Patent Publication Number: US-2009239463-A1

Title: Diffuser for a heating, ventilating, and air conditioning system

Description:
FIELD OF THE INVENTION 
     The invention relates to a climate control system for a vehicle, and more particularly to a diffuser formed in a control module for a heating, ventilating, and air conditioning system having an apparatus disposed therein to reduce a separation of a fluid flowing therethrough. 
     BACKGROUND OF THE INVENTION 
     A vehicle typically includes a climate control system which maintains a temperature within a passenger compartment of the vehicle at a comfortable level by providing heating, cooling, and ventilation. Comfort is maintained in the passenger compartment by an integrated mechanism referred to in the art as a heating, ventilating and air conditioning (HVAC) system. The HVAC system conditions air flowing therethrough and distributes the conditioned air throughout the passenger compartment. The flow of air through the HVAC system is controlled by a control module disposed in the HVAC system. 
     The control module can include a diffuser formed therein to reduce a flow velocity of the air and increase a pressure thereof entering a heat exchanger disposed adjacent thereto. An adverse pressure gradient caused by the sudden expansion at the inlet of the diffuser, however, typically causes a separation of the flow of air therethrough. The separation of the flow of air through the diffuser produces an undesired amount of noise heard by passengers in the passenger compartment of the vehicle, and causes uneven flow coverage of the heat exchanger. Accordingly, vehicle manufacturers have used a variety of devices disposed in the diffuser to reduce the noise produced by the diffuser and improve the flow coverage of the heat exchanger. 
     One such device is disclosed in U.S. Pat. No. 4,712,611, hereby incorporated herein by reference in its entirety. The device disclosed is a grid disposed between a diffuser and a heat exchanger. The grid has a profile adapted to distribute a flow of air to the heat exchanger and peripheral portions thereof. The grid extends over approximately 60% to 80% of a face of the heat exchanger. 
     While the prior art HVAC systems perform adequately, it is desirable to produce a diffuser for an HVAC system having an apparatus disposed therein, wherein the apparatus reduces a separation of a fluid flow therethrough, and wherein an effectiveness thereof is maximized and a cost thereof is minimized. 
     SUMMARY OF THE INVENTION 
     In concordance and agreement with the present invention, a diffuser for a HVAC system having an apparatus disposed therein, wherein the apparatus reduces a separation of a fluid flow therethrough, and wherein an effectiveness thereof is maximized and a cost thereof is minimized, has surprisingly been discovered. 
     In one embodiment, the diffuser for a heating, ventilating, and air conditioning system comprises a housing having a hollow interior; a flow distribution apparatus disposed in the housing adapted to minimize a separation of a flow of fluid through the housing, wherein the apparatus is one of an article integrally formed with the housing and a plate-like device formed separately from the housing and disposed therein. 
     In another embodiment, the diffuser for a heating, ventilating, and air conditioning system comprises a housing having a hollow interior; a flow distribution apparatus disposed in the housing adapted to minimize a separation of a flow of fluid through the housing, wherein the apparatus is one of an article integrally formed with the housing and a plate-like device formed separately from the housing and disposed therein, the plate-like device having a plurality of apertures formed therein. 
     In another embodiment, the control module for a heating, ventilating, and air conditioning system comprises a housing having a hollow interior; a diffuser formed in the main housing; and a flow distribution apparatus disposed in the housing adapted to minimize a separation of a flow of fluid through the housing, wherein the apparatus is one of an article integrally formed with the housing and a plate-like device formed separately from the housing and disposed therein, the plate-like device having a plurality of apertures formed therein, wherein at least one of the apertures includes a tab disposed thereon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above, as well as other objects and advantages of the invention, will become readily apparent to those skilled in the art from reading the following detailed description of various embodiments of the invention when considered in the light of the accompanying drawings in which: 
         FIG. 1  is a fragmentary cross-sectional view of an HVAC module including a diffuser having an apparatus disposed therein according to an embodiment of the invention; 
         FIG. 2  is a fragmentary cross-sectional view of an HVAC module including a diffuser having an apparatus disposed therein according to another embodiment of the invention; 
         FIG. 3  is a fragmentary cross-sectional view of an HVAC module including a diffuser having an apparatus disposed therein according to another embodiment of the invention; 
         FIG. 4  is a front elevational view of the apparatus illustrated in  FIG. 2 ; 
         FIG. 5  is a front elevational view of the apparatus illustrated in  FIG. 2  according to another embodiment of the invention; 
         FIG. 6  is a front elevational view of the apparatus illustrated in  FIG. 2  according to another embodiment of the invention; 
         FIG. 7  is a front elevational view of the apparatus illustrated in  FIG. 2  according to another embodiment of the invention; 
         FIG. 8  is a front elevational view of the apparatus illustrated in  FIG. 5  according to another embodiment of the invention; 
         FIG. 9  is a front elevational view of the apparatus illustrated in  FIG. 8  according to another embodiment of the invention; 
         FIG. 10  is a side elevational view of the apparatus illustrated in  FIG. 9 ; 
         FIG. 11  is a front elevational view of the apparatus illustrated in  FIG. 2  according to another embodiment of the invention; and 
         FIG. 12  is a side elevational view of the apparatus illustrated in  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following detailed description and appended drawings describe and illustrate an exemplary embodiment of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. 
       FIGS. 1 ,  2 , and  3  show a control module  10  of a heating, ventilating, and air conditioning (HVAC) system or climate control system according to an embodiment of the invention. As used herein, the term air refers to a fluid in a gaseous state. The control module  10  typically provides heating, ventilation, and air conditioning for a passenger compartment of a vehicle (not shown). In the embodiment shown, the control module  10  controls at least a temperature of the passenger compartment. 
     The control module  10  illustrated includes a hollow main housing  14  with an air flow conduit  15  formed therein. The housing  14  includes an inlet section  16 , a mixing and conditioning section  18  adapted to receive at least one of a heat exchanger  20  and a heater core (not shown) therein, and an outlet and distribution section (not shown). In the embodiment shown, an air inlet  22  is formed in the inlet section  16 . The air inlet  22  is in fluid communication with a supply of air (not shown). The supply of air can be provided from outside of the vehicle, recirculated from the passenger compartment of the vehicle, or a mixture of the two, for example. The inlet section  16  is adapted to receive a blower wheel (not shown) therein to cause air to flow through the control module  10 . 
     The inlet section  16  also includes a diffuser  24  formed therein. A wall  26  of the housing  14  slopes laterally outwardly from the air inlet  22  to the mixing and conditioning section  18  to form the diffuser  24 . An inlet  27  of the diffuser  24  has a substantially smaller cross-sectional size than the outlet  28  of the diffuser  24 . The diffuser  24  is provided with an apparatus  30  to control a separation of the air flowing therethrough. The apparatus  30  is adapted to reduce aero-acoustic noise, improve a flow coverage of the heat exchanger  20  disposed in the mixing and conditioning section  18 , and minimize a pressure loss of the HVAC system. In the embodiment shown, a pressure loss coefficient of the apparatus  30  is less than two. The apparatus  30  can be an article integrally formed with the diffuser  24  or an article separately formed from the diffuser  24  and disposed therein. The apparatus  30  can be produced from any conventional material such as a plastic and metal, for example. 
     As illustrated in  FIG. 1 , the apparatus  30  includes a plurality of columns  32 . The columns  32  have a generally circular cross-sectional shape. It is understood that the columns  32  can have other shapes as desired. The columns  32  are spaced apart to form a plurality of air flow paths  33  therebetween. In the embodiment shown, the columns  32  extend horizontally across a diameter of the diffuser  24 , although it is understood that the columns  32  can extend across the diameter of the diffuser  24  in any direction such as vertically and diagonally, for example. 
     The apparatus  30  can also be a plate-like device  34  disposed in the diffuser  24 , as shown in  FIGS. 2 and 3 . The device  34  shown is generally rectangular in shape and extends across a width and a height of the diffuser  24 . In the embodiment shown in  FIG. 2 , the device  34  is substantially planar, although it is understood that the device  34  can have a substantially arcuate shape as shown in  FIG. 3 , if desired. The device  34  includes a plurality of perforations  36  formed therein to define a plurality of flow paths  37 . The perforations  36  cause a redistribution of the flow of air therethrough. The perforations  36  can be formed in the device  34  in a pattern having a number of the perforations  36  increase in a direction radially outwardly from the center of the device  34 , as illustrated in  FIG. 4 , or can be substantially uniformly spaced, as illustrated in  FIGS. 5  thru  12 . It is understood that the perforations  36  can be formed in the device  34  in other patterns as desired. 
