Abstract:
Combustion air for use in an engine is normally compressed by a compressor which adds heat during the process of increasing the density of the combustion air. To decrease the heat content of the combustion air, an aftercooler is used. When compressing combustion air to a higher density, the combustion air is compressed by a first compressor section to a first preestablished pressure and temperature and by a second compressor section to a second preestablished pressure and temperature. To decrease the heat content of the highly compressed dense combustion air, a first aftercooler having an air to liquid configuration is used and a second aftercooler having an air to air configuration is used.

Description:
TECHNICAL FIELD  
         [0001]    This disclosure relates generally to cooling of combustion air for use in an engine and more particularly to a method and apparatus for cooling combustion air with a jacket water aftercooler and an air to air aftercooler.  
         BACKGROUND  
         [0002]    As the quest for improved engine efficiency is sought, the supply of intake air becomes more critical. The quantity of intake air can be increased by compressing the air to a higher density. With the increased pressure of the intake air, the intake air is heated to a higher temperature which can further add to the emissions emitted from such engines. With the requirement for greater cooling, the operation of the engine, operating components and accessories can be compromised. Thus, the engine, operating components and accessories may fail prematurely. To overcome the increased temperature, systems have been sought to reduce the temperature of the intake air. One such system is disclosed in Japanese Patent Number JP20002200480 published Aug. 8, 2000 being invented by Hiroshi Fujimoto et. al. In the disclosure an engine uses a Miller cycle to improve the combustion efficiency and improve fuel consumption. A first supercharger compresses the intake air and the compressed intake air is passed through a first cooler. From the first cooler the intake air is further compressed by a second supercharger and passed through a second cooler prior to being introduced into a combustion chamber of a cylinder of the engine. The disclosure further discloses an Exhaust Gas Recirculation (EGR) means for use with the Miller cycle, series supercharged series cooled intake air engine.  
           [0003]    The present disclosure is directed to overcoming one or more of the problems as set forth above.  
         SUMMARY OF THE INVENTION  
         [0004]    In one aspect a combustion air cooling system for use with an engine is disclosed. The engine has an exhaust manifold, an intake manifold and at least one cylinder bore having a piston assembly therein being movable between a top dead center position (TDC) and a bottom dead center position (BDC). At least one intake valve mechanism being movable between an open position and a closed position during operation of the engine is provided. And, a flow of combustion air being communicated between the intake manifold and the at least one cylinder bore during the open position and the flow of combustion air being prevented from communicating between the intake manifold and the at least one cylinder bore during the closed position is provided. The combustion air cooling system comprises an engine cooling system including a heat exchanger being of a liquid to an air type heat exchanger configuration and a liquid coolant pump. The liquid coolant pump is attached to the engine and has a coolant pump outlet portion and a coolant pump inlet portion. The heat exchanger has a liquid coolant inlet and a liquid coolant outlet. The liquid coolant pump, during operation of the engine, causes a first flow of liquid to circulate between the engine and the heat exchanger. The engine cooling system has a flow of recipient fluid being an atmospheric air passing therethrough. A first turbocharger is positioned on the engine. The first turbocharger has a turbine section and during operation of the engine the turbine section being driven by a flow of exhaust gas exiting a second turbocharger, a compressor section being driven by the turbine section. The compressor section has an inlet portion and an outlet portion. The combustion air after passing from the inlet portion through the outlet portion has a first preestablished pressure. The second turbocharger is position on the engine. The second turbocharger has a turbine section and during operation of the engine the turbine section being driven by the flow of exhaust gas exiting said exhaust manifold. A compressor section is driven by the turbine section, has an inlet portion and an outlet portion. The combustion air after passing through the outlet portion of the first turbocharger entering the inlet portion of the second turbocharger and passes through the outlet portion and has a second preestablished pressure being greater than the first preestablished pressure exiting the first turbocharger. A first aftercooler is of an air to a liquid type heat exchanger configuration and has a recipient fluid therein. The first aftercooler has a donor portion and a recipient portion being connected to the engine. The donor portion has a combustion air inlet portion a combustion air transfer portion and a combustion air outlet portion. The recipient portion has a liquid coolant inlet portion a liquid coolant transfer portion and a liquid coolant outlet portion. The first aftercooler has the liquid from the engine cooling system being the recipient fluid. The first aftercooler has the combustion air being the donor fluid and exiting the combustion air outlet portion of the first aftercooler at a first preestablished temperature. And, a second aftercooler being of an air to air type heat exchanger configuration and having a recipient fluid therein, having a donor portion and a recipient portion being connected to the engine. The donor portion having a combustion air inlet portion a combustion air transfer portion and a combustion air outlet portion. The recipient portion having an atmospheric air inlet portion, an atmospheric air transfer portion and an atmospheric air outlet portion. The second aftercooler having the atmospheric air being the recipient fluid. The second aftercooler has the combustion air being the donor fluid and exiting the combustion air outlet portion of the second aftercooler at a second preestablished temperature being less than the first preestablished temperature. The combustion air at the second preestablished pressure and the second preestablished temperature being communicated to the intake manifold and the at least one cylinder bore.  
