Abstract:
A heat exchanging device ( 10 ) and method for boosting fuel economy in the internal combustion engines of motor vehicles uses a shell and tube structure whereby that portion of the fuel line, i.e. an inner structure ( 20 ), that is downstream from the fuel line filter ( 204 ), the fuel pump ( 202 ) and the fuel tank ( 200 ), and upstream from the fuel injector ( 206 ) or carburetor, is placed in heat-exchanging relationship with a portion of the cooling system, i.e. an outer structure ( 40 ), that is downstream from the engine block ( 102 ) and upstream of the heater core ( 114 ) of the motor vehicle.

Description:
[0001]    This application claims the benefit and priority of U.S. Provisional Patent Application No. 60/984,387 filed Nov. 1, 2007. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to devices that are used with the internal combustion engine of a motor vehicle. More specifically, it relates to a shell and tube heat exchanger that is used to transfer heat generated within an internal combustion engine to a portion of the fuel line such that the fuel is heated prior to combustion thereby realizing an increase in the mileage obtained per unit of fuel used by the motor vehicle as compared to conventional use of the internal combustion engine. It also relates to a method for boosting fuel economy in a motor vehicle wherein the heat exchanger is disposed within a particular position relative to the fuel line and relative to the cooling system of the motor vehicle. 
       BACKGROUND OF THE INVENTION 
       [0003]    Shell and tube heat exchangers are known in the art. Such heat exchangers typically utilize two fluids, of different starting temperatures, that flow through the heat exchanger. One fluid flows through a centrally-disposed tube and the other fluid flows outside of the tube but inside a shell that overlays the tube, or a portion of it. Heat from one fluid is thus transferred from one fluid to the other through the tube walls. There can be, and in fact are, many variations of the shell and tube design that exist in many different areas of technology. 
         [0004]    In the area of fuel economy, however, which area is continuing to be a major factor in the movement away from fossil fuels to other fuels, the harsh reality is that gasoline will continue to be the major fuel for motor vehicles for many years to come. This will likely continue until we are able to eventually wean ourselves away from what is currently the almost exclusive use of gasoline as a fuel source for motor vehicles in this country. Accordingly, it was a goal of this inventor to utilize a shell and tube configuration to remove heat from the coolant that flows within the cooling system of a motor vehicle to the fuel passing through the fuel system to the combustible engine. Another goal, however, is to utilize such a shell and tube configuration in such a way that has never before been used with motor vehicles of current manufacture. In this way, motor vehicles can be retrofitted with a fuel economy boosting device and new vehicles may be considered for fabrication with it as original equipment as well. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides such a device that, when used properly, helps to boost fuel economy in a motor vehicle wherein a heat exchanger is disposed within a particular position relative to the fuel line and relative to the cooling system of the motor vehicle. Accordingly, the present invention is considered to cover the device itself as well as the method in which it is used. 
         [0006]    The device of the present invention provides for a heat exchanging device that uses a shell and tube structure whereby that portion of the fuel line, i.e. the tube, that is downstream from the fuel line filter, the fuel pump and the fuel tank, and upstream from the fuel injector or carburetor, is placed in heat-exchanging relationship with a portion of the cooling system, i.e. the shell, that is downstream from the engine and upstream from the heater core of the motor vehicle. When configured and placed in this fashion, fuel savings of up to twenty percent (20%) has been realized in tests conducted on behalf of this inventor. 
         [0007]    The foregoing and other features of the device and method of the present invention will be apparent from the detailed description that follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a top, front and left side perspective view of a preferred embodiment of a heat transferring device that is constructed in accordance with the present invention. 
           [0009]      FIG. 2  is a schematic diagram of the typical cooling system and typical fuel system of a motor vehicle that would use the heat transferring device and method of the present invention. 
           [0010]      FIG. 3  is an enlarged and partially cross-sectioned front elevational view of the heat transferring device shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    Referring now to the drawings in detail, wherein like numbered elements correspond to like elements throughout,  FIG. 1  is a perspective view of a preferred embodiment of the heat transferring device, generally identified  10 , which is constructed in accordance with the present invention. Referring specifically to  FIG. 2 , which is a partially cross-sectioned front elevational view of the heat transferring device  10  shown in  FIG. 1 , it will be seen that the heat transferring device  10  comprises two principal structures. The first principal structure is an inner tube-like cylindrical structure  20  that is partially surrounded by a second structure, which is an outer cylindrical structure  40 . 
         [0012]    Again referring to  FIG. 2 , it will be seen that the inner tube-like cylindrical structure  20  comprises a first end  26  and second end  28 . The first end  26  of the inner cylindrical structure  20  is sealingly connected to a fuel-line outlet  24 . Similarly, the second end  28  of the inner cylindrical structure  20  is sealingly connected to a fuel line inlet  22 . In application, there is an inflow  32  of fuel through the fuel line inlet  22 , a through flow  34  of fuel within the inner cylindrical structure  20  and an outflow  36  of fuel at the fuel line outlet  24 . 
         [0013]    Continuing with reference to  FIG. 2 , it will be seen that the outer cylindrical structure  40  essentially “overwraps” a portion of the inner cylindrical structure  20 . The outer cylindrical structure  40  including a sidewall  42 , the sidewall having a first end  46  and a second end  48 . At the first end  46  of the outer cylindrical structure  40  is a first sealed end cap  56 . Similarly, at the second end  48  of the outer cylindrical structure  40  there is a second sealed end cap  58 . The first and second sealed end caps  56 ,  58 , respectively, each include an aperture (not shown) through which a portion of the inner cylindrical structure  20  passes. The sidewall  42  and the sealed end caps  56 ,  58  of the outer cylindrical structure  40  comprise and form an inner chamber  44  of the outer cylindrical structure  40 . 
         [0014]    In application, it will be seen that an inlet port  52  is sealingly provided at the first end  46  of the outer cylindrical structure  40  as is an outlet port  54  that is located at the second end  48  of the outer cylindrical structure  40 . See also  FIG. 1 . The inlet port  52  of the outer cylindrical structure  40  is sealingly attached to a coolant inlet line  62 . Similarly, the outlet port  54  of the outer cylindrical structure  40  is sealingly connected to a coolant outlet line  64 . 
         [0015]    Also in application is the fact that the coolant inlet line  62  and the inlet port  52  of the outer cylindrical structure  40  provide for the inlet flow  72  of coolant into the outer cylindrical structure chamber  44 . Within the inner chamber  44  of the outer cylindrical structure  40 , a through flow  74  of coolant is provided. Coolant then leaves the inner chamber  44  of the outer cylindrical structure  40  by means of the outlet port  54  of the outer cylindrical structure  40  and the coolant outlet line  64  thereby providing for an outflow  76  of coolant. 
         [0016]    During the time that the coolant flows  74  through the outer cylindrical structure  40  and the fuel flows  34  through the inner cylindrical structure  20 , there is an exchange of heat between those two elements whereby the heat contained in the through flow  74  of coolant is effectively transferred to the through flow  34  of fuel that passes through the inner cylindrical structure  20 , the inner cylindrical structure  20  being constructed of a heat-conductive metal material in the preferred embodiment. 
         [0017]    In application, it will be seen in  FIG. 3  that the heat exchanging device  10  of the present invention is utilized within the combined fuel system and cooling system, generally identified  100 , of a typical internal combustion engine  102  that is used in a typical motor vehicle (not shown) as is well known in the art. As shown schematically, the engine  102  contains a plurality of flow-through chambers  104  which carry heat from the cyclical combustions occurring within the piston bores (not shown) within the engine block  102 . This flow is generated by a pump  106  that pushes coolant through a radiator  108 , the radiator  108  being cooled by a combination of air flow that moves through the engine compartment simply by movement of the motor vehicle during operation and by fan-cooled air that is pushed across the radiator  108  by a fan  110 . As the coolant flows back into the engine  102  by means of an inlet coolant line  112 , it is carried through the engine and exits the engine at the line  62  which is then passed through the heat exchanging device  10  and through a line  64  to a heater core  114  that allows heated air to be blown by means of a fan  116  into the passenger compartment of the automobile (not shown). 
         [0018]    It is to be understood that the heater core  114  is also a radiator-like device that is typically located under the dashboard of the vehicle and is solely used for heating the passenger compartment. The hot coolant, passing from the vehicle&#39;s engine at about 210° F., is passed through a winding tube of the core  114 , the tubing also including fins to increase the surface for heat transfer to the air that is forced past them by the fan  116 . Hot coolant passing through the heater core  116  gives up heat before returning to the engine cooling circuit. As coolant exits the heater core  114  by means of the coolant line  118 , the entire cycle is repeated. 
         [0019]    As alluded to above, as the heated coolant passes through the heat exchanging device  10 , the fuel passing through it is heated as well. As shown in  FIG. 3 , the fuel system of the automobile comprises a fuel supply  200 , the fuel being pumped  202  and then filtered  204  on its way to fuel injectors  206  that inject fuel into the combustion chambers (not shown) of the internal combustion engine. As also alluded to above, the coolant passing to the heat exchanging device  10  does so at about 210° F. It is also known to this inventor that gasoline combusts at about 400° F. and flames over at about 300° F., which is well above the temperature of the coolant. Accordingly, there is no problem of pre-combustion of the gasoline fuel that passes through the heat exchanging device  10 . This should not be a problem as the internal cylindrical structure  20  is completely sealed relative to the outer cylindrical structure  40 . 
         [0020]    It has also been found by this inventor that drawing the heat from the coolant at the point just upstream of the heater core  114  optimizes performance. Performance also appears to be optimized where the overall length of the exposed internal cylindrical structure  20  within the chamber  44  of the outer cylindrical structure  40  is about three and one-half inches. Further optimization occurs where the internal cylindrical structure  20  is a one-eighth inch inner diameter tube and the outer cylindrical structure  40  is a three-quarters inch diameter tube. 
         [0021]    Field testing of the heat exchanging device  10  was conducted using road load matching procedures and technique in accordance with SAE J2264 chassis dynamometer simulation. As a result, it was determined that up to a fifteen percent (15%) boost in miles per gallon has been realized in various types of motor vehicles using the device  10 . Typical energy conservation resulted in anywhere from a three percent (3%) boost in miles per gallon to the fifteen percent figure mentioned above. The device  10  has also been used in diesel engine vehicles where energy conservation valves were in the twenty percent (20%) range. There is no doubt in the mind of this inventor that the increase in mileage is due to the utilization of the device  10  as outlined above. 
         [0022]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details disclosed and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept.