Abstract:
A seat temperature control system having a temperature controlled seat for use in a vehicle is disclosed. The temperature controlled seat may comprise a seat bottom, a seat back and an air conditioning system. The seat bottom includes a bottom heat exchanger fluid coil configured to direct a cooling fluid therethrough from a bottom inlet end to a bottom outlet end. The seat back includes a back heat exchanger fluid coil configured to direct the cooling fluid therethrough from a back inlet end to a back outlet end. The air conditioning system includes a coils inlet line in fluid communication with the bottom inlet end and the back inlet end, and a coils outlet line in fluid communication with the bottom outlet end and the back outlet end. The air conditioning system provides cooling fluid to the coils and receives cooling fluid from the coils.

Description:
BACKGROUND OF INVENTION 
       [0001]    The present invention relates generally to temperature controlled vehicle seats, and more particularly to vehicle seats having coils therein for passing refrigerant or coolant therethrough. 
         [0002]    In order to improve the comfort of passengers in automotive vehicles, some have supplemented the vehicle heating, ventilation and air conditioning (HVAC) system with heated or cooled seats. For example, some seats include an electric element that heats up when a current is passed through it. Others route some of the cooled air from the HVAC system through the seats. While others employ thermoelectric based seat heating and cooling. These arrangements are meant to improve the passenger comfort by supplementing the heating or cooling provided by the vehicle HVAC system. But these seat systems do not achieve the heating and/or cooling as efficiently as is desired. 
       SUMMARY OF INVENTION 
       [0003]    An embodiment contemplates a temperature controlled seat for use in a vehicle. The temperature controlled seat may comprise a seat bottom, a seat back and an air conditioning system. The seat bottom extends in a generally horizontal direction and includes a bottom heat exchanger fluid coil therein, with the bottom heat exchanger fluid coil configured to direct a cooling fluid therethrough from a bottom inlet end to a bottom outlet end. The seat back is located adjacent to the seat bottom and extends in a generally vertical direction and includes a back heat exchanger fluid coil therein, with the back heat exchanger fluid coil configured to direct the cooling fluid therethrough from a back inlet end to a back outlet end. The air conditioning system includes a coils inlet line in fluid communication with the bottom inlet end and the back inlet end, and a coils outlet line in fluid communication with the bottom outlet end and the back outlet end, with the air conditioning system configured to provide the cooling fluid to the coils inlet line and receive the cooling fluid from the coils outlet line. 
         [0004]    An embodiment contemplates a seat temperature control system for a vehicle. The seat temperature control system may include a first temperature controlled seat and a first air conditioning system. The first temperature controlled seat includes a first seat bottom and a first seat back, with at least one of the first seat bottom and the first seat back including a first heat exchanger fluid coil therein configured to direct a cooling fluid therethrough from a first inlet end to a first outlet end. The first air conditioning system includes a first coils inlet line in fluid communication with the first inlet end and a first coils outlet line in fluid communication with the first outlet end, with the first air conditioning system configured to provide the cooling fluid to the first coils inlet line and receive the cooling fluid from the first coils outlet line. 
         [0005]    An embodiment contemplates a seat temperature control system for a vehicle comprising a temperature controlled seat and a refrigeration unit. The temperature controlled seat includes a seat bottom and a seat back, at least one of the seat bottom and the seat back includes a heat exchanger fluid coil therein configured to direct a refrigerant therethrough from an inlet end to an outlet end. The refrigeration unit is mounted adjacent to at least one of the seat back and the seat bottom and includes an expansion device in fluid communication with the inlet end, a condenser in fluid communication with the expansion device, and an electrically driven compressor in fluid communication with the condenser and the outlet end. 
         [0006]    An advantage of an embodiment is that the cooling and/or heating of vehicle seats is achieved relatively efficiently, thus providing additional passenger comfort with high efficiency. That is, improved time to occupant comfort is achieved with reduced energy consumption versus previous seat thermal management systems. Also, the cooling and/or heating of the seats can be accomplished before an occupant enters the vehicle, thus further improving passenger comfort. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0007]      FIG. 1  is a schematic, front elevation view of a temperature controlled vehicle seat. 
           [0008]      FIG. 2  is a schematic, side elevation view of a temperature controlled vehicle seat. 
           [0009]      FIG. 3  is a schematic view of a seat temperature control system. 
           [0010]      FIG. 4  is a schematic view of a second embodiment of a seat temperature control system. 
           [0011]      FIG. 5  is a schematic view of a third embodiment of a seat temperature control system. 