           [0005]    In another aspect, a method of cooling combustion air for use with an engine is disclosed. The engine has a block at least one cylinder bore being positioned in the block and has a piston assembly operatively positioned therein. A plurality of cooling passages are position in the block, an intake manifold and an exhaust manifold are a part of the engine. The method of cooling comprises providing an engine cooling system. The engine cooling system has a heat exchanger being of a liquid to an air type heat exchanger. Providing a first flow of liquid coolant through the heat exchanger and the engine. Compressing a flow of combustion air to a first preestablished pressure and a first preestablished temperature. Compressing the flow of combustion air to a second preestablished pressure and a second preestablished temperature. Cooling the flow of combustion air to a first temperature using a second flow of the liquid coolant through a first aftercooler having a recipient fluid being the flow of liquid coolant through the engine. And, cooling the flow of combustion air to a second temperature using a second aftercooler having a recipient fluid being an atmospheric air.  
           [0006]    In another aspect a combustion air cooling system is used with an engine. The engine has a block including a plurality of cooling passages, a least a cylinder bore having a flow of combustion fluid and a flow of combustible fluid being supplied thereto. The combustion fluid and the combustible fluid combusting and forming an exhaust. The combustion air cooling system comprises an engine cooling system being in communication with the engine and including a heat exchanger being of a liquid to an air type heat exchanger configuration and a liquid coolant pump. The liquid coolant pump defines a first flow of a liquid coolant. The first flow circulates through the liquid coolant pump, the plurality of cooling passages in the block and the heat exchanger. A first compressor section is attached to the engine and has an inlet portion and an outlet portion. The first compressor section compresses the combustion fluid to a first preestablished pressure and a first preestablished temperature. A second compressor section is attached to the engine and has an inlet portion and an outlet portion. The inlet portion of the second compressor section is connected to the outlet portion of the first compressor section, the second compressor section compressing the combustion fluid to a second preestablished pressure and a second preestablished temperature. A turbine section is attached to the engine and is driven by the exhaust from the at least one cylinder bore. The turbine section drives the first compressor section and the second compressor section by a shaft. A first aftercooler being of an air to a liquid type heat exchanger configuration is attached to the engine and has the combustion fluid flowing therethrough as the air and the liquid coolant flowing therethrough as the liquid. The first aftercooler has an inlet portion and an outlet portion and a liquid coolant inlet portion and a liquid coolant outlet portion. A second aftercooler being of an air to air type heat exchanger configuration is in communication with the engine and has the combustion fluid flowing therethrough as one of the air and has an atmospheric air flowing therethrough as an other of the air. The second aftercooler has a combustion air inlet portion being connected to the outlet portion of the first aftercooler and a combustion air outlet portion being connected to the at least one cylinder bore. And, a second flow of the liquid coolant, the liquid coolant pump defines the second flow of the liquid coolant. The second flow of the coolant circulates through at least the liquid coolant pump and the first aftercooler. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a schematic view of a combustion air cooling system and an environment in which the combustion air cooling system operates.  
