Apparatus and method for controlling intake air temperature

Abstract

A method for operating an internal combustion engine and a method for controlling an intake air temperature in an engine of a vehicle are provided. The engine includes: an intake system configured to deliver intake air to an internal combustion engine; an exhaust system configured to exhaust exhaust gas from the internal combustion engine; and an exhaust gas recirculation ("EGR") system configured to selectively deliver a portion of the exhaust gas to the intake system. The internal combustion engine is located in the lower hood area; the air intake system includes a first air intake duct having an outlet in communication with the air intake system and having an inlet outside the under hood region to receive ambient air; and the air intake system includes a second air intake duct having an outlet in communication with the air intake system and having an inlet located within the under-hood region to receive air warmed by the internal combustion engine.

Description

[0001] The technical field relates generally to internal combustion engine arrangements and, more particularly, to arrangements for controlling intake air temperature. Background Art

[0002] Contemporary internal combustion engines, including diesel engines and gasoline engines, often utilize exhaust gas recirculation ("EGR"). This improves fuel consumption and reduces regulated tailpipe exhaust gas emissions. An EGR system typically includes an EGR valve that is located after the combustion chamber (engine cylinder) in the exhaust system and can be opened to different levels under the control of an engine control unit (ECU). The EGR valve can therefore precisely adjust the amount of exhaust gas that is recirculated as a steering flow and mixed with fresh intake air.

[0003] The EGR valve allows harmful gases to re-enter the intake system, changing the chemical composition of the return air, which causes the fuel mixture to burn slower, lower combustion chamber temperatures, and reduce nitrogen oxides (NOx) and carbon dioxide production to improve efficiency and air quality.

[0004] After combustion, the exhaust gas contains water vapor. When the EGR valve is partially opened and the fresh air introduced into the intake system is cold enough, the water vapor may condense and freeze in the intake system.

[0005] Therefore, it is desirable to provide apparatus and methods for controlling intake air temperature, such as to avoid freezing of water from a recirculated exhaust gas stream.Additionally, other desirable features and characteristics of the present disclosure will become apparent from the ensuing description, in conjunction with the accompanying drawings and the foregoing introduction. Summary of the invention

[0006] In one embodiment, an internal combustion engine includes: an intake system configured to deliver intake air to the internal combustion engine; an exhaust system configured to exhaust exhaust gas from the internal combustion engine; and an exhaust gas recirculation ("EGR") system configured to selectively deliver a portion of the exhaust gas to the intake system. The internal combustion engine is located in an under-hood region; the intake system includes a first intake duct having an outlet in communication with the intake system and having an inlet located outside the under-hood region to receive ambient air; and the intake system includes a second intake duct having an outlet in communication with the intake system and having an inlet located in the under-hood region to receive air warmed by the internal combustion engine.

[0007] In an exemplary embodiment, the internal combustion engine further includes a first valve configured to restrict the flow of ambient air to the intake system and a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system.

[0008] In an exemplary embodiment, the internal combustion engine further includes: a first valve configured to restrict the flow of ambient air to the intake system; a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system; and a control module configured to selectively open and close the first valve and the second valve to obtain a desired first flow rate of ambient air and a desired second flow rate of air warmed by the internal combustion engine.

[0009] In an exemplary embodiment, the internal combustion engine also includes: a first valve configured to restrict the flow of ambient air to the intake system; a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system; a sensor for obtaining data related to the operation of the internal combustion engine; and a control module configured to determine a desired first flow rate of ambient air to the intake system and a desired second flow rate of air warmed by the internal combustion engine based on the data, and configured to selectively open and close the first valve and the second valve to obtain the desired first flow rate of ambient air and the desired second flow rate of air warmed by the internal combustion engine.

[0010] In an exemplary embodiment, the internal combustion engine also includes an EGR valve configured to restrict the flow of a portion of the exhaust gas to the intake system; a first valve configured to restrict the flow of ambient air to the intake system; a second valve configured to restrict the flow of air heated by the internal combustion engine to the intake system; a sensor for obtaining data related to the operation of the internal combustion engine; and a control module configured to: determine a desired EGR operating mode based on the data; determine a desired first flow rate of ambient air to the intake system and a desired second flow rate of air heated by the internal combustion engine based on the data; selectively open and close the first valve and the second valve to obtain the desired first flow rate of ambient air and the desired second flow rate of air heated by the internal combustion engine; and selectively open and close the EGR valve to operate the internal combustion engine in the desired EGR operating mode.

[0011] In an exemplary embodiment, the internal combustion engine also includes an exhaust heat transfer hood, wherein: a portion of the exhaust system is located in the exhaust heat transfer hood; an inlet of the second intake duct located in the under-hood area to receive air warmed by the internal combustion engine is a first inlet; the first inlet is connected to the exhaust heat transfer hood; and the second intake duct includes a second inlet located outside the under-hood area to receive ambient air.

[0012] In an exemplary embodiment of an internal combustion engine, an exhaust system includes an exhaust manifold; and an exhaust heat transfer shield conforms to a contour of the exhaust manifold.

[0013] In an exemplary embodiment, the internal combustion engine further includes: a first valve configured to restrict the flow of ambient air through the first intake duct to the intake system; a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system; and a third valve configured to restrict the flow of ambient air through the second intake duct to the exhaust heat transfer shield.

[0014] In an exemplary embodiment, the internal combustion engine also includes: an EGR valve configured to restrict the flow of a portion of exhaust gas to an intake system; a sensor for obtaining data related to the operation of the internal combustion engine; and a control module configured to: determine a desired EGR operating mode based on the data; determine a desired first flow rate of ambient air to the intake system through a first intake duct, determine a desired second flow rate of air warmed by the internal combustion engine to the intake system, and determine a desired third flow rate of ambient air to the exhaust heat transfer hood through a second intake duct based on the data; selectively open and close the first valve, the second valve, and the third valve to obtain the desired first flow rate, the desired second flow rate, and the desired third flow rate; and selectively open and close the EGR valve to operate the internal combustion engine in the desired EGR operating mode.

