Abstract:
An engine fuel and air cooling system for vehicles exchanges heat between a coolant and air conditioning system refrigerant. The system provides a cabin cooling only mode, a cabin and engine fuel and air cooling mode, and an engine fuel and air cooling only mode. A refrigerant distribution manifold distributes the refrigerant for each mode. The engine fuel and air cooling is provided to a supercharger intercooler to cool air provided to the engine, and to fuel rails to cool fuel provided to the engine. In one embodiment the fuel rails include an inner fuel path surrounded by a coolant path to cool the fuel provided to fuel injectors.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a Continuation in Part of U.S. patent application Ser. No. 13/135,062, filed Jun. 24, 2011 and is a Continuation in Part of U.S. patent application Ser. No. 14/076,253 filed Nov. 10, 2013, which applications are incorporated in its entirety herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to internal combustion engines and in particular to reducing the temperature of fuel and air provided to the engines to improve performance. 
         [0003]    Many modern vehicles have small displacement supercharged or turbo charged engines to improve mileage, or moderate to large displacement supercharged or turbo charged engines to improve performance. An unavoidable consequence of supercharging or turbo charging is an increase in intake air temperature. The increased air temperature may cause detonation (e.g., pre-ignition or pinging) under acceleration when the fuel air mixture is ignited prematurely, and limits the amount of boost (increased air pressure) which may be used. Uncontrolled detonation may damage or destroy the engine. 
         [0004]    Heat enchanters, commonly referred to as intercoolers, are often added to supercharged or turbo charged engines between the supercharger or turbo charger and the engine to at least somewhat cool the intake air. These intercoolers maybe air to air, or air to coolant. The air to coolant intercoolers require a second coolant to air heat exchanger in an ambient air stream to cool the coolant. Unfortunately, it is often difficult to obtain the desired amount of cooling with known intercoolers, thus limiting potential of the supercharger of turbo charger to increase performance. 
         [0005]    Additionally, detonation may be reduced by cooling the liquid fuel provided to the engine, having a similar effect as cooling the intake air. Common methods for cooling liquid fuel include containers filled with ice and coiled fuel lines passing through the containers. Unfortunately, the fuel may be immediately heated upon leaving the container, and the ice melts quickly, making this approach only useful for a very brief period of time. 
         [0006]    U.S. Pat. No. 6,269,804 discloses fuel rails having a coolant line running therethrough. Unfortunately, the fuel is exposed to the fuel rail housing, and presence of the coolant line provides very little reduction in fuel temperature. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention addresses the above and other needs by providing an engine fuel and air cooling system for vehicles which exchanges heat between a coolant and air conditioning system refrigerant. The system provides a cabin cooling only mode, a cabin and engine fuel and air cooling mode, and an engine fuel and air cooling only mode. A refrigerant distribution manifold distributes the refrigerant for each mode. The engine fuel and air cooling is provided to a supercharger intercooler to cool air provided to the engine, and to fuel rails to cool fuel provided to the engine. In one embodiment the fuel rails include an inner fuel path surrounded by a coolant path to cool the fuel provided to fuel injectors. 
         [0008]    In accordance with one aspect of the invention, there is provided a fuel and air cooling system including primary and secondary expansion valves for fuel and air cooling. The primary expansion valve is sized to operate with the cabin air conditioning on and is generally between 0.25 and one tons. The secondary expansion valve is sized between 1.5 and 2 ton to operate with the primary expansion valve when the cabin air conditioning of off. Thus, the combined primary and secondary fuel and air circuit expansion valve tonnage is between 1.75 and 3 tons. 
         [0009]    In accordance with another aspect of the invention, there is provided a fuel and air cooling system including a manifold block. A cabin valve, primary and secondary fuel and air circuit valves, and primary and secondary fuel and air circuit expansion valves reside in a manifold block. The manifold block provide a compact and efficient arrangement of the cabin valve, the primary and secondary fuel and air circuit valves, and the primary and secondary fuel and air circuit expansion valves. Because modern vehicles have only limited space for added equipment, the compact arraignment of the cabin valve, the primary and secondary fuel and air circuit valves, and the primary and secondary fuel and air circuit expansion valves is important in adapting the fuel and air cooling system to many vehicles. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0010]    The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
           [0011]      FIG. 1  is a general diagram of a fuel and air cooling system according to the present invention, for use with an internal combustion engine. 