         [0008]    [0008]FIG. 2 is view of a combustion air cooling system and its environment.  
         [0009]    [0009]FIG. 3 is a partially cross sectioned view of an engine.  
     
    
     DETAILED DESCRIPTION  
       [0010]    In FIGS. 1 and 2, a work machine or a vehicle  10  is shows having a chassis  12 . Examples of such work machine could be a track type loader or a motor grader. And, an example of a vehicle could be an on-highway truck such as a semi-tractor or a dump truck or a delivery truck. An engine  14  is positioned in the chassis  12 . In this application, the engine  14  is of the 4-cycle configuration but as an alternative could be of another configuration such as a 2-cycle configuration. An engine cooling system  16  is positioned in the chassis  12  and communicates a liquid coolant, represented by the arrows  18  between a heat exchanger or radiator  20 , being of a liquid to air type heat exchanger configuration, and the engine  14 . In this application, the coolant  18  is a liquid such as a mixture of water and antifreeze. A fan  22  is positioned in the engine cooling system  16  and operatively causes a flow of a recipient fluid, represented by the arrows  24 , such as atmospheric air, to pass through the heat exchanger  20 . In this application, the coolant  18  acts as a donor fluid and the atmospheric air  24  acts as the recipient fluid. The fan  22  in this application is driven by an electric motor, not shown, but as an alternative could be driven by another source such as a hydraulic motor or could be driven directly from the engine  14 .  
         [0011]    The heat exchanger  20 , in this application, has a pair of side tanks  30  having a plurality of tubes and fins  34  interposed the pair of side tanks  30  in a conventional manner. As an alternative, the heat exchanger  20  could be of other designs, one such having a top tank and a bottom tank and vertical tubes and fins without changing the gest of the disclosure. A liquid coolant outlet  36  is positioned in one of the pair of side tanks  30  near a bottom and has a lower flexible hose  38  communicating between the liquid coolant inlet  36  and the engine  14  in a conventional manner. A liquid coolant inlet  40  is positioned in the other of the pair of side tanks  30  near a top and communicates with the engine  14  by way of an upper flexible hose  42  in a conventional manner.  
         [0012]    As best shown in FIG. 3, the engine  14  has a cylinder head  48  connected to a block  49  in which is rotatably positioned a crankshaft  50  and at least a cylinder bore  51  having a piston assembly  52  therein connected to the crankshaft  50  in a conventional manner. The block  49  has a plurality of cooling passages  53  positioned therein in a conventional manner. The cylinder bore  51  may be formed in the block  49  or within a sleeve or a cylinder liner without changing the gest of the disclosure. The piston assembly  52  moves between a top dead center position, TDC, and a bottom dead center position, BDC, in a conventional manner. The 4 cycles include a rotation of the crankshaft  50  from 0 degrees to 180 degrees being an intake stroke, from 180 degrees to 360 degrees being an compression stroke, from 360 degrees to 540 degrees being a combustion stroke. The engine  14  has a flow of fuel  54  being supplied by a fuel injector  55 . The engine  14  has an intake manifold  57  having a flow of compressed or pressurized combustion air, represented by the arrows  58 , therein, as will be explained later. The flow of pressurized combustion air  58  communicates with the cylinder bore  51  in a conventional manner such as through the head  48  having at least a passage  60  and at least an intake valve mechanism  62  positioned therein. The intake valve mechanism  62  is operated between an open position  64 , shown in phantom, and a closed position  66 . The engine  14  has an exhaust manifold  70  having a flow of exhaust gas, represented by the arrows  72  therein. The exhaust gas  72  communicates with the cylinder bore  51  in a convention manner such as through at least a passage  74  and at least an exhaust valve mechanism  76 . The exhaust valve mechanism  76  is operated between an open position  78 , shown in phantom, and a closed position  80 . In this application, the intake valve or valves and the exhaust valve or valves are actuated by a camshaft, not shown, of a conventional design. However, as an alternative, the intake valve or valves and the exhaust valve or valves could be operated by other means such as a hydraulically, an electrically or a combination type of actuation or actuator.  
