Combustion control of ammonia fuel engines

Abstract

The subject matter herein may be embodied, inter alia, in a method performed in connection with an internal combustion engine, the method including the steps of receiving a pressure signal from a combustion chamber pressure sensor while a volume is in a first range, the first range corresponding to a portion of a compression phase, the received pressure being a first pressure; supplying a first pulse of fuel at a first location of the body during the compression phase based on the received pressure signal; and supplying a second pulse of fuel at a second location of the body during the compression phase based on the received pressure signal.

Description

TECHNICAL FIELD

[0001] This application claims priority based on U.S. Patent Application No. 63 / 248,877 filed on September 27, 2021 and U.S. Patent Application No. 17 / 935,495 filed on September 26, 2022, and the entire contents of the above U.S. patent applications are incorporated herein by reference.

[0002] The present specification relates to combustion control and exhaust gas control for dual-fuel engines. BACKGROUND ART

[0003] Internal combustion engines, including diesel engines and diesel-ammonia dual-fuel engines, ignite an air-fuel mixture to cause combustion in one or more engine cylinders. A typical internal combustion engine system injects fuel and air into a combustion chamber (e.g., a cylinder) of the engine, and ignites the air-fuel mixture using an ignition device such as a spark plug, a pilot amount of diesel fuel for compression ignition, or via volumetric autoignition. In response to consumer and regulatory requirements, conventional internal combustion engines are pushing the boundaries of combustion towards more fuel-efficient operating modes, such as using lean combustion, advanced combustion or low-temperature combustion to suppress fuel combustion. However, diesel-ammonia combustion causes the production of nitrous oxide as an exhaust pollutant and the emission of excess ammonia fuel (i.e., ammonia slip). SUMMARY OF THE INVENTION

[0004] In general, the present specification describes systems and methods for combustion and exhaust gas control of dual-fuel engines.

[0005] In the first example, a device for controlling the operation of an internal combustion engine, the internal combustion engine comprising a body sealed in a combustion chamber, the body being movable to a top dead center position to compress a gas or at least one of a gas / liquid mixture in the compression phase, and movable from the top dead center position by the expanding combustion gases in the expansion phase. Each position of the body defines a volume of the combustion chamber, and the device comprises a processor that receives input from a position sensor configured to sense a position of the body corresponding to a volume of the combustion chamber, and input from a combustion chamber pressure sensor, the processor being configured to receive a pressure signal from the combustion chamber pressure sensor while the volume is in a first range, the first range corresponding to a portion of the compression phase, the received pressure being a first pressure, and based on the received pressure signal, supplying a first signal configured to supply a first pulse of fuel at a first position of the body during the compression phase, and based on the received pressure signal, supplying a second signal configured to supply a second pulse of fuel at a second position of the body during the compression phase.

[0006] In the second example relating to the first example, the first signal is further configured to prepare an air / fuel mixture that is close to auto-ignition during compression.

[0007] In the third example relating to the first or second example, the second signal is further configured to initiate combustion in the combustion chamber.

[0008] In the fourth example relating to any of the first to third examples, the second signal is further configured to control at least one of CA50 or CA10.

[0009] In the fifth example relating to any of the first to fourth examples, the second signal is further configured to control the NH3 / NOx ratio resulting from the combustion of diesel fuel, ammonia fuel, and air.

[0010] In the sixth example relating to the fifth example, the ratio is approximately 1.

[0011] In the seventh example relating to the sixth example, the ratio is less than approximately 1.2.

[0012] In the eighth example relating to any of the first to seventh examples, the apparatus further comprises an exhaust aftertreatment system configured to receive free ammonia present in the exhaust gas and to catalyze NOx based on the ammonia.

[0013] In the ninth example, a method is performed in relation to an internal combustion engine having a body sealed in a combustion chamber, the body being movable to a point position to compress a gas or at least one of a gas / liquid mixture in a compression phase, and movable from the point position by expanding a combustion gas in an expansion phase, each position of the body defining the volume of the combustion chamber, the method receiving a pressure signal from a combustion chamber pressure sensor while the volume is in a first range, the first range corresponding to a portion of the compression phase, the received pressure being a first pressure, supplying a first pulse of fuel at a first position of the body during the compression phase based on the received pressure signal, and supplying a second pulse of fuel at a second position of the body during the compression phase based on the received pressure signal.

[0014] In the 10th example relating to the 9th example, the first pulse of fuel is further configured to prepare an air / fuel mixture that is close to autoignition.

[0015] In the eleventh example relating to the ninth or tenth example, the method further comprises the step of initiating combustion in the combustion chamber based on a second pulse of fuel.

[0016] In the twelfth example relating to any of the ninth to eleventh examples, the method further comprises controlling at least one of CA50 or CA10 based on at least one of a first pulse of fuel or a second pulse of fuel.

[0017] In the 13th example relating to any of the 9th to 12th examples, the method further comprises controlling the ratio of NH3 / NOx produced from the combustion of diesel fuel, ammonia fuel, and air based on at least one of a first pulse of fuel or a second pulse of fuel.

[0018] In the 14th example relating to the 13th example, the ratio is approximately 1.

[0019] In the 15th example relating to the 14th example, the ratio is less than approximately 1.2.

[0020] In the 16th example relating to any of the 9th to 15th examples, the method further comprises the steps of receiving free ammonia present in the exhaust gas by an exhaust aftertreatment system, and catalyzing NOx based on the free ammonia by the exhaust aftertreatment system.

[0021] In the 17th example relating to the 16th example, the method further comprises the step of controlling the amount of free ammonia present in the exhaust gas based on at least one of a first pulse of fuel or a second pulse of fuel.

[0022] In one embodiment, there is a device for controlling the operation of an internal combustion engine, the internal combustion engine having a body sealed in a combustion chamber, the body being movable to a top dead center position to compress a gas or at least one of a gas / liquid mixture in a compression phase, and movable from the top dead center position by expanding a combustion gas in an expansion phase, each position of the body comprising a processor that receives input from a position sensor configured to define the volume of the combustion chamber and sense a position of the body corresponding to the volume of the combustion chamber, and input from a combustion chamber pressure sensor, the processor being configured to receive a pressure signal from the combustion chamber pressure sensor while the volume is in a first range, the first range corresponding to a portion of the compression phase, the received pressure being a first pressure, and based on the received pressure signal, supplying a first signal configured to supply a first pulse of fuel at a first position of the body during the compression phase, and based on the received pressure signal, supplying a second signal configured to supply a second pulse of fuel at a second position of the body during the compression phase.