           [0012]      FIG. 6  is a schematic view of a fourth embodiment of a seat temperature control system. 
           [0013]      FIG. 7  is a schematic view of a fifth embodiment of a seat temperature control system. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIGS. 1-2 , a temperature controlled seat, indicated generally at  10 , is shown. The temperature controlled seat  10  includes a seat bottom  12  and a seat back  14 . The seat bottom  12  may include a seat fan  15  for moving air through the seat bottom  12 . Alternatively or in addition, a seat back fan (not shown) may also be employed. The seat back  14  includes heat exchanger fluid coils  16 , and the set bottom  12  includes heat exchanger fluid coils  18 . A coils inlet line  20  connects to the fluid coils  16 ,  18  for directing a fluid, such as refrigerant or a liquid coolant, into the fluid coils  16 ,  18 . A coils outlet line  22  connects to the fluid coils  16 ,  18  for receiving the fluid from the coils  16 ,  18 . The coils inlet and outlet lines  20 ,  22  connect to refrigerant systems (not shown in  FIGS. 1 and 2 ), which will be discussed below relative to the various embodiments. 
         [0015]      FIG. 3  illustrates a first embodiment of a seat temperature control system  24  having a pair of temperature controlled seats  10 . The seats  10  may be, for example, a vehicle right front seat and left front seat. Of course, other numbers of seats  10  may be employed in this system  24 . Each seat  10  has a seat bottom  12 , with heat exchanger fluid coils  18 , and a seat back  14 , with heat exchanger fluid coils  16 . The coils inlet and outlet lines  20 ,  22  for the left and right seats  10  connect, respectively, to left and right miniature refrigeration units  26 , which form part of the seat temperature control system  24 . 
         [0016]    Each miniature refrigeration unit  26  includes a refrigerant compressor  28 , a condenser  30 , a fan  32  for moving air through the condenser  30 , and an expansion device  34 . The compressors  28  may include integrated electric motors or, alternatively, separate electric motors (not shown) may drive each of the compressors  28 . Each fan  32  may also be driven by an electric motor. The expansion devices  34  may be, for example, orifice tubes, thermal expansion valves, or capillary lines. 
         [0017]    The operation of the seat temperature control system  24  will now be discussed with reference to  FIGS. 1-3 . Upon a vehicle occupant requesting seat cooling for a particular seat  10 , the compressor  28  and fan  32  for that seat  10  are activated. A vehicle HVAC system does not have to be operating for the seat cooling to take place. Refrigerant compressed by the compressor  28  flows through the condenser  30  where heat is removed. The refrigerant then flows through the expansion device  34 , dropping the temperature of the refrigerant, and then flows through the coils inlet line  20  to the heat exchanger fluid coils  16 ,  18 , of the seat back  14  and seat bottom  12 , respectively. The heat exchanger fluid coils  16 ,  18  in effect act as an evaporator in a refrigerant loop, absorbing heat from the seat  10 . The seat fan  15  may also be activated in order to facilitate heat transfer. The cooled seat  10 , then, cools the vehicle occupant. Since each seat  10  has its own miniature refrigeration unit  26 , each may have separate controls to allow for different rates of cooling for each seat  10 . 
         [0018]    Also, since the vehicle HVAC system does not need to be operating, the seat cooling may be accomplished as a preconditioning event prior to occupants entering the vehicle. For example, preconditioning of the seat  10  may occur simultaneously with a remote engine start feature on a hot day or may be a separate remotely activated feature. 
         [0019]    On the other hand, if the HVAC system is operating during seat cooling, then the amount of seat cooling can be used as a factor to adjust the main HVAC system. That is, if the seat is at a certain temperature due to seat cooling, then the HVAC control temperature may be offset to account for this. Thus, the power consumption of the HVAC system may be reduced. 
         [0020]      FIG. 4  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. While only one temperature controlled seat  110  is shown, more than one seat in a vehicle may be included as part of the seat temperature control system  124 . 
         [0021]    In this embodiment, the seat bottom and back  112 ,  114  still include heat exchanger fluid coils  118 ,  116 , respectively. And, the heat exchanger fluid coils  116 ,  118  are connected to the miniature refrigeration unit  126 . This miniature refrigeration unit  126 , however, can now operate as a heat pump, thus providing both cooling and heating to the seat  110 . The refrigeration unit  126  includes the expansion device  134 , condenser  130  and fan  132 . The refrigeration unit  126  also includes the compressor  128  connected to a four-way valve  138 , allowing for the reversal in direction of flow of the refrigerant through the fluid coils  116 ,  188 , expansion device  134  and condenser  130 , thus allowing for seat heating in addition to seat cooling. While this refrigeration unit  126  may add more cost and complexity versus the cooling only unit of  FIG. 3 , it provides the additional capability of heating the seat  110 . 