         [0013]    The engine  14  has a conventional lubricating system  81  including a lubricating pump  82  and an oil cooler  83  in which the coolant  18  acts as a recipient fluid and cools a lubricant, represented by the arrow  84 . The lubricant  84  acts as a donor fluid. The oil cooler  83  has a recipient coolant outlet portion  85 .  
         [0014]    The engine cooling system  16  includes a coolant pump  86  attached to the block  49  in a conventional manner. The coolant pump  86  operatively causes a first flow, indicated by arrow  18 A, of the coolant  18  to circulate between the engine  14  and the heat exchanger  20 . The coolant pump  86  has a coolant pump outlet portion  87  and a coolant pump inlet portion  88 . A thermostat  89  regulates the flow of the coolant  18 , during cold conditions of the coolant  18  and the engine  14 , in a conventional manner. The thermostat  89  is positioned within a thermostat housing  90  in a conventional manner. The combination of the thermostat  89  and the fan  22  maintain the coolant  18  at a generally constant operating temperature. For example, in this application the operating temperature of the coolant  18  is maintained at about 90 degrees centigrade. For example, the coolant  18  at the coolant outlet  36  of the respective one of the pair of side tanks  30  has an operating temperature of about 80 degrees centigrade and the coolant  18  at the coolant inlet  40  in the other one of the pair of side tanks  30  has an operating temperature range of about 100 degrees centigrade. Thus, the heat exchanger  20  in this application has a cooling range between the coolant inlet  40  and the coolant outlet  36 .  
         [0015]    The engine  14  has a combustion air induction system  91 . The combustion air induction system  91  includes a first turbocharger  92 . The first turbocharger  92  has a compressor section  94  having a compressor wheel  96  therein. The first turbocharger  92  has a turbine section  98  having a turbine wheel  99  being connected to a shaft  100 . The shaft  100  is connected to the compressor wheel  96  in a conventional manner. The flow of exhaust gas  72  is communicated from a turbine section  101  of a second turbocharger  102  to the turbine section  98  in a conventional manner, such as by a pipes  103 . The flow of pressurized combustion air  58  is communicated between the compressor section  94  to the intake manifold  57  in a conventional manner, such as by a pipe  104 . In this application, a filter  105  is interposed the atmospheric air, also represented by the arrows  24 , and an inlet portion  106  of the compressor section  94 . Atmospheric air  24  passes through the filter  105 , through a pipe  107  and into the compressor section  94  and is compressed to a first preestablished pressure ratio for use as the compressed combustion air  58 . The compressed combustion air  58  exits an outlet portion  108  of the compressor section  94 . In this application, a first preestablished pressure ratio of the combustion air is about 3 atmospheres or in this application about 2.4 atmospheres. And, the temperature of the compressed combustion air  58  exiting the first turbocharger  92  is about 130 degrees centigrade.  
         [0016]    The combustion air induction system  91  includes the second turbocharger  102 . The second turbocharger  102  has a compressor section  112  having a compressor wheel  114  therein. The second turbocharger  102  has the turbine section  101  having a turbine wheel  118  being connected to a shaft  120 . The shaft  120  is connected to the compressor wheel  114  in a conventional manner. The flow of exhaust gas  72  is communicated from the exhaust manifold  70  to the turbine section  101  in a conventional manner, such as by a pipe  122 . The flow of compressed combustion air  58  from the outlet portion  108  of the first turbocharger  92  is communicated to an inlet portion  123  of the compressor section  112  in a conventional manner, such as by the pipe  124 . The compressed combustion air  58  exits an outlet portion  126  of the compressor section  112  and is transferred to the intake manifold  57  in a conventional manner, such as by the pipe  104 . The compressor section  112  of the second turbocharger  102  further pressurizes the compressed combustion air  58  from the first turbocharger  92  to a second preestablished pressure ratio. In this application, the second preestablished pressure ratio of the combustion air is about 5 atmospheres or in this application about 4.5 atmospheres. And, the temperature of the compressed combustion air  58  exiting the second turbocharger  102  has a temperature of about 230 degrees centigrade. As an alternative, the first and/or the second preestablished pressure ratio of the first and/or the second turbochargers  92 , 102  can be varied without changing the gest of the disclosure. The physical relationship of the compressor section  94  of the first turbocharger  92  and the compressor section  112  of the second turbocharger  102  are in an efficient flow communication relationship. The less the flow restrictions, elbows, changes in cross section and turbulence, the more efficient the flow of combustion air  58 . From the first turbocharger  92 , the flow of exhaust gas  72  exits to atmosphere by way of a muffler  128 .  
