Abstract:
An engine management system that maximizes the efficiency of internal combustion engines (gasoline or diesel) based on the performance demanded of the engine and the environmental conditions that the engine is operating in. The engine intake and cooling systems are arranged such that that the engine intake air temperature and pressure and coolant temperature are continuously optimized to provide reduced emissions on start-up and increased efficiency and performance in all environmental conditions.

Description:
BACKGROUND 
       [0001]    The present disclosure relates to vehicle engine management systems and more particularly, to systems and methods for protecting and improving the vehicle engine performance. 
         [0002]    In the cooling system of vehicles, excess heat from the engine is removed by an engine coolant. In a typical turbo and/or supercharged engine equipped with an air to air intercooler system (AAICS), such as that illustrated in  FIG. 1 , a coolant at temperature T 11  is circulated through the engine to absorb the heat from the engine. Engine heat increases the temperature of the coolant to T 12 . In AAICS  100 , the coolant returning from the engine  110  passes through a radiator  120  which receives ambient air having a temperature of T A . Heat removed from the engine by the coolant dissipates into the atmosphere. The temperature of the coolant decreases from T 12  to T 11 . The coolant continues to circulate through the engine and (passes through) the radiator in this manner to remove heat from the engine. The coolant is typically in a liquid form that does not freeze in cold settings. 
         [0003]    Typically, the ambient temperature for T A  is below 60° C. The coolant temperature T 11  (going into the engine) is approximately 80° C. and the coolant temperature T 12  (coming out of the engine) is approximately 100° C. Therefore, the relationship between the ambient temperature and the various coolant temperatures is T A &lt;T 11 &lt;T 12 . 
         [0004]    AAICS  100  also includes a compressor  130  that receives ambient air at temperature T A  and pressure at P A . Turbo compressor  130  compresses the air to temperature T 13  and pressure P 13 . The pressurized air is then passed through radiator  140 . Radiator  140  receives ambient air with a temperature of T A  and pressure of P A . The temperature and pressure of the compressed air that passes through radiator  140  are reduced to T 14  and P 14 . 
         [0005]    The air from the radiator at T 14 , P 14  is then also provided to engine  110  as engine intake air. Engine  110 , therefore, receives coolant at temperature T 11  and air at temperature T 14  and pressure P 14 . The heat generated by the engine and the engine intake air increases the coolant temperature to T 12 . 
         [0006]    The ambient temperature T A  can be below 60° C. and the ambient pressure can be at approximately one (1) bar. T 13  can be approximately 240° C. and P 13  can be approximately at two (2) bars. T 14  can be approximately 90° C. and P 14  can be at two (2) bars. 
         [0007]    Therefore, the relationship between the ambient temperature and the various air temperatures can be represented by T A &lt;T 14 &lt;T 13 . The relationship between the ambient pressure and the various air pressures can be represented by P A &lt;P 14 ≅P 13  where “≅” represents P 14  being approximately equal to P 13 . The relationship between the various coolant and air temperatures can be represented by T A &lt;T 11 &lt;T 14 &lt;T 12 &lt;T 13 . 
         [0008]    Other existing cooling systems include an air to water intercooler system (AWICS) such as that illustrated in  FIG. 2 . In AWICS  200 , coolant returning from engine  210  at T 22  passes through radiator  220  (which receives ambient air at T A ) to reduce the temperature to T 21 . The coolant then passes through radiator  240  and then flows back to the engine. 
         [0009]    The value of ambient temperature T A  can be, for example, less than 60° C. while that of the coolant T 21  can be approximately 70° C. and that of T 22  can be approximately 100° C. The relationship between the ambient temperature and the various coolant temperatures can be represented by T A &lt;T 21 &lt;T 22 . 
         [0010]    Compressor  230  receives ambient air at temperature T A  and pressure at P A . The air is compressed and the temperature of the compressed air increases to T 23  and the pressure increases to P 23 . The compressed air passes through radiator  240 . Radiator  240  (unlike  140 ), does not receive ambient air. 
         [0011]    Heat transfers from the compressed air to the engine coolant in radiator  240  which results in the temperature of the coolant increasing from T 21  to T 25  after passing through radiator  240 . The coolant circulates through engine  210 . The temperature of the compressed air decreases to T 24  after passing through radiator  240  and the pressure decreases to P 24 . The compressed air is supplied to the engine as engine intake air. 
         [0012]    The value of T 23  can be approximately 240° C. and P 23  can be approximately at two (2) bars. T 24  can be approximately 95° C. and P 24  can be at two (2) bars. T 25  can be approximately 80° C. 