[0015] In another embodiment, a method for operating an internal combustion engine includes: delivering intake air to the internal combustion engine with an intake system, wherein: the intake system and the internal combustion engine are located in an under-hood area; a first operating mode causes ambient air from outside the under-hood area to flow to form intake air; and a second operating mode causes heated air warmed by the internal combustion engine to flow to form at least a portion of the intake air; exhaust gas from the internal combustion engine to the exhaust system; and selectively delivering a portion of the exhaust gas to the intake system as part of the intake air.

[0016] In an exemplary embodiment, the method further includes obtaining data related to operation of the internal combustion engine; and determining whether to operate the internal combustion engine in the first operating mode or the second operating mode based on the data.

[0017] In an exemplary embodiment, the method further includes obtaining data related to operation of the internal combustion engine; determining whether exhaust gas recirculation ("EGR") is required based on the data; and when EGR is required, delivering a portion of the exhaust gas to the intake system as part of the intake air.

[0018] In an exemplary embodiment of the method, the internal combustion engine includes an exhaust heat transfer hood; a portion of the exhaust system is located in the exhaust heat transfer hood; and the heated air warmed by the internal combustion engine is air from the exhaust heat transfer hood.

[0019] In an exemplary embodiment of the method, a sub-mode of the first operating mode flows ambient air from outside the under-hood area to the exhaust heat transfer hood.

[0020] In another embodiment, a method for controlling intake air temperature in an engine of a vehicle includes selectively recirculating a portion of exhaust gases from the engine to an intake system of the engine to reduce the temperature of the engine; determining whether ambient air outside the vehicle is cooler than a selected temperature; and in response to determining that the ambient air outside the vehicle is cooler than the selected temperature, flowing heated air from an under-hood area of ​​the vehicle to the intake system of the engine.

[0021] In an exemplary embodiment, the method further includes: determining whether ambient air outside the vehicle is not cooler than a selected temperature; in response to determining that the ambient air outside the vehicle is not cooler than the selected temperature, reducing or stopping the flow of heated air from an under-hood area of ​​the vehicle to an intake system of the engine; and flowing ambient air from outside the vehicle to the intake system of the engine.

[0022] In an exemplary embodiment, the method further includes maintaining the intake air temperature within a desired temperature range by controlling the flow of heated air from an under-hood region of the vehicle to an intake system of the engine and controlling the flow of ambient air from outside the vehicle to the intake system of the engine.

[0023] In an exemplary embodiment of the method, the engine includes an exhaust manifold and an exhaust heat transfer hood; the exhaust heat transfer hood is adjacent to the exhaust manifold; and flowing heated air from an under-hood area of ​​the vehicle to an intake system of the engine includes flowing heated air from the exhaust heat transfer hood to an intake system of the engine.

[0024] In an exemplary embodiment of the method, the engine includes an exhaust heat transfer hood; causing heated air from an under-hood area of ​​the vehicle to flow to an intake system of the engine includes: causing the heated air from the exhaust heat transfer hood to flow to the intake system of the engine; and the method also includes: determining whether the ambient air outside the vehicle is not cooler than a selected temperature; and in response to determining that the ambient air outside the vehicle is not cooler than the selected temperature, stopping the flow of the heated air from the exhaust heat transfer hood to the intake system of the engine, and causing ambient air from outside the vehicle to flow to the exhaust heat transfer hood.

[0025] In an exemplary embodiment of the method, the vehicle includes: a front damper configured to adjust the flow of free ambient air entering the under-hood area of ​​the vehicle; and the method also includes: selectively partially closing the front damper to increase the under-hood air temperature and selectively fully opening the front damper to reduce the under-hood air temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Hereinafter, the present disclosure will be described in conjunction with the following drawings, wherein like reference numerals refer to like elements, and wherein:

[0027] Figure 1 is a schematic diagram of a vehicle and an internal combustion engine suitable for use with an exemplary embodiment of the present disclosure;

[0028] Figure 2 is a schematic diagram of a vehicle and an internal combustion engine suitable for use with an exemplary embodiment of the present disclosure;

[0029] Figure 3 The control module is used to perform the operation according to the embodiment of the present disclosure. Figure 1 or Figure 2 A flowchart for use when performing a method of an internal combustion engine; and

[0030] Figure 4 is a perspective view of an engine and other components under the hood of a vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] The following detailed description is merely exemplary in nature and is not intended to limit the application and use of the embodiments herein. In addition, there is no intention to be bound by any express or implied theory presented in the foregoing introduction and the invention content or the following detailed description. As used herein, the term "module" refers to any hardware, software, firmware, electronic control unit or component, processing logic, and / or processor device, alone or in any combination, including but not limited to: application-specific integrated circuits (ASICs), electronic circuits, processors (shared, dedicated or groups) and memories that execute one or more software or firmware programs, combinational logic circuits, and / or other suitable components that provide the described functions.

[0032] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that such block components may be implemented by any number of hardware, software, and / or firmware components configured to perform specified functions. For example, embodiments of the present disclosure may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., that may implement various functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any number of autonomous driving systems including cruise control systems, automatic driver assistance systems, and autonomous driving systems, and that the vehicle system described herein is merely an example embodiment of the present disclosure.