         [0017]    As an alternative, the first turbocharger  92  and the second turbocharger  102  can be combined into a singe turbocharger housing. For example, the turbine wheel  99 , 118  would be combined to form a single turbine wheel on a single shaft. The single shaft would drive the individual compressor wheel  96  and compressor wheel  114  within a common housing. Thus, forming a turbocharger having a dual compressor section.  
         [0018]    The combustion air induction system  91  includes a combustion air cooling system  129 . The combustion air cooling system  129  has a first aftercooler  130  positioned therein which may be attached to the engine  14 . In this application, the first aftercooler  130  is attached to the engine  14  and is of an air to a liquid type heat exchanger configuration. If looking toward a front of the engine  14 , the first aftercooler  130  is positioned near the front lower left portion of the engine block  49 . The first aftercooler  130  has a donor portion  132  in communication with the compressed combustion air  58  and a recipient portion  134  in communication with the coolant  18 . The donor portion  132  has a combustion air inlet portion  136 , a combustion air transfer portion  138  and a combustion air outlet portion  140 . The recipient portion  134  has a liquid coolant inlet portion  142 , a liquid coolant transfer portion  144  and a liquid coolant outlet portion  146 . The combustion air inlet portion  136  is connected to the outlet portion  126  of the compressor section  112  of the second turbocharger  102  in a conventional manner such as by a pipe or a plurality of pipes  148 . The combustion air inlet portion  136  of the first aftercooler  130  is position in line with the outlet portion  126  of the compressor section  112  of the second turbocharger  102 . As an alternative, the first aftercooler  130  could be interposed the first turbocharger  92  and the second turbocharger  102 . With this alternative, the combustion air inlet portion  136  would be connected to the outlet portion  108  of the compressor section  94  of the first turbocharger  92  and the combustion air outlet portion  140  of the first aftercooler  130  would be connected to the inlet portion  123  of the compressor section  112  of the second turbocharger  102 . Compressed combustion air  58  entering the inlet portion  136  of the first aftercooler is at about 230 degrees centigrade and the compressed combustion air  58  exiting the first aftercooler is at about 170 degrees centigrade. The liquid coolant inlet portion  142  is connected to the coolant pump outlet portion  87  of the coolant pump  86 . And, a second flow  18 B of the coolant  18  is formed by the coolant pump  86  and the first aftercooler  130 . As an alternative, the liquid coolant  18  could be from a second source and not be identical to the liquid coolant  18  used to cool the engine  14 .  
         [0019]    The combustion air induction system  91  has a second aftercooler  160  positioned therein which, in this application, is positioned in front and/or aligned and above the heat exchanger  20  and the engine  14 , and is attached to the chassis  12  in a conventional manner. In this application the second aftercooler  160  is of an air to air type heat exchanger configuration. The second aftercooler  160  has a donor portion  162  in communication with the compressed combustion air  58  and a recipient portion  164  in communication with the atmospheric air  24 . The donor portion  162  has a combustion air inlet portion  166 , a combustion air transfer portion  168  and a combustion air outlet portion  170 . The recipient portion  164  has an atmospheric air inlet portion  172 , an atmospheric air transfer portion  174  and an atmospheric air outlet portion  176 . The combustion air inlet portion  166  is connected to the outlet portion  140  of the donor portion  132  of the first aftercooler  130  in a conventional manner such as by a pipe or a plurality of pipes  178 . The atmospheric air inlet portion  172  is in communication with the atmospheric air  24  above the heat exchanger  20 . As an alternative, the second aftercooler could be positioned at a position other than being above and in front and/or aligned with the heat exchanger  20  and the engine  14  without changing the gest of the system. However, it is contemplated that the atmospheric air passing through the second aftercooler  160  will be at too high a temperature to adequately cool the heat exchanger  20  to an adequate temperature for cooling the engine  14 . With the alternative of above, with the first aftercooler  130  interposed the first turbocharger  92  and the second turbocharger  102 , the combustion air inlet portion  166  would be connected to the outlet portion  126  of the compressor section  112  of the second turbocharger  102 . And, the combustion air outlet portion  170  would be connected to the intake manifold  57  of the engine  14 . The compressed combustion air  58  exiting the combustion outlet portion  170  of the second aftercooler  160  has a temperature being about 49 degrees centigrade on a day having a temperature of about 25 degrees centigrade.  
