Abstract:
The present disclosure provides a system for controlling the climate of a vehicle. The system includes a thermoelectric module and a heat exchanger. The thermoelectric module includes thermoelectric elements powered by electric energy. The thermoelectric elements emit or absorb heat energy based on the polarity of the electrical energy provided. The thermoelectric module and the heat exchanger heat or cool the air flow provided to the cabin of the vehicle.

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
       [0001]    Any and all applications for which a foreign or domestic priority claim are identified in the Application Data Sheet as filed with the present application, are incorporated by reference, and made a part of this specification. 
       BACKGROUND 
       [0002]    Field 
         [0003]    The present invention generally relates to a climate control system for hybrid vehicles. 
         [0004]    Description of Related Art 
         [0005]    Hybrid vehicles, vehicles driven by both an internal combustion engine and an electric motor, are becoming more well known. For hybrid vehicles to increasingly become commercially adopted, these vehicles need to provide the same features and comforts as current traditional vehicles. In order to achieve maximum efficiency, hybrid vehicles employ a start/stop strategy, meaning the vehicle&#39;s internal combustion engine shuts down to conserve energy during normal idle conditions. During this period, it is still important to maintain comfort in the vehicle. In order to keep the cabin comfortable during cool temperatures, coolant is generally circulated through the heater core to provide cabin heat. However, in warm weather climates, the only method for keeping the cabin cool is by running the internal combustion engine to drive the compressor of an air conditioning system. Vehicles on the road today with such start/stop strategies allow the consumer to keep the engine running, while stopped at idle conditions, to maintain cabin comfort. Unfortunately, running the engine during vehicle idle periods eliminates the fuel economy savings obtained by shutting off the engine during idle operation. 
         [0006]    As seen from the above, it is apparent that there exists a need for an improved climate control system for hybrid vehicles. 
       SUMMARY 
       [0007]    In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides a system for controlling the climate within the passenger cabin of a hybrid vehicle. The system includes a thermoelectric module, a heat exchanger, a pump, and a valve. 
         [0008]    The thermoelectric module includes thermoelectric elements, powered by electric energy, that emit or absorb heat energy based on the polarity of the electrical energy provided. A tube containing coolant runs proximate to the thermoelectric elements. To aid in the transfer of heat energy, a blower is provided to generate an air flow across the thermoelectric elements and the tube. The coolant is provided from the thermoelectric module to a heat exchanger that heats or cools the air flow provided to the cabin of the vehicle. The pump pressurizes the coolant flow through the tube and coolant lines, and in a cooling mode, the valve is configured to selectively bypass the engine coolant system of the vehicle. 
         [0009]    In another aspect of the present invention, the system includes a heater core and an evaporator in fluid communication with the heat exchanger. The air flow to the passenger cabin may be supplementally heated by the heater core or supplementally cooled by the evaporator. 
         [0010]    In another aspect of the present invention, the system includes a controller in electrical communication with the thermoelectric module. The controller is configured to switch the polarity of electrical energy supplied to the thermoelectric module to alternatively heat or cool the coolant. In addition, the controller is configured to direct electrical energy generated by a regenerative braking system to the thermoelectric module for use in controlling the interior climate of the vehicle. 
         [0011]    Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a block diagram of a climate control system, in a supplemental cooling mode, embodying the principles of the present invention; 
           [0013]      FIG. 2  is a sectional front view of a thermoelectric module embodying the principles of the present invention; 
           [0014]      FIG. 3  is a block diagram of a climate control system, in a supplemental cooling mode, embodying the principles of the present invention; 
           [0015]      FIG. 4  is a block diagram of a climate control system, in a supplemental heating mode, embodying the principles of the present invention; and 
           [0016]      FIG. 5  is a block diagram of a climate control system, in an engine off cooling mode, embodying the principles of the present invention. 
           [0017]      FIG. 6  is a block diagram of a climate control system, in an engine off heating mode, embodying the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring now to  FIG. 1 , a system embodying the principles of the present invention is illustrated therein and designated at  10 . As its primary components, the system  10  includes a thermoelectric module  12 , a heat exchanger  14 , an evaporator  16 , a heater core  18 , a valve  22 , a coolant pump  26 , and a controller  27 . As further discussed below, the thermoelectric module  12 , in conjunction with the heat exchanger  14 , allows the system  10  to provide heating or cooling with the internal combustion engine shut off, or alternatively, to provide supplemental heating or cooling while the internal combustion engine is running. 