           [0012]      FIG. 2  is a diagram of the fuel and air cooling system according to the present invention, with refrigerant cool features turned off. 
           [0013]      FIG. 3  shows a typical physical layout of the fuel and air cooling system according to the present invention, with refrigerant cool features turned off. 
           [0014]      FIG. 4  is a diagram of the fuel and air cooling system according to the present invention, with refrigerant cooling provided to cabin interior only. 
           [0015]      FIG. 5  is a diagram of the fuel and air cooling system according to the present invention, with refrigerant cooling provided to cabin interior and partially to the fuel and air. 
           [0016]      FIG. 6  is a diagram of the fuel and air cooling system according to the present invention, with refrigerant cooling provided to the fuel and air only. 
           [0017]      FIG. 7  shows a refrigerant manifold according to the present invention. 
           [0018]      FIG. 8  is an exploded view of a coaxial fuel and coolant rail according to the present invention. 
           [0019]      FIG. 9  shows fuel cooling blocks clamped over fuel lines entering fuel injector hats according to the present invention. 
           [0020]      FIG. 10  shows a cross-sectional view of the fuel cooling blocks according to the present invention. 
       
    
    
       [0021]    Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. 
         [0023]    Where the terms “about” or “generally” are associated with an element of the invention, it is intended to describe a feature&#39;s appearance to the human eye or human perception, and not a precise measurement. 
         [0024]    The term “fuel” is used herein to refer to liquid fuel (gasoline, diesel, alcohol and the like) mixed with air for combustion in internal combustion engines. 
         [0025]    The term “supercharger” is used hereafter to refer to any type of forced induction device including belt driven superchargers and turbo superchargers. 
         [0026]    The term “refrigerant” is used herein to refer to common refrigerants used in automotive air conditioning systems. Preferred refrigerants have a vaporization temperature at or below −61 degrees Fahrenheit at ambient pressure. 
         [0027]    The term “coolant” is used herein to refer to common liquid coolant used to cool internal combustion engines. These include, water, glycol, a water and rust inhibitor mix, a water glycol mix, and the like. Coolants have a vaporization temperature above 212 degrees Fahrenheit at ambient pressure. 
         [0028]    A general diagram of a fuel and air cooling system  10  according to the present invention, for use with an internal combustion engine, is shown in  FIG. 1 . The fuel and air cooling system  10  includes a flow of fuel  12  from a fuel tank  11 , a flow of refrigerant  14 , a flow of coolant  16 , and flows of ambient air  18 . The refrigerant  14  starts at a compressor  24  which compresses the refrigerant. The compressed coolant  14  passed through an optional accessory heater  26 . The optional accessory heater  26  may provide heat for ancillary functions, such as beverage heating, glove heating, etc. The compressed refrigerant  14  then passes through a condenser  26 . The condenser  26  also receives a flow of ambient air  18  and acts as a heat exchanger to cool the refrigerant  14 . A high pressure cutout  30  follows the condenser  26  and stops the compressor  24  whenever the refrigerant pressure becomes excessive. The refrigerant  14  then splits between a flow of cabin refrigerant  14   a  and a flow of fuel and air refrigerant  14   b.    
         [0029]    The flow of cabin refrigerant  14   a  passes through a cabin air conditioning system including a cabin circuit valve  32   a  and then a cabin circuit expansion valve  34   a,  a cabin heat exchanger (also called an evaporator coil)  36  residing in or proximal to a vehicle cabin  37 , a cabin thermostat  38 , and optionally, a heat exchanger  40  for cooling fuel, oil, coolant, beverages, and the like. 
         [0030]    The flow of fuel and air refrigerant  14   b  is separated into two parallel flows to pass through a fuel system including a primary fuel and air circuit valve  32   b  and then a primary fuel and air circuit expansion valve  34   b,  and secondary fuel and air circuit valve  32   c  and then a secondary fuel and air circuit expansion valve  34   c,  and then recombine. The recombined flow of fuel and air refrigerant  14   b  passed through a heat exchanger  48 , optionally through a fuel pre-cooler  20 , and re-joins the flow of cabin refrigerant  14   a  at refrigerant node  41  to return to the compressor  24 . 