         [0020]    The combustion air cooling system  129  includes a flow control mechanism  190 , such as a valve. As an alternative, the flow control mechanism  190  could be an orifice or a pipe or tube having a preestablished flow therethrough and/or cross sectional area. The flow control mechanism  190  is positioned near the coolant pump outlet portion  87 . The flow control mechanism  190 , in this application, is independent of the coolant pump  86 . However, as an alternative, the flow control mechanism  190  could be formed as an integral portion of the coolant pump  86  without changing the essence of the system. The flow control mechanism  190 , if the valve as shown in FIG. 1, is operational between a closed position  192  and an open position  194 , shown in phantom. The flow control valve  190  is infinitely variable between the closed position  192  and the open position  194 . As an alternative, the flow control mechanism  190  could be variable between the closed position  192  and the open position  194  is a series of fixed positions without changing the essence of the system. The flow control mechanism  190  is operatively moved between the closed position  192  and the open position  194  by a controller  196 . The controller  196  senses engine parameters and/or atmospheric condition and depending on a set of fixed preestablished parameters positions the flow control valve  190  between the closed position  192  and the open position  194 . Some of the parameters sensed and used by the controller  196  are the temperature and atmospheric pressure of the atmospheric air  24 , the compressed combustion air  58  temperature and pressure, and the coolant  18  temperature. Other parameters, such as other pressures, engine load etc., can be used to control the position of the flow control mechanism  190 .  
         [0021]    Industrial Applicability  
         [0022]    In the application example below, the air induction system  91  and the combustion air cooling system  129  is used with the engine  14  in an on-highway truck. The engine  14  is started. Combustion of pressurized combustion air  58  and fuel  54  takes place and exhaust  72  occurs. For example, on a day where the atmospheric air  24  is at a temperature of about 25 degrees centigrade, atmospheric air  24  enters the filter  105  and is cleansed before entering pipe  107  and passing to the compressor section  94  of the first turbocharger  92 . The compressor wheel  96  compresses the atmospheric air  24  to the first preestablished pressure and temperature, about 2.4 atmospheres and about 130 degrees centigrade. The pressurized combustion air  58  from the compressor section  94  enters the compressor section  112  of the second turbocharger  102 . The compressor wheel  114  compresses the first preestablished pressure and temperature to the second preestablished pressurized and temperature, about 4.5 atmospheres and about 230 degrees centigrade. From the second turbocharger  102  the pressurized combustion air  58  passes through the plurality of pipes  148  to the first aftercooler  130 . Within the first aftercooler  130  the pressurized combustion air  58  acts as the donor fluid, enters the inlet portion  136 , passes into the transfer portion  138  and donates a portion of its heat to the recipient fluid, liquid coolant  18 . After donating a portion of its heat to the liquid coolant  18 , the pressurized combustion air  58  exits the outlet portion  140  at a temperature of about 170 degrees centigrade. The partially cooled pressurized combustion air  58  passes through the plurality of pipes  178  and enters the second aftercooler  160 . The pressurized combustion air  58  enters the combustion air inlet portion  166  and passes into the combustion air transfer portion  168  and donates another portion of its heat to the recipient fluid, atmospheric air  24 . After donating another portion of its heat to the atmospheric air  24 , the pressurized combustion air  58  exits the combustion air outlet portion  170  at a temperature of about 49 degrees centigrade and enters the pipe  104  leading to the intake manifold  56 .  