     As shown in  FIGS. 4  thru  12 , the device  34  includes an upper edge  40 , a lower edge  42 , and opposing side edges  44 ,  46 . A plurality of apertures  48  may be formed in the device  34 . The apertures  48  can have any shape such as triangular, as shown in  FIG. 5 , rectangular, as shown in  FIG. 6 , and semi-circular, as shown in  FIG. 7 , for example. The apertures  48  increase the flow of air along the wall  26  of the diffuser  24 , reduce the separation of the flow of air therethrough, and minimize a pressure loss thereof. 
     As shown in  FIGS. 8  thru  12 , the device  34  can further include a tab  54  disposed in at least one of the apertures  48 . In the embodiment shown, the tab  54  is formed from a portion of the device  34  used to produce the apertures  48 . It is understood that the tab  54  can be formed separately from the device  34  and attached thereto, if desired. The tab  54  extends laterally from the device  34 , as shown in  FIGS. 10 and 12 , to generate a vortex in the flow of air therethrough. The vortex further increases the flow of air along the wall  26  of the diffuser  24 , reduces the separation of the flow of air through the device  34 , and minimizes a pressure loss thereof. The tab  54  has a substantially triangular shape, although it is understood that the tab  54  can have any shape and size as desired. Corners  56 ,  58  of a base  60  of the tab  54  can be disposed on respective sides  62 ,  64  of at least one of the apertures  48 , as shown in  FIGS. 8 and 9 . Alternatively, the corners  56 ,  58  and the base  60  can be disposed on one of the sides  62 ,  64  of at least one of the apertures  48 , as shown in  FIG. 11 . It is understood that the tab  54  can be disposed in the apertures  48  as desired. As illustrated in  FIGS. 9 and 11 , the tab  54  can include at least one perforation  68  formed therein. 
     In operation, the HVAC system conditions air by heating or cooling the air, and providing the conditioned air to the passenger compartment of the vehicle. Air from the supply of air is received in the housing  14  through the air inlet  22  by the blower wheel. During rotation of the blower wheel, air is caused to flow into the air flow conduit  15  of the inlet section  16 . From the air flow conduit  15 , the air flows into the diffuser  24  formed therein. The diffuser  24  reduces a flow velocity of the air flowing therethough and increases a pressure thereof. In the diffuser  24 , the air flows through the apparatus  30  to reduce the flow separation caused by the adverse pressure gradient produced by the sudden expansion at the inlet of the diffuser  24 . 
     When the apparatus  30  is the plurality of columns  32  as shown in  FIG. 1 , or the plate-like device  34  as shown in  FIGS. 2 and 3 , the stream of air is caused to flow through the respective flow paths  33 ,  37  and along the wall  26  of the diffuser  24 . The flow of air through the flow paths  33 ,  37  and along the wall  26  of the diffuser  24  causes a substantially even air flow distribution. Accordingly, the flow velocity and the pressure of the air flowing through the diffuser  24  is stabilized and controlled, minimizing the separation of air flow therethrough. Thus, noise and a loss of pressure thereof are minimized, and coverage of the heat exchanger  20  is maximized. 
     Additionally, when the device  34  includes the apertures  48  formed therein, air flow along the wall  26  of the diffuser  24  is increased. Moreover, when at least one of the apertures  48  includes the tab  54  disposed therein, a vortex is generated in the air stream flowing through the device  34 . The vortex also causes the air to flow along the wall  26  of the diffuser  24 . The increased air flow along the wall  26  of the diffuser  24  increases the flow velocity of the air along the wall  26  of the diffuser  24  further reducing the adverse pressure gradient and, thereby, the separation of air flow through the diffuser  24 . Accordingly, noise and the loss of pressure thereof are further minimized, and the coverage of the heat exchanger  20  is further maximized. 
     The air from the diffuser  24  then flows from the inlet section  16  into the mixing and conditioning section  18  of the housing  14 . In the mixing and conditioning section  18 , the air is conditioned to a desired temperature by at least one of the heat exchanger  20  and the heater core. The conditioned air stream then exits the mixing and conditioning section  18  and flows into and through the outlet and distribution section of the control module  10  to the passenger compartment of the vehicle. 
     From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.