[0033] For the sake of brevity, conventional techniques and components related to other functional aspects of vehicle mechanical parts and systems (and the various operating components of the systems) may not be described in detail herein. In addition, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and / or physical connections between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in embodiments of the present invention. It should also be understood that the drawings are illustrative only and may not be drawn to scale.

[0034] Additionally, the following description relates to elements or features that are "connected" or "coupled" together. As used herein, "connection" may refer to one element / feature being directly joined to another element / feature (or being directly communicated with another element / feature), and not necessarily mechanically. Similarly, "coupling" may refer to one element / feature being directly or indirectly joined to another element / feature (or being directly or indirectly communicated with another element / feature), and not necessarily mechanically. However, it should be understood that although two elements may be described as "connected" in one embodiment below, in alternative embodiments, similar elements may be "coupled" and vice versa. Therefore, although the schematic diagrams shown herein depict example arrangements of elements, additional intervening elements, devices, features, or components may be present in actual embodiments.

[0035] The term "intake air" as used herein refers to any air flow including a portion of air that may be mixed with a portion of exhaust gas or other gases as is common in the industry. For example, a mixture of ambient air and / or heated air from within an engine compartment and a portion of recirculated exhaust gas may be referred to as intake air, as is common.

[0036] An exemplary vehicle, internal combustion engine, and method are provided to avoid ice formation of water from EGR diverted flow at an engine air intake system. In an exemplary embodiment, heated air from an under-hood area of ​​a vehicle is mixed with fresh ambient air from outside the vehicle to increase the temperature of the intake air before mixing with the EGR diverted flow. As a result, ice formation at the intake air system is avoided.

[0037] Freezing of water in the EGR diverted flow occurs only at sufficiently low temperatures. Therefore, sensors and control modules are provided to monitor ambient air temperature, i.e., the temperature of fresh air from outside the vehicle, and the temperature at various locations within the vehicle. The control module can control the flow of ambient air from outside the vehicle to the intake system, the flow of heated air from inside the vehicle to the intake system, and the flow of diverted EGR exhaust gas flow to the intake system.

[0038] Additionally, some embodiments may provide for flowing ambient air from outside the vehicle directly to the exhaust manifold to provide cooling thereof.

[0039] In summary, the embodiments herein achieve intake air temperature control by mixing preheated air from under the vehicle hood with ambient air under low ambient temperature conditions. For applications with diesel or gasoline engines with low-pressure EGR, this method avoids ice formation when the diverted EGR flow is flowing under high speed and load conditions. As a secondary benefit, when the ambient temperature is high and the vehicle is operating at high speed and load, air from outside the hood can flow directly to the exhaust manifold to reduce exhaust and catalyst temperatures. In addition, a control logic has been developed to determine whether to activate EGR based on ambient temperature, vehicle speed and load. Controlling the intake air temperature can achieve better fuel economy and emissions for low and medium speed / load operations under cold ambient conditions.

[0040] Referring to the drawings, wherein like reference numerals refer to like parts. Figure 1 1 is a simplified schematic diagram of an embodiment of an internal combustion engine 100 for a vehicle suitable for use with an exemplary embodiment of the present disclosure. The vehicle 110 may be any vehicle having an internal combustion engine 100. The vehicle 110 may be any of a number of different types of vehicles, such as, for example, a sedan, van, truck, or sport utility vehicle (SUV), and may be two-wheel drive (2WD), four-wheel drive (4WD), or all-wheel drive (AWD). In various embodiments, the vehicle 110 may incorporate any of or a combination of a number of different types of engines, such as, for example, a gasoline or diesel fuel combustion engine, a flexible fuel vehicle (FFV) engine (i.e., one that uses a mixture of gasoline and alcohol).

[0041] exist Figure 1 , an exemplary internal combustion engine, generally designated 100, is shown as being equipped for efficient operation under various conditions. As shown, an intake system 60 is configured to deliver intake air 101 to the internal combustion engine 100. In addition, an exhaust system is configured to exhaust exhaust gas 102 from the internal combustion engine 100. In addition, an exhaust gas recirculation ("EGR") system 90 is configured to selectively deliver a portion 103 of the exhausted exhaust gas 102 to the intake system 60. Typically, the exhausted exhaust gas 102 is lower in oxygen than the intake air 101. With less oxygen received, the diluted fuel mixture may burn more slowly, reducing temperatures in the engine combustion chamber and reducing the production of nitrogen oxides.

[0042] As shown, the internal combustion engine 100 is located in the under-hood area 21, i.e., under the hood of a vehicle 110 powered by the engine 100. As shown, the intake system 60 may also be located in the under-hood area 21. In addition, a portion of the exhaust system 80 may be located in the under-hood area 21.

[0043] The intake system 60 may include an air filter 66 and an air flow meter 68 downstream of the air filter 66. In addition, the intake system 60 may include an intake throttle valve 62 for receiving intake air 101 from the air flow meter 68. The intake system 60 includes an intake manifold 61 downstream of the intake throttle valve 62.

[0044] The internal combustion engine 100 includes a plurality of cylinders 69 into which air flows from an intake manifold 61. Specifically, the manifold 61 receives a compressed intake charge of intake air 101 from the intake system 60 through an intake throttle valve 62 and delivers the charge to the plurality of cylinders 69.

[0045] Cylinder 69 receives a combination of a charge of intake air 101 and fuel delivered by fuel rail 59. The intake air / fuel mixture is combusted in cylinder 69 using a spark from spark plug 82, causing a piston (not shown) therein to reciprocate. Spark plug 82 may be operated by a high voltage cable 83. The reciprocating motion of the piston rotates a crankshaft (not shown) to transmit power to a vehicle powertrain (not shown), or in the case of a stationary application of internal combustion engine 100, to a generator or other stationary recipient of such power (not shown).

[0046] The exhaust system 80 includes an exhaust manifold 81. Figure 1 , the exhaust manifold 81 is a split manifold 81 that provides two flow paths for the exhaust gas 102 exiting the engine 100 .

[0047] Exhaust manifold 81 is in fluid communication with cylinder 69 and is configured to remove combusted components of the intake air charge / fuel mixture (i.e., exhaust gas 102). Exhaust manifold 81 delivers exhaust gas 102 to various exhaust aftertreatment devices configured to treat various regulated components of exhaust gas 102 before releasing exhaust gas 102 to the atmosphere.

[0048] For example, the exhaust system 80 may include a close coupled catalytic converter 70 and an underfloor catalytic converter 76 that receive exhaust gas 102 from an exhaust manifold 81. Additionally, the exhaust system 80 may include a muffler 78 through which the exhaust gas 102 passes before being released.

[0049] As shown in the figure, various sensors are provided in the exhaust system 80. For example, the exhaust system 80 may include a front oxygen sensor 73 located in front of the close-coupled catalytic converter 70 and a rear oxygen sensor 77 located in the rear of the close-coupled catalytic converter 70.

[0050] Likewise, the intake system 60 is provided with various sensors. For example, an intake manifold pressure sensor 63 is provided at the intake manifold 61. In addition, a temperature sensor 67 is provided downstream of the intake throttle valve 62. In addition, a pressure sensor 65 is provided at the fuel rail 59.

[0051] As shown, the internal combustion engine 100 also includes an exhaust gas recirculation ("EGR") system 90. The EGR system 90 is configured to selectively remove a portion 103 of the exhaust gas 102 and recirculate the diverted portion 103 to the intake system 60. As shown, the EGR system 90 includes an EGR cooler 92 for cooling the diverted portion 103. In addition, the EGR system 90 includes an EGR valve 97 for selectively opening and closing to enable and disable the flow of the diverted portion 103 and metering the flow of the diverted portion 103 to a desired flow rate. In addition, the EGR system 90 includes an EGR diffuser 94, which defines a passage for evenly distributing the diverted portion 103 to the intake charge of the intake air 101 at the intake manifold 61.

[0052] The EGR system 90 also includes various sensors. For example, an upstream temperature sensor 91 is disposed upstream of the EGR cooler 92, and a downstream temperature sensor 93 is disposed downstream of the EGR cooler 92. In addition, a differential pressure sensor 95 is disposed at the EGR valve 97 to determine the differential pressure across the EGR valve 97. In addition, the EGR system 90 may include an analog temperature sensor 98 located upstream of the close-coupled catalytic converter 70 of the exhaust system 80.

[0053] In addition, the air intake system 60 includes a first duct 30 for receiving ambient air 104 from outside the under-hood region 21. As shown, the first duct 30 includes a first end 31, which may be an inlet located outside the under-hood region 21. In addition, the first duct 30 extends into the under-hood region 21 to a second end 32, which may be an outlet for other lines connected to the air intake system 60, that is, the second end 32 is in communication with the air intake system 60. As shown, an air flow control valve 35 is located in the first duct 30 for controlling the flow of ambient air 104 to the air intake system 60. In some embodiments, the first end 31 is the only component or feature of the air intake system 60 located outside the under-hood region 21.

[0054] In addition, the air intake system 60 includes a second duct 40 for receiving heated air 105 from the under-hood area 21, i.e., air heated by the engine 100. As shown, the second duct 40 includes a first end 41, which may be an inlet located in the under-hood area 21. In addition, the second duct 40 extends to a second end 42, which may be an outlet connected to other lines of the air intake system 60, i.e., the second end 42 is in communication with the air intake system 60. In some embodiments, the second duct 40 may be connected to the first duct 30 downstream of the air flow control valve 35, but other arrangements are also contemplated. As shown, the air flow control valve 45 is located in the second duct 40 for controlling the flow of heated air 105 to the air intake system 60.

[0055] like Figure 1 As further shown, the engine 100 may be provided with an optional front shutter 23. The front shutter 23 may be closed to stop or reduce the flow of ambient air from outside the under-hood area 21 into the under-hood area 21, i.e., free-flowing ambient air, rather than air flowing in the first duct 30. When the front shutter 23 is open, ambient air may enter the under-hood area 21 from outside the under-hood area 21. The engine 100 is also provided with a radiator 25 and an engine cooling fan 27. The front shutter 23, the radiator 25 and the engine cooling fan 27 are located in the under-hood area 21.

[0056] As further shown, the engine 100 is provided with a controller or control module 99, which is configured to selectively open and close the valves 35 and 45 to obtain a desired first flow rate of ambient air 104 and a desired second flow rate of heated air 105. The control module 99 may include an engine control module (ECM) or an engine control unit (ECU), or may be a part of an engine control module (ECM) or an engine control unit (ECU), or may be an engine control module (ECM) or an engine control unit (ECU). The control module 99 may include any type of processing element or vehicle controller, and may be equipped with non-volatile memory, random access memory (RAM), discrete and analog input / output (I / O), a central processing unit and / or a communication interface for networking within a vehicle communication network. The control module 99 may also be configured to operate the EGR valve 97 at any given time based on specific engine operating conditions to adjust the volume of the diverted exhaust gas 103 introduced into the intake system 60.

[0057] The control module 99 collects information about the operation of the internal combustion engine 100 from sensors in the intake system 60, the exhaust system 80, and the EGR system 90, such as temperatures of the exhaust system, engine coolant, compressed combustion charge, ambient, etc., and pressures, exhaust system conditions, and driver demand to determine an appropriate flow of diverted exhaust gas 103 (if any) to be recirculated to the intake system 60, to determine an appropriate flow of ambient air 104 to the intake system 60 (if any), and to determine an appropriate flow of heated under-hood air 105 to the intake system 60 (if any).

[0058] The control module 99 may communicate with other sensors in the vehicle 110 outside of the illustrated intake system 60, exhaust system 80, and EGR system 90. For example, the control module 99 may receive wheel speed information from a wheel speed sensor.

[0059] Figure 2 Another embodiment of an internal combustion engine 100 is illustrated having an intake system 60 for use with an EGR system 90 for delivering intake air 101 having desired characteristics. Figure 1 The engine 100 shares many common features and its description will not be repeated. In addition, for the purpose of clarity, portions of the exhaust system 80 and the EGR system 90 are not illustrated.

[0060] exist Figure 2 In FIG. 8 , an exhaust system 80 is provided with a heat transfer shield 50, which is illustrated as surrounding or enclosing an exhaust manifold 81. The heat transfer shield 50 defines an exhaust manifold in-sub-region 51 that is at least partially isolated from the remainder of the under-hood region 21.

[0061] like Figure 2 As shown, the air intake system 60 includes a first duct 30 for receiving ambient air 104 from outside the under-hood area 21. As shown, the first duct 30 includes a first end 31, which may be an inlet located outside the under-hood area 21. In addition, the first duct 30 extends into the under-hood area 21 to a second end 32, such as an outlet, connected to other lines of the air intake system 60, that is, the second end 32 is in communication with the air intake system 60. As shown, an air flow control valve 35 is located in the first duct 30 for controlling the flow of ambient air 104 to the air intake system 60.

[0062] exist Figure 2 In, with Figure 1 Compared with the embodiment of the present invention, the second pipe 40 has a different structure. Figure 2 In the embodiment of FIG. 5 , the second duct 40 is bifurcated and includes a first leg 44 extending to the heat transfer shield 50 and a second leg 46 extending to the outside of the under-hood region 21 .

[0063] exist Figure 2 , the first end 41 of the second duct 40 terminates the first leg 44 and is located at the heat transfer shield 50 surrounding the exhaust manifold 81. Therefore, the first end 41 of the second duct 40 is in fluid communication with the exhaust manifold inner sub-region 51. During certain operating modes, the first end 41 of the second duct 40 can be an inlet. As configured, the first end 41 of the second duct 40 can receive heated air 105 from the exhaust manifold inner sub-region 51, that is, air that has been heated by the engine 100 and, in particular, by the exhaust manifold 81.

[0064] As shown, the second conduit 40 extends to a second end 42, which may be an outlet for other lines connected to the intake system 60, i.e., the second end 42 is in communication with the intake system 60. In some embodiments, the second conduit 40 may be connected to the first conduit 30 downstream of the air flow control valve 35, but other arrangements are also contemplated. As shown, the air flow control valve 45 is located in the second conduit 40 for controlling flow to the intake system 60.

[0065] As shown, the second leg 46 of the second duct 40 extends to a third end 43 located outside the under-hood region 21. The third end 43 of the second duct 40 may be an inlet for receiving ambient air 104 from outside the under-hood region 21. As shown, an air flow control valve 48 is located in the second leg 46 of the second duct 40 for controlling the flow of ambient air 104 through the second leg 46.

[0066] During certain operating modes, the first end 41 of the second conduit 40 is an inlet for receiving heated air 105 from the in-exhaust manifold sub-region 51 within the heat transfer hood 50. During other operating modes, the first end 41 of the second conduit 40 is an outlet for delivering ambient air 104 from the third end to the in-exhaust manifold sub-region 51 within the heat transfer hood 50. Thus, the valves 35, 45, and 48 can be controlled to provide the desired flow to the intake system 60 and to or from the heat transfer hood 50.

[0067] For example, the flow of ambient air 104 through first conduit 30 to intake system 60 is controlled by valve 35; the flow of ambient air 104 through second leg 46 can be directed to first end 41 by opening valve 48 and closing valve 45; and the flow of heated air 105 through second leg 46 can be directed to intake system 60 by closing valve 48 and opening valve 45. By controlling the flow rates through the various valves, intake air 101 of specific characteristics can be obtained.

[0068] In an exemplary embodiment, a method for operating an internal combustion engine 100 is used Figure 1 and Figure 2The method includes delivering intake air 101 to the internal combustion engine 100 with the intake system 60. As described above, the intake system 60 and the internal combustion engine 100 are located in the under-hood area 21 of the vehicle 110. In a first operating mode, ambient air 104 flows in from outside the under-hood area 21 to form the intake air 101. Specifically, the first duct 30 delivers the ambient air 104 to the intake system 60. In the first operating mode, heated air 105 is not delivered to the intake system 60, that is, the valve 45 is closed.

[0069] In the second operating mode, the second conduit 40 can convey exhaust gas from the under-hood region 21 (including from the exhaust manifold inner sub-region 51 (such as Figure 2 ) or from outside the exhaust manifold sub-area 51 (such as Figure 1 Specifically, the second duct 40 delivers the heated air 105 to the intake system 60. Therefore, the valve 45 is opened. Figure 2 In an embodiment of the present invention, valve 48 may be closed. In a second operating mode, ambient air 104 may be delivered to the intake system 60, i.e., valve 35 is open; or ambient air 104 may not be delivered to the intake system 60, i.e., valve 35 is closed. More specifically, the flow rates of ambient air 104 and heated air 105 may be controlled, i.e., closed or opened to a selected degree to obtain a desired intake air 101, such as intake air 101 at a desired temperature.

[0070] The method of operation also includes exhausting exhaust gas 102 from the internal combustion engine 100 to the exhaust system 80 and selectively delivering a portion 103 of the exhausted exhaust gas 102 to the intake system 60 as part of the intake air 101 .

[0071] In an exemplary embodiment, the method includes obtaining data related to the operation of the internal combustion engine 100, such as from the sensors described above. Further, in the method, the control module 99 determines whether to operate the internal combustion engine 100 in a first operating mode or a second operating mode based on the data. Further, the control module 99 determines whether exhaust gas recirculation ("EGR") is required based on the data, and the method includes delivering a portion 103 of the exhausted exhaust gas 102 to the intake system 60 as part of the intake air 101 when EGR is required.

[0072] for Figure 2 For an embodiment of the present invention, the method includes, in a sub-mode of the first operating mode, flowing ambient air 104 from outside the under-hood area 21 to the exhaust heat transfer hood 50 .

[0073] In another embodiment, a method for controlling intake air temperature in an engine 100 of a vehicle includes selectively recirculating a portion 103 of exhaust gas 102 from the engine 100 to an intake system 60 of the engine 100 to reduce the temperature of the engine 100. In addition, the method includes determining whether ambient air 104 outside the vehicle is cooler than a selected temperature. In response to determining that the ambient air 104 outside the vehicle is cooler than the selected temperature, the method includes flowing heated air 105 from an under-hood area 21 of the vehicle to the intake system 60 of the engine 100.

[0074] In an exemplary embodiment, the method includes determining whether ambient air 104 outside the vehicle is not cooler than a selected temperature, and in response to determining that the ambient air outside the vehicle is not cooler than the selected temperature, reducing or stopping the flow of heated air 105 from the under-hood area 21 to the intake system 60 and flowing ambient air 104 from outside the vehicle to the intake system 60.

[0075] In an exemplary embodiment, the method includes maintaining the intake air temperature within a desired temperature range by controlling the flow of heated air 105 from the under-hood area 21 to the intake system 60 and controlling the flow of ambient air 104 from outside the vehicle to the intake system 60 .

[0076] exist Figure 2 In an embodiment, the method may include determining whether the ambient air outside the vehicle is not cooler than a selected temperature, and in response to determining that the ambient air outside the vehicle is not cooler than the selected temperature, stopping the flow of heated air 105 from the exhaust heat transfer hood 50 to the intake system 60 and allowing ambient air 104 from outside the vehicle to flow to the exhaust heat transfer hood 50.

[0077] Now refer to Figure 3 , a flow chart is provided for executing a method 300 for operating an internal combustion engine 100. The method 300 provides an intake air temperature control strategy under different ambient temperature conditions.

[0078] As shown, method 300 includes obtaining engine control module (ECM) data, such as engine speed, torque, intake air temperature, vehicle speed, etc. at operation 310 .

[0079] At inquiry 320 , method 300 determines whether the ambient air temperature is below a selected temperature. For example, the selected temperature may be zero degrees Celsius (0° C.). Other selected temperatures are contemplated, for example, the selected temperature may be any temperature within a range of -7° C. to 10° C.

[0080] If query 320 determines that the ambient air temperature is not below the selected temperature, method 300 continues at query 330, where method 300 determines whether the vehicle speed is greater than a selected speed and whether the engine load (i.e., the torque output of the engine) is greater than an upper selected load. For example, the selected speed may be sixty miles per hour (60 mph). Other selected vehicle speeds are contemplated, for example, the selected vehicle speed may be any speed in the range of 30 mph to 80 mph. Additionally, the upper selected load may be an engine load of sixty percent (60%). Other upper selected loads are contemplated, for example, the selected load may be any load in the range of 30% to 90%. As used herein, engine load is measured as a percentage of the maximum power output of the engine at a given engine speed.

[0081] If inquiry 330 determines that the vehicle speed is not greater than the selected speed or the engine load is not greater than the upper selected load, then method 300 continues at inquiry 340 where method 300 determines whether the engine load is greater than a lower selected load. For example, the lower selected load may be fifty percent (50%) of the engine load. Other lower selected loads are contemplated, for example, the selected load may be any load within a range of 20% to 70%.

[0082] If query 340 determines that the engine load is greater than the lower selected load, then method 300 continues at operation 350 and the engine operates normally, ie, heated air 105 is not delivered to the intake system 60 .

[0083] After operation 350 , method 300 continues at inquiry 360 and determines if the engine speed is greater than zero (0 rpm).

[0084] If query 360 determines that the engine speed is not greater than zero (0 rpm), method 300 continues at operation 370 and operation of method 300 is suspended. If query 360 determines that the engine speed is greater than zero (0 rpm), method 300 returns to operation 310.

[0085] If query 320 determines that the ambient air temperature is less than the selected temperature, method 300 continues at query 380, where method 300 determines whether the vehicle speed is greater than a selected vehicle speed, whether the engine load is greater than a lower selected load, and whether the ambient air temperature is greater than a lower selected temperature. In certain embodiments, the selected vehicle speed is sixty miles per hour (60 mph), the lower selected load is fifty percent (50%), and the lower selected ambient air temperature is negative seven degrees Celsius (-7° C.). Other selected vehicle speeds are contemplated, for example, the selected vehicle speed can be any speed in the range of 30 mph to 80 mph. Other lower selected loads are contemplated, for example, the selected load can be any load in the range of 20% to 70%. Other lower selected temperatures are contemplated, for example, the lower selected temperature can be any temperature in the range of -15° C. to 5° C.

[0086] If query 380 determines that the vehicle speed is greater than a selected vehicle speed, the engine load is greater than a lower selected load, and the ambient air temperature is greater than a lower selected temperature, the method 300 continues at operation 381 and controls the air flow control valve to direct heated air from the under-hood area to the intake system and control the temperature of the intake air to a temperature above zero degrees (0° C.). The conditions at operation 381 may be considered high vehicle speed / load and low temperature. Operation 381 may use EGR to reduce exhaust gas temperature without engine enrichment to comply with PEMS regulations. After operation 381, the method 300 returns to operation 310.

[0087] If query 380 determines that the vehicle speed is not greater than a selected vehicle speed, the engine load is not greater than a lower selected load, or the ambient air temperature is not greater than a lower selected temperature, then method 300 continues at operation 382 and uses a normal intake system, i.e., does not deliver heated air to the intake system, and operates the engine without an EGR system, i.e., does not deliver a portion of the exhaust gas to the intake system. After operation 382, ​​method 300 returns to operation 310.

[0088] If query 330 determines that the vehicle speed is greater than the selected speed and the engine load is greater than the upper selected load, the method 300 continues at operation 331 and controls the air flow control valve to direct ambient air from outside the vehicle directly to the exhaust manifold to reduce exhaust gas temperature and catalyst aging. At operation 331, only ambient air (no heated air) is delivered to the intake system. At operation 331, the EGR system is not operated to deliver a portion of the exhaust gas to the intake system. After operation 331, the method 300 returns to operation 310.

[0089] If query 340 determines that the engine load is not greater than the lower selected load, the method 300 continues at operation 341 and controls the air flow control valve and damper to achieve an optimized intake air temperature for low emissions and better fuel economy. At operation 341, only ambient air (no heated air) is delivered to the intake system. At operation 341, the EGR system can be operated to deliver a portion of the exhaust gas to the intake system if necessary. After operation 341, the method 300 returns to operation 310.

[0090] Now refer to Figure 4 , further described Figure 2 The position of the first end 41 of the second pipe 40 of the embodiment. Figure 4 The portion of the vehicle 110 in which the engine 100 is located is illustrated. As shown, the vehicle 110 has a hood 120; a front portion 130, such as a grille; a chassis 140; and a passenger compartment 150. Figure 1 and Figure 2 The under-hood region 21 referred to in FIG. 1 is located between the hood 120 and the chassis 140, and between the front portion 130 and the cabin 150. An outer hood region 160 is also identified.

[0091] Figure 4 Four additional under-hood sub-regions Z1, Z2, Z3 and Z4 are identified in FIG. Sub-region Z1 is located at the exhaust heat shield and connecting duct. Sub-region Z2 is located in the engine top region, i.e., above the engine 100. Sub-region Z3 is located in the engine top region near the radiator. Sub-region Z4 is located directly behind the radiator.

[0092] Cross Reference Figure 2 and Figure 4 , it can be seen that sub-region Z1 includes the exhaust manifold inner sub-region 51. In addition, the heat transfer shield 50 can be formed to have a shape that conforms to the contour of the exhaust manifold 81 to optimize heat absorption from the exhaust gas for transfer to the heated air 105. In addition, the heat transfer shield 50 has the following additional function: by directing the ambient air 104 from the front 130 of the vehicle 110 to the heat transfer shield 50 as described above, it is possible to cool the engine when operating at a high load during high ambient air temperature conditions.

[0093] Cross Reference Figure 1 , Figure 2 and Figure 4 It can be seen that the first end 41 of the second conduit 40 can be located at any sub-region Z1 , Z2 , Z3 , Z4 , including in the sub-region 51 in the exhaust manifold.

[0094] In summary, embodiments herein control intake air temperature by selecting whether to deliver heated air from various under-hood regions, including regions inside the exhaust manifold, to the intake system. Embodiments herein determine whether to divert a portion of the exhaust gas to the intake system using the EGR system based on ambient temperature, vehicle speed, and load. Embodiments herein control intake manifold temperature during low and medium speed and load operation to cool the intake manifold by delivering ambient air directly to the intake manifold, achieving better fuel economy and emissions in cold ambient conditions.

[0095] The embodiments herein allow engine operation to meet portable emissions measurement system (PEMS) emissions requirements without vehicle speed derating (currently, vehicle speed is derated to 65 mph when performing full load towing), while solving the problem of ice formation when flowing EGR in ambient temperatures from -7°C to 0°C.

[0096] Embodiments herein further reduce exhaust temperatures when operating under normal or high ambient temperature conditions, which can improve catalyst reliability or potential platinum group metal (PGM) loading reduction.

[0097] Embodiments herein improve -7°C (20°F) Federal Test Procedure (FTP) emissions or fuel economy under low ambient air temperature conditions.

[0098] Embodiments herein provide for controlling intake air temperature at all ambient air temperatures, even below freezing where EGR is typically disabled due to icing issues.

[0099] In embodiments herein, at ambient air temperatures from -7°C to 0°C, or even lower air temperatures, heated air from an under-hood area or exhaust manifold area can be used to avoid ice formation in the intake system when EGR is used to deliver a portion of the exhaust gases to the intake system.

[0100] In the embodiments herein, at low vehicle speeds and ambient air temperatures ranging from -7°C to 0°C or even lower, no EGR is required to meet PEMS regulatory requirements.

[0101] In the embodiments herein, both EGR bypass and under-hood heated air can be used to improve intake manifold air temperature in cold ambient conditions.

[0102] In the embodiments herein, heated air from two exhaust manifold heat transfer shields can be delivered to the intake system at ambient air temperatures from -7°C to 0°C, or even lower air temperatures, to avoid ice formation in the intake system when flowing EGR.

[0103] In embodiments herein, when ambient air temperatures are hot, ambient air from the exterior vehicle hood can flow directly to the exhaust manifold to reduce exhaust temperatures at higher vehicle speed and load conditions.

