimkar
Original assignee: Denso International America Inc
Current assignee: Denso International America Inc
Priority date: 2008-12-22
Filing date: 2008-12-22
Publication date: 2010-06-24

Abstract

A climate control system includes a compressor that circulates fluid between a condenser and an evaporator, an electric motor that drives a blower that includes a quantity of fan blades, and a duct fluidly coupling the blower and the evaporator. The blower forces air through the duct to the evaporator. A resistor is in electrical communication with the motor and has a quantity of fins extending into the passage of the duct. The duct may include a contoured wall that bulges outward and away from the resistor fins to enlarge a volume of the duct adjacent or beside the quantity of fins to allow a first portion of the air from the blower to flow around the fins while a second portion of the air cools the fins.

Description

FIELD

The present disclosure relates to a climate control system and more particularly to a duct providing air flow around a blower resistor and at an evaporator.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art. Vehicles, such as automotive vehicles, for example, may include air conditioning or climate control systems to control the temperature within a cab or passenger compartment of the vehicle. Such climate control systems typically include a fan forcing heated or cooled air through vents in the vehicle to heat or cool the cab or passenger compartment. Typically, a control button, switch or knob in the passenger compartment allows a passenger or driver to selectively control the speed of the fan to adjust the velocity of the air that is forced into the passenger compartment. The control button, switch or knob may be in electrical communication with a resistor, which in turn, may be in electrical communication with a motor driving the fan. In response to actuation of the control button, switch or knob, the resistor may vary the magnitude of electrical current that is able to reach the fan motor, thereby varying the rotational speed of the motor and fan.
While in use, the resistor may generate heat. In order to cool the resistor, at least a portion of it may be disposed in an airflow path generated by the fan. However, this can adversely affect the characteristics of the airflow, which can subsequently adversely affect the performance of the climate control system and create undesirable noise.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. In one form, the present disclosure provides a climate control system which may include a heat exchanger and a blower adapted to force air through the heat exchanger. The blower may employ a quantity of fan blades and an electric motor adapted or configured to cause rotary motion of the fan blades. A resistor with numerous fins may be wired to be in electrical communication with the motor. An air duct may fluidly couple the heat exchanger and the blower such that an airflow path is formed through the duct. The plurality of fins may extend inwardly into the duct such that the fins are perpendicular or generally perpendicular to the airflow path. The duct may include a first cross-sectional area upstream of the quantity of fins and a second cross-sectional area generally aligned with one of the quantity of fins in the direction of the airflow path. The second cross-sectional area may be larger than the first cross-sectional area. A first portion of the air may flow through the quantity of fins, while a second portion of the air may flow around the quantity of fins.
In another form, the present disclosure provides a climate control system which may include a condenser, an evaporator in fluid communication with the condenser, a compressor in fluid communication with the condenser and the evaporator and adapted to circulate a fluid between the condenser and the evaporator. The climate control system may further employ a blower that includes a quantity of fan blades and an electric motor. A duct may fluidly couple the blower and the evaporator such that the blower may force air through the duct to the evaporator. A resistor may be in electrical communication with the motor and possess a quantity of fins extending inwardly into the duct. The duct may include a contoured portion that bulges outwardly and expands a volume of the duct adjacent the quantity of fins, thereby allowing a first portion of the air to flow around the quantity of fins while a second portion of the air cools the quantity of fins.
In yet another form, the present disclosure may provide a climate control system for a vehicle which may include a heat exchanger, a duct defining an airflow passage having a first end and a second end. The second end of the passage may connect to the heat exchanger. A blower may be coupled to the first end of the duct to force air through the duct and the heat exchanger and into a passenger compartment of the vehicle to affect a temperature change within the passenger compartment. A resistor may be in electrical communication with the blower and have a quantity of cooling members disposed within the airflow passage. The duct may include an outwardly extending bulge feature having a first end disposed upstream of the resistor and a second end disposed downstream of the resistor. The bulge feature may allow a first portion of the air to flow through and a second portion of the air to flow between the quantity of cooling members such that the airflow between the heat exchanger and the resistor is substantially unidirectional.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a schematic view of a vehicle having a climate control system according to principles of the present disclosure;

FIG. 2 is a perspective view of a blower according to principles of the present disclosure;

FIG. 3 is a plan view of the blower of FIG. 2;

FIG. 4 is a partial cross-sectional view of a duct according to principles of the present disclosure;

FIG. 5 is a cross-sectional view of the duct according to principles of the present disclosure;

FIG. 6 is a partial cross-sectional view of a prior art duct depicting characteristics of air flow therethrough ; and

FIG. 7 is a partial cross-sectional view of the duct of FIG. 2 depicting characteristics of air flow therethrough.

Corresponding reference numerals indicate corresponding parts throughout the views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to FIGS. 1-5 and 7.
With reference to FIGS. 1-7, a climate control system 10 is provided and may include a compressor 12, a condenser 14, an expansion valve 16, an evaporator 18 and a blower 20. The climate control system 10 may be installed in a vehicle 22, as shown in FIG. 1, to ventilate, heat and/or cool a passenger compartment 24 of the vehicle 22.
The compressor 12 may be a reciprocating compressor, a rotary vane type compressor, a scroll compressor, for example or any other suitable type. The compressor 12 may circulate a refrigerant, such as R-134a, R-12, carbon dioxide or any other suitable fluid or coolant, through the climate control system 10. The compressor 12 may draw relatively low pressure refrigerant through an inlet port 26, compress the refrigerant to a relatively high pressure and discharge the high pressure, high temperature refrigerant through a discharge port 28.
The condenser 14 may include a first coil or heat exchanger 30. The high pressure, high temperature refrigerant may flow from the compressor 12 into the first coil 30, where the refrigerant rejects heat to the surrounding ambient air. A fan or other source of airflow may force air across the first coil 30 to improve heat transfer from the refrigerant to the ambient air.
The evaporator 18 may include a second coil or heat exchanger 32. Refrigerant may flow from the condenser 14, through the expansion valve 16 and into the second coil 32. Refrigerant flowing through the second coil 32 absorbs heat from air being forced across the second coil 32 by the blower 20. The resulting cooled air may subsequently flow through vents in the passenger compartment 24 of the vehicle 22, thereby lowering the temperature of the passenger compartment and cooling the passenger compartment 24. The refrigerant may then return to the compressor 12, where the cycle may repeat itself.
Although the function of the climate control system 10 is described above as a cooling system, it will be appreciated that the climate control system 10 could be configured to operate as a heating system. In such a configuration, the functions of the first and second coils 30, 32 are switched, i.e., the refrigerant will reject heat in the second coil 32 and absorb heat in the first coil 30. Specifically, in a heating mode, a four-way valve can be switched from a cooling mode to the heating mode such that the second coil 32 will receive high pressure refrigerant from the compressor 12. The refrigerant will reject heat to the ambient air as it passes through the second coil 32, thereby heating the ambient air. The blower 20 may force the heated air into the passenger compartment 24. The refrigerant may then flow from the second coil 32 to the first coil 30, where the refrigerant may absorb ambient heat. From the first coil 30, the refrigerant may flow back to the compressor 12, and where the cycle may be repeated.
Referring now to FIGS. 2 and 3, the blower 20 may include a fan housing 34, a fan 36 and a duct 38 fluidly coupling the fan housing 34 with the evaporator 18. The fan 36 may include a plurality of radially disposed fan blades 37 adapted to rotate about a longitudinal axis of the fan to produce an airflow. An electric fan motor 40 may rotate the fan 36 within the fan housing 34. The fan motor 40 may be powered by a vehicle battery or any other suitable source of vehicle electric current.
The fan housing 34 can be a generally cylindrical enclosure having an outlet 44 and may be formed from any suitable metallic or polymeric material, for example. The fan housing 34 may at least partially surround the fan 36 and fan motor 40. The fan 36 may rotate within the fan housing 34 to produce an airflow which may be channeled through the outlet 44.
Referring now to FIGS. 2-5, and 7, the duct 38 may be a relatively thin-walled hollow member including a first end 46 and a second end 48. The first end 46 may be coupled with the outlet 44 of the fan housing 34, and the second end 48 may be coupled to the evaporator 18. The duct 38 may extend generally tangentially from the fan housing 34 to the evaporator 18 providing fluid communication therebetween such that fan 36 may force air to flow from the fan housing 34, through and within the duct 38 to the evaporator 18. The duct 38 may be formed from any suitable material including, for example, a metallic or polymeric material. The duct 38 could be coupled to the evaporator 18 and the fan housing 34 by any suitable means including, for example, snap or interference fitting, adhesive bonding, mechanical fasteners, welding, joining or any other means or combination of means. It should be appreciated that the duct 38 could be integrally formed with the fan housing 34 and/or the evaporator 18.
A resistor 42 (FIG. 5) may be mounted to an outer surface 52 of the duct 38 and may be in electrical communication with the fan motor 40. The resistor 42 may selectively reduce and increase the electrical resistance between the battery and the fan motor 40 to vary the amount of electrical current that the fan motor 40 receives, thereby selectively reducing and increasing the rotational speed of the fan 36.
The resistor 42 may include a plurality of fins 54 which may be elongated members formed from a metallic material or any other suitable material having a relatively high coefficient of thermal conductivity. The fins 54 could be generally cylindrical, as shown in the figures. However, it will be appreciated that the fins 54 could be generally flat members, could be tapered towards their tips, or any other shape suited to facilitate heat transfer from the resistor 42 to ambient air. The quantity of fins 54 may extend through apertures 56 in the outer surface 52 and into the duct 38, generally perpendicular to the direction of the air flowing therethrough, such that the air may flow across and between the fins 54. In this manner, the fins 54 may facilitate heat transfer from the resistor 42 to the air flowing through the duct 38, thereby cooling the resistor 42.
The duct 38 may include a feature such as a bulge 58 generally adjacent to the plurality of fins 54. The bulge 58 may be an outwardly protruding contoured surface 60 having a first end 62 disposed upstream of the plurality of fins 54, a second end 64 disposed downstream of the plurality of fins 54, and a crown 66 disposed between the first and second ends 62, 64. For purposes of the present disclosure, the crown 66 is defined as the portion of the bulge feature 58 at which the cross-sectional area of the duct 38 in the direction of flow is the greatest. The contoured surface 60 is formed such that the cross-sectional area of the duct 38 increases in the direction of the airflow between the first end 62 and the crown 66, and then decreases between the crown 66 and the second end 64 to facilitate airflow around the plurality of fins 54. Stated another way, the bulge 58 forms an increased cross-sectional area of the duct 38 that is generally aligned with the plurality of fins 54. The cross-sectional area of the duct 38 at the bulge 58 may be larger than the cross-sectional area of the duct 38 upstream of the plurality of fins 54 and the cross-sectional area of the duct 38 downstream of the plurality of fins 54. In this manner, the bulge 58 provides an unobstructed airflow path around the plurality of fins 54. It should be appreciated that the duct 38 could employ a second bulge adjacent the plurality of fins and opposite the bulge 58, thereby forming unobstructed airflow paths around both sides of the plurality of fins 54. This is, with reference to FIGS. 4 and 7, the duct 38 could have a second bulge that is a mirror image of the first bulge 58, with the second bulge located in the duct wall of the duct 38 that is depicted as a straight wall in FIGS. 4 and 7. Thus, a longitudinal centerline through the resistor and parallel to the straight side, as depicted in FIG. 7, could be the line about which a mirror image of bulges could be formed.
Operation of the blower 20 will now be described. As described above, the fan motor 40 causes the fan 36 to rotate, thereby creating an air flow through the outlet 44 of the fan housing 34, through the duct 38 and across the coil 32 of the evaporator 18. The refrigerant flowing through the coil 32 absorbs heat from the air being forced across the coil 32 by the fan 36, thereby cooling the air as it flows past the coil 32. This cooled air is channeled through a vent in the vehicle 22 and into the passenger compartment 24 to cool the space therein and any occupants of the passenger compartment 24. As described above, the plurality of fins 54 extend into the duct 38 in such a manner that a portion of the air flowing through the duct 38 may flow across, through and between the fins 54, as depicted in FIG. 7. The fins 54 conduct heat from the body of the resistor 42 and the fins 54 subsequently reject or expel this heat to the air flowing through the duct 38.
FIG. 6 depicts a portion of a prior art duct. In the prior art duct, the plurality of fins 54 substantially obstruct the airflow therethrough, causing the air to swirl and/or flow turbulently downstream of the fins 54. This swirling effect may decrease the net velocity of the air flow through the duct and/or cause localized areas of stagnant airflow at the evaporator.
In the duct 38 of the present disclosure, a first portion of the air may flow through the plurality of fins 54 (thereby cooling the resistor 42), while the bulge feature 58 allows a second portion of the air to flow around the plurality of fins 54, as shown in FIG. 7. The first and second portions of the airflow may merge or blend downstream of the fins 54. This merged or blended airflow may create substantially unidirectional, less turbulent and more uniform airflow downstream of the fins 54 and at the evaporator 18. Further, the blending or merging effect of the first and second portions of airflow may minimize any reduction of the velocity of the air flow caused by the fins 54.
This less turbulent flow may reduce the audible noise of the air flowing through the duct 38 that may be heard within the passenger compartment of the vehicle 22. Since the magnitude and uniformity of the air flow may be substantially maintained downstream of the fins 54, stagnation points in the airflow may be reduced or eliminated, thereby reducing backpressure in the duct 38. The resultant uniform and unidirectional airflow along the length of the duct 38 in the direction of the evaporator 18 may reduce or eliminate localized freeze points on the evaporator 18, which can develop in response to a lack of positive airflow across the coil 32 of the evaporator 18.
The bulge 58 improves the overall airflow characteristics through the duct 38, especially around the resistor fins 54, thereby improving the performance, capacity and efficiency of the climate control system 10, while still allowing a portion of the airflow to cool the fins 54 and thereby cool the resistor 42. It will be appreciated that the geometry and dimensions of the bulge 58 may vary depending on several factors including, for example, the amount of heat generated and retained by the resistor 42, the size and heat transfer properties of the quantity of fins 54, the dimensions of the duct 38, and/or other design features of the blower 20, resistor 42 and/or the climate control system 10.
Although the climate control system 10 is described above and shown in FIG. 1 as being installed in an automotive vehicle 22, it will be appreciated that the principles of the present disclosure are not limited to vehicular climate control systems. Accordingly, a blower including the duct 38 described herein could be integrated into any air conditioning, heat pump or climate control system, for example, or any other suitable application.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope of the inventive embodiments to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims

1. A climate control system comprising:

a heat exchanger;

a plurality of fan blades of a blower positioned to force air through the heat exchanger;

a motor driving the plurality of fan blades;

a resistor in electrical communication with the motor, the resistor having a plurality of fins; and

a duct defining an airflow path that fluidly couples the heat exchanger and the blower, the plurality of fins extending into the duct and perpendicular to the airflow path, the duct including a first cross-sectional area upstream of the plurality of fins and a second cross-sectional area surrounding the plurality of fins in the direction of the airflow path, the second cross-sectional area being larger than the first cross-sectional area,

wherein a first portion of the air flows through the plurality of fins and a second portion of the air flows around the plurality of fins.

2. The climate control system of claim 1, wherein the duct includes a third cross-sectional area downstream of the resistor that is smaller than the second cross-sectional area.

3. The climate control system of claim 2, wherein a contoured surface interconnects the first and second cross-sectional areas and forms a bulge.

4. The climate control system of claim 3, wherein in cross-section, the contoured surface is not parallel to a duct wall on an opposite side of the fins as the contoured surface.

5. The climate control system of claim 4, wherein the second portion of the air is directed around first and second sides of the plurality of fins.

6. The climate control system of claim 5, wherein airflow between the heat exchanger and the plurality of fins is substantially unidirectional.

7. The climate control system of claim 6, wherein airflow downstream of the plurality of fins is substantially uniform.

8. The climate control system of claim 7, wherein the blower and heat exchanger are in a vehicle.

9. A climate control system comprising:

a condenser;

an evaporator in fluid communication with the condenser;

a compressor in fluid communication with the condenser and the evaporator and adapted to circulate a fluid therebetween;

a blower including a plurality of fan blades and a motor;

a duct fluidly coupling the blower and the evaporator, the blower forcing air through the duct to the evaporator; and

a resistor in electrical communication with the motor and having a plurality of fins extending inwardly into the duct;

wherein the duct includes a contoured portion bulging outward and expanding a volume of the duct adjacent the plurality of fins, thereby allowing a first portion of the air to flow around the plurality of fins while a second portion of the air cools the plurality of fins.

10. The climate control system of claim 9, wherein the volume of the duct gradually increases in the direction of the airflow between a first end of the contoured portion and a crown of the contoured portion.

11. The climate control system of claim 10, wherein the volume of the duct gradually decreases in the direction of the airflow between the crown and a second end of the contoured portion, the second end of the contoured portion being on a side of the plurality of fins opposite to the first end of the contoured portion.

12. The climate control system of claim 11, wherein airflow between the evaporator and the resistor is substantially unidirectional.

13. The climate control system of claim 12, wherein in cross-section, a first duct wall on one side of the plurality of fins is not parallel to a second duct wall on an opposite of the plurality of the fins.

14. The climate control system of claim 13, wherein the contoured portion bulges away from the plurality of fins.

15. A climate control system for a vehicle comprising:

a heat exchanger;

a duct defining an airflow passage and having a first end and a second end, the second end connecting to the heat exchanger;

a blower coupled to the first end of the duct to force air through the duct and the heat exchanger and into a passenger compartment of the vehicle; and

a resistor in electrical communication with the blower, the resistor having a plurality of cooling members disposed within the airflow passage,

wherein the duct defines an outwardly extending bulge at the resistor, the duct having a first end disposed upstream of the resistor and a second end disposed downstream of the resistor, the bulge allowing a first portion of the air to bypass the resistor and a second portion of the air to flow between the plurality of cooling members such that the airflow between the heat exchanger and the resistor is substantially unidirectional.

16. The climate control system of claim 15, wherein from a same distance from a reference point of the resistor, the duct includes a first cross-sectional area at the first end of the bulge and a second cross-sectional area at a second end of the bulge, the first and second cross-sectional areas being equal.

17. The climate control system of claim 16, wherein the bulge creates a larger duct cross-section for airflow and reduces backpressure at the heat exchanger.