         [0023]    From the intake manifold  56 , the pressurized combustion air  58  flows in a generally conventional fashion within the engine  14 . For example in the normal four cycle engine  14  operation, the intake valve mechanism  62  is positioned in the open position  64  before top dead center (TDC) during the exhaust stroke and remains in the open position  64  during the intake stroke to about bottom dead center (BDC). However, with the engine  14  operated with the Miller cycle, the intake valve mechanism  62  is positioned in the open position  64  before top dead center (TDC) in the exhaust stroke and remains in the open position  64  past bottom dead center (BDC) and into the compression stroke from about 150 degrees to about 60 before top dead center (BTDC) depending on the speed of the engine  14 . As the piston assembly  52  travel from the top dead center position (0-180 degrees) pressurized combustion air  58  passes through the passage  60  and with the intake valve mechanism  62  in the open position  64  into the cylinder bore  51 . With the pressurized combustion air  58  being at a pressure of about 4.5 atmospheres, the pressurized combustion air  58  pushes the piston assembly  52  adding energy to rotate the crankshaft  50 . Thus, increasing the efficiency of the engine  14 . At bottom dead center (BDC) the pressure of the intake manifold  57  and the cylinder bore  51  are about equal. As the piston assembly  52  begins to move up, toward top dead center (TDC), flow continues because of the momentum of the flow  58 . However, the flow  58  eventually reverses back into the intake manifold  57  as the intake valve mechanism  62  is held in the open position  64  further into the compression stroke.  
         [0024]    If the air induction system  91  and the combustion air cooling system  129  are used with a convention engine cycle, not the Miller cycle, the highly compressed combustion air  58  enters the intake manifold  56 . And, with the intake valve mechanism  62  in the open position  64 , the compressed combustion air  58  passes through the passage  60  into the cylinder bore  51 . And, with the highly pressurized combustion air  58  the efficiency derived from the force of pushing on the piston assembly  52  is still attained. And, with the highly pressurized combustion air  58  a greater quantity of combustion air  58  is availabe to mix with fuel  54 . Thus, a leaner burning, lower emission and more efficient engine is obtained.  
         [0025]    The exhaust  72  from the combustion process, during the exhaust stroke, exits the cylinder bore  51  with the exhaust valve mechanism  76  in the open position  78 . The exhaust  72  passes through the passage  74  and enters the exhaust manifold  70 . From the exhaust manifold  70 , the exhaust  72  enters the turbine section  101  driving the turbine wheel  118  and the shaft  120  causing the compressor wheel  114  to pressurize the combustion air  58  to the second preestablished pressure and temperature. From the turbine section  101  of the second turbocharger  102 , the partially spent exhaust  72  passes through the pipe  103  and enters the turbine section  98  of the first turbocharger  92 . The exhaust  72  drives the turbine wheel  99  and the shaft  100  causing the compressor wheel  96  to pressurize the combustion air  58  to the first preestablished pressure and temperature. As state earlier, if two turbine wheel  99 , 118  are combined into a single turbine wheel, and the two shafts  100 , 120  are combined and each of the compressor wheels  96  and  114  are positioned on the single shaft the exhaust  72  will drive the single turbine wheel.  
         [0026]    The engine cooling system  16  has atmospheric air  24  flowing through the radiator  20 . The fan  22 , when rotating, draws atmospheric air  24  through the radiator  20 . With the vehicle traveling down the open road, the velocity of the vehicle  10  causes atmospheric air  24  to pass through the radiator  20 . The atmospheric air  24  acts as the recipient fluid to cool the donor fluid, liquid coolant  18 . The coolant pump  86  is driven by the engine  14  and causes a flow of liquid coolant  18  to exit the coolant pump outlet portion  87  an passes through the plurality of cooling passages  53  in the block  49  absorbing heat. With the thermostat  89  open, the liquid coolant  18  passes through the upper flex hose  42  and enters the liquid coolant inlet  40  of the radiator  20  and passes through the tubes of the tubes and fins  34 . The fins of the tube and fins  34  transfer heat from the liquid coolant  18  to the atmospheric air  24 . The cooled liquid  18  exits the liquid coolant outlet  36  and passes through the flex hose  38  to the coolant pump inlet portion  88  and is recirculated by the coolant pump  86 .  
