Abstract:
A secondary loop air conditioning system for a vehicle that includes a condenser and an integrated assembly is disclosed. The condenser has a first condenser header spaced from a second condenser header, a condenser core extending between the first and second condenser headers, and a refrigerant inlet operatively engaging the first condenser header. The integrated assembly includes a chiller mounted to the first condenser header and having a liquid inlet and a liquid outlet configured to be in fluid communication with a secondary loop of the air conditioning system, and an expansion device in fluid communication with the condenser and mounted adjacent to the chiller for directing refrigerant into the chiller, and a refrigerant outlet. Also, a receiver/dryer area may be located in one of the condenser and the integrated assembly.

Description:
BACKGROUND OF INVENTION 
     The present invention relates generally to air conditioning systems for vehicles, and more particularly to secondary loop air conditioning systems. 
     In a typical secondary loop air conditioning system for a vehicle, a primary loop may include an engine driven compressor mounted for coupling to a front end accessory drive, a condenser mounted in a condenser, radiator, fan module (CRFM), an accumulator and expansion valve mounted separate from the compressor and condenser, and a refrigerant-to-liquid chiller mounted separately from the other components. The typical secondary loop air conditioning system may also include a secondary loop having a liquid-to-air heat exchanger mounted in a heating, ventilation and air conditioning (HVAC) module, a liquid reservoir and a pump for pumping the liquid through the chiller, heat exchanger and reservoir. While these secondary loop systems provide for some additional flexibility in configuring and operating the air conditioning system, they also add extra components and add additional packaging concerns when locating the components in the vehicle. Moreover, they may still require nearly as much refrigerant in the primary loop as conventional single loop refrigerant systems. 
     SUMMARY OF INVENTION 
     An embodiment contemplates an air conditioning system for a vehicle that may comprise a condenser and an integrated assembly. The condenser may have a first condenser header spaced from a second condenser header, a condenser core extending between the first and second condenser headers, and a refrigerant inlet operatively engaging the first condenser header. The integrated assembly may include a chiller mounted to the first condenser header and having a liquid inlet and a liquid outlet configured to be in fluid communication with a secondary loop of the air conditioning system, an expansion device in fluid communication with the condenser and mounted adjacent to the chiller for directing refrigerant into the chiller, and a refrigerant outlet. Also, a receiver/dryer area may be located in one of the condenser and the integrated assembly. 
     An embodiment contemplates an air conditioning system for a vehicle. The air conditioning system may include a refrigerant compressor, a condenser having a first condenser header spaced from a second condenser header, a condenser core extending between the first and second condenser headers, and a refrigerant inlet operatively engaging the first condenser header. The air conditioning system may also include an integrated assembly including a chiller mounted to the first condenser header and having a liquid inlet and a liquid outlet, an expansion device in fluid communication with the condenser and mounted adjacent to the chiller for directing refrigerant into the chiller, and a refrigerant outlet; a pump in fluid communication with the liquid outlet; and a cooler in fluid communication with the pump and the liquid inlet. 
     An embodiment contemplates an air conditioning system for a vehicle comprising a primary refrigerant loop and a secondary liquid loop. The primary refrigerant loop may include a refrigerant compressor; a condenser having a first condenser header spaced from a second condenser header, a condenser core extending between the first and second condenser headers, and a refrigerant inlet operatively engaging the first condenser header; an integrated assembly including a chiller mounted to the first condenser header, an expansion device in fluid communication with the condenser and mounted adjacent to the chiller for directing a refrigerant into the chiller, and a refrigerant outlet; and a sub-cool core located between the second condenser header and the integrated assembly and configured to direct the refrigerant from the second condenser header directly into the integrated assembly. The secondary liquid loop may include the chiller having a liquid inlet and a liquid outlet; a pump in fluid communication with the liquid outlet; and a cooler in fluid communication with the pump and the liquid inlet. 
     An advantage of an embodiment is that, by locating an integrated expansion device, chiller and receiver/dryer on a condenser header, a compact arrangement of components is created that allows for easier packaging in the vehicle. The number of lines extending between components is reduced. Also, a suction line length can be minimized by integrating the chiller on the same end of the condenser as the compressor is located. The compact arrangement of components for the refrigerant loop, then, allows for a minimal amount of refrigerant to be used in the overall air conditioning system. Moreover, the refrigerant does not enter the passenger compartment. Accordingly, some refrigerants that otherwise might not be suitable for use in a vehicle air conditioning system, such as flammable or mildly toxic refrigerants, may be used. 
