Control system for internal combustion engine, internal combustion engine configured to control combustion, and control method thereof

Abstract

A control system for an internal combustion engine includes: a temperature sensor configured to measure an exhaust gas temperature from a cylinder of the internal combustion engine; a NOx sensor configured to measure an exhaust NOx amount from the cylinder; and a controller operably connected to the temperature sensor and the NOx sensor. The controller is configured to: receive a measured exhaust gas temperature from the temperature sensor and a measured exhaust gas NOx amount from the NOx sensor; calculating a current combustion performance of the cylinder based on the measured exhaust temperature and the measured exhaust NOx amount; determining whether to adjust one or more of the plurality of operational parameters; and controlling one or more of the plurality of operating parameters based on the current combustion performance.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 346,779, filed on May 27, 2022, entitled “Control System for Internal Combustion Engine, Internal Combustion Engine Configured to Control Combustion, and Method of Control Thereof,” which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to systems and methods for controlling internal combustion engines. background

[0003] In an internal combustion engine system including a multi-cylinder engine (e.g., a compression ignition or spark ignition internal combustion engine, etc.), combustion within each cylinder of the multi-cylinder engine is an important aspect of engine performance. Increasingly stringent environmental standards and the need to reduce emissions such as nitrogen oxides (NOx) have led to an increased demand for internal combustion engine systems with improved combustion performance. Overview

[0004] In some embodiments, a control system for an internal combustion engine includes: a temperature sensor configured to measure an exhaust temperature from a cylinder of the internal combustion engine; a NOx sensor configured to measure an exhaust NOx amount from the cylinder; and a controller operably connected to the temperature sensor and the NOx sensor, the controller being configured to: receive a measured exhaust temperature from the temperature sensor and a measured exhaust NOx amount from the NOx sensor; calculate a current combustion performance of the cylinder based on the measured exhaust temperature and the measured exhaust NOx amount; and determine whether to adjust one or more of a plurality of operating parameters and control one or more of the plurality of operating parameters based on the current combustion performance.

[0005] In some embodiments, the plurality of operating parameters includes at least one of: air-fuel ratio, fuel composition, exhaust gas recirculation fraction, spark timing value, injection timing value, timing of valve opening or closing events, or geometric compression ratio.

[0006] In some embodiments, the cylinder is one of a plurality of cylinders of an internal combustion engine, each of the plurality of cylinders being provided with a respective NOx sensor and a respective temperature sensor.

[0007] In some embodiments, the controller is configured to control a target combustion performance of each of the plurality of cylinders to balance a collective combustion performance among the plurality of cylinders.

[0008] In some embodiments, the controller is configured to adjust at least one of an overall engine air-fuel ratio or an overall engine exhaust gas recirculation ratio in response to the measured exhaust temperature and the measured exhaust NOx amount.

[0009] In some embodiments, the internal combustion engine is a port injected hydrogen fuel engine or a direct injection hydrogen fuel engine.

[0010] In some embodiments, an internal combustion engine system configured to control combustion includes: an internal combustion engine having a plurality of cylinders, each cylinder having a temperature sensor and a NOx sensor; and a control system configured to control the plurality of cylinders of the internal combustion engine. The control system includes a controller configured to: receive information related to a plurality of operating parameters of each of the plurality of cylinders of the internal combustion engine; measure, for each of the plurality of cylinders of the internal combustion engine, an exhaust temperature from a temperature sensor and an exhaust NOx amount from a NOx sensor; for each of the plurality of cylinders of the internal combustion engine, evaluate one or more of the plurality of operating parameters relative to the measured exhaust temperature and the measured exhaust NOx amount; and, for one or more of the plurality of cylinders of the internal combustion engine, adjust one or more of the plurality of operating parameters to control combustion between the plurality of cylinders.

[0011] In some embodiments, each cylinder of the plurality of cylinders includes an exhaust manifold or exhaust port configured to receive exhaust gas; a temperature sensor and a NOx sensor coupled to the exhaust manifold or exhaust port for measuring exhaust temperature and exhaust NOx amount of the exhaust gas.

[0012] In some embodiments, the plurality of operating parameters include (i) an exhaust gas recirculation ratio of an exhaust gas recirculation system of the internal combustion engine, (ii) a spark timing value of an ignition system of the internal combustion engine, (iii) an injection duration and injection pressure of a fuel injection system of the internal combustion engine, (iv) a timing of a valve opening or closing event of a cam of the internal combustion engine, (v) an air-fuel ratio of the internal combustion engine, (vi) a geometric compression ratio of one or more of a plurality of cylinders of the internal combustion engine, and (vii) a fuel composition. The controller is configured to receive information associated with each of the plurality of operating parameters to evaluate combustion of the internal combustion engine.

[0013] In some embodiments, the internal combustion engine system also includes a knock sensor that is communicatively coupled to the controller and is configured to measure engine knock. The controller is configured to adjust one or more operating parameters based on the measured engine knock and for one or more of the plurality of cylinders, based on the measured exhaust temperature and the measured exhaust NOx amount.

[0014] In some embodiments, the controller is configured to determine whether the overall engine combustion performance is different from the target engine performance, and adjust the overall engine air-fuel ratio and the overall engine exhaust gas recirculation ratio in response to the measured exhaust temperature and the measured exhaust NOx amount of one or more cylinders among the plurality of cylinders.

[0015] In some embodiments, the controller is configured to adjust the estimated plurality of operating conditions to balance the plurality of operating conditions across the plurality of cylinders.

[0016] In some embodiments, the internal combustion engine is one of a spark-ignited engine, a pilot-ignited engine, a compression-ignited engine, or a dual-fuel engine.

[0017] In some embodiments, the controller is configured to determine whether knock occurs in response to a measured exhaust temperature and a measured exhaust NOx amount for one or more of the plurality of cylinders.

[0018] In some embodiments, the internal combustion engine is at least one of a hydrogen fueled engine, a natural gas fueled engine, a propane fueled engine, or an ammonia fueled engine.

[0019] In some embodiments, a method for controlling an internal combustion engine system includes: measuring the exhaust temperature of exhaust gas from a cylinder by a temperature sensor of the cylinder of the internal combustion engine; measuring the exhaust NOx amount of the exhaust gas by a NOx sensor of the cylinder; receiving the measured exhaust temperature and the measured exhaust NOx amount from the temperature sensor and the NOx sensor by a controller; determining target combustion performance of the cylinder based on the measured exhaust temperature and the measured exhaust NOx amount; determining whether to adjust one or more of a plurality of operating parameters; and controlling one or more of the plurality of operating parameters based on the target combustion performance.

[0020] In some embodiments, determining whether to adjust the plurality of operating parameters includes determining whether to adjust one or more of the following: air-fuel ratio, fuel composition, exhaust gas recirculation fraction, spark timing value, injection timing value, timing of valve opening or closing events, or geometric compression ratio.

[0021] In some embodiments, the method further includes adjusting, by the controller, one or more of the plurality of operating parameters to balance combustion performance among the plurality of cylinders.

[0022] In some embodiments, the method also includes measuring knock via a knock sensor coupled to the engine; and adjusting at least one of a total engine air-fuel ratio or a total engine exhaust gas recirculation ratio by a controller in response to the detected knock, the measured exhaust temperature, and the measured exhaust NOx amount for each of a plurality of cylinders of the engine.

[0023] In some embodiments, the step of measuring the exhaust temperature and NOx amount of the exhaust gas of the cylinder of the internal combustion engine includes measuring the exhaust temperature and NOx amount of the exhaust gas in the exhaust manifold or the exhaust port of the cylinder of the internal combustion engine, and the temperature sensor and the NOx sensor are coupled to one of the exhaust manifold or the exhaust port.

[0024] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present teachings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals refer to like elements unless otherwise specified, and in which: Figure 1 is a schematic diagram of a portion of an internal combustion engine system according to an exemplary embodiment; Figure 2 According to an exemplary embodiment Figure 1 A schematic diagram of a portion of an internal combustion engine system; Figure 3 According to an exemplary embodiment Figure 1 A schematic diagram of a cylinder and control system of an internal combustion engine system; and Figure 4 is a flow chart illustrating a method for controlling an internal combustion engine system according to an exemplary embodiment. Detailed Description

[0026] What follows is a more detailed description of various concepts and implementations related to methods and systems for providing control of an internal combustion engine system. The various concepts introduced above and discussed in more detail below can be implemented in any of a variety of ways, as the concepts described are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0027] In general, embodiments of the present disclosure relate to internal combustion engine systems and control systems for balancing combustion in a multi-cylinder engine while reducing NOx emissions. In some embodiments, the system balances combustion in a multi-cylinder engine while reducing the possibility of engine knock and / or misfire. Such a system may include a temperature sensor and a NOx sensor to measure exhaust temperature and exhaust NOx amount. Some embodiments determine whether to adjust multiple operating parameters affecting combustion performance for each cylinder by measuring exhaust temperature and exhaust NOx amount, thereby balancing combustion performance in a multi-cylinder engine. Some systems disclosed herein measure both exhaust temperature and exhaust NOx amount. Such a system may allow a more comprehensive assessment of operating parameters affecting combustion. The systems and techniques described herein may be beneficial to hydrogen engines and / or engines using hydrogen-containing fuels (as well as other types of engines and / or fuels), because for each cylinder, exhaust temperature and exhaust NOx amount are used to assess and adjust multiple operating conditions of each cylinder. Such a system may allow more accurate monitoring and / or control of combustion to reduce variations between each cylinder.

[0028] The present disclosure describes techniques for addressing cylinder-to-cylinder combustion variations that are particularly severe in hydrogen internal combustion engines.

[0029] In particular, various exemplary embodiments may provide for balancing combustion performance and reducing NOx emissions in a multi-cylinder engine, such as a multi-cylinder hydrogen internal combustion engine. Thus, some embodiments may have reduced costs and / or physical modifications associated with in-cylinder pressure sensing that require physically mounting the in-cylinder pressure sensor in the cylinder head. Additionally, the amount of information associated with the reduction of NOx emissions may be increased by utilizing a combination of exhaust temperature and exhaust NOx amount.

[0030] The generation of NOx during combustion is primarily driven by the combustion temperature. Exhaust port temperature in diesel and dual fuel engines can be used to identify imbalances between cylinder combustion performance. However, exhaust port temperature is not necessarily indicative of combustion performance due to, for example, fuel dilution, non-uniform fuel mixtures, and local hot spots during combustion, or any combination thereof. Therefore, exhaust port temperature alone is only one parameter of combustion performance and provides less information for combustion control in a diluted charge (e.g., lean burn, cooled exhaust gas recirculation (EGR), etc.) spark ignition engine or a pilot engine.

[0031] As used herein, the term “charge” refers to the mixture of air, fuel, and exhaust gases present within a cylinder or in an intake manifold.

[0032] Some embodiments provide control techniques for hydrogen internal combustion engines (and other engines) that do not allow the introduction of hydrogen fuel far enough upstream of the cylinder head to provide a well-mixed fuel-air charge to the intake manifold (e.g., by introducing the hydrogen fuel through a mixer located upstream of the compressor inlet of a turbocharger, etc.). Hydrogen (or a fuel mixture comprising at least 5% hydrogen by volume) is highly flammable and presents significant backfire management challenges, particularly in engines where the hydrogen fuel is not well mixed. The present disclosure provides combustion balancing of multiple cylinders within an engine that receives a fuel mixture containing hydrogen (e.g., a natural gas-hydrogen mixture, etc.) and may or may not provide a well-mixed hydrogen and liquid fuel mixture for combustion. The hydrogen content of such a mixture may vary (e.g., a fuel mixture comprising hydrogen, pure hydrogen fuel, etc.).

[0033] The exemplary technology described herein solves the unique challenge of balancing combustion in a multi-cylinder engine that is a hydrogen engine or otherwise utilizes a hydrogen fuel mixture. As an example of such a challenge, an engine that is not designed for equal charge flow distribution in multiple cylinders and / or an engine that uses a fuel mixture containing hydrogen can provide a variable air-fuel ratio to each cylinder and a stratification of the air-fuel ratio in each cylinder (i.e., spatial variation, etc.). Although the introduction of a charge flow upstream of a turbocharger generally provides a more uniform fuel mixture, such an upstream mixing system is not suitable for hydrogen fuel mixtures because they produce a large amount of highly combustible fuel mixtures in the intake system and increase the probability of flashback. In addition, the internal combustion engine system and control system described herein can provide a more robust control for balancing combustion performance. In particular, the system herein can measure exhaust temperature and exhaust NOx amount, rather than relying on a single parameter, to evaluate and adjust multiple operating parameters that affect combustion performance. In this way, the system described herein can monitor and control combustion more accurately for each cylinder to reduce the variation between each cylinder. Therefore, the system is particularly advantageous for hydrogen engines and / or engines using hydrogen fuel mixtures with significant cylinder combustion variations.

[0034] The implementation described herein relates to an internal combustion engine system configured to control the combustion of an internal combustion engine and a method for controlling such an internal combustion engine. The internal combustion engine system includes a plurality of cylinders each having a temperature sensor and a NOx sensor and a control system configured to control the plurality of cylinders of the internal combustion engine. The control system includes a controller configured to: receive information related to a plurality of operating parameters of each of the plurality of cylinders of the internal combustion engine; for each of the plurality of cylinders of the internal combustion engine, measure the exhaust temperature from the temperature sensor and the amount of NOx from the NOx sensor; for each of the plurality of cylinders of the internal combustion engine, evaluate one or more of the plurality of operating parameters relative to the measured exhaust temperature and the measured amount of NOx; and for one or more of the plurality of cylinders of the internal combustion engine, adjust one or more of the plurality of operating parameters to control the combustion between the plurality of cylinders.

[0035] The present application provides at least one exemplary embodiment of an internal combustion engine system 20 that is configured to control combustion in an internal combustion engine 30 of a vehicle (e.g., a passenger car, a commercial vehicle, a construction vehicle, etc.) using a control system 120. The internal combustion engine system 20 may also be configured to control combustion in an internal combustion engine 30 of various other equipment powered by the engine 30 (e.g., stationary equipment such as a generator set, a locomotive or other rail equipment, agricultural or construction equipment, an industrial vehicle (such as a mining haul truck), a ship, an airplane, a helicopter, or other equipment capable of flying, etc.). Specifically, the internal combustion engine system 20 controls combustion to balance combustion performance between the multiple cylinders 31 using a control system 120 configured to control multiple cylinders 31 of the internal combustion engine 30 (e.g., a multi-cylinder engine, etc.). As explained in more detail herein, the internal combustion engine system 20 controls combustion to balance combustion performance between the multiple cylinders 31 based on both measured exhaust temperature and measured exhaust NOx amount. The exhaust temperature and the exhaust NOx amount are used to (i) calculate target combustion performance of the plurality of cylinders 31, (ii) determine whether to adjust one or more of the plurality of operating parameters based on the target combustion performance, and (iii) adjust one or more of the plurality of operating parameters for one or more of the plurality of cylinders 31 of the internal combustion engine 30 to control combustion among the plurality of cylinders 31.

[0036] Referring generally to the accompanying drawings, Figure 1-Figure 3An exemplary control system 120 of an internal combustion engine system 20 is depicted. The internal combustion engine system 20 is configured to control combustion and includes: an internal combustion engine 30 having a plurality of cylinders 31, each cylinder 31 having a temperature sensor 202 and a NOx sensor 204; and a control system 120 configured to control the plurality of cylinders 31 of the internal combustion engine 30. The control system 120 includes a controller 200 configured to receive information related to a plurality of operating parameters of each of the plurality of cylinders 31 of the internal combustion engine 30. The controller 200 is also configured to measure, for each of the plurality of cylinders 31 of the internal combustion engine 30, an exhaust temperature from the temperature sensor 202 and an exhaust NOx amount from the NOx sensor 204. In addition, the controller 200 is also configured to evaluate, for each of the plurality of cylinders 31 of the internal combustion engine 30, one or more of the plurality of operating parameters relative to the measured exhaust temperature and the measured exhaust NOx amount. Furthermore, the controller 200 is configured to adjust one or more of a plurality of operating parameters for one or more of the plurality of cylinders 31 of the internal combustion engine 30 to control combustion among the plurality of cylinders 31 .

[0037] Furthermore, in some embodiments, the control system 120 of the internal combustion engine 30 includes a temperature sensor 202 configured to measure the exhaust gas temperature from the cylinder 31 of the internal combustion engine 30 in the exhaust manifold 32. The control system 120 also includes a NOx sensor 204 configured to measure the exhaust NOx amount from the cylinder 31 in the exhaust manifold 32. Furthermore, the control system 120 includes a controller 200 operatively connected to the temperature sensor 202 and the NOx sensor 204. The controller 200 is configured to: receive the measured exhaust gas temperature from the temperature sensor 202 and the measured exhaust NOx amount from the NOx sensor 204; calculate the target combustion performance of the cylinder 31 based on the measured exhaust temperature and the measured exhaust NOx amount; and determine whether to adjust one or more of the plurality of operating parameters and control one or more of the plurality of operating parameters based on the target combustion performance.

[0038] Figure 1-Figure 2 is a schematic diagram of a portion of an internal combustion engine system 20 according to an exemplary embodiment. Figure 2 yes Figure 1 Schematic diagram of the cylinder 31 and the control system 120 of the internal combustion engine system 20. Figure 1-Figure 2As reflected, the internal combustion engine system 20 includes a fuel supply system 21. The fuel supply system 21 can operate with the internal combustion engine system 20 to provide a fuel supply to the internal combustion engine 30 from a first fuel source 102 and a second fuel source 104. The internal combustion engine system 20 includes an internal combustion engine 30. The internal combustion engine 30 is configured to be connected to an intake system 22 for providing a charge flow to the internal combustion engine 30 and an exhaust system 24 for outputting exhaust gas. In some embodiments, the internal combustion engine 30 is configured as a lean burn engine, such as a diesel cycle engine. In some embodiments, the internal combustion engine 30 is configured as an Otto cycle or a spark ignition engine. In some embodiments, the internal combustion engine 30 (e.g., a diesel cycle engine, a spark ignition engine, etc.) can be configured as a dual fuel engine. More specifically, a dual fuel engine is an engine configured to use a primary fuel (e.g., a liquid fuel, such as diesel fuel) from a first fuel source 102 and a secondary fuel (e.g., a gaseous fuel, such as hydrogen or natural gas) from a second fuel source 104. In some embodiments, the primary fuel and the secondary fuel have different properties, such as different auto-ignition temperatures, flame speeds, etc. Generally speaking, in a diesel cycle, the start of combustion is controlled by the timing of fuel injection. In contrast, a spark ignition cycle is a standard Otto cycle where the start of ignition is controlled by spark timing.

[0039] In some embodiments, as described above, the primary fuel is a liquid fuel, and the secondary fuel may be, for example, hydrogen, a mixture containing hydrogen, natural gas, biogas, methane, propane, ethanol, producer gas, field gas, liquefied natural gas, compressed natural gas, or landfill gas. However, as discussed in further detail herein, the foregoing are merely examples of fuels, and other types of primary and secondary fuels are not excluded, such as any suitable liquid fuel and gas fuel or a combination thereof. For example, in some embodiments, the first fuel is a hydrogen fuel and the second fuel is ammonia or natural gas. The first fuel and the second fuel are combined into a blend, which is a mixture containing the two fuels. In some embodiments, the first fuel and the second fuel are delivered via separate mechanisms (e.g., the first fuel is delivered via a direct injector, and the second fuel is delivered via different introduction points (such as, an intake port injector)), and then mixed. In some embodiments, the internal combustion engine is a dual-fuel engine configured to receive a mixture of the first fuel and the second fuel, and determining whether to adjust one or more of the plurality of operating parameters includes determining whether to adjust the fuel composition, which corresponds to the ratio of the first fuel to the second fuel in the mixture. In some embodiments, the fuel composition is adjusted to achieve target combustion properties.

[0040] In addition, in some embodiments, the internal combustion engine 30 is one of a spark ignition engine, a pilot ignition engine, a compression ignition engine, or a dual fuel engine. In some embodiments, the internal combustion engine 30 is a hydrogen fuel engine with air intake injection or a direct injection hydrogen fuel engine. In some embodiments, the internal combustion engine 30 is at least one of a hydrogen fuel engine, a natural gas fuel engine, a propane fuel engine, or an ammonia fuel engine.

[0041] refer to Figure 1-Figure 3 , the first fuel source 102 includes a first fuel pump 105 connected to the controller 200. The second fuel source 104 includes a second fuel pump 106 connected to the controller 200. The first fuel pump 105 and the second fuel pump 106 are each configured to provide pressurized fuel. However, in some embodiments of the internal combustion engine system 20, such as using a gaseous fuel (e.g., hydrogen, natural gas, etc.), the first fuel pump 105 and / or the second fuel pump 106 may be omitted. Figure 1-Figure 2 As shown, the internal combustion engine system 20 also includes cylinders 31a, 31b, 31c and 31d. Each of the cylinders 31a-31d includes an injector, such as Figure 1-Figure 2 Each of the illustrated cylinders 31a-31d is associated with either a direct injector 116a-116d or a port injector 118a-118d.

[0042] The first fuel pump 105 is connected to each of the direct injectors 116a-116d and / or the injectors 118a-118d through the first fuel line 109. The first fuel pump 105 is operable to provide a first fuel flow from the first fuel source 102 to each of the cylinders 31a-31d. More specifically, the direct injectors 116a-116d or the port injectors 118a-118d associated with each of the cylinders 31a-31d control the first fuel flow to adjust the injection timing of each of the first fuel flow and the cylinders 31a-31d. The first fuel pump 105 is configured to supply the first fuel flow at any one or more of the rate, amount and / or timing determined by the controller 200 to produce the desired power and exhaust output from the cylinder 31 from the first fuel source 102. The second fuel source 104 is connected to the inlet of the compressor 50 with the mixer 117 through the second fuel line 108. The shutoff valve 112 may be disposed in the second fuel line 108. The shutoff valve 112 may be disposed at one or more other locations in the fuel supply system 21 connected to the controller 200. The second fuel pump 106 is operable to provide a second fuel flow from the second fuel source 104. In particular, the second fuel pump 106 is configured to provide the second fuel flow in an amount determined by the controller 200 to produce a desired power and exhaust output from the cylinder 31 using the fuel from the second fuel source 104.

[0043] refer to Figure 1-Figure 2 As described above, the internal combustion engine system 20 includes an intake system 22. The intake system 22 includes one or more inlet supply conduits 26 connected to the engine intake manifold 28, which distributes the charge flow to the cylinders 31 of the engine 30. In some embodiments, the intake system 22 receives the charge flow from the turbocharger 46 upstream of the intake system 22. In some embodiments, the turbocharger 46 is omitted. The intake system 22 includes an intake manifold 28, which has an intake port 136 and is configured to distribute the charge flow to the internal combustion engine 30. In some embodiments, the intake system 22 includes an after-cooler and / or an inter-cooler. In some embodiments, the internal combustion engine system 20 includes multiple turbochargers arranged in parallel or in series (e.g., two-stage turbocharging).

[0044] refer to Figure 1-Figure 2 In some embodiments, the intake system 22 further includes a compressor 50. The compressor 50 compresses fuel from, for example, the second fuel source 104 using a charge flow for delivery to the combustion chambers 132 of the plurality of cylinders 31. The intake system 22 further includes a compressor bypass 72 that connects a downstream or outlet side of the compressor 50 to an upstream or inlet side of the compressor 50. The compressor bypass 72 includes a control valve 74 that selectively opens to allow the charge flow to return to the inlet side of the compressor 50. The selective opening of the control valve 74 allows for a reduction in compressor surge under certain operating conditions, such as when the intake throttle 76 is closed.

[0045] refer to Figure 1-Figure 2 As described above, the internal combustion engine system 20 includes an exhaust system 24. The exhaust system 24 releases exhaust gas generated by the combustion of fuel by the internal combustion engine 30. The exhaust system 24 includes an exhaust manifold 32 having an exhaust port 138 and configured to receive the exhaust gas. The exhaust system 24 includes an exhaust conduit 34 extending from the exhaust manifold 32 to the turbine 48 of the turbocharger 46. In one embodiment, the exhaust conduit 34 is fluidly coupled to the exhaust manifold 32 and may also include one or more intermediate flow passages, conduits, or other structures.

[0046] refer to Figure 1-Figure 2As described above, the exhaust conduit 34 extends to the turbine 48 of the turbocharger 46 to provide exhaust gas to the turbocharger 46, although the turbocharger 46 is not required. The turbine 48 may include a controllable wastegate 70 or other suitable bypass that is operable to selectively bypass at least a portion of the exhaust flow from the turbine 48 to reduce boost pressure and engine torque under certain operating conditions. In another embodiment, the turbine 48 is a variable geometry turbine having an inlet that is selectively adjusted to allow a desired amount of exhaust flow to pass therethrough.

[0047] refer to Figure 1-Figure 2 , the internal combustion engine 30 includes a cylinder 31 (eg, a combustion cylinder, etc.). Figure 1-Figure 2 In the illustrated embodiment, the internal combustion engine 30 includes four cylinders 31a-31d (collectively referred to as a plurality of cylinders 31) arranged in line. However, the number of the plurality of cylinders 31 may vary, and the arrangement of the plurality of cylinders 31 may be any arrangement and is not limited to Figure 1 . In some embodiments, each of the plurality of cylinders 31 is connected to the intake system 22 to receive a charge flow distributed to each cylinder 31. In addition, each cylinder 31 includes a piston 130 and a cylinder head 134. In some embodiments, the cylinder head 134 is not provided with an internal sensor equipped to the cylinder head compared to the in-cylinder pressure sensor system. Each cylinder 31, its respective piston 130 and cylinder head 134 form a combustion chamber 132. In the illustrated embodiment, the internal combustion engine 30 includes four such combustion chambers 132. However, it is contemplated that the internal combustion engine 30 may include a greater or lesser number of cylinders 31 and combustion chambers 132, and that the cylinders 31 and combustion chambers 132 may be arranged in an inline configuration, a V-shaped configuration, or any other suitable configuration. In some embodiments, each of the plurality of cylinders 31 includes at least one injector 116, 118 for delivering fuel to the combustion chamber 132. In some embodiments, the injectors 116 , 118 are, for example, direct injectors 116 a - 116 d or port injectors 118 a - 118 d for providing fuel to the cylinder 31 .

[0048] refer to Figure 3 The internal combustion engine system 20 includes a control system 120 (e.g., a controller, a microcontroller, an engine control unit (ECU), etc.). The control system 120, for example, can be configured to control a plurality of cylinders 31 of the internal combustion engine 30. More specifically, the control system 120 can include various control components for customizing the contribution of a gaseous fuel source, such as from the second fuel source 104, to operating conditions in the cylinders 31.

[0049] The internal combustion engine system 20 includes a temperature sensor 202 (e.g., a thermocouple, a thermometer, a thermistor, etc.). In some embodiments, the control system 120 is configured to communicate with the temperature sensor 202. In some embodiments, the temperature sensor 202 is coupled to the exhaust manifold 32. More specifically, the temperature sensor 202 is configured to be coupled to the exhaust port 138 of the exhaust manifold 32 or a portion of the exhaust manifold 32 other than the exhaust port 138. Further, in some embodiments, each of the plurality of cylinders 31 includes a respective temperature sensor 202. The temperature sensor 202 is configured to measure the exhaust gas temperature of the exhaust gas.

[0050] When balancing the combustion performance in multiple cylinders 31, measuring the exhaust gas temperature helps manage (e.g., reduce, etc.) NOx emissions. NOx emissions can provide a mechanism for controlling the engine system 20. In some embodiments, the main purpose of the control based on NOx emissions may not be to reduce NOx emissions itself. For example, in some embodiments, the temperature information from one or more temperature sensors 202 and the NOx information from one or more NOx sensors 204 can be used as follows. In this example, the focus of control is the total air-fuel ratio of the cylinder and combustion phasing. Combustion phasing is a function of the air-fuel ratio and EGR ratio and ignition timing. Increasing the air-fuel ratio or EGR ratio generally reduces the exhaust temperature and reduces NOx. Delaying combustion phasing generally reduces NOx, but initially increases the exhaust temperature. Then, as misfire or incomplete combustion begins, the exhaust temperature decreases. In a control scheme that only considers NOx, it may occur that NOx is at the target but the combustion is incomplete. Incomplete combustion is undesirable. Even if the NOx target is met, a control scheme that only uses NOx information may cause the engine to operate under undesirable operating conditions.

[0051] The system described herein utilizes NOx information and exhaust temperature information and is capable of identifying and / or detecting undesirable operating conditions. Systems utilizing both NOx information and temperature information are configured to identify or detect incomplete combustion. For example, NOx information may indicate a target value (e.g., desired NOx output), but incomplete combustion results in too low an exhaust temperature (e.g., an exhaust temperature below an exhaust temperature threshold or a target range). Systems utilizing only exhaust temperature information may indicate that the exhaust temperature is at a target (e.g., within a desired range), but combustion is delayed and has a lean (low) air-fuel ratio. This may result in NOx output being below target, indicating poor engine efficiency. By using both NOx information and exhaust temperature information, the control system 120 may determine whether it is desired to change ignition timing, air-fuel ratio, EGR ratio, or other parameters.

[0052] Cylinder balancing can also be improved by utilizing both NOx information and temperature information. For example, if all cylinders are operated in the same manner, techniques exist for determining whether target operating conditions have been reached, for example, by evaluating intake manifold pressure and / or engine power (e.g., from a generator), or utilizing The lambda sensor evaluates the total However, if significant cylinder-to-cylinder variation occurs, typical methods and control schemes do not work. Some cylinders may be too rich (air-fuel ratio is too low) while other cylinders may be too lean (air-fuel ratio is too high). The control system 120 utilizes NOx information and temperature information to improve the response and operation of the engine system 20.

[0053] In some embodiments, the control system 120 is configured to perform control to meet target NOx emissions (e.g., NOx emissions output within a target range, or below a target threshold) and achieve desired combustion phasing (e.g., CA50) at a target crank angle. In some embodiments, the control system 120 may adjust the air-fuel ratio ( ) and spark timing to achieve the desired results. Spark timing and Many combinations of can provide the same or similar NOx output. Similarly, spark timing and Different combinations of may provide the same or similar exhaust temperatures. If both NOx information and exhaust temperature information are known (e.g., from temperature sensor 202 and NOx sensor 204), control system 120 may adjust spark timing and To achieve a desired combination of NOx output and combustion phasing (eg, CA50). Combustion phasing (eg, CA50) can be important because it affects engine performance (eg, fuel economy, etc.) and can be used for engine calibration.

[0054] In some embodiments, if the engine system 20 has a consistent fuel composition, it is easier to determine how to adjust the exhaust NOx level. For example, the control system 120 may target a specific spark timing that may be adjusted based on a timing table and the amount of knock sensed. However, in some embodiments, the fuel composition may not be fixed or consistent. For example, if the secondary fuel includes natural gas, some hydrogen may sometimes be mixed in, and the percentage of hydrogen may result in significant changes in combustion. In response to different fuel mixtures, different spark timing and different value may be beneficial.

[0055] The amount of exhaust NOx is primarily driven by the highest temperature (e.g., maximum temperature, etc.) in the cylinder 31. More specifically, NOx production during combustion is directly related to the adiabatic flame temperature (AFT) of the fuel mixture, which is the temperature of the complete combustion products in a constant volume combustion process without doing work, transferring heat, or changing kinetic energy or potential energy. Therefore, cylinders 31 and / or portions of cylinders 31 with higher exhaust gas temperatures may also exhibit higher amounts of exhaust NOx. In addition, the exhaust gas temperature also indicates the ratio of air and fuel used for combustion (e.g., air-fuel ratio, etc.) and combustion timing. This is particularly true for engines using a fuel mixture containing a component (such as hydrogen) with a relatively low ignition energy (e.g., the amount of energy required to start combustion, etc.).

[0056] In some embodiments, the control system 120 is configured to control the internal combustion engine system 20 using information related to NOx emissions. For example, the control system 120 is configured to use both the total air-fuel ratio of the cylinder and combustion phasing. Combustion phasing is a function of the air-fuel ratio, EGR ratio, and ignition timing. Increasing the air-fuel ratio or EGR ratio generally reduces exhaust temperature and reduces NOx. Delaying combustion phasing generally reduces NOx, but initially increases exhaust temperature, and then reduces exhaust temperature as misfire or incomplete combustion begins. If only NOx is considered, undesirable incomplete combustion may still occur despite NOx being at a target level. In this case, the engine may be running under undesirable operating conditions even if the NOx target is nominally met. On the other hand, by also considering the exhaust temperature, the control system 120 is configured to detect one or more undesirable operating conditions (if only NOx is considered, it would be impossible to discern these undesirable operating conditions in other ways). For example, in the case where NOx is at a target value and incomplete combustion causes the exhaust temperature to be too low, the control system 120 is configured to determine that the exhaust temperature is below the target value. Similarly, if only exhaust temperature is considered, exhaust temperature at the target value may be obtained with combustion retarded and a lean (high) air-fuel ratio. This will result in NOx values ​​below the target value, indicating poor engine efficiency. Using both NOx and exhaust temperature helps determine whether one or more operating parameters (e.g., ignition timing, air-fuel ratio, or EGR rate) should be changed.

[0057] Additionally, in some embodiments, considering the performance of each cylinder allows evaluation of engine performance to account for variations between cylinders. In particular, if each cylinder operates equivalently, factors such as intake manifold pressure, engine power, or the overall air-fuel ratio of the exhaust (such as the overall air-fuel ratio determined using an air-fuel ratio sensor) indicate whether target operating conditions are met. However, when there is significant cylinder-to-cylinder variation, reliance on these parameters cannot account for the specific air-fuel ratio of an individual cylinder. As an example, some cylinders may be too rich (the air-fuel ratio is too low) while other cylinders may be too lean (the air-fuel ratio is too high). Therefore, certain embodiments of the technology according to the present disclosure provide measurements within the cylinder as described below.

[0058] Further, in some embodiments, the control system 120 is configured to receive a target exhaust port temperature and a target NOx emission value. The control system 120 is configured to adjust one or more operating parameters, including air-fuel ratio and spark timing. Various combinations of spark timing and air-fuel ratio produce equivalent NOx values ​​or equivalent exhaust temperatures. The control system 120 is configured to adjust the air-fuel ratio based on the NOx level of the exhaust. For example, the control system 120 is configured to adjust the spark timing based on the timing table and the sensed amount of knock. When the fuel composition changes over time rather than being fixed, such as when natural gas is not consistently mixed with the same amount of hydrogen or when natural gas is not always mixed with hydrogen, adjustment of the air-fuel ratio becomes more difficult. In this case, significant combustion changes mean that different spark timing and air-fuel ratio should be used.

[0059] Reference again Figure 3 , the internal combustion engine system 20 includes a NOx sensor 204. In some embodiments, the control system 120 includes the NOx sensor 204. The NOx sensor 204 is configured to measure an exhaust NOx amount of the exhaust gas. As described above, the exhaust NOx amount is related to the adiabatic flame temperature (AFT). Therefore, the exhaust NOx amount is affected by the peak AFT (e.g., within the cylinder 31 and / or an area of ​​the cylinder 31 with a higher exhaust gas temperature, etc.) and the center of mass and / or crank angle of the heat release position associated with approximately 50% heat release. In some embodiments, the NOx sensor 204 is coupled to the exhaust manifold 32. In some embodiments, the NOx sensor 204 is coupled to the exhaust port 138 of the exhaust manifold 32 or a portion of the exhaust manifold 32 other than the exhaust port 138. Further, in some embodiments, each of the plurality of cylinders 31 may include a NOx sensor 204. Although the exemplary non-limiting embodiments discussed herein provide the temperature sensor 202 and the NOx sensor 204 as separate sensors, in some embodiments, the temperature sensor 202 and the NOx sensor 204 may be combined in a single sensor (e.g., an integrated sensor or a combined sensor, etc.). For example, in some embodiments, the integrated sensor is configured to simultaneously detect multiple physical quantities, including temperature and NOx amount.

[0060] In some embodiments, the internal combustion engine system 20 includes a knock sensor 206. In some embodiments, the control system 120 includes the knock sensor 206. The knock sensor 206 is configured to measure engine knock (e.g., identify knock events, etc.), which is an undesirable premature and rapid combustion associated with engine damage, reduced efficiency, and reduced engine power output. Preferably, the knock sensor 206 is coupled to one of the intake manifold 28, the cylinder head 134, or the engine block 35 that at least partially defines the cylinder 31. However, in some embodiments, the knock sensor 206 is coupled to the exhaust manifold 32. In some embodiments, the knock sensor 206 is coupled to the exhaust port 138 of the exhaust manifold 32 or a portion of the exhaust manifold 32 other than the exhaust port 138. Further, in some embodiments, each of the plurality of cylinders 31 may include a knock sensor 206. Although the exemplary non-limiting embodiments discussed herein describe the temperature sensor 202, the NOx sensor 204, and the knock sensor 206 as separate sensors, in some embodiments, the temperature sensor 202, the NOx sensor 204, and the knock sensor 206 may be combined in a single sensor or in any other combination. In some embodiments, the knock sensor is any physical or virtual sensing device that determines knock (e.g., a knock sensor, a cylinder pressure sensor, an ionization sensor, an optical sensor, etc.).

[0061] In some embodiments, the internal combustion engine system 20 includes a pressure sensor 208 (e.g., an in-cylinder pressure sensor (ICPS)). In some embodiments, the control system 120 includes the pressure sensor 208. The pressure sensor 208 is configured to measure a signal indicating one or more of knock, peak cylinder pressure, or heat release rate. In some embodiments, the pressure sensor 208 in the form of an ICPS measures cylinder pressure. The obtained signal is processed to give an indication of one or more of knock, heat release rate, peak cylinder pressure, combustion phasing (e.g., CA50, crankshaft angle at which approximately 50% of the heat has been released), etc. In some embodiments, the pressure sensor 208 is coupled to the combustion chamber or cylinder head 134. In some embodiments, the pressure sensor 208 may be located elsewhere, including in the intake manifold 28 or one of the engine blocks 35 that at least partially define the cylinders 31. However, in some embodiments, the pressure sensor 208 is coupled to the exhaust manifold 32. Further, in some embodiments, each of the plurality of cylinders 31 may include a pressure sensor 208. Although the exemplary non-limiting embodiments discussed herein describe the temperature sensor 202, the NOx sensor 204, the knock sensor 206, and the pressure sensor 208 as separate sensors, in some embodiments, the temperature sensor 202, the NOx sensor 204, the knock sensor 206, and the pressure sensor 208 may be combined in a single sensor or in any other combination.

[0062] refer to Figure 3 In some embodiments, the control system 120 includes a controller 200 (e.g., a processor, a control circuit, etc.). The controller 200 may include one or more of the following: a programmable microcontroller or microprocessor, a logic circuit, a digital / analog circuit, a programmable logic circuit, a field programmable logic gate array, a memory, etc. The controller 200 receives input from one or more components in the control system 120 and provides control signals to actuate one or more actuators or circuits within the control system 120. The controller 200 may be communicatively coupled to a memory (volatile or non-volatile memory) that may store data and instructions that may be executed by the controller. In some cases, the data and instructions may be stored in one or more non-volatile computer-readable storage media, such as, for example, a flash drive, a read-only memory (ROM), cloud storage, etc.

[0063] In some embodiments, the controller 200 is configured to receive information related to a plurality of operating parameters of each of the plurality of cylinders 31 of the internal combustion engine 30. For example, the controller 200 may be operably connected (e.g., coupled, electrically coupled, attached, communicatively coupled, etc.) to the temperature sensor 202 and the NOx sensor 204. The controller 200 may also be communicatively connected to the knock sensor 206. In this manner, the controller 200 is capable of receiving inputs from one or more components in the control system 120 and providing control signals to actuate one or more actuators or circuits within the control system 120. Thus, the controller 200 is configured to receive the measured exhaust temperature from the temperature sensor 202 and the measured exhaust NOx amount from the NOx sensor 204. In at least some embodiments, the controller 200 is configured to measure the exhaust temperature from the temperature sensor 202 and the exhaust NOx amount from the NOx sensor 204 for each of the plurality of cylinders 31 of the internal combustion engine 30. In some embodiments, the controller 200 is configured to determine whether a knock event (e.g., a standard knock or a silent knock) has occurred in response to the measured exhaust temperature and the measured exhaust NOx amount for one or more of the plurality of cylinders 31. Similarly, in some embodiments, the controller 200 is also configured to detect silent knock based on the measured exhaust temperature and the measured NOx amount. Silent knock is a knock associated with premature ignition that occurs too early to be heard. In this case, detection by the knock sensor 206 is not possible. Detection of silent knock is advantageous because silent knock may cause engine damage and undesirably high NOx emissions.

[0064] In some embodiments, the controller 200 is also configured to calculate target combustion performance for individual cylinders and / or the entire engine 30. Based on the measured exhaust temperature and the measured exhaust NOx amount, the target combustion performance can be associated with one or more of higher engine efficiency, higher engine power output, and reduced emission levels of the cylinder 31. In some embodiments, the measured exhaust temperature and the measured exhaust NOx amount are compared with the target exhaust temperature value and the target exhaust NOx amount, respectively, to determine the target combustion performance. The controller 200 is configured to determine the values ​​of the target exhaust temperature and the target exhaust NOx amount from, for example, a lookup table or a predetermined model based on engine operating conditions (e.g., RMP<torque, intake manifold temperature (IMT), intake manifold pressure (IMP), coolant type, etc.).

[0065] The controller 200 is also configured to determine whether to adjust one or more of the multiple operating parameters based on the target combustion performance. For example, the controller 200 can evaluate one or more of the multiple operating parameters for each of the multiple cylinders 31 relative to the measured exhaust temperature and the measured exhaust NOx amount. Based on the determination of whether to adjust one or more operating parameters, the controller 200 is configured to perform adjustments. For example, the controller 200 is configured to adjust one or more of the multiple operating parameters for one or more of the multiple cylinders 31 to balance the combustion within the multiple cylinders 31, thereby achieving the target combustion performance. In some embodiments, the controller 200 is also configured to adjust the operating parameters based on the measured engine knock and / or the detected silent knock.

[0066] As described above, the controller 200 is configured to receive the measured exhaust temperature and the measured exhaust NOx amount to evaluate the combustion of the internal combustion engine 30, and determine whether to adjust and / or control one or more of the multiple operating parameters based on the target combustion performance. Although the exhaust NOx amount is largely driven by the adiabatic flame temperature, the exhaust temperature is only one parameter used to balance the combustion and may not be indicative of cylinder combustion performance. For example, lean charge spark-ignition engines and pilot-ignition engines may experience charge dilution, where "dilution" refers to the addition of air (i.e., a leaner air-fuel ratio) or recirculated exhaust gas (EGR) (i.e., a higher EGR ratio) to the charge flow. The engine can be operated with lean burn operation or with charge dilution by using EGR (i.e., adding exhaust gas to the charge). When air is used to dilute the fuel, the air-fuel ratio Increases. In addition, as charge dilution increases, the adiabatic flame temperature decreases, which generally reduces the exhaust temperature measured at the exhaust port 138. However, as dilution increases, combustion slows, causing the combustion event to occur later in the engine cycle. Therefore, in various exemplary embodiments of the present disclosure, both the measured exhaust NOx amount and the measured exhaust temperature are used to adjust at least one of the following: air-fuel ratio, fuel composition, exhaust gas recirculation ratio, spark timing value, injection timing value, timing of valve opening or closing events, or geometric compression ratio, or any combination thereof.

[0067] For example, the controller 200 may adjust the spark timing value (eg, the timing of spark ignition, etc.) to avoid or reduce the likelihood of a knock event in one of the plurality of cylinders 31. As another example, the controller 200 may adjust , is an excess air ratio related to the air-fuel ratio and not equal to the air-fuel ratio. According to the embodiment of this invention, =[air-fuel ratio] / [stoichiometric air fuel ratio]. is an indicator of the power output and fuel consumption of the internal combustion engine 30. Therefore, adjusting the air-fuel ratio λ affects NOx emissions, engine power output, knock margin, combustion stability, and exhaust temperature. As another example, exhaust gas recirculation (EGR) is a process of recirculating exhaust gas back into the cylinder 31 (e.g., using an EGR system, a cooled EGR system, etc.) to reduce both oxygen concentration and combustion temperature. Therefore, since the exhaust NOx amount is directly related to the combustion temperature, adjusting the exhaust gas recirculation ratio promotes the reduction of the exhaust NOx amount.

[0068] In addition to determining whether to adjust the operating parameters and / or in addition to performing the adjustment of the operating parameters, the controller 200 can also determine whether the overall engine combustion performance is different from the target engine performance. For example, the controller 200 can be configured to adjust the overall engine air-fuel ratio and the overall engine exhaust gas recirculation ratio in response to the measured exhaust temperature and the measured exhaust NOx amount.

[0069] In some embodiments, a method for controlling an internal combustion engine is performed. The method according to some embodiments includes measuring both exhaust temperature and NOx amount (i.e., the amount of NOx in the exhaust gas). The method also includes receiving information related to one or more operating parameters, the one or more operating parameters including but not limited to: engine speed, engine load, engine intake manifold temperature (i.e., the temperature of the air or charge inside the intake manifold, not the temperature of the metal), oil temperature, coolant temperature, ambient air temperature, intake manifold pressure, intake throttle position, ignition timing, turbine RPM, etc. The method includes calculating a target exhaust temperature and a target NOx amount based on a plurality of operating parameters. The method also includes comparing the measured exhaust temperature and the measured NOx amount with the target exhaust temperature and the target NOx amount. The method also includes adjusting one or more engine parameters, wherein the engine parameters include, for example, but not limited to, air-fuel ratio, spark timing, and EGR ratio. More specifically, the method also includes adjusting one or more engine parameters to reduce (i) the difference between the measured exhaust temperature and the target exhaust temperature and / or (ii) the difference between the measured NOx amount and the target NOx amount. The aforementioned operations may be repeated iteratively.

[0070] In some embodiments, a method for controlling an internal combustion engine includes one or more cylinder-specific measurements. In particular, the method includes measuring both exhaust temperature and NOx quantity. The method also includes comparing the measured exhaust temperature and the measured NOx quantity of each cylinder in a plurality of cylinders of the internal combustion engine. The method also includes adjusting one or more operating parameters of the individual cylinders. The operating parameters include, but are not limited to, fuel flow rate, air flow rate, spark timing, and camshaft phasing. In particular, the method includes adjusting one or more operating parameters of the individual cylinders so as to coordinate the measured exhaust temperature and the measured NOx quantity between the plurality of cylinders. In particular, adjusting one or more operating parameters of each cylinder until each cylinder is within a specific tolerance band for both exhaust temperature and NOx quantity. As an example, the method includes adjusting one or more operating parameters until each individual cylinder is within a given exhaust temperature (e.g., an average exhaust temperature in all cylinders or a target exhaust temperature determined by consulting a lookup table). 5 C inside, in 10 C or in 15 As another example, the method includes adjusting one or more operating parameters until each individual cylinder is within a given NOx amount (e.g., an average NOx amount across all cylinders or a target NOx amount determined by consulting a lookup table). Within 5%, within 7.5% or below In some embodiments, the method may continuously make adjustments to reduce or even minimize the differences between individual cylinders. In some embodiments, the method is considered to have produced successful results if the difference is 5%, even if the target is 0%. For example, the control system 120 may include a threshold difference (e.g., 5%). Although the method is operable to achieve a 0% difference, the control system 120 may stop adjusting once the threshold difference is reached.

[0071] Figure 4 A method 400 (eg, process, etc.) of controlling the internal combustion engine system 20 (eg, by using the control system 120, etc.) is illustrated. The operations described below are exemplary and non-limiting, and in some embodiments, include optional operations that may be omitted and operations that may be performed in a different order than described.

[0072] By way of example and not limitation, Figure 4The method 400 for controlling the internal combustion engine system 20 shown can be implemented in any engine described in the present disclosure. In some embodiments, the method 400 includes: measuring the exhaust temperature of the exhaust gas of the cylinder 31 by the temperature sensor 202 of the cylinder 31 of the internal combustion engine 30; measuring the exhaust NOx amount of the exhaust gas by the NOx sensor 204 of the cylinder 31; receiving the measured exhaust temperature and the measured exhaust NOx amount from the temperature sensor 202 and the NOx sensor 204 by the controller 200; determining the target combustion performance of the cylinder 31 based on the measured exhaust temperature and the measured exhaust NOx amount; and determining whether to adjust one or more of the multiple operating parameters and controlling one or more of the multiple operating parameters based on the target combustion performance.

[0073] The method 400 begins at step 402 by measuring the exhaust temperature of the exhaust gas of the cylinder 31 of the internal combustion engine 30 by the temperature sensor 202 of the cylinder 31. The method 400 continues at step 404 by measuring the exhaust NOx amount of the exhaust gas by the NOx sensor 204 of the cylinder 31.

[0074] In some embodiments, steps 402 and 404 include measuring exhaust temperature and NOx levels of exhaust gas in exhaust manifold 32 or exhaust port 138 of cylinder 31 of internal combustion engine 30 , respectively, to which temperature sensor 202 and NOx sensor 204 are coupled.

[0075] The method 400 continues in step 406 by receiving the measured exhaust temperature and the measured exhaust NOx amount from the temperature sensor 202 and the NOx sensor 204, respectively, by the controller 200. Additionally, in some embodiments, the controller 200 may receive engine operating conditions, including one or more of the following: RPM, load, intake manifold temperature, intake manifold pressure, oil temperature, coolant temperature, ambient air pressure, injection pressure, injection timing or duration, ignition timing (e.g., spark ignition, etc.), fuel flow rate, air flow rate, EGR rate, etc. In some embodiments, the controller 200 uses the received temperature, NOx amount, and engine operating conditions to determine the current combustion performance of the engine or each cylinder.

[0076] Method 400 continues in step 408 by determining a target combustion performance for cylinder 31 based on the measured exhaust temperature and the measured exhaust NOx amount. In some embodiments, the target combustion performance is also based on engine operating conditions. In some embodiments, the target combustion performance is a dynamic parameter that changes over time and is a function of engine operating conditions.

[0077] The method 400 continues in step 410 by determining whether to adjust one or more of the plurality of operating parameters and controlling one or more of the plurality of operating parameters based on the target combustion performance. In some embodiments, the controller 200 compares the current combustion performance and the target combustion performance to determine the difference. The controller 200 can then adjust the operating parameters of the engine to minimize the difference between the current combustion performance and the target combustion performance.

[0078] In some embodiments, the controller 200 compares the measured exhaust temperature and the measured exhaust NOx amount with the target combustion performance. Based on the comparison, an error term for NOx and exhaust temperature is determined. Then, the controller 200 makes one or more adjustments to the engine parameters (e.g., air-fuel ratio, spark timing, EGR ratio) to minimize the error term for NOx and exhaust temperature.

[0079] In some embodiments, the controller 200 compares the measured values ​​of the exhaust temperature and exhaust NOx amount of each different cylinder separately. Then, the controller 200 adjusts one or more individual cylinders (e.g., adjusts the fuel flow rate, air flow rate, spark timing, camshaft phasing, etc.) so that the exhaust temperature and exhaust NOx amount measured for all cylinders are within a certain tolerance band (e.g., 10 degrees Celsius, or the measured NOx amount 5%).

[0080] In some embodiments, the step 410 of determining whether to adjust one or more of the plurality of operating parameters and controlling one or more of the plurality of operating parameters based on the target combustion performance includes determining whether to adjust one or more of the following parameters. The one or more operating parameters include, but are not limited to: air-fuel ratio, fuel composition, exhaust gas recirculation ratio, spark timing value, injection timing value (e.g., injection duration and / or injection pressure), timing of valve opening or closing events, intake and / or exhaust throttle position, exhaust valve position, compressor bypass valve position, position of variable geometry turbine, or geometric compression ratio. In some embodiments, the operating parameters are applied to individual cylinders (e.g., cylinder-specific control). In some embodiments, the operating parameters are applied to each bank (e.g., individually and separately to each bank). In some embodiments, the operating parameters are applied to all cylinders at the engine level. In some embodiments, determining whether to adjust one or more of these parameters can be based on any combination of the aforementioned parameters. As an example, the controller 200 is configured to determine whether to adjust one or more of the operating parameters based on the input fuel composition of the dual fuel mixture. In some embodiments, the controller 200 receives information related to the fuel composition of the ratio of the two fuels as the dual fuel mixture.

[0081] The method 400 optionally includes adjusting, by the controller 200, one or more of the plurality of operating parameters to balance combustion performance among the plurality of cylinders 31. The method 400 optionally includes measuring knock via a knock sensor 206 coupled to the engine 30, and adjusting, by the controller 200, a total engine air-fuel ratio and a total engine exhaust gas recirculation ratio in response to the detected knock, the measured exhaust temperature, and the measured exhaust NOx amount for each cylinder 31 of the plurality of cylinders 31 of the engine 30.

[0082] Although the exemplary non-limiting embodiment of method 400 described above includes step 402 before step 404, method 400 is not limited thereto. Rather, steps 402 and 404 may occur in any order (ie, steps 402 ... 404, steps 404 ... 402) and / or may occur simultaneously.

[0083] Although this specification contains various implementation details, these should not be interpreted as limitations on the scope of what may be claimed, but rather as descriptions of features specific to a particular implementation. For example, an engine described in conjunction with a particular fuel or fuel mixture may be configured to receive different fuels or fuel mixtures. Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable sub-combination. In addition, although features may be described as functioning in certain combinations and even initially claimed as such, one or more features from the claimed combination may be deleted from the combination in some cases, and the claimed combination may be directed to a sub-combination or a variation of the sub-combination.

[0084] As used herein, the terms "substantially," "generally," "approximately," and similar terms are intended to have a broad meaning consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of the present disclosure relates. Those skilled in the art who review the present disclosure should understand that these terms are intended to allow for the description of certain features described and claimed without limiting the scope of such features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations to the subject matter described and claimed are considered to be within the scope of the appended claims.

[0085] As used herein, the term "coupled" and similar terms refer to the connection of two components directly or indirectly to each other. Such connection may be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such connection may be achieved by the two components, or the two components and any additional intermediate components, being integrally formed as a single unitary body with one another, or by the two components, or the two components and any additional intermediate components, being attached to one another.

[0086] As used herein, the term "fluidically coupled to" and the like means that two components or objects have a path formed between the two components or objects in which a fluid (such as air, liquid, reductant, air-reductant mixture, exhaust gas, hydrocarbons, air-hydrocarbon mixture) can flow, with or without intervening components or objects. Examples of fluid couplings or structures for achieving fluid communication may include pipes, conduits, channels, or any other suitable components for achieving fluid flow from one component or object to another component or object.

[0087] It is important to note that the construction and arrangement of the various systems shown in the various example implementations are illustrative only and not restrictive. It is desired to protect all changes and modifications that fall within the spirit and / or scope of the described implementations. It should be understood that some features may not be required, and implementations lacking various features may be conceived to be within the scope of the present disclosure, which is defined by the appended claims.

[0088] In the context of a list of elements, the term "or" is used in its inclusive sense (rather than its exclusive sense) so that when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Unless otherwise specifically stated, conjunctive language such as the phrase "at least one of X, Y, and Z" should be understood with the context that is commonly used to convey that an item, term, etc. can be X, Y, Z, X and Y, X and Z, Y and Z, or X, Y and Z (i.e., any combination of X, Y, and Z). Therefore, unless otherwise stated, such conjunctive language is generally not intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z to be present.

[0089] It is important to note that the construction and arrangement of the various systems and operations according to the various techniques shown in the various example implementations are illustrative only and not restrictive. It is desired to protect all changes and modifications that fall within the spirit and / or scope of the described implementations. It should be understood that some features may not be required, and implementations lacking various features may be conceived to be within the scope of the present disclosure, which is defined by the appended claims.

Claims

1. A control system for an internal combustion engine, the control system comprising: a temperature sensor configured to measure a temperature of exhaust gas from a cylinder of the internal combustion engine; a NOx sensor configured to measure an amount of exhaust NOx from the cylinder; and a controller operably connected to the temperature sensor and the NOx sensor, the controller being configured to: - receiving the measured exhaust gas temperature from the temperature sensor and the measured exhaust gas NOx amount from the NOx sensor; - calculating the current combustion performance of the cylinder based on the measured exhaust gas temperature and the measured exhaust NOx amount; - determining whether to adjust one or more of a plurality of operating parameters; as well as - Based on the current combustion performance, controlling the one or more operating parameters of the plurality of operating parameters.

2. The control system according to claim 1, wherein: The controller is configured to determine whether to adjust the plurality of operating parameters, the plurality of operating parameters including at least one of: air-fuel ratio, fuel composition, exhaust gas recirculation ratio, spark timing value, injection duration and injection pressure, timing of valve opening or closing events, or geometric compression ratio.

3. The control system according to claim 1, wherein: The cylinder is one of a plurality of cylinders of the internal combustion engine, each of the plurality of cylinders having a respective NOx sensor and a respective temperature sensor.

4. The control system according to claim 3, wherein: The controller is configured to control a current combustion performance of each of the plurality of cylinders to balance a collective combustion performance among the plurality of cylinders.

5. The control system according to claim 1, wherein: The controller is configured to adjust at least one of an overall engine air-fuel ratio or an overall engine exhaust gas recirculation ratio in response to the measured exhaust temperature and the measured exhaust NOx amount.

6. The control system according to claim 1, wherein: The internal combustion engine is a port-injected hydrogen fuel engine or a direct-injection hydrogen fuel engine.

7. The control system according to claim 1, wherein: The controller is configured to: determine a target combustion performance based on engine operating conditions; comparing the current combustion performance with the target combustion performance; as well as The one or more operating parameters of the plurality of operating parameters are controlled based on a comparison of the current combustion properties with the target combustion properties.

8. An internal combustion engine system configured to control combustion, the internal combustion engine system comprising: an internal combustion engine comprising a plurality of cylinders, each cylinder having a temperature sensor and a NOx sensor; and A control system configured to control the plurality of cylinders of the internal combustion engine, the control system comprising a controller configured to: - receiving information related to a plurality of operating parameters of each of the plurality of cylinders of the internal combustion engine; - measuring, for each of the plurality of cylinders of the internal combustion engine, an exhaust gas temperature from the temperature sensor and an exhaust gas NOx amount from the NOx sensor; - for each of the plurality of cylinders of the internal combustion engine, evaluating one or more of the plurality of operating parameters relative to the measured exhaust temperature and the measured exhaust NOx amount; as well as - For one or more cylinders of the plurality of cylinders of the internal combustion engine, adjusting one or more operating parameters of the plurality of operating parameters to control combustion between the plurality of cylinders.

9. The internal combustion engine system according to claim 8, wherein: Each cylinder of the plurality of cylinders includes an exhaust manifold or an exhaust port configured to receive exhaust gas, and the temperature sensor and the NOx sensor are coupled to the exhaust manifold or the exhaust port to measure an exhaust temperature and an exhaust NOx amount of the exhaust gas.

10. The internal combustion engine system according to claim 8, wherein: The controller is configured to receive information related to the plurality of operating parameters, the plurality of operating parameters comprising: (i) an exhaust gas recirculation ratio of an exhaust gas recirculation system of the internal combustion engine, (ii) a spark timing value of an ignition system of the internal combustion engine, (iii) an injection duration and injection pressure of a fuel injection system of the internal combustion engine, (iv) a timing of a valve opening or closing event of a cam of the internal combustion engine, (v) an air-fuel ratio of the internal combustion engine, (vi) a geometric compression ratio of one or more of the plurality of cylinders of the internal combustion engine, and (vii) a fuel composition, and Wherein, the controller is configured to receive information related to each of the plurality of operating parameters to evaluate combustion of the internal combustion engine.

11. The internal combustion engine system of claim 10, further comprising a knock sensor communicatively coupled to the controller and configured to measure engine knock, in, The controller is configured to adjust the one or more operating parameters based on measured engine knock and, for one or more cylinders of the plurality of cylinders, based on measured exhaust temperature and measured exhaust NOx amount.

12. The internal combustion engine system according to claim 10, wherein: The controller is configured to determine whether the overall engine combustion performance is different from the target engine performance, and adjust at least one of the overall engine air-fuel ratio and the overall engine exhaust gas recirculation ratio in response to the measured exhaust temperature and the measured exhaust NOx amount of one or more cylinders of the plurality of cylinders.

13. The internal combustion engine system according to claim 10, wherein: The controller is configured to adjust the estimated plurality of operating parameters to balance the plurality of operating parameters within the plurality of cylinders.

14. The internal combustion engine system according to claim 10, wherein: The internal combustion engine is one of a spark ignition engine, a pilot ignition engine, a compression ignition engine or a dual fuel engine.

15. The internal combustion engine system according to claim 10, wherein: The controller is configured to determine whether a knock event occurs in response to a measured exhaust temperature and a measured exhaust NOx amount of one or more cylinders of the plurality of cylinders.

16. The internal combustion engine system according to claim 10, wherein: The internal combustion engine is at least one of a hydrogen fuel engine, a natural gas fuel engine, a propane fuel engine, or an ammonia fuel engine.

17. A method for controlling an internal combustion engine system, the method comprising: measuring the exhaust gas temperature of the exhaust gas of the cylinder by a temperature sensor of the cylinder of the internal combustion engine; measuring an exhaust NOx amount of the exhaust gas by a NOx sensor of the cylinder; receiving, by a controller, a measured exhaust temperature and a measured exhaust NOx amount from the temperature sensor and the NOx sensor; determining a target combustion performance of the cylinder based on the measured exhaust temperature and the measured exhaust NOx amount; determining whether to adjust one or more of a plurality of operating parameters; as well as Based on the target combustion performance, the one or more operating parameters of the plurality of operating parameters are controlled.

18. The method according to claim 17, wherein: Determining whether to adjust the plurality of operating parameters includes determining whether to adjust one or more of: air-fuel ratio, fuel composition, exhaust gas recirculation fraction, spark timing values, injection timing values, timing of valve opening or closing events, or geometric compression ratio.

19. The method of claim 18, further comprising adjusting, by the controller, one or more of the plurality of operating parameters to balance combustion performance among a plurality of cylinders.

20. The method of claim 18, further comprising: measuring knock via a knock sensor coupled to the engine; and At least one of an overall engine air-fuel ratio or an overall engine exhaust gas recirculation ratio is adjusted by the controller in response to the detected knock, the measured exhaust temperature, and the measured exhaust NOx amount of each of a plurality of cylinders of the engine.

21. The method according to claim 18, wherein: Measuring the exhaust temperature and NOx amount of the exhaust gas of the cylinder of the internal combustion engine includes measuring the exhaust temperature and NOx amount of the exhaust gas in an exhaust manifold or an exhaust port of the cylinder of the internal combustion engine, the temperature sensor and the NOx sensor being coupled to one of the exhaust manifold or the exhaust port.

22. The method according to claim 18, wherein: The internal combustion engine is a dual fuel engine configured to receive a mixture of a first fuel and a second fuel, and wherein determining whether to adjust one or more of the plurality of operating parameters comprises determining whether to adjust a fuel composition corresponding to a ratio of the first fuel to the second fuel in the mixture.

23. The method of claim 22, further comprising adjusting the fuel composition to achieve target combustion properties.

24. The method according to claim 22, wherein: Determining whether to adjust one or more of the plurality of operating parameters includes determining whether to adjust a ratio of the first fuel to the second fuel in the mixture, the first fuel comprising hydrogen and the second fuel comprising natural gas or ammonia.

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