         [0027]    The first aftercooler  130  of the combustion air cooling system  129  as stated above uses the same liquid coolant  18  as does the engine cooling system  16 . The liquid coolant  18  is circulated by the coolant pump  86 . A portion of the flow of liquid coolant  18  exiting the coolant outlet portion  87  is circulated to the liquid coolant inlet portion  142  of the first aftercooler  130 . The liquid coolant  18  acts as the recipient fluid and in the liquid coolant transfer portion  144  and heat is absorbed from the pressurized combustion air  58 . The heated liquid coolant  18  exits the liquid coolant outlet portion  146  and is circulated to the coolant outlet portion  85  of the oil cooler  83 . Within the coolant outlet portion  85  of the oil cooler  83  the liquid coolant  18  is mixed with the liquid coolant  18  used to cooling the engine  14  and passes through the plurality of cooling passages  53  in the engine  14 . The mixed liquid coolant  18  passes through the engine  14  to the thermostat housing  90 . The coolant outlet portion  87  of the coolant pump  86  acts to divide the liquid coolant into the first flow  18 A, between the engine  14  and the heat exchanger or radiator  20  by the coolant pump  86 , and a second flow  18 B, between the first aftercooler  130  and the engine  14  by the coolant pump  86 . By separating the coolant flow  18  into the first flow  18 A and the second flow  18 B, the flow of coolant  18  through the radiator  20  of the engine cooling system  16  is maintained at a level which will resists erosion of the structure of the tubes of the tubes and fins  34 . To compensate for the greater cooling requirement of the radiator  20 , a thicker core, wider tubes and fins  34  will be used verses that used today in an equivalent engine cooling system  16 . As mentioned earlier, several alternatives are contemplated for dividing the flow of liquid coolant into the first flow  18 A and the second flow  18 B. Another version will use the flow control valve  190 . The positioning of the flow control valve  190  between the closed position  192  and the open position  194  will vary the flow rate between the first flow  18 A and the second flow  18 B. Several methods are contemplated for varying the position of the control valve  190  between the closed position and the open position. For example, the controller  196  will have input from the engine  14  operation. Such parameters could be coolant  18  temperature, pressurized combustion air  58  temperature and atmospheric air  24  temperature. Other parameters could be atmospheric pressure, vehicle speed or air flow through the radiator  20 . An orifice or preestablished cross sectional area of the liquid coolant inlet portion  142  could also be used to established the flow rate of the first flow  18 A and the second flow  18 B.  
         [0028]    The second aftercooler  160  of the combustion air cooling system  129  uses the air to air configuration. The pressurized combustion air  58  is the donor fluid and atmospheric air  24  is the recipient fluid. With the second aftercooler  160  placed above the radiator  20  fresh unspent atmospheric air  24  is used. The unspent atmospheric air  24  enter the atmospheric air inlet portion  172 , passes through the atmospheric air transfer portion  174  and absorbs heat from the pressurized combustion air  58  and exits the atmospheric outlet portion  176 . The spent atmospheric air  24  is dissipated to the atmosphere. The pressurized combustion air  58  enters the combustion air inlet portion  166 , passes through the combustion air transfer portion  168  where a portion of the heat within the pressurized combustion air  58  is extracted by the atmospheric air  24  and passes through the combustion air outlet portion  170 . The cooled pressurized combustion air  58  passes through the pipe  104  into the intake manifold  57 . And, as discussed above, enters the cylinder bore  51 .  
         [0029]    Other aspects, objects and advantages of this combustion air cooling system  129  can be obtained from a study of the drawings, the disclosure and the appended claims.