     An advantage of an embodiment is that multiple cooling point air conditioning systems can be provided with a negligible increase in refrigerant charge versus a single point system. Only one chiller is used versus multiple evaporators for a conventional air conditioning system. This eliminates potential oil trapping issues that may arise with multiple cooling point (double evaporator) systems when a rear unit is turned off. 
     An advantage of an embodiment is that the expansion device mounted in the engine compartment with the integrated assembly, so the flow noise from this device is eliminated from the passenger compartment. Moreover, compressor working noise is greatly reduced or eliminated from the passenger compartment since the refrigerant lines do not enter the passenger compartment either. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic illustration of a vehicle air conditioning system. 
         FIG. 2  is a schematic illustration of an integrated expansion device, chiller and receiver/dryer assembly mounted to a condenser. 
         FIG. 3  schematic illustration similar to  FIG. 2 , but illustrating a second embodiment. 
         FIG. 4  is a schematic illustration similar to  FIG. 2 , but illustrating a third embodiment. 
         FIG. 5  is a schematic illustration similar to  FIG. 2 , but illustrating a fourth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a vehicle, indicated generally at  10 , is shown. The vehicle  10  includes an engine compartment  12  and a passenger compartment  14 , with an air conditioning system  16  mounted in portions of the compartments  12 ,  14 . The air conditioning system  16  has a primary (refrigerant) loop  18  and a secondary (liquid) loop  20 . 
     The primary loop  18  includes a compressor  22  and a refrigerant line  24  leading from a compressor output  26  to a refrigerant inlet  28  of a condenser  30 . The refrigerant lines in  FIG. 1  are illustrated as dash-dot-dash lines. The condenser  30  may be part of a condenser, radiator, fan module (CRFM)  31 . The primary loop  18  also includes an integrated expansion device, chiller, receiver/dryer assembly  32  that is mounted to the condenser  30 . The integrated assembly  32  has a refrigerant outlet  36  connected to a suction line  38  leading to an inlet  40  to the compressor  22 , thereby completing the primary loop  18 . Preferably, the integrated assembly  32  is mounted on the same end of the condenser  30  as the compressor  22  is located in order to minimize the length of the suction line  38 . The refrigerant contained in the primary loop  18  does not enter the passenger compartment  14 , and, given the compact arrangement of the components, the loop  18  is relatively small. Thus, types of refrigerants that might not otherwise be desirable for use in a passenger vehicle may be employed. 
     The secondary loop  20  includes a chiller  42  of the integrated assembly  32 , an expansion tank  44 , a pump  46 , a cooler  48 , and liquid lines  50  extending between these components. The liquid lines  50  are shown in  FIG. 1  as phantom lines to distinguish them from the refrigerant lines. The cooler  48  may be mounted in a HVAC module  52  in the passenger compartment  14 . The liquid in the secondary loop  20  may be, for example, a mix of water and ethylene glycol. Although, the liquid that flows through the secondary loop  20  may be comprised of other types of suitable liquids with desirable thermal transfer properties, if so desired. 
       FIG. 2  illustrates the integrated expansion device, chiller, receiver/dryer assembly  32  and condenser  30  of  FIG. 1  in more detail. The condenser  30  includes a first condenser header  34  upon which the refrigerant inlet  28  is located. The integrated assembly  32  is mounted to the first condenser header  34 . The condenser  30  also includes a condenser core  54  located above a sub-cool core  56 , which both extend to a second condenser header  58 . The sub-cool core  56  opens to a receiver/dryer area  60  in the integrated assembly  32 . 
     The receiver/dryer area  60  includes a desiccant  62  located therein, and opens to an expansion device  64 —which may be, for example, and orifice tube. The orifice device  64  directs the refrigerant into a chiller core  66  of the chiller  42 . Located opposite the chiller core  66  from the expansion device  64  is the refrigerant outlet  36  leading to the suction line  38 . A liquid inlet  68  to, and a liquid outlet  70  from the chiller  42  connect to the liquid lines  50  in the secondary loop. The integrated assembly  32  also includes a charge port  72  and a suction pressure sensor  74  mounted on top. One will note that most components of the refrigerant loop are integrated and packaged into a relatively small area. 
     The operation of the air conditioning system  16  will now be discussed relative to  FIGS. 1 and 2 . The unnumbered arrows in  FIGS. 2-5  represent the direction of flow of refrigerant and liquid into and out of the integrated assembly  32 . The compressor  22  and the pump  46  are driven, causing the refrigerant and the liquid to flow through the primary loop  18  and the secondary loop  20 , respectively. 
     In the primary loop  18 , after the refrigerant is compressed in the compressor  22 , the refrigerant flows through the refrigerant line  24  to the refrigerant inlet  28  on the first condenser header  34 . The refrigerant flows through the condenser core  54 , the second condenser header  58 , and the sub-cool core  56 . As with a conventional condenser, heat is transferred from the refrigerant to air flowing through the condenser  30 . From the sub-cool core  56 , the refrigerant flows into the receiver/dryer area  60  containing the desiccant  62 , where moisture is removed from the refrigerant. The refrigerant then flows through the expansion device  64 , dropping the temperature of the refrigerant, before flowing through the chiller  42 . The refrigerant then flows through the refrigerant outlet  36  and the suction line  38  and back to the compressor  22 . 
     In the secondary loop  20 , the liquid flows through the liquid inlet  68  and through the chiller core  66 , where heat is transferred to the refrigerant. The liquid then flows through the liquid outlet  70  and through one of the liquid lines  50  to the pump  46 . As the liquid flows past the expansion tank  44 , liquid may be removed from or added to the secondary loop  20 . The pump  46  pumps the liquid through another liquid line  50  to the cooler  48 , where it absorbs heat from air flowing through the HVAC module  52 . The liquid then flows back to the chiller inlet  68 . 
       FIG. 3  illustrates a second embodiment. Since this embodiment is similar to the first, similar element numbers will be used for similar elements, but employing 100-series numbers.  FIG. 3  shows an alternate embodiment of the integrated expansion device, chiller, receiver/dryer assembly  32  and condenser  30  shown in  FIG. 2 . 
     The integrated assembly  132  is still mounted to the first condenser header  134 , but the refrigerant inlet  128  is located on the bottom of the first condenser header  134  while the sub-cool core  156  is located on top of the condenser core  154 . The second condenser header  158  is still on the opposite side of the condenser core  154  from the integrated assembly  132 . The receiver/dryer area  160  and desiccant  162  are still adjacent to and receive refrigerant from the sub-cool core  156 , but now are located above the chiller  142 . The expansion device  164  directs the refrigerant downward from the receiver/dryer area  160  to the chiller core  166 . The refrigerant outlet  136  (connecting to the suction line  138 ) is located below the chiller core  166 . The charge port  172  and the suction pressure sensor  174  are now located near the bottom of the integrated assembly  132 . Also, the liquid inlet  168  is now located below the liquid outlet  170 . The operation of the air conditioning system  116  is essentially the same as in the first embodiment and so will not be discussed further. 
       FIG. 4  illustrates a third embodiment. Since this embodiment is similar to the first, similar element numbers will be used for similar elements, but employing 200-series numbers.  FIG. 4  shows another alternate embodiment of the integrated expansion device, chiller, receiver/dryer assembly  32  and condenser  30  shown in  FIG. 2 . 
     The integrated assembly  232  is still mounted to the first condenser header  234 , but the refrigerant inlet  228  is now located on the bottom of the first condenser header  234  while the sub-cool core  256  is located on top of the condenser core  254 . The second condenser header  258  is still on the opposite side of the condenser core  254  from the integrated assembly  232 , but the receiver/dryer area  260  and the desiccant  262  are located in the second condenser header  258 . The expansion device  264  is mounted on top of the chiller  242  and directs refrigerant downward into the chiller core  266 . The chiller  242  is a plate type of heat exchanger, with the refrigerant outlet  236  extending from the bottom of the chiller  242 . The liquid inlet  268  is located adjacent to the refrigerant outlet  236 , and the liquid outlet  270  is located above the liquid inlet  268 . 
       FIG. 5  illustrates a fourth embodiment. Since this embodiment is similar to the first, similar element numbers will be used for similar elements, but employing 300-series numbers.  FIG. 5  shows an alternate embodiment of the integrated expansion device, chiller, receiver/dryer assembly  32  and condenser  30  shown in  FIG. 2 . 
     The integrated assembly  332  is again mounted to the first condenser header  334 , with a condenser core  354  and sub-cool core  356  mounted between the first condenser header  334  and the second condenser header  358 . An expansion device  364  is mounted adjacent to and receives refrigerant from the sub-cool core  356 . An oil ring  376  is located between the expansion device  364  and the chiller core  366 . The chiller core  366  may be a vertical extrusion. Another oil ring  378  is located above the chiller core  366 , with a snap retainer  380  above the oil ring  378 . The refrigerant outlet  336  extends upward above the snap retainer  380 . Also, the liquid inlet  368  and liquid outlet  370  extend upward above the snap retainer  380 . 
     While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.