         [0019]    Now referring to  FIG. 2 , a sectional view of the thermoelectric module  12  is provided. The thermoelectric module  12  includes a series of thermoelectric elements  48  that generate a temperature change from electrical energy. If the electrical energy is provided in one polarity, the thermoelectric elements  48  will generate heat energy causing a rise in the ambient temperature around the thermoelectric elements  48 . Alternatively, if electrical energy is provided to the thermoelectric elements  48  in an opposite polarity, the thermoelectric elements  48  will absorb heat energy, thereby cooling the ambient temperature around the thermoelectric elements  48 . To transfer heating or cooling from the thermoelectric elements  48 , a heat transfer medium, namely coolant, flows through a coolant tube  42  located proximate to the thermoelectric elements  48 . To aid in this heat transfer to the coolant, one or more blowers  40  generate an air flow across the thermoelectric elements  48  and the coolant tube  42 . In addition, an air scoop  50  may be provided to direct air leaving or entering the thermoelectric module  12 . The coolant is provided to the thermoelectric elements  48  circulates through an inlet connection  44  to the rest of the system through an outlet connection  46 , thereby enabling the transferring of the temperature change generated by the thermoelectric elements  48 . 
         [0020]    Referring again to  FIG. 1 , the thermoelectric module  12  is in fluid communication, via the coolant, with the heat exchanger  14  along line  30 . The blower  15  creates an air flow  20  across the heat exchanger  14 , and the air flow  20  extracts heating or cooling from the coolant supplied by the thermoelectric module  12  thereby altering the temperature of the air flow  20 . In a heating mode, the thermoelectric module  12  provides heated coolant thereby heating the air flow  20 . Alternatively in a cooling mode, the thermoelectric module  12  provides cooled coolant, thereby cooling the air flow  20 . From the heat exchanger  14  the air flow  20  is communicated over heat transfer surfaces of both the evaporator  16  and heater core  18 . 
         [0021]    The coolant exits the heat exchanger  14  along line  32  and is provided to valve  22  that selectively allows the coolant to flow along line  38  into the engine coolant system  24  or back to the coolant pump  26 . Generally, the engine coolant system  24  will heat the coolant and return a portion of the coolant along line  36  to the heater core  18  and to the valve  22  which passes it back to the coolant pump  26 . Alternatively, the valve  22  can solely direct the coolant from line  32  directly to line  34 , bypassing the engine coolant system  24 . This latter flow circuit is particularly beneficial in the cooling mode of the system  10 . 
         [0022]    The controller  27  allows the system to work in multiple heating and cooling modes. For example, the controller  27  can switch the polarity of the electrical energy provided to the thermoelectric module, thereby heating the coolant with one polarity, and cooling the coolant with the opposite polarity. In addition, the controller  27  can manipulate the valve  22  to bypass the engine cooling system  24  in cooling mode, thereby isolating the coolant from the heat generated by the engine in the engine coolant system  24 . 
         [0023]    The controller  27  is also connected to a regenerative braking system  29 . The regenerative braking system  29  generates electrical energy from the kinetic energy of the vehicle as the vehicle is slowed down. The controller  27  can direct the energy from the regenerative braking system  29  to an energy storage device, a battery, (not shown) or directly to the thermoelectric module  12 , providing an ample source of power to adjust the climate of the vehicle. If provided directly to the thermoelectric module  12 , the controller  27  can change the polarity of the electrical energy provided from the regenerative braking system  29  allowing the energy to be used by the thermoelectric module  12  in both heating and cooling modes. 
         [0024]    Now referring to  FIG. 3 , the system  10  is shown in a supplemental cooling mode while the internal combustion engine is running. During “engine on” supplemental cooling, the thermoelectric module  12  is used in conjunction with the evaporator  16  to cool the passenger cabin of the vehicle. The combined use of the thermoelectric module  12  and the evaporator  16  provides a faster time to comfort. As illustrated in  FIG. 3 , the lines with a single small dash convey heated coolant from the heat exchanger  14  while the lines with two smaller dashes convey cooled coolant to the heat exchanger  14 . 
         [0025]    In the “engine on” supplemental cooling mode, the coolant flows through the thermoelectric module  12 , where heat is removed from the coolant, and thereafter along line  30  to the heat exchanger  14 . The heat exchanger  14  cools the air flow  20  which is then provided to the evaporator  16  for additional cooling before it flows to the passenger cabin of the vehicle. From the heat exchanger  14 , coolant flows along line  32  to the valve  22 , which is manipulated by the controller  27  to bypass the engine coolant system  24  thereby isolating the coolant from the heat generated by the engine. From the valve  22  the coolant flows along line  34  to the coolant pump  26  where the coolant flow is pressurized then provided back to the thermoelectric module  12  along line  28 . In this mode of operation, the thermoelectric module  12  operates for the first couple minutes to quickly pull down the temperature of the air flow  20 . If the temperature of the air coming into the heat exchanger  14  is less than the temperature of the air flowing into the thermoelectric module  12 , the thermoelectric module  12  and pump  26  are not operated thereby conserving vehicle energy. 