         [0031]    The coolant  16  is circulated by a pump  56 . The coolant  16  splits into a flow of refrigerated coolant  16   a  and a flow of air cooled coolant  16   b.  The refrigerated coolant  16   a  passes through the heat exchanger  48  where it is cooled by the fuel and air refrigerant  14   b.  The air cooled coolant  16   b  passed through a heat exchanger (radiator)  60  where it is cooled by the flow of ambient air  18 . After being cooled, the refrigerated coolant  16   a  and air cooled coolant  16   b  join at coolant node  51 , and flow sequentially through an intake air intercooler  50  and fuel rails  22 . Supercharging heats the air compressed in the supercharger and the intercooler  50  is preferably, but not necessarily, a supercharger intercooler and cools air compressed by a supercharger before entry into an engine. The flow of coolant through the fuel rails  22  cools the fuel  12  before injection into the engine. The coolant flow  16  then proceeds through a sight glass and filter  52 , optionally through an intake air pre-cooler  53 , past an expansion/reservoir tank  54 , and back to the coolant pump  56 . 
         [0032]    A refrigerant manifold  62  preferably houses the solenoid valves  32   a ,  32   b,  and  32   c,  and the expansion valves  34   b  and  34   c.  The cabin circuit expansion valve  34   a  is preferably the original equipment expansion valve of the vehicle the fuel and air cooling system  10  is installed in. The refrigerated coolant  16   a  preferably passes through the refrigerant manifold  62  to cool the refrigerant manifold  62 . Details of the refrigerant manifold  62  are shown in  FIG. 7 . The primary expansion valve  34   b  is sized to operate with the cabin air conditioning on and is generally between 0.25 and one tons (or 3,000 to 12,000 BTUs). The secondary expansion valve  34   c  is sized between 1.5 and 2 ton (or 18,000 to 24,000 BTUs) to operate with the primary expansion valve when the cabin air conditioning of off. 
         [0033]    A diagram of a fuel and air cooling system  10  with refrigerant cooling features (e. g., the compressor  24 ) turned off is shown in  FIG. 2 . The only active fuel and air cooling path is the air cooled coolant  16   b  through the heat exchanger  60  shown as heavier lines. The air cooled coolant  16   b  passed through the heat exchanger  60  where it is cooled by the flow of ambient air  18 . After being cooled, the air cooled coolant  16   b  flows sequentially through the supercharger intercooler  50  and fuel rails  22 . The intercooler  50  cools the air compressed by the supercharger before entry into the engine. The flow of the air cooled coolant  16   b  through the fuel rails  22  cools the fuel  12  before injection into the engine. The coolant flow  16  then proceeds through the sight glass and filter  52 , optionally through the intake air pre-cooler  53 , past an expansion/reservoir tank  54 , and back to the coolant pump  56 . 
         [0034]    An example of a physical layout of the fuel and air cooling system  10 , in the fuel and air cooling mode of  FIG. 2 , is shown in  FIG. 3 . 
         [0035]    A diagram of a fuel and air cooling system  10  with refrigerant cooling only provided for the cabin  37  is shown in  FIG. 4 . The only active fuel and air cooling path is the air cooled coolant  16   b  through the heat exchanger  60  shown as heavier lines. The cabin circuit solenoid valve  34   a  is open allowing the cabin refrigerant  14   a  to flow freely, and the primary and secondary fuel and air circuit solenoid valves  34   b  and  34   c  are closed. The cabin refrigerant  14   a  flows through the cabin circuit expansion valve, the cabin heat exchanger  36 , and back to the compressor  24 . 
         [0036]    A diagram of the fuel and air cooling system  10 , with refrigerant cooling provided to cabin interior and the fuel and air is shown in  FIG. 5 . The cabin circuit solenoid valve  34   a  is open allowing the cabin refrigerant  14   a  to flow freely, and the primary fuel and air circuit solenoid valve  34   b  is open allowing a partial flow of fuel and air refrigerant. The secondary fuel and air circuit solenoid valve  34   c  is closed. The cabin refrigerant  14   a  flows through the cabin circuit expansion valve, the cabin heat exchanger  36 , and back to the compressor  24 . The fuel and air refrigerant  14   b  flows through the primary fuel and air circuit expansion valve  34   b  and through the refrigerant to coolant heat exchanger  48 , and then joins the cabin refrigerant  14   a  and returns to the compressor  24 . 
