Abstract:
One embodiment is a unique system of EGR catalyzation with reduced EGR heating. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS: 
       [0001]    The present application claims priority to U.S. Provisional Patent Application No. 61/010,733 filed Jan. 11, 2008, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Exhaust gas recirculation (“EGR”) may be used in connection with internal combustion engines to reduce emissions or for other purposes. Present approaches to EGR suffer from a variety of drawbacks, limitations, disadvantages and problems including, for example, those respecting reduction or prevention of deposits such as carbonaceous deposits, reducing or avoiding heating of EGR, and others. There is a need for the unique and inventive apparatuses, systems, and methods disclosed herein. 
       SUMMARY 
       [0003]    One embodiment is a unique system of EGR catalyzation with reduced EGR heating. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0004]      FIG. 1  is a schematic of a system including an internal combustion engine. 
           [0005]      FIG. 2  is a schematic of a cooled EGR system. 
           [0006]      FIG. 3  is a schematic of a cooled EGR system. 
           [0007]      FIG. 4  is a schematic of a cooled EGR system. 
           [0008]      FIG. 5  is a schematic of a vehicle including an engine and a cooled EGR system. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the figures and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby created, and that the invention includes and protects such alterations and modifications to the illustrated embodiments, and such further applications of the principles of the invention illustrated therein as would occur to one skilled in the art to which the invention relates. 
         [0010]    With reference to  FIG. 1 , there is illustrated a system  10  including an internal combustion engine  12  having an intake manifold  14  with an intake conduit  20  coupled thereto. The intake conduit  20  is coupled to an intake  22  which supplies ambient air to intake conduit  20 . Preferably, the intake conduit  20  is coupled to an outlet of compressor  16  of turbocharger  18  or of another type of supercharger. Compressor  16  receives fresh air from intake  22  and outputs compressed air. System  10  may include an air throttle  66  disposed between the intake manifold  14  and the intake conduit  22 . System  10  preferably includes a charge air cooler  24  disposed downstream from compressor  16  and which cools compressed air received from compressor  16 . 
         [0011]    Engine  12  further includes an exhaust manifold  30  having an exhaust conduit  32  coupled thereto. Exhaust flow from conduit  32  drives a turbine  26  of turbocharger  18  which is mechanically coupled to compressor  16  via drive shaft  28 . Turbine  26  preferably outlets to an aftertreatment system or to ambient via the exhaust conduit  34 . A portion of the exhaust from conduit  32  may be recirculated via EGR conduit  38 . The rate of exhaust gas recirculation or EGR may be controlled by EGR valve  36  which is illustrated as being upstream of EGR cooler  40 , but could also be positioned downstream from EGR cooler  40 , or intermediate EGR cooler  40  and catalyst unit  90 . Regardless of the location or presence of EGR valve  36 , catalyst unit  90  is preferably positioned at a location upstream of EGR cooler  40 . Catalyst unit  90  preferably includes a non-oxidizing catalyst or a mildly oxidizing catalyst which are referred to herein as a substantially non-oxidizing catalyst. Substantially non-oxidizing catalysts are catalysts which are operable to catalyze one or more chemical reactions which decrease the molecular weight of hydrocarbon compounds present in exhaust gas without increasing the temperature of the exhaust gas or with a reduced temperature increase relative to that which would occur with an oxidizing catalyst. Examples of substantially non-oxidizing catalysts include solid acid catalysts and zeolite catalysts. Hydrocarbon cracking is an exemplary reaction which is catalyzed by substantially non-oxidizing catalysts. 
         [0012]    System  10  also preferably includes a control circuit  42  that is microprocessor-based and operable to control and manage the operation of engine  12 , for example, an engine control module (ECM), engine control unit (ECU). Control circuit  42  includes a number of inputs for receiving signals from various sensors or sensing systems associated with system  10 . For example, system  10  preferably includes an engine speed sensor  44  electrically connected to an engine speed input, ES, of control circuit  42  via signal path  46 . Engine speed sensor  44  is operable to sense rotational speed of the engine  12  and produce an engine speed signal on signal path  46  indicative of engine rotational speed. System  10  also preferably includes a mass air flow sensor  48  disposed in fluid communication with the intake conduit  20  of engine  12 , and electrically connected to a mass flow of air input (MFA) of control circuit  42  via signal path  50 . Mass air flow sensor  48  is operable to produce a mass flow rate signal on signal path  50  indicative of the mass flow rate of fresh air flowing into the intake conduit  20 . System  10  also preferably includes a lambda sensor  80  disposed in fluid communication with exhaust conduit  34  and electrically connected to a lambda input of control circuit  42  via signal path  82 , as shown in  FIG. 1 . Control circuit  42  also preferably includes a number of outputs for controlling one or more fluid handling mechanisms associated with system  10 . For example, EGR valve  36  includes an EGR valve actuator  62  electrically connected to an EGR valve control output (EGRC) of control circuit  42  via signal path  63 . Control circuit  42  is operable to produce an EGR valve control signal on signal path  63 , and EGR valve actuator  62  is responsive to the EGR valve control signal on signal path  63  to control the position of EGR valve  36  relative to a reference position. In addition, air throttle  66  includes an air throttle actuator  68  electrically connected to an air throttle control output (ATC) of control circuit  42  via signal path  70 . Control circuit  42  is operable to produce an air throttle control signal on signal path  70 , and air throttle actuator  68  is responsive to the air throttle control signal on signal path  70  to control the position of air throttle  66  relative to a reference position. System  10  also preferably includes a fueling system  72  electrically connected to a fuel command output (FC) of control computer  42  via signal path  74 . Fueling system  72  is responsive to fueling control signals produced by control circuit  42  on signal path  74  to supply fuel to engine  12 , and control circuit  42  is operable to produce such fueling control signals. 
         [0013]    With reference to  FIG. 2  there is illustrated an exemplary cooled EGR system  200  which includes an EGR valve  236  which is flow coupled to a substantially non-oxidizing catalyst unit  290  which is flow coupled to an EGR cooler  240 . During operation exhaust flows from an engine, exhaust manifold, exhaust conduit or other exhaust source to EGR valve  236  which is preferably operable to control the amount or rate of exhaust flow but could also simply be an on/off valve. Exhaust next flows to substantially non-oxidizing catalyst unit  290  which includes one or more substantially non-oxidizing catalysts operable to catalyze one or more reactions of hydrocarbons in the exhaust in order to convert higher molecular weight hydrocarbons into lower molecular weight hydrocarbons while avoiding, minimizing, controlling or reducing any temperature increase of the exhaust owing to the catalyzed reaction(s). Exhaust then flows to EGR cooler  240  which cools the exhaust. From EGR cooler  240 , exhaust may optionally flow through one or more additional coolers, and may be mixed with intake or charge air before being provided to an intake manifold or directly to one or more engine cylinders. 
         [0014]    With reference to  FIG. 3  there is illustrated an exemplary cooled EGR system  300  which includes a substantially non-oxidizing catalyst unit  390  which is flow coupled to an EGR cooler  340  which is flow coupled to an EGR valve  336 . During operation exhaust flows from an engine, exhaust manifold, exhaust conduit or other exhaust source to substantially non-oxidizing catalyst unit  290  which includes one or more substantially non-oxidizing catalysts operable to catalyze one or more reactions of hydrocarbons in the exhaust in order to convert higher molecular weight hydrocarbons into lower molecular weight hydrocarbons while avoiding, minimizing, controlling or reducing any temperature increase of the exhaust owing to the catalyzed reaction(s). Exhaust next flows to EGR cooler  340  which cools the exhaust. Exhaust then flows to EGR valve  336  which is preferably operable to control the amount or rate of exhaust flow but could also simply be an on/off valve. From EGR valve  336 , exhaust may optionally flow through one or more additional coolers and may be mixed with intake or charge air before being provided to an intake manifold or directly to one or more engine cylinders. 
         [0015]    With reference to  FIG. 4  there is illustrated an exemplary cooled EGR system  400  which includes a substantially non-oxidizing catalyst unit  490  which is flow coupled to an EGR valve  436  which is flow coupled to an EGR cooler  440 . During operation exhaust flows from an engine, exhaust manifold, exhaust conduit or other exhaust source to substantially non-oxidizing catalyst unit  490  which includes one or more substantially non-oxidizing catalysts operable to catalyze one or more reactions of hydrocarbons in the exhaust in order to convert higher molecular weight hydrocarbons into lower molecular weight hydrocarbons while avoiding, minimizing, controlling or reducing any temperature increase of the exhaust owing to the catalyzed reaction(s). Exhaust next flows to EGR valve  436  which is preferably operable to selectably control the amount or rate of exhaust flow but could also simply be an on/off valve. Exhaust then flows to EGR cooler  440  which cools the exhaust. From EGR cooler  440  exhaust may optionally flow through one or more additional coolers and may be mixed with intake or charge air before being provided to an intake manifold or directly to one or more engine cylinders. 
         [0016]    With reference to  FIG. 5 , there is illustrated a vehicle  500 . Vehicle  500  is shown as a semi tractor, but could also be a variety of types of vehicles, for example, light duty trucks, medium duty trucks, heavy duty trucks, buses, cars, motorhomes, fire and emergency vehicles, construction vehicles, boats and other marine vehicles, and rail vehicles such as locomotives. Vehicle  500  includes an engine  540 , which is preferably a diesel engine but could be a spark ignition or other type of internal combustion engine, and a cooled EGR system  530  which preferably includes one or more EGR coolers operable to cool EGR to provided to engine  440 , one or more substantially non-oxidizing catalyst units which could be the same as or similar to those described above, and one or more valves, pumps or other EGR controls. Further embodiments contemplate that engine  540  could be used in other applications including, for example, in generator sets, or industrial, mining, or oil and gas equipment. 
         [0017]    As is evident from the figures and text presented above, a variety of embodiments according to the present invention are contemplated. Certain exemplary embodiments include a system comprising an EGR cooler operable to receive EGR gas at a first temperature and output EGR gas at a second temperature, the first temperature being greater than the second temperature; and a substantially non-oxidizing catalyst unit configured to intake EGR gas at an intake and output EGR gas at an output; wherein the EGR cooler and the substantially non-oxidizing catalyst unit are flow coupled and the substantially non-oxidizing catalyst unit is positioned upstream of the EGR cooler. In further exemplary embodiments the substantially non-oxidizing catalyst unit is operable to catalyze hydrocarbon cracking; the substantially non-oxidizing catalyst unit includes a solid acid catalyst; the substantially non-oxidizing catalyst unit includes a zeolite catalyst composition; the substantially non-oxidizing catalyst unit is operable to catalyze a reaction of hydrocarbons without increasing the temperature of EGR gas within the substantially non-oxidizing catalyst unit; and/or the substantially non-oxidizing catalyst unit is operable to catalyze a reaction of hydrocarbons while increasing the temperature of EGR gas within the substantially non-oxidizing catalyst unit by less than about 10 degrees centigrade. Further exemplary embodiments include an internal combustion engine and an exhaust manifold, the exhaust manifold being in fluid communication with the intake of the substantially non-oxidizing catalyst unit. 
         [0018]    Certain exemplary embodiments include a system comprising an engine; an EGR conduit flow coupled the engine to receive exhaust gas therefrom; means for reducing molecular weight of hydrocarbon molecules in exhaust gas flow coupled to the EGR conduit; and means for cooling the EGR flow coupled to the means for reducing molecular weight of hydrocarbon molecules in exhaust gas. In further exemplary embodiments the means for cooling the EGR includes an engine coolant cooled EGR cooler; the means for reducing molecular weight of hydrocarbon molecules in exhaust gas includes a zeolite catalyst; the means for reducing molecular weight of hydrocarbon molecules in exhaust gas includes a hydrocarbon cracking catalyst; and/or the means for reducing molecular weight of hydrocarbon molecules in exhaust gas includes a solid acid catalyst. In further exemplary embodiments the engine is a diesel engine; and/or the diesel engine is configured to be the prime mover of a vehicle. 
         [0019]    Certain exemplary embodiments include a method comprising operating an internal combustion engine to produce exhaust including one or more hydrocarbon compounds; treating a portion of the exhaust with a substantially non-oxidizing catalyst effective to reduce the molecular weight of the one or more hydrocarbon compounds; cooling the portion of the exhaust; and providing the portion of the exhaust to an intake of the internal combustion engine. In further exemplary embodiments the treating a portion of the exhaust with a substantially non-oxidizing catalyst effective to reduce the molecular weight of the one or more hydrocarbon compounds includes a hydrocarbon cracking reaction; the treating a portion of the exhaust with a substantially non-oxidizing catalyst effective to reduce the molecular weight of the one or more hydrocarbon compounds includes exposing the one or more hydrocarbon compounds to a hydrocarbon cracking catalyst; the treating a portion of the exhaust with a substantially non-oxidizing catalyst effective to reduce the molecular weight of the one or more hydrocarbon compounds includes exposing the one or more hydrocarbon compounds to a solid acid catalyst; the treating a portion of the exhaust with a substantially non-oxidizing catalyst effective to reduce the molecular weight of the one or more hydrocarbon compounds includes exposing the one or more hydrocarbon compounds to a zeolite catalyst; and/or the treating a portion of the exhaust with a substantially non-oxidizing catalyst occurs in a single catalyst unit positioned upstream from an EGR cooler. 
         [0020]    While exemplary embodiments of the invention have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.