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 
       [0001]    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 
       [0002]    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. 
         [0003]    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 
       [0004]    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. 
         [0005]    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. 
         [0006]    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. 
         [0007]    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 
         [0008]    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. 
           [0009]      FIG. 1  is a schematic view of a vehicle having a climate control system according to principles of the present disclosure; 
           [0010]      FIG. 2  is a perspective view of a blower according to principles of the present disclosure; 
           [0011]      FIG. 3  is a plan view of the blower of  FIG. 2 ; 
           [0012]      FIG. 4  is a partial cross-sectional view of a duct according to principles of the present disclosure; 
           [0013]      FIG. 5  is a cross-sectional view of the duct according to principles of the present disclosure; 
           [0014]      FIG. 6  is a partial cross-sectional view of a prior art duct depicting characteristics of air flow therethrough ; and 
           [0015]      FIG. 7  is a partial cross-sectional view of the duct of  FIG. 2  depicting characteristics of air flow therethrough. 
       
    
    
       [0016]    Corresponding reference numerals indicate corresponding parts throughout the views of the drawings. 
       DETAILED DESCRIPTION 
       [0017]    Example embodiments will now be described more fully with reference to  FIGS. 1-5  and  7 . 
         [0018]    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 . 
         [0019]    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 . 
         [0020]    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. 
         [0021]    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. 
         [0022]    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. 
         [0023]    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. 
         [0024]    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 . 
         [0025]    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 . 
         [0026]    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 . 
         [0027]    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 . 
         [0028]    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. 
         [0029]    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 . 
         [0030]      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. 
         [0031]    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 . 
         [0032]    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 . 
         [0033]    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 . 
         [0034]    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. 
         [0035]    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. 
         [0036]    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. 
         [0037]    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. 
         [0038]    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&#39;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. 
         [0039]    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.