         [0037]    The coolant pump  56   b  pumps the coolant  16  to the two way valve  58  which is set to allow the refrigerated coolant  16   a  to pass through the coolant heat exchanger  48  to be cooled by the fuel and air refrigerant  14   b.  After being cooled, the refrigerated coolant  16   a  flows sequentially through the supercharger intercooler  50  and fuel rails  22 . In the intercooler  50 , the refrigerated coolant  16   a  cools the air compressed by the supercharger before entry into the engine. The refrigerated coolant  16   a  flows through the fuel rails  22  to cool the fuel  12  before injection into the engine. The coolant flow  16  then proceeds through the sight glass and filter  52 , optionally through the intake air pre-cooler  53 , past an expansion/reservoir tank  54 , and back to the coolant pump  56 . 
         [0038]    A diagram of the fuel and air cooling system  10  with refrigerant cooling provided to the fuel and air only is shown in  FIG. 6 . The cabin circuit solenoid valve  34   a  is closed preventing the cabin refrigerant  14   a  from flowing, and the primary and secondary fuel and air circuit solenoid valves  34   b  and  34   c  are open allowing a maximum flow of fuel and air refrigerant. The fuel and air refrigerant  14   b  flows through the primary and secondary fuel and air circuit expansion valves  34   b  and  43   c,  and through the refrigerant to coolant heat exchanger  48 , and then returns to the compressor  24 . 
         [0039]    The coolant pump  56   b  pumps the coolant  16  to the two way valve  58  which is set to allow the refrigerated coolant  16   a  to pass through the coolant heat exchanger  48  to be cooled by the fuel and air refrigerant  14   b.  After being cooled, the refrigerated coolant  16   a  flows sequentially through the supercharger intercooler  50  and fuel rails  22 . In the intercooler  50 , the refrigerated coolant  16   a  cools the air compressed by the supercharger before entry into the engine. The refrigerated coolant  16   a  flows through the fuel rails  22  to cool the fuel  12  before injection into the engine. The coolant flow  16  then proceeds through the sight glass and filter  52 , optionally through the intake air pre-cooler  53 , past an expansion/reservoir tank  54 , and back to the coolant pump  56 . 
         [0040]    The refrigerant manifold  62  is shown in  FIG. 7 . The three solenoid valves  32   a,    32   b,  and  32   c  are located in ports  32   a ′,  32   b ′ and  32   c ′ respectively. The refrigerant  14  enters the refrigerant manifold  62  and connects to the ports  32   a ′,  32   b ′, and  32   c ′. The valve  32   a  controls the cabin refrigerant  14   a  flowing from the refrigerant manifold  62  to the cabin expansion valve  43   a  residing outside the refrigerant manifold  62 . The solenoid valves  32   b  and  32   c  control flows of the fuel and air refrigerant to the fuel and air expansion valves  34   b  and  34   c  respectively. Flow from the fuel and air expansion valves  34   b  and  34   c  combine and exit the refrigerant manifold  62  to the refrigerant to coolant heat exchanger  48  (see  FIG. 1 ). The refrigerated coolant  16   a  flows though the refrigerant manifold  62  to cool the refrigerant manifold  62 . 
         [0041]    An exploded view of a coaxial fuel and coolant rail  80  is shown in  FIG. 8 . The rail  80  includes an outer coolant tube  72  and an inner fuel rail  74 . The outer coolant tube  72  is shown separated in halves for the purpose of illustration only, and the coaxial fuel and coolant rail  80  may be constructed in other manners. A fuel inlet  76  passes through the outer coolant tube  72  and into the fuel rail  74 . Injector hats  78  extend down from the fuel rail  74  and seal to fuel injectors. Coolant inlet  80   a  and outlet  80   b  reside at opposite ends of the outer coolant tube  72 . At least one temperature sensor  82  extends through the outer coolant tube  72  and into the fuel rail  74  to measure fuel temperature, and a pressure sensor fitting  76  extends through the outer coolant tube  72  and into the fuel rail  74  to measure fuel pressure. 
         [0042]    Fuel cooling blocks  96  clamped over fuel lines  94  and fuel injector hats  78  are shown in  FIG. 9  and a cross-sectional view of the fuel cooling blocks  96  is shown in  FIG. 10 . The flow of coolant  16  passes through one side of the fuel cooling blocks  96  and then back through an opposite side. The fuel lines  94  reach from a fuel manifold  92  and into the fuel cooling blocks  96 , and the into the fuel injector hats  78 , thus cooling the fuel  12  just before injection of the fuel  12  into the engine. 
         [0043]    While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.