[0023] Various embodiments may include some, all, or none of the following features: A first signal may be configured to prepare an air / fuel mixture close to auto-ignition. A second signal may be further configured to initiate combustion in the combustion chamber. The second signal may be configured to control at least one of CA50 or CA10. The second signal may be configured to control the NH3 / NOx ratio resulting from the combustion of diesel fuel, ammonia fuel, and air. The ratio may be approximately 1, or greater than 1.2. The device may include an exhaust aftertreatment system configured to receive free ammonia present in the exhaust gas and catalyze NOx based on the ammonia.

[0024] In one embodiment, a method is performed in relation to an internal combustion engine having a body sealed in a combustion chamber, the body being movable to a point position to compress a gas or at least one of a gas / liquid mixture in a compression phase, and movable from the point position by expanding a combustion gas in an expansion phase. Each position of the body defines the volume of the combustion chamber, the method receives a pressure signal from a combustion chamber pressure sensor while the volume is in a first range, the first range corresponding to a portion of the compression phase, the received pressure is a first pressure, and based on the received pressure signal, a first pulse of fuel is supplied at the first position of the body during the compression phase, and based on the received pressure signal, a second pulse of fuel is supplied at the second position of the body during the compression phase.

[0025] Various implementations may include some, all, or none of the following features: The first pulse of fuel may be further configured to prepare an air / fuel mixture close to autoignition. The method may include a step of initiating combustion in the combustion chamber based on a second pulse of fuel. The method may include a step of controlling CA50 based on at least one of the first pulse of fuel or the second pulse of fuel. The method may include a step of controlling the ratio of NH3 / NOx resulting from the combustion of diesel fuel, ammonia fuel, and air during the expansion phase based on at least one of the first pulse of fuel or the second pulse of fuel. The ratio may be about 1. The ratio may be between 1.0 and about 1.2. The method may include a step of receiving free ammonia present in the exhaust gas by an exhaust aftertreatment system and catalyzing NOx based on the free ammonia by an exhaust aftertreatment system. The method may include a step of controlling the amount of free ammonia present in the exhaust gas based on at least one of the first pulse of fuel or the second pulse of fuel.

[0026] The systems and technologies described herein may offer one or more of the following advantages: Firstly, the systems can improve the usability of ammonia as a renewable fuel source (for example, by improving the combustion of NH3, a fuel that is difficult to burn; NH3 itself has the advantage of reducing GHGs because it does not contain carbon). Secondly, the systems can improve the emissions resulting from fuel combustion (for example, by using NH3 slip to reduce NOx in SCRs). Thirdly, the systems can reduce or eliminate the need for high-grade urea (e.g., diesel exhaust fluid or "DEF") and associated supply systems used in exhaust gas aftertreatment systems.

[0027] Details of one or more embodiments are described in the attached drawings and the following description. Other features and advantages will become apparent from the description and drawings and the claims. [Brief explanation of the drawing]

[0028] [Figure 1] It is a schematic diagram showing an example of an internal combustion engine system.

[0029] [Figure 2] It is a schematic cross-sectional view of a cylinder of an internal combustion engine including an engine control system.

[0030] [Figure 3] It is a cross-sectional view of another cylinder of an internal combustion engine.

[0031] [Figure 4] It is a chart showing an example of a cylinder stroke. [Figure 5] It is a chart showing an example of a cylinder stroke.

[0032] [Figure 6] It is a schematic diagram showing an example of an engine control system.

[0033] [Figure 7] It is a schematic half-cross-sectional view showing an example of a gas mixer.

[0034] [Figure 8] It is a chart showing an example of gas concentration resulting from combustion of ammonia in a cylinder.

[0035] [Figure 9] It is a schematic cross-sectional view showing an example of a diesel aftertreatment system.

[0036] [Figure 10] It is a chart showing an example of exhaust gas products.

[0037] [Figure 11] It is a flow diagram showing an example of a process for controlling an internal combustion engine system.

[0038] [Figure 12] This is a schematic diagram showing an example of a typical computer system. [Modes for carrying out the invention]

[0039] Low-carbon and zero-carbon fuels are needed for internal combustion engines. The technical goal of engine development is to achieve high efficiency and high power density while achieving near-zero emissions.

[0040] Hydrogen is considered a primary candidate as a fuel to achieve these objectives. Hydrogen is an excellent combustion fuel with low ignition energy, a wide AFR (air-fuel ratio), and a fast combustion rate. However, pure hydrogen (H2) is energy-intensive to produce, and its natural state is a gas at standard conditions. Therefore, for use in transportation, hydrogen must be pressurized (e.g., 10,000 psi) or liquefied (e.g., at temperatures below -250°C), and handling it safely (due to leakage, explosiveness, etc.) is difficult.

[0041] An alternative to pure H2 is to add nitrogen molecules to produce ammonia (NH3). Ammonia has a higher energy density than H2 because it can be stored as a liquid at a gauge pressure of only about 15 psi. Ammonia can be used as a fuel, but it has almost opposite properties to hydrogen. Ammonia is difficult to ignite, burns slowly, burns at low temperatures, and almost always requires some kind of combustion enhancer. A practical method of introducing ammonia as fuel is to vaporize liquid ammonia in a suitable coolant-circulating heat exchanger and inject it as vapor into the port. This is also known as port fuel injection (PFI), and it produces a premixed gas of air and ammonia. It is also possible to inject ammonia directly into the cylinder using a high-pressure direct injector, or, in the case of dual fuel, a high-pressure dual-fuel (HPDF) injector.

[0042] To improve the ignition of ammonia, diesel fuel can be used to improve combustion initiation and combustion rate. Ammonia combustion in diesel can produce two regulated emissions in addition to N2O: NOx and unburned ammonia (NH3), which may be produced if the catalytic converter is ineffective. NOx can arise from the high-temperature diesel-driven diffusion flame and available nitrogen in the atmosphere (e.g., 79% N2, 21% O2). Unburned ammonia, also known as ammonia slip, arises from a process similar to that known to cause methane slip (direct combustion short circuit, piston / cylinder wall gap region quench, bulk flame quench, etc.) in natural gas dual-fuel engines. The systems and methods described herein control ammonia combustion in dual-fuel applications so that both NOx emissions and ammonia slip (NH3) are controlledly reduced or eliminated. While this specification describes diesel dual-fuel applications, similar concepts can be applied to other dual-fuel applications that burn ammonia.

[0043] Figure 1 shows an example of an engine system 100. The engine system 100 includes an intake manifold 104 that is fluidly coupled to an oxygen source (e.g., air) and combined with diesel fuel (e.g., by direct injection) and ammonia fuel (e.g., by port injection or direct injection). The engine system 100 is configured as a four-stroke (intake, compression, combustion, exhaust, etc.) engine. The engine system 100 includes a cylinder bank 102a with four cylinders and a cylinder bank 102b with four cylinders. The illustrated embodiment includes an eight-cylinder engine having two banks of four cylinders, but the engine system 100 can have a suitable number of banks with a suitable number of cylinders. Also, although the illustrated embodiment is depicted and described as a piston engine, aspects of this disclosure can also be applied to other types of internal combustion engines, such as rotary engines.

[0044] In certain embodiments, the throttle 112 is positioned in an intake plenum 103 upstream of the intake manifold 104 to regulate the pressure in the intake manifold 104, for example, to control exhaust gas recirculation (EGR).

[0045] The exhaust manifold 106a is configured to receive combustion products (exhaust) from the combustion chamber of cylinder bank 102a. In other words, the exhaust manifold 106a is fluidically coupled to the outlet of the combustion chamber of cylinder bank 102a. The EGR passage 108a or conduit fluidly couples the exhaust manifold 106a to an ammonia gas injector 114 configured to supply ammonia gas fuel to the intake manifold 104 (e.g., port injection of ammonia gas fuel). In some embodiments, the ammonia gas injector 114 can be configured as a direct injection system configured to supply ammonia gas fuel directly to the combustion chamber. In the illustrated embodiment, the EGR throttle valve 126a is located in the gas passage 108a between the exhaust manifold 106a and the ammonia gas injector 114 and is used to regulate the EGR flow. In certain embodiments, the exhaust gas cooler 110a is located in the EGR passage 108a between the exhaust manifold 106a and the ammonia gas injector 114. The exhaust gas cooler 110a is operable to lower the temperature of the exhaust gas before it enters the ammonia gas injector 114. The exhaust gas cooler 110a is a heat exchanger such as an air-to-air exchanger or an air-to-water exchanger. In some implementations, the EGR flow may be recirculated to the intake manifold 104 upstream of the ammonia gas injector 114, downstream of the ammonia gas injector 114, or at the location of the ammonia gas injector 114.

[0046] The exhaust manifold 106b is configured to receive combustion products (exhaust) from the combustion chamber of cylinder bank 102b. In other words, the exhaust manifold 106b is fluidically coupled to the outlet of the combustion chamber of cylinder bank 102b. The EGR passage 108b or conduit fluidly couples the exhaust manifold 106b to the intake manifold 104. In the illustrated embodiment, the EGR throttle valve 126b is located in the EGR passage 108b between the exhaust manifold 106b and the ammonia gas injector 114 and is used to regulate the flow of EGR. The EGR throttle valve 126b regulates the flow of EGR by adjusting the cross-sectional area of ​​the EGR passage 108b through the EGR throttle valve 126b.

[0047] The exhaust gas cooler 110b is positioned in the EGR passage 108b between the exhaust manifold 106b and the ammonia gas injector 114. The exhaust gas cooler 110b is operable to lower the temperature of the exhaust gas before it enters the ammonia gas injector 114. The exhaust gas cooler 110b is a heat exchanger, such as an air-to-air exchanger or an air-to-water exchanger.

[0048] In some implementations, the engine system 100 includes a compressor 118 upstream of the throttle 112. In engines without a throttle but with a compressor 118, such as a diesel engine without a throttle, the throttle 112 is not necessary, and the ammonia gas injector 114 may be downstream of the compressor 118. The compressor 118 may include a centrifugal compressor, a positive displacement compressor, or another type of compressor to increase the pressure in the air within the intake plenum 103 during engine operation.

[0049] In the illustrated embodiment, the compressor 118 is part of a turbocharger. That is, the turbine 122 is located downstream of the exhaust manifolds 106a and 106b and rotates as the exhaust gases expand through the turbine 122. The turbine 122 is coupled to the compressor 118, for example, via a shaft, which gives rotation to the compressor 118. Although the illustrated example depicts and illustrates a turbocharger for increasing the pressure in the intake manifold, other compression methods could also be used, such as an electric or engine-driven compressor (e.g., a supercharger).

[0050] The engine system 100 includes an intercooler 120 configured to cool the compressed air in the intake plenum 103 before it enters the ammonia gas injector 114 and the intake manifold 104. The intercooler can be operated to lower the temperature of the compressed air before it enters the intake manifold 104. The intercooler is a heat exchanger such as an air-to-air exchanger or an air-to-water exchanger.

[0051] The fuel supply device 130 is configured to provide fuel for combustion in the engine system 100 (e.g., the cylinders of cylinder blocks 102a and 102b). In the illustrated example, the fuel supply device 130 is configured to supply ammonia gas as fuel to the ammonia gas injector 114. Examples of such configurations are described in more detail in the description of Figure 2. In some embodiments, the fuel supply device 130 may be configured to supply fuel to the intake plenum 103 (e.g., upstream of the throttle 112). In some embodiments, the fuel supply device 130 may be configured to supply fuel downstream from the ammonia gas injector 114 (e.g., to the intake manifold 104, into the cylinders via direct injection).

[0052] In some implementations, the fuel supply device 130 may be a high-pressure fuel supply. For example, the fuel supply device may be configured to supply pressurized gaseous ammonia, hydrogen, methane, or other suitable flammable gas. In another example, the fuel supply device may be configured to supply liquefied ammonia, hydrogen, methane, or other suitable flammable gas that can be stored and / or supplied in a liquefied form.

[0053] The exhaust aftertreatment system 150 (for example, a catalytic converter) is coupled to the exhaust manifolds 106a and 106b and is configured to reduce the amount of regulated emissions exiting the exhaust pipe 160. An example of the exhaust aftertreatment system is further described in the explanation of Figure 9.

[0054] Lean fuel-air mixtures are used in many current internal combustion engines to reduce regulated emissions, and recent reductions in emissions regulations have pushed NOx limits down to the lower limits of 1, 1 / 2, 1 / 4, and 1 / 8 TA Luft (where 1 TA Luft is 1.0 gm / kw-hr of NOx emissions). As fuel quality and atmospheric conditions change, engine controllers can sometimes have difficulty maintaining the correct air-fuel ratio (AFR being richer than necessary). Furthermore, fuel injectors are prone to wear, eventually leading to inconsistencies in their performance.

[0055] Currently, combustion monitoring via cylinder pressure is used in almost all engines in research and development environments to develop engine combustion strategies and their control. However, cylinder pressure-based monitoring systems in production engines are underdeveloped and underpowered due to the slow processors commonly available in current production ECUs. They are expensive and unreliable, limiting their applicability to only the highest power density and highest efficiency applications where the benefits may justify the cost. With the emergence of new, more capable ECUs and improved reliability of pressure sensors, the widespread adoption of pressure sensing is expected to be imminent. However, even when ECU capabilities and sensor reliability meet the targets, an "efficient and meaningful algorithm" remains necessary. This disclosure presents, as an example of such an efficient and meaningful algorithm, the ability to control fuel supply and combustion to control exhaust emissions of NOx and NH3, and ultimately reduce or eliminate them. Several exemplary methods described herein can control combustion by sampling cylinder pressure during each combustion event and supplying a precisely timed fuel pulse accordingly. In this embodiment, the detection information is immediately transmitted to the ECU, and corrective actions are taken.

[0056] Some of the concepts described herein involve controlling the engine using in-cylinder pressure measurements processed by an engine control unit (ECU). The concepts disclosed herein can provide the ability to control combustion and / or exhaust emissions without requiring a high-power processor, and in certain examples, without requiring a separate high-power ECU to process the pressure signal into combustion metrics such as heat-dissipation-derived parameters, separate from the ECU that determines and controls ignition timing and fuel supply. Using in-cylinder pressure measurements can, in some cases, eliminate the need to use multiple other sensors for engine control. For example, mass airflow sensors, NOx (nitrogen oxide) sensors, knock sensors, or exhaust temperature sensors can be eliminated. Furthermore, in certain examples, the concepts disclosed herein may be better adapted to variations in fuel quality (e.g., variations in energy content (MBTU / m3)).

[0057] In certain cases, the ECU has the capability to process high-speed cylinder pressure data with a crank resolution of 0.25°, creating a comprehensive set of diagnostics for monitoring cylinder pressure, and has an embedded processor that can filter and average combustion diagnostics in real time, i.e., concurrently with engine operation, with sufficient current for use in the control loop to control the engine. In some cases, processing and control are performed within a single cycle for each cylinder. In some cases, the ECU can process up to 20 cylinders in real time, with a total processing time of approximately 2.5 milliseconds per cylinder. Real-time combustion metrics calculated by the ECU include the location of peak pressure (Ploc) and maximum pressure (Pmax) at a crank angle or time, pressure at a specific fixed crank angle or volume in one or more cylinders, etc.

[0058] Conventional built-in pressure monitoring systems can be found in closed-loop control of modern four-cylinder reciprocating diesel engines, in both conventional natural gas-diesel dual-fuel modes and in laboratory-controlled reaction compression ignition (RCCI), gas-diesel modes. However, these concepts are not common and do not adequately apply to other engine configurations, such as engines with fewer or more cylinders, engines with different fuel types, and non-reciprocating engines. The concepts disclosed herein are intended to be implemented beyond laboratory settings, in a built-in ECU.

[0059] According to the concept of this specification, combustion can be controlled on a per-cylinder and per-engine cycle basis by monitoring the cylinder pressure and engine shaft position (e.g., by a crank angle sensor and / or by other means), smoothing and averaging the pressure in the cylinder before and after an ignition event that represents an equal combustion chamber volume (e.g., the same cylinder position before and after top dead center), and comparing the averaged pressure difference before and after with a predetermined threshold from a measured specific volume indicating negative combustion quality. In some cases, the cylinder pressure measured during the compression and / or combustion stroke can be used by the ECU to modify the fuel timing and fuel supply amount in the subsequent compression and / or combustion stroke (e.g., the next cycle).

[0060] In some implementations, the sensed pressure is processed using vector central average smoothing before being used in algorithms to identify insufficient combustion events. According to embodiments herein, when the algorithm compares the exhaust stroke pressure to the compression stroke pressure at the same cylinder volume (see PV diagram), an equivolumetric state can usually be characterized as equal absolute values ​​of the engine crank angle relative to TDC (e.g., the smoothed pressure at 90° after TDC of the exhaust stroke compared to 90° before TDC of the compression stroke, and / or in other ways).

[0061] According to embodiments of this specification, the calculation of the pressure difference between the expansion stroke and the compression stroke is input into an algorithm used to determine whether each combustion event is "good" or "bad".

[0062] Some embodiments of this specification include a method using continuous monitoring of the cylinder pressure of each cylinder. This method compares the pressure during the combustion stroke with the pressure during the compression stroke at the same engine crank angle. Embodiments of this specification include a method for selecting 1 to 5 key crank angles for comparison. In some cases, the key crank angles are preset, and in some cases, the key crank angles change during operation. Embodiments of this specification include using appropriate smoothing and averaging of the pressure signal to reduce the influence of noise on the pressure trace. Embodiments of this specification include triggering an alarm state signal when an insufficient combustion event is detected by the ECU, which enables the main ECU or main engine control algorithm to shut off fuel and ignition combustion to protect the engine and avoid exhaust explosions of engine ignition.

[0063] In some cases, the concepts herein include dual-fuel diesel-ammonia gas engines that identify IMEP and combustion center of gravity (CA50) using cylinder pressure monitoring as a primary method based on novel functions such as heat release, while monitoring and control can also be performed using more conventional pressure-only methods, such as the magnitude and location of peak pressure, while adjusting ignition and fuel supply to balance the cylinder and safely keep the peak pressure below the engine's design limits. One such in-cylinder pressure measurement and combustion metrics calculation system is disclosed in U.S. Patent Application No. 15 / 099,486, “Combustion Pressure Feedback-Based Engine Control with Variable Resolution Sampling Window.” Combustion parameters such as combustion start position (SOC or CA10), combustion center (CA50), rate of pressure rise (RPR), and maintaining Pmax below engine limits are provided to the engine controller and can then be controlled.

[0064] In conventional ECU systems, memory and processor limitations may sometimes limit pressure trace analysis to customized information directly linked to the engine control strategy, with the processor for identifying combustion metrics being integrated into the same device as a remnant of the engine control unit. In implementations with limited memory or processor, conventional ECU systems may select only a small fraction of combustion metrics and use surrogate analysis that serves only one type of pre-designed engine control objective, but this is not common.

[0065] In some examples of this ECU system, the system converts high-speed cylinder pressure data into meaningful low-speed data, notifying the user of the engine's operating status (e.g., whether combustion is sufficient or insufficient) even within a small number of engine cycles or a single cycle, and providing stable and reliable smart sensor input to the ECU, thereby achieving the following advantages. In some cases, the pressure data supplied to the ECU system also enables engine protection through appropriate actuator changes, providing overpressure (Pmax) protection, rate of pressure rise (RPR) protection, and knock detection. In some cases, the ECU system calculates combustion quality metrics to identify the above actuator changes (e.g., ignition timing, in-cylinder injection and port injection timing and duration, AFR control, throttle position).

[0066] In some cases, a system is incorporated into the built-in controller that communicates directly with the main controller or via a Controller Area Network (CAN) link with minimal time delay. Alternatively, one or more of the combustion quality detection methods described above may be executed directly on the ECU's main processor, assuming sufficient computing power is available.

[0067] In some cases, engine control systems are configured to improve the knock margin of ammonia engines, improve the maximum ammonia-to-diesel fuel substitution rate in ammonia-diesel dual-fuel applications, and precisely control the combustion phasing of cold combustion (LTC) strategies such as premixed compression ignition (HCCI), reactivity-controlled compression ignition (RCCI), and premixed-filled compression ignition (PCCI), thereby improving efficiency with equal emissions or engine reliability within all engine protection limits.

[0068] Referring first to Figure 2, an engine system 200 is shown as an example of the system. In some implementations, engine system 200 may be an example of engine system 100 in Figure 1. Engine system 200 includes an engine control unit 202, an air / fuel module 204, an ignition module 206, and an engine (indicated here as a reciprocating engine) 201. Figure 2 shows, for example, an internal combustion engine 200. For the purposes of this disclosure, engine system 200 is described as a gaseous fuel reciprocating piston engine. In certain examples, the engine operates on ammonia fuel. The engine may be any other type of combustion engine in terms of both the type of fuel (gaseous (e.g., ammonia, natural gas, hydrogen), liquid (e.g., gasoline, diesel fuel, and / or others), in-phase or mixed-phase multi-fuel and / or other configurations) and the physical configuration of the engine (e.g., reciprocating, Wankel rotary, and / or other configurations). Although the engine control unit 202, air / fuel module 204, and ignition module 206 are shown separately, modules 202, 204, and 206 can be combined into a single module or be part of an engine controller with other inputs and outputs.

[0069] The reciprocating engine 201 includes an engine cylinder 208, a piston 210, an intake valve 212, and an exhaust valve 214. Engine 201 includes an engine block containing one or more cylinders 208 (only one is shown in Figure 2). Engine 200 includes a combustion chamber 260 formed by the cylinder 208, the piston 210, and the head 230. The ignition device 220 is positioned within the head 230 to allow the ignition device 220 to access the combustible mixture. Generally, the term “ignition device” can refer to a direct fuel injection device in a pre-chamber and / or a spark plug or other ignition device. In the case of a spark plug, the spark gap 222 of the spark plug 220 is positioned within the combustion chamber 260. Other types of ignition devices may be used, such as compression ignition, laser ignition, hot surface ignition, and / or other types of ignition devices. The piston 210 in each cylinder 208 is movable from the top dead center (TDC) position to compress the combustible mixture filler as a gas or gas / liquid mixture in the compression phase, and from the bottom dead center (BDC) position to expand the combustion gases in the expansion phase. The engine 200 includes a crankshaft 240 that connects each piston 210 so that the piston 208 in each cylinder 208 moves between the TDC and BDC positions, rotating the crankshaft 240. The TDC position is the position of the piston 210 where the combustion chamber 260 has the minimum volume (i.e., the position where the piston 210 is closest to the spark plug 220 and the top of the combustion chamber 260), and the BDC position is the position of the piston 210 where the combustion chamber 260 has the maximum volume (i.e., the position where the piston 210 is furthest from the ignition device 220 and the top of the combustion chamber 260).

[0070] The cylinder head 230 defines an intake passage 231 and an exhaust passage 232. The intake passage 231 leads air or an air-fuel mixture from the intake manifold 216 to the combustion chamber 260. The exhaust passage 232 leads exhaust gases from the combustion chamber 260 to the exhaust manifold 218. The intake manifold 216 communicates with the cylinder 208 via the intake passage 231 and the intake valve 212. The exhaust manifold 218 receives exhaust gases from the cylinder 208 via the exhaust valve 214 and the exhaust passage 232. The intake valve 212 and the exhaust valve 214 are controlled via the valve drive assembly of each cylinder. This is controlled electronically, mechanically, hydraulically or pneumatically, or via a camshaft (not shown).

[0071] The movement of the piston 210 between the TDC position and BDC position within each cylinder 208 defines the intake stroke, compression stroke, combustion or power stroke, and exhaust stroke. The intake stroke is the movement of the piston 210 away from the ignition device 220 with the intake valve 212 open, drawing the fuel / air mixture into the combustion chamber 260 through the intake passage 231. The compression stroke is the movement of the piston 210 toward the ignition device 220 with the air / fuel mixture entering the combustion chamber 260, with both the intake valve 212 and the exhaust valve 214 closed, allowing the piston 210 to move and compress the fuel / air mixture in the combustion chamber 260. The combustion or power stroke is the movement of the piston 210 away from the ignition device 220, which occurs after the combustion stroke when the combustible air / fuel mixture is ignited. The ignited fuel / air mixture burns, rapidly increasing the pressure in the combustion chamber 260 and adding an expansion force to the movement of the piston 210 away from the ignition device 220. The exhaust stroke is the movement of the piston 210 toward the ignition device 220 after the combustion stroke, opening the exhaust valve 214 and allowing the piston 210 to discharge the combustion gases into the exhaust manifold 218 through the exhaust passage 218.

[0072] Engine 200 includes a fuel supply system 224, such as a fuel injector, gas mixer, or other fuel supply device, to deliver ammonia fuel to the intake manifold 216 or directly to the combustion chamber 260. In some cases, the engine system 200 may also include another type of internal combustion engine 201 without pistons / cylinders, such as a Wankel engine (i.e., an engine with a rotor inside the combustion chamber).

[0073] During engine operation, i.e., during combustion events in combustion chamber 260, the air / fuel module 204 supplies ammonia fuel to the airflow entering the intake manifold before it enters the combustion chamber 260. The ignition module 206 controls the ignition of the air / fuel mixture in combustion chamber 260 by adjusting the timing of diesel fuel injection into combustion chamber 260, thereby initiating combustion of the fuel / air mixture in combustion chamber 260 during a series of ignition events between each successive compression stroke and combustion stroke of the piston 210. During each ignition event, the ignition module 206 controls the ignition timing and supplies power to the ignition device 220. The air / fuel module 204 controls the fuel injector 224 and the throttle valve 226 to supply air and fuel to the engine cylinder 208 in a target ratio. The air / fuel module 204 receives feedback from the engine control module 202 to adjust the air / fuel ratio. The ignition module 206 controls the ignition device 220 by controlling the flow of current from a power source (e.g., alternator, battery). In addition to the embodiments of the system disclosed below, the ECU 202 adjusts the operation of the ignition module 206 based on engine speed and load.

[0074] In some cases, the ECU 202 includes the ignition module 206 and the fuel / air module 204 as an integrated software algorithm executed by the ECU 202's processor, thereby operating the engine as a single hardware module in response to inputs received from one or more sensors (not shown) that may be located throughout the engine. In some cases, the ECU 202 includes separate software algorithms corresponding to the described operation of the fuel / air module 204 and the ignition module 206. In some cases, the ECU 202 includes individual hardware modules that assist in realizing or controlling the described functions of the fuel / air module 204 and the ignition module 206. For example, the ignition module 206 of the ECU 202 may include an ASIC for regulating the current supply to the ignition device 220. Multiple sensor systems exist for monitoring the operating parameters of the engine 200, including, for example, a crankshaft sensor, engine speed sensor, engine load sensor, intake manifold pressure sensor, cylinder pressure sensor, etc. Generally, these sensors generate signals in response to the engine's operating parameters. For example, the crankshaft sensor 271 reads and generates a signal indicating the angular position of the crankshaft 240. In an exemplary embodiment, a high-speed pressure sensor 272 measures the cylinder pressure of the engine 200 during operation. Sensors 271, 272 may be directly connected to the ECU 202 to facilitate sensing, or, in some cases, integrated with a Real-Time Combustion Diagnostics and Control (RT-CDC) unit configured to acquire high-speed data from one or more sensors and provide low-speed data output to the ECU 202. In some cases, the ignition control described herein is a standalone ignition control system that provides the operation of the ECU 202 and the ignition module 206. Sensors may be integrated into the ECU 202 or one of the control modules such as the RT-CDC. Other sensors are also possible, and the system described herein may include multiple sensors to facilitate sensing of the engine operating parameters described above.

[0075] Figure 3 is an enlarged cross-sectional view of cylinder 308 of internal combustion engine 301. In some embodiments, engine 301 may be a modification of engine 201 illustrated in Figure 2.

[0076] Engine 301 includes an engine cylinder 308, a piston 310, an intake valve 312, and an exhaust valve 314. Engine 301 includes an engine block containing one or more cylinders 308 (only one is shown in Figure 3). Engine 301 includes a combustion chamber 360 formed by a cylinder 302, a piston 310, and a head 330.

[0077] A port fuel injector (not shown) supplies ammonia gas fuel to the intake plenum 313 upstream from cylinder 308. A direct fuel injector 320 is positioned within the head 330 and supplies diesel fuel for combustion. In some implementations, such as when direct injection is used instead of port injection, the direct fuel injector 320 may also include a direct injector for ammonia fuel. A piston 310 in each cylinder 308 moves between a top dead center (TDC) position and a bottom dead center (BDC) position. The piston 308 moves between the TDC and BDC positions in each cylinder 308, rotating the crankshaft. The TDC position is the position of the piston 310 where the combustion chamber 360 has the minimum volume (i.e., the position where the piston 310 is closest to the direct fuel injector 320 and the top of the combustion chamber 360), and the BDC position is the position of the piston 310 where the combustion chamber 360 has the maximum volume (i.e., the position where the piston 310 is furthest from the spark plug 320 and the top of the combustion chamber 360).

[0078] The piston 310 has a surface 390. A piston bowl 392 of a predetermined shape is defined on the piston 310 and opens at the surface 390. The shoulder 394 is defined at the boundary between the piston surface 390 and the piston bowl 392. A crevice 396 is defined between the piston 310 and the cylinder 308.

[0079] The direct fuel injector 320 is configured to spray a conical jet 380 of fuel (e.g., diesel) into the combustion chamber 360. The direct fuel injector 320 is configured so that the conical jet 380 is dispersed at an angle 382 of approximately 50° to 70°. This differs from conventional spray patterns, which typically have dispersion angles of 120° to 140°. In some implementations, the direct fuel injector 320 may include one or more nozzles (e.g., 4 to 8 individual nozzles) configured to spray diesel fuel into the combustion chamber 360. In some implementations, the conical jet 380 may be supplied by multiple injector nozzles, each of which is configured to spray a portion of the conical jet 380.

[0080] The conical jet 380 is configured to direct fuel toward the shoulder 394 when the piston is in a predetermined position during the compression stroke. In some implementations, the impact of fuel on the shoulder 394 may improve the distribution of diesel particles. For example, diesel particles in the crevice region can help burn ammonia in the crevice region, reducing ammonia slip (by initiating combustion starting with diesel vapor from vaporized diesel droplets in the crevice region, for example). In another example, diesel particles in the piston bowl 392 can help improve the combustion rate by adding highly reactive diesel vapor to a less reactive ammonia-air mixture, for example. In yet another example, the injection time and angle 382 may be configured to bring the resulting air / fuel mixture closer to the auto-ignition conditions at TDC. In yet another example, auto-ignition can be controlled by the injection time. Early injection can evaporate diesel droplets and mix them with ammonia, while late injection can provide a more layered lambda. During compression, diesel droplets evaporate, and their vapors mix with air to provide a spectrum of the air-fuel mixture (e.g., lambda distribution), where the zone most likely to ignite is close to the stoichiometric mixture ratio (e.g., lambda 1.0), surrounded by other regions that are too rich or too lean. When early injection is used, most of the mixture is well mixed and therefore lean, but with later injection, there is more of a zone that is not well mixed (e.g., layered), making autoignition more likely. In another example, the ignition and angle 382 can be configured so that engine 301 can run at a high compression ratio and with high efficiency.

[0081] Figure 4 shows Chart 400 as an example of cylinder stroke. Chart 400 shows line 410 representing an example of combustion chamber pressure as a function of crank angle in an engine configured to use direct injection of ammonia and diesel fuel. In some implementations, Chart 400 can represent an example of cylinder pressure in an example of engine system 100 in Figure 1, an example of engine system 200 in Figure 2, or an example of engine 301 in Figure 3.

[0082] At a crank angle of approximately -360° just before top dead center (TDC), exhaust valve occlusion (EVC) 420 occurs, and the intake stroke 422 begins. As air is drawn into the cylinder, the pressure 410 remains low. At a crank angle of approximately -320°, ammonia injection 424 begins. Bottom dead center (BDC) 426 occurs at -180°, ending the intake stroke 422 and beginning the compression stroke 440. Intake valve occlusion (IVC) also occurs near BDC, effectively sealing the compression chamber.

[0083] As the compression stroke 440 begins, the pressure 410 slowly starts to rise. At a predetermined crank angle (e.g., approximately -70° in the illustrated example), a first pulse 442 of diesel fuel is injected into the combustion chamber, preparing an air / fuel mixture close to autoignition. In some implementations, the timing and / or placement of the first pulse 442 may be based on variable inputs such as the pressure 410 (e.g., measured by a high-speed pressure sensor 272 in the cylinder), measured air pressure / density, measured air temperature, fuel parameters, or a combination thereof, and / or other appropriate variables or parameters that may affect combustion. In some implementations, the predetermined crank angle may be based on engine operating parameters such as engine load, engine speed, or a combination thereof, and other appropriate operating conditions.

[0084] As the compression stroke 440 continues, the pressure 410 continues to rise. At a given crank angle (e.g., approximately -8° in the illustrated example, and / or may be a function of engine load and / or speed), a second pulse 444 of diesel fuel is injected into the combustion chamber to initiate combustion and control CA50 (e.g., the crank angle at which 50% of combustion occurs), CA10 (e.g., the time of combustion initiation), and / or the NH3 / NOx ratio of the combustion cycle. In some implementations, the timing and / or placement of the second pulse 444 may be based on variable inputs such as pressure 410 (e.g., measured by an exemplary high-speed pressure sensor 272), measured air pressure / density, measured air temperature, fuel parameters, and combinations thereof, and / or other appropriate variables or parameters that may affect combustion. In some implementations, a change in the combustion phase (e.g., characterized by either CA10 or CA50) may change the NH3 / NOx ratio coming out of the engine. In some implementations, such a function can be implemented using a feedback mechanism that monitors NOx or NH3 emissions from the catalyst and adjusts the combustion phase accordingly to achieve a target ratio.

[0085] The compression stroke 440 is terminated at TDC 450 (e.g., 0°). Depending on the implementation, NH3 can be reduced using selective catalytic reduction (SCR) so that the NH3 / NOx ratio can be maintained slightly above 1 (e.g., >1 (plus or minus about 0.3), about 1 to about 1.2).

[0086] In practice, a predetermined crank angle may be based on engine operating parameters such as engine load, engine speed, or a combination thereof, and other appropriate operating conditions. In practice, the crank angle, fuel supply settings, and cylinder pressure used and identified in a combustion cycle may be processed to change the crank angle and fuel supply settings used in a subsequent (e.g., next) combustion cycle.

[0087] Figure 5 shows chart 500, an example of cylinder stroke. Chart 500 shows line 510, representing an example of combustion chamber pressure as a function of crank angle in an engine configured to use port injection of ammonia gas fuel. In some implementations, chart 500 can represent an example of cylinder pressure in an example of engine system 100 in Figure 1, an example of engine system 200 in Figure 2, or an example of engine 301 in Figure 3.

[0088] At a crank angle of approximately -360° just before TDC, exhaust valve blockage (EVC) 520 occurs, and the intake stroke 522 begins. As air is drawn into the cylinder, the pressure 510 remains low. At a crank angle of approximately -320°, ammonia injection 524 begins. BDC 526 occurs at -180°, ending the intake stroke 522 and starting the compression stroke 540. IVC also occurs near BDC, effectively sealing the compression chamber.

[0089] As the compression stroke 540 begins, the pressure 510 slowly starts to rise. At a predetermined crank angle (e.g., about -70° in the illustrated example), a first pulse 542 of diesel fuel is injected into the combustion chamber, preparing an air / fuel mixture close to autoignition. In some implementations, the timing and / or placement of the first pulse 542 may be based on variable inputs such as (e.g., pressure 510 as measured by the high-speed pressure sensor 272), measured air pressure / density, measured air temperature, fuel parameters, and combinations thereof, and / or other appropriate variables or parameters that may affect combustion. In some implementations, the predetermined crank angle may be based on engine operating parameters such as engine load, engine speed, or combinations thereof, and other appropriate operating conditions.

[0090] As the compression stroke 540 continues, the pressure 510 continues to rise. At a predetermined crank angle (for example, about -8° in the illustrated example, and / or may be a function of engine load and / or speed), a second pulse 544 of diesel fuel is injected into the combustion chamber to initiate combustion, controlling CA50 and the NH3 / NOx ratio of the combustion cycle. In some implementations, the timing and / or placement of the second pulse 544 may be based on variable inputs such as pressure 510 (measured by a high-speed pressure sensor 272), measured air pressure / density, measured air temperature, fuel parameters, and combinations thereof, and / or other appropriate variables or parameters that may affect combustion.

[0091] The compression stroke 540 is terminated at TDC 550 (e.g., 0°). Depending on the implementation, NH3 can be reduced using selective catalytic reduction (SCR) so that the NH3 / NOx ratio can be maintained slightly above 1 (e.g., >1, approximately 1 to approximately 1.2).

[0092] In some implementations, a predetermined crank angle may be based on engine operating parameters such as engine load, engine speed, or a combination thereof, and other appropriate operating conditions. In some implementations, the crank angle, fuel supply settings, and cylinder pressure used and identified in the combustion cycle may be processed to change the crank angle and fuel supply settings used in subsequent (e.g., the next) combustion cycles.

[0093] Figure 6 is a schematic diagram of an example of the engine control system 600. In some implementations, the engine control system 600 may be all or part of the example of the engine control system 202 in Figure 2. Figure 6 shows the ECU 602 within the engine control system 600 configured to control the engine 601. As described above, high-speed pressure data 672 is generated by pressure sensors 672, each mounted to have direct access to the combustion chamber. The pressure signal 673 is captured at a high crank synchronization rate, such as a resolution of 0.25° or 2880 samples per cycle of the engine 601. In some implementations, this composite crank angle signal can be generated from a low-resolution crank position signal. For example, in a typical crank angle encoder 671 that generates a crank angle signal 615 by sensing the passage of the edges of teeth on a disk, the disk is mounted to rotate with the crank, and the resolution of the crank position is based on the number of teeth. The resolution of a typical 60-2 tooth wheel is 6°. However, in some cases, interpolation can be used to determine the crank angle in the space between edges. Thus, the spacing between edges can be calculated by dividing the previously observed tooth period by the number of edges required to achieve the desired angular sampling resolution. The encoder system can be resynchronized at each edge to account for slight variations between crank teeth that may be observed even at a constant average engine speed.

[0094] In some cases, the resulting high-resolution pressure signal 673 can be used by the combustion analysis routine of the ECU 602 to generate combustion analysis 619 on a per-cylinder, per-cycle basis, e.g., IMEP, Pmax, CA50, NOx emissions, NH3 emissions, and combustion quality (e.g., good combustion, poor combustion, misfire). The metrics 619 are then used as feedback signals by the ECU 102 to adjust key combustion performance characteristics by adjusting the engine control actuator settings 619. In an exemplary embodiment, the crank angle signal 615 is used to analyze the pressure signal 673 during each combustion event at pre-TDC and post-TDC crank angles (e.g., two equal main combustion chamber volumes) to determine whether the combustion event in the main combustion chamber of the engine 601 indicates poor combustion or misfire based on the difference between the two pressure signals and a threshold value associated with the sampled crank angle or range of crank angles.

[0095] In conventional (non-LTC) dual-fuel operation, combustion phase is a critical factor for efficiency, emissions, and knock margin. Good control of combustion phase can significantly improve the maximum gas replacement rate. Since not all engine variables (e.g., manifold absolute temperature (MAT), manifold absolute pressure (MAP), and injection rail pressure) can be kept within tight tolerances, the typical open-loop method of controlling combustion phase can be greatly enhanced by certain feedback mechanisms.

[0096] Reactivity-controlled compression ignition (RCCI) is one of many LTC strategies to dramatically reduce NOx production while simultaneously achieving rapid combustion of lean mixtures and improving efficiency. In RCCI, two fuels with different responsiveness are introduced early into the combustion chamber, and the phase of combustion initiation and combustion speed are adjusted. In gas-diesel RCCI, natural gas is injected into the intake port and diesel fuel is injected directly into the combustion chamber. Using a diesel common rail, it is possible to inject diesel fuel at various times and amounts up to the limits of the injection system. Typically, diesel fuel is injected much earlier than in conventional diesel fuel or gas-diesel dual fuel, from immediately after intake valve closure (IVC) to 70° before top dead center (BTDC, where TDC is the crank position when the piston is at its highest point in the cylinder). Furthermore, the sign of the "gain" switch is the opposite of diesel and dual-fuel combustion in RCCI, where earlier timing of diesel fuel results in a later combustion phase, and earlier timing of diesel fuel results in an earlier combustion phase.

[0097] Figure 7 is a schematic half-cross-sectional view showing an example of a gas mixer 700. In some embodiments, the gas mixer 700 may be an example of the ammonia gas injector 114 in Figure 1. The gas mixer 700 includes a gas housing 702 defining a mixing chamber 704 having an air passage 705. The mixing chamber 704 is configured as a convergence-divergence nozzle 706 having a conical convergence portion 708a into which the air passage 705 constricts and a conical divergence portion 708b into which the air passage 705 expands to an outlet 710. In some embodiments, the outlet 710 can be fluidly coupled to an intake manifold, such as an example of the intake manifold 104 in Figure 1.

[0098] The gas mixer 700 includes an air inlet 712 to a convergence-divergence nozzle 706. In some embodiments, the air inlet 712 can be fluidically coupled to an intake plenum, such as the intake plenum 103 in Figure 1. A conical convergence section 708a defines an air nozzle for the incoming airflow. Generally, air flows along the airflow path 705, through the air inlet 712 upstream of the convergence-divergence nozzle 706, converges in the conical convergence section 708a, expands in the conical divergence section 708b, and exits through the outlet 710. The conical convergence section 708a converges in the direction of flow toward the convergence end. That is, the downstream end (outlet) of the conical convergence section 708a has a smaller cross-sectional area (e.g., a smaller flow area) than the upstream end (air inlet 712). The conical divergence portion 708b diverges in the direction of flow toward the proximal divergence end of the outlet 710. In other words, the downstream end (outlet 710) of the conical divergence portion 708b has a larger cross-sectional area (e.g., a smaller flow area) than the upstream end.

[0099] The narrowing of the conical converging section 708a increases the velocity of the airflow as it passes along the airflow channel 705. In the conical diverging section 708b, the cross-sectional area of ​​the flow channel increases along the airflow channel 705. The increase in cross-sectional area slows the velocity and increases the pressure of the fluid flow. In certain examples, the increase in cross-sectional area can be such that it