         [0022]      FIG. 5  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. While only one temperature controlled seat  210  is shown, more than one seat in a vehicle may be included as part of the seat temperature control system  224 . 
         [0023]    In this embodiment, the heat exchanger fluid coils  216  in the seat back  214  have a separate coils outlet line  240  connecting to the miniature refrigeration unit  226 . This coils outlet line  240  includes a seat back shut-off valve  242  that can selectively stop the flow of refrigerant through the seat back fluid coils  216 . Also, the coils outlet line  222  extending from the fluid coils  218  in the seat bottom  212  includes a seat bottom shut-off valve  244  that can selectively stop the flow of refrigerant through the seat bottom fluid coils  218 . This provides added flexibility for the temperature controlled seat  210  in that a seat occupant may wish to only cool the seat back  214  or the seat bottom  212  rather than both. 
         [0024]    The seat temperature control system  224  of this embodiment may include the additional functionality of the heat pump refrigeration unit described with reference to  FIG. 4 . In addition, to reduce the cost, one may employ only one of the two shut-off valves  242 ,  244 —even though the functionality is now reduced somewhat. 
         [0025]      FIG. 6  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. This seat temperature control system  324  is shown with four temperature controlled seats  310 , a right front seat, a left front seat, a right rear seat and a left rear seat. The number of seats  310  shown is only an example, and other numbers of seats may be included in the seat temperature control system  324 . 
         [0026]    In this embodiment, the refrigerant for the temperature controlled seats  310  is provided by the vehicle refrigerant system  326 . The vehicle refrigerant system  326  includes a compressor  328 , a condenser  330  and a fan  332 , but the refrigerant flowing from the condenser  330  does not all flow through an expansion device  346  leading to an HVAC module evaporator  348 . Some of the refrigerant is directed to individual expansion devices  334 , each connected to the coils inlet line  320  for the corresponding seat  310 . Each seat  310  also includes fluid coils  318  in the seat bottom  312  and fluid coils  316  in the seat back  314  and may include a seat fan  315 . 
         [0027]    While this embodiment minimizes the number of compressors and condensers in the vehicle (versus the previously discussed embodiments) and thus the cost, seat cooling is limited to operating only when the overall vehicle refrigerant system  326  is operating. 
         [0028]      FIG. 7  illustrates a fifth embodiment. Since this embodiment is similar to the fourth, similar element numbers will be used for similar elements, but employing 400-series numbers. 
         [0029]    As with the fourth embodiment a vehicle air conditioning system  426  is employed rather than miniature refrigeration units for each seat in the seat temperature control system  424 . However, this air conditioning system  426  is a secondary loop type of system. That is, the refrigerant (primary) loop  452  may be contained entirely within an engine compartment  454  of a vehicle  456 . The primary loop  452  may include a compressor  428 , a condenser  430 , a fan  432  and an expansion device  434 . Also, a refrigerant-to-liquid heat exchanger  458  is part of the primary loop  452  and a secondary (coolant) loop  460 . 
         [0030]    The secondary loop  460  employs a liquid, such as, for example, engine coolant, which transfers its heat to the refrigerant in the refrigerant-to-liquid heat exchanger  458 . The secondary loop  460  may also include a liquid pump  462 , a coolant inlet line  464  that directs the liquid to a chiller  466  and to coils inlet lines  420 , coils outlet lines  422  that direct coolant back to the refrigerant-to-liquid heat exchanger  458 , and seat back fluid coils  416  and seat bottom fluid coils  418  for each seat  410  that connect between the corresponding coils inlet and outlet lines  420 ,  422 . The secondary loop  460  may be located partially in the engine compartment  454  and partially in a passenger compartment  468  of the vehicle  456 . 
         [0031]    Each seat  410  may also have a seat shut-off valve  470  for selectively blocking the flow of coolant into the coils  416 ,  418  for that particular seat  410 . Accordingly, seats where no one is sitting will not be cooled. In addition, an extra valve and coolant line (not shown) may be added for each seat to allow the additional flexibility of controlling seat back cooling separate from seat bottom cooling (similar to that shown in  FIG. 5 ). Also, each seat may have a seat fan  415  for facilitating the cooling effect for the seat occupants. 
         [0032]    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.