[0104] In the embodiments herein, by balancing the air flow rates from outside the vehicle and under the hood or exhaust manifold heat transfer hood area, the intake air temperature can be controlled to achieve better PEM and cycle emissions performance at low ambient air temperature operations.

[0105] In embodiments herein, heated air may be received from selected areas within the under-hood area.

[0106] In the embodiments herein, the shape of the heat transfer shield is contoured to the shape of the exhaust manifold to optimize heat extraction from the heated air.

[0107] In the embodiments herein, the heat transfer shield has the additional function of enabling cooling of the engine when the engine is operating at high loads in high ambient temperature conditions.

[0108] Embodiments herein control intake manifold temperature for low and medium speed and load operation to achieve better fuel economy and emissions in low temperature ambient conditions.

[0109] Embodiments herein partially close the front damper to increase underhood air temperature when operating at low speeds and loads at low ambient temperatures.

[0110] The embodiments herein fully open the front shutter during high load operation.

[0111] Embodiments herein reduce EGR coolant flow in an EGR cooler to increase EGR exhaust gas temperature entering an intake system in order to achieve an intake air temperature greater than 0°C.

[0112] The embodiments herein use a higher proportion of EGR exhaust gas in the intake air to achieve an intake air temperature greater than 0°C when operating at an ambient air temperature of -7°C.

[0113] Although at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be understood that there are a large number of variations. It should also be understood that the exemplary embodiment or multiple exemplary embodiments are only examples and are not intended to limit the scope, applicability or configuration of the present disclosure in any way. On the contrary, the foregoing summary and detailed description will provide a convenient roadmap for implementing the exemplary embodiment or multiple exemplary embodiments for those skilled in the art. It should be understood that various changes can be made to the functions and arrangements of the elements without departing from the scope of the present disclosure as set forth in the attached claims and their legal equivalents.

Claims

1. An internal combustion engine, comprising: an intake system configured to deliver intake air to the internal combustion engine; an exhaust system configured to exhaust exhaust gas from the internal combustion engine; as well as an exhaust gas recirculation ("EGR") system configured to selectively deliver a portion of the exhaust gas to the intake system; wherein the internal combustion engine is located in the under-hood area; wherein the air intake system includes a first air intake duct having an outlet in communication with the air intake system and having an inlet located outside the under-hood region to receive ambient air; and The air intake system includes a second air intake duct having an outlet in communication with the air intake system and having an inlet located in the under-hood area to receive air warmed by the internal combustion engine.

2. The internal combustion engine according to claim 1, further comprising: a first valve configured to restrict the flow of ambient air to the intake system; a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system; a sensor for obtaining data related to the operation of the internal combustion engine; as well as a control module configured to determine a desired first flow rate of the ambient air and a desired second flow rate of the air warmed by the internal combustion engine to the intake system based on the data, and configured to selectively open and close the first valve and the second valve to obtain the desired first flow rate of the ambient air and the desired second flow rate of the air warmed by the internal combustion engine.

3. The internal combustion engine of claim 1 , further comprising: an EGR valve configured to restrict flow of the portion of the exhaust gas to the intake system; a first valve configured to restrict the flow of ambient air to the intake system; a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system; a sensor for obtaining data related to the operation of the internal combustion engine; as well as A control module, wherein the control module is configured to: determining a desired ESG operating mode based on the data; determining a desired first flow rate of the ambient air to the intake system and a desired second flow rate of the air warmed by the internal combustion engine based on the data; selectively opening and closing the first valve and the second valve to obtain the desired first flow rate of the ambient air and the desired second flow rate of the air warmed by the internal combustion engine; as well as The EGR valve is selectively opened and closed to operate the internal combustion engine in the desired EGR operating mode.

4. The internal combustion engine of claim 1, further comprising an exhaust heat transfer shield, wherein: A portion of the exhaust system is located in the exhaust heat transfer hood; The inlet of the second air intake duct located in the under-hood region to receive air warmed by the internal combustion engine is a first inlet; The first inlet is in communication with the exhaust heat transfer hood; and The second air intake duct includes a second inlet located outside the under-hood region to receive ambient air.

5. The internal combustion engine according to claim 4, further comprising: a first valve configured to restrict the flow of ambient air through the first intake duct to the intake system; a second valve configured to restrict the flow of air warmed by the internal combustion engine to the intake system; and A third valve is configured to restrict the flow of ambient air through the second air inlet duct to the exhaust heat transfer hood.

6. A method for operating an internal combustion engine, the method comprising: Intake air is delivered to the internal combustion engine by an intake system, wherein: The air intake system and the internal combustion engine are located in the under-hood area; a first operating mode flows ambient air from outside the under-hood region to form the intake air; and a second operating mode flowing heated air warmed by the internal combustion engine to form at least a portion of the intake air; exhausting exhaust gas from the internal combustion engine to an exhaust system; and A portion of the exhaust gas is selectively delivered to the intake system as a portion of the intake air.

7. The method according to claim 6, further comprising: obtaining data related to operation of the internal combustion engine; as well as Based on the data, it is determined whether to operate the internal combustion engine in the first operating mode or in the second operating mode.

8. The method according to claim 6, further comprising: obtaining data related to operation of the internal combustion engine; determining whether exhaust gas recirculation ("EGR") is required based on the data; as well as When EGR is required, the portion of the exhaust gas is delivered to the intake system as part of the intake air.

9. The method according to claim 6, wherein: The internal combustion engine includes an exhaust heat transfer shroud; A portion of the exhaust system is located in the exhaust heat transfer hood; and The heated air warmed by the internal combustion engine is air from the exhaust heat transfer hood.

10. The method according to claim 9, wherein: A sub-mode of the first operating mode flows ambient air from outside the under-hood region to the exhaust heat transfer hood.

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