         [0013]    The relationship between the various air temperatures for AWICS  200  can be expressed as T A &lt;T 24 &lt;T 23 . The relationship between the pressure values can be represented by for example, P A &lt;P 24 ≅P 23  where “≅” represents P 24  being approximately equal to P 23 . The relationship between the various coolant temperatures and the various air temperatures can be represented by T A &lt;T 21 &lt;T 25 &lt;T 24 &lt;T 22 &lt;T 23 . 
         [0014]    In the AAICS of  FIG. 1 , radiators  120  and  140  and compressor  130  receive ambient air. In the AWICS of  FIG. 2 , radiator  220  and compressor  230  receive ambient air. Radiator  240  does not receive ambient air. Radiator  220  will likely be larger in size than radiator  120  since radiator  220  is responsible for all the heat being rejected by the cooling system to the ambient air. 
         [0015]    In existing systems, such as AAICS  100  of  FIG. 1  and AWICS  200  of  FIG. 2  described above, the temperature of the engine intake air is higher than the temperature of the coolant circulating through the engine. In normal engine operation (not necessarily while engines are being warmed up), it is typically desirable to have lower engine intake air temperatures to facilitate a more efficient engine performance. 
       SUMMARY 
       [0016]    According to an exemplary embodiment, an engine management system is disclosed. The engine management system comprises: a first radiator for providing coolant to an engine and for cooling the coolant returning from the engine utilizing air at ambient temperature; a compressor for compressing air received at ambient temperature and ambient pressure and for outputting the compressed air; a second radiator located between the first radiator and the engine for receiving compressed air from the compressor and the coolant from the first radiator and for supplying the coolant to the engine and for outputting the compressed air; and a variable expansion valve for receiving the compressed air output from the second radiator and for outputting the expanded air to the engine wherein a level of expansion or compression of the variable expansion valve is based on a required engine performance level. 
         [0017]    According to another exemplary embodiment, an engine management system comprises: a first radiator for providing coolant to an engine and for cooling the coolant returning from the engine utilizing air at ambient temperature; a compressor for compressing air received at ambient temperature and ambient pressure and for outputting the compressed air; a second radiator located between the first radiator and the engine for receiving compressed air from the compressor and the coolant from the first radiator and for supplying the coolant to the engine and for outputting the compressed air; an expansion valve for receiving the compressed air output from the second radiator and for outputting an expanded air; and a plurality of flow paths for selectively directing air to the engine, wherein a selected one of the flow paths corresponds to a particular engine performance level. 
         [0018]    According a further exemplary embodiment, a method for providing intake air to a vehicle engine is disclosed. The method comprises: receiving air having an ambient temperature and an ambient pressure by a compressor; compressing the received air wherein the compressed air has a first temperature and a first pressure; and selectively providing the compressed air via at least one of a plurality of flow paths to the engine, the flow path being determined by verifying an operating mode of the engine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The several features, objects, and advantages of exemplary embodiments will be understood by reading this description in conjunction with the drawings. The same reference numbers in different drawings identify the same or similar elements. In the drawings: 
           [0020]      FIG. 1  illustrates an air to air intercooler system; 
           [0021]      FIG. 2  illustrates an air to water intercooler system; 
           [0022]      FIG. 3  illustrates an air to water intercooler system in accordance with an exemplary embodiment; 
           [0023]      FIG. 4  illustrates an air to water intercooler system in accordance with other exemplary embodiment; and 
           [0024]      FIG. 5  illustrates a method in accordance with exemplary embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    In the following description, numerous specific details are given to provide a thorough understanding of embodiments. The embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the exemplary embodiments. 
         [0026]    Reference throughout this specification to an “exemplary embodiment” or “exemplary embodiments” means that a particular feature, structure, or characteristic as described is included in at least one embodiment. Thus, the appearances of these terms and similar phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. The headings provided herein are for convenience only and do not interpret the scope or meaning of the embodiments. 
         [0027]    According to exemplary embodiments, a compressor (one or more turbo and/or supercharges) and a variable expansion valve may be utilized to decrease the temperature of engine intake air. 
         [0028]    An exemplary air to water intercooler system (AWICS) as illustrated in  FIG. 3  includes a variable expansion valve  350 . In AWICS  300 , coolant returning from engine  310  at T 32  is passed through radiator  320 . Radiator  320  receives ambient air at T A . The temperature of the coolant is reduced to T 31  after the coolant passes through radiator  320 . The coolant is then passed through radiator  340 . 
         [0029]    Compressor  330  receives ambient air having a temperature of T A  and pressure of P A . Compressor  330  can compress the received air. The temperature of the compressed air increases to T 33  and the pressure increases to P 33 . The compressed air also passes through radiator  340 . Radiator  340  (like radiator  240 ), does not receive ambient air. 
         [0030]    Due to heat transfer from the compressed air to the engine coolant in radiator  340 , the temperature of the coolant increases to T 35  after the coolant passes through radiator  340 . The coolant at temperature T 35  is circulated through engine  310 . The temperature of the compressed air from compressor  330  decreases to T 34  after the air passes through radiator  340  and the pressure decreases to P 34 . 
         [0031]    Air from radiator  340  may pass through variable expansion valve  350  resulting in a further decrease in temperature of the compressed air to T 36  and a further decrease in pressure to P 36 . The level or degree of expansion or compression of valve  350  may vary based on a specified criterion. The criterion may include a desired level of efficiency or performance of the engine for example. 
         [0032]    For a high performance mode, the valve may be compressed. That is, the level of compression may be high or the level of expansion may be low. For a low or economical mode, the valve may be expanded. That is, the level of expansion may be high or the level of compression may be low. The variable expansion valve may be expanded or compressed to optimize or maximize the performance and efficiency of the engine. Various performance modes may be specified or selected within a vehicle in which an exemplary engine management system as described herein may be included. 
         [0033]    The selection may be via a selector button accessible to the user of the vehicle for example (i.e. performance or efficiency modes). The modes may also be determined automatically by the engine management system based on sensor readings representing the vehicle user&#39;s operating manner and/or the user settings above. 
         [0034]    The coolant at temperature T 35  can be circulated through engine  310 . Air from variable expansion valve  350  at temperature T 36  and pressure P 36  can also be provided to the engine as engine intake air. The air from the variable expansion valve  350  may be referred to as “expanded” air. 
         [0035]    In accordance with exemplary embodiments, the temperature of the air after passing through variable expansion valve  350  (i.e. T 36 ) may decrease. For a high performance mode, the temperature of the air provided to the engine can be at a level that is below the temperature of the ambient air (T A ). 
         [0036]    The ambient temperature T A  can be, for example, less than 60° C. while that of coolant temperature T 31  can be approximately 70° C., that of coolant temperature T 32  can be approximately 100° C. and that of coolant temperature T 35  can be approximately 80° C. The relationship between the ambient temperature and various coolant temperatures can be represented by T A &lt;T 31 &lt;T 35 &lt;T 32  for example. 
         [0037]    The value of P A  can be, for example, at approximately one (1) bar. Air temperature T 33  can be, for example, approximately 270° C. and air pressure P 33  can be approximately at two and one half (2.5) bars. Air temperature T 34  can be approximately 105° C. and air pressure P 34  can be at two and one half (2.5) bars. Air temperature T 36  can be approximately 35° C. and air pressure P 36  can be at two (2) bars. 
         [0038]    The relationship between the ambient temperature and the various air temperatures can be represented by T 36 &lt;T A &lt;T 34 &lt;T 33  for example. The relationship between the ambient temperature and the various coolant and air temperatures can be expressed by T 36 &lt;T A &lt;T 31 &lt;T 35 &lt;T 32 &lt;T 34 &lt;T 33  for example. The relationship between the ambient pressure and the various air pressures can be represented by P A &lt;P 36 &lt;P 34 ≅P 33  for example where “≅” represents P 34  being approximately equal to P 33 . 
         [0039]    In AWICS  300  of  FIG. 3 , radiator  320  and compressor  330  are exposed to ambient air. Radiator  340  does not receive ambient air. Radiator  320  may be larger in dimension or size than radiator  120 . 
         [0040]    The various performance modes described herein may also be realized by an exemplary AWICS  400  as illustrated in  FIG. 4 . AWICS  400  may utilize one of a plurality of flow paths for providing engine intake air based on a desired performance level. Compressor  430 , radiator  440  may correspond to their respective counterparts  330  and  340  in AWICS  300  of  FIG. 3 . Various performance levels or modes for the engine may be available such as an Economy Mode (EM), a Combination Mode (CM) and a Power Mode (PM). 
         [0041]    If a performance mode is required as described above with reference to  FIG. 3 , the engine intake air may be provided via flow path PM passing through expansion valve  450 . Expansion valve  450  can reduce the temperature of the air from radiator to engine  410  (T 46 ) to a level that is lower than the ambient temperature T A . Expansion valve  450  can be similar to expansion valve  350  of  FIG. 3  in that it can be a variable expansion valve. 
         [0042]    If an economy mode is required, the engine intake air may be provided via flow path EM directly from the turbo compressor  430  at T 43  without utilizing radiator  440  and expansion valve  450 . 
         [0043]    If a combination mode (that is between, or a combination of, a performance mode and an economy mode) is required, the engine intake air may be provided at T 44  via flow path CM which bypasses expansion valve  450 . 
         [0044]    In an economy mode, a flow path valve  435  may direct compressed air directly to the engine. In this mode, since compressed air is not directed to radiator  440 , coolant temperature entering radiator  440  may be equal to coolant temperature leaving radiator  440  (i.e. T 41 =T 45 ). In a combination mode, a flow path switch  445  may direct air output from radiator  440  to the engine. A flow path switch  445  may direct air from the selected path (i.e. one of EM, CM and PM) to the engine. 
         [0045]    While the various modes described herein indicate the air flowing to the engine from the compressor via one of the paths, during a switch over between modes, the air may flow along more than one path. For example, if the vehicle is in an economy mode, the air may flow along path EM. If the mode is switched to a performance mode, the air flow can commence along flow path PM during the switchover of the modes while air may still be flowing along path EM. The flow paths can be adjusted continuously to maximize the performance and efficiency of the engine. 
         [0046]    A method in accordance with exemplary embodiments may be illustrated with reference to  FIG. 5 . According to exemplary method  500 , air may be received by a compressor at  505 . The received air may be ambient air and therefore, be at an ambient temperature and an ambient pressure. The received air may be compressed at  510 . The compressed air may be at a first temperature that is higher than the ambient temperature. The compressed air may be at a first pressure that is higher than the ambient pressure. An operating mode of the engine may be verified at  515 . The compressed air may be selectively provided via at least one of a plurality of paths to the engine at  520  depending on the verified operating mode of the engine. The operating mode may be one of an economy mode, a combination mode and a performance mode. 
         [0047]    If the operating mode is an economy mode, the compressed air may be provided to the engine via a first flow path at  525  (economy mode or EM of  FIG. 4 ). The compressed air may be at a first temperature that is higher than the ambient temperature and at a first pressure that is higher than the ambient pressure. 
         [0048]    If the operating mode is a combination mode, the compressed air at a first temperature that is higher than the ambient temperature and at a first pressure that is higher than the ambient pressure may be provided to a radiator (radiator  440  of  FIG. 4 ) at  530 . The air output from the radiator may be provided to the engine via a second flow path at  535  (CM of  FIG. 4 ). The air output from the radiator may be at a second temperature lower than the first temperature and at a second pressure lower than the first pressure. 
         [0049]    If the operating mode is a performance mode, the compressed air at a first temperature that is higher than the ambient temperature and at a first pressure that is higher than the ambient pressure may be provided to a radiator (radiator  440  of  FIG. 4 ) at  540 . The air output from the radiator at a second temperature lower than the first temperature and at a second pressure lower than the first pressure may be provided to an expansion valve (expansion valve  450  of  FIG. 4 ) at  545 . Air output from the expansion valve at a third temperature lower than the second temperature and at a third pressure lower than the second pressure may be provided to the engine via third flow path (PM of  FIG. 4 ) at  550 . 
         [0050]    The step of selectively providing air may be general in nature while the steps for providing air via one at least one of the flow paths may be more specific and are illustrated by dashed flow lines. 
         [0051]    Multiple advantages may be realized utilizing exemplary embodiments as described above. Engine intake air at lower temperatures (such as T 36 ) is highly desirable from an engine efficiency and performance point of view. A lower intake air temperature allows a lower octane fuel to be used without causing pre-combustion in gasoline equipped engines. Simultaneously, during engine warm up, engine intake air temperatures higher than ambient air temperature can be desirable for providing a faster warm up (or reaching operating temperature more quickly) and corresponding reduction in engine emissions. The higher intake air temperatures realized by providing compressed air directly into the engine facilitates such faster warm up. 
         [0052]    The numerical values provided for temperature and pressure are for illustrative and exemplary purposes only and are not limiting in any manner. Turbo compressors described herein may be mechanically or electrically driven. Although exemplary embodiments have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of embodiments without departing from the spirit and scope of the disclosure. Such modifications are intended to be covered by the appended claims. 
         [0053]    Further, in the description and the appended claims the meaning of “comprising” is not to be understood as excluding other elements or steps. Further, “a” or “an” does not exclude a plurality, and a single unit may fulfill the functions of several means recited in the claims. 
         [0054]    The above description of illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Although specific embodiments of and examples are described herein for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the disclosure, as will be recognized by those skilled in relevant art. 
         [0055]    The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments. 
         [0056]    These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.