         [0026]    The system  10  in “engine on” supplemental heating mode is seen in  FIG. 4 . In the “engine on” supplemental heating mode, the thermoelectric module  12  is used in conjunction with the heater core  18 . Using the thermoelectric module  12  in combination with the heater core  18  provides a faster time to comfort. Warm coolant from the engine is pumped through the thermoelectric module  12  where further heat is added. The coolant flows from the thermoelectric module  12  along line  30  to the heat exchanger  14 , upstream of the heater core  18 . The heat exchanger  14  first heats the air flow  20  that is received by the heater core  18 . The heater core  18  emits heat from the engine coolant system  24  to further heat the air flow  20  before it is provided to the passenger cabin of the vehicle. 
         [0027]    Coolant from the heat exchanger  14  is passed along line  32  to the valve  22 , which in the supplemental “engine on” heating mode, allows coolant to return to the engine coolant system along line  38 . The engine coolant system  24  provides heat from the engine to the coolant, some of which then flows to the heater core  18  and along line  36  to the valve  22 . From the valve  22 , the coolant flows along line  34  through the coolant pump  26  and returns along line  28  to the thermoelectric module  12 . If the engine coolant system  24  provides sufficient means for pumping the coolant through the system, the coolant pump  26  is deactivated in this mode. Preferably, the thermoelectric module  12  operates for the first couple of minutes of heat up, and ceases to operate when the temperature of the coolant from the engine alone reaches the desired temperature to provide proper passenger cabin heating. 
         [0028]    Now referring to  FIG. 5 , an “engine off” cooling mode is provided. The “engine off” cooling mode is used to maintain a comfortable cabin for a limited amount of time during an idle engine shutdown. In this mode, the evaporator is non-operative as the engine has been shut down. The cooling provided by the thermal inertia in the coolant and the thermoelectric module  12  allows the engine to shutdown and save fuel, while still allowing the passenger cabin to be cooled. 
         [0029]    Coolant flows through the thermoelectric module  12  where heat is removed from the coolant. From the thermoelectric module  12 , the coolant flows along line  30  to the heat exchanger  14 . Heat is absorbed by the coolant from the air flow  20  in the heat exchanger  14 . The coolant flows from the heat exchanger  14  along line  32  to the valve  22 . Manipulated by the controller  27  to bypass the engine coolant system  14 , the valve  22  isolates the coolant from the engine heat. The coolant flows from the valve  22  along line  34  back to the coolant pump  26 , which generates coolant flow by pressurizing the coolant in the lines. The coolant is then received back by thermoelectric module  12  along line  28 , where heat is absorbed from the coolant again. 
         [0030]    The controller  27  monitors vehicle speed and braking to predict if a stop is imminent. If a stop is predicted, regenerating braking energy from the regenerative braking system  29  is used by the thermoelectric module  12  to cool the coolant. During the stop, the thermoelectric module  12  continues to operate to maintain the cool coolant temperature as heat is added from the cabin. 
         [0031]    Now referring to  FIG. 6 , an “engine off” heating mode is schematically shown. The “engine off” heating mode is used to maintain a comfortable cabin temperature for a limited amount of time during an idle engine shutdown. The heat provided by the thermoelectric module  12 , the thermal inertia in the coolant, and the thermal inertia in the engine block allows the system  10  to heat the cabin of the vehicle while allowing the engine to shutdown and save fuel. 
         [0032]    In this mode of operation, warm coolant from the engine is pumped by the coolant pump  26  through the thermoelectric module  12  where heat is added. Coolant flows from the thermoelectric module  12  along line  30  to the heat exchanger  14 . In the heat exchanger  14 , heat is absorbed by the air flow  20  from the coolant. The heated air flow  20  is then provided to the heater core  18  where before the air flow  20  is provided to the cabin, further heat is absorbed from the coolant provided by the engine coolant system  24 , The cooled coolant then flows from the heat exchanger  14  along line  32  to the valve  22 , which is opened to provide the coolant to the engine coolant system  24 . The engine coolant system  24  adds heat from the engine block to the coolant, which is returned to the heater core  18  and along line  36  to the valve  22  and the coolant pump  26 . If the engine coolant system  24  has a pump to provide sufficient coolant pressure through the system  10 , the coolant pump  26  is deactivated. From the pump  26 , the coolant flows along line  28  back to the thermoelectric module  12  where further heat is added. In addition, the controller  27  monitors the vehicle speed and braking to predict if a stop is imminent. If a stop is predicted, the regenerative braking energy from the regenerative braking system  29  is used by the thermoelectric module  12  to heat the coolant. During the stop, the thermoelectric module  12  continues to operate and maintain the warm coolant temperature as heat is removed from the cabin. 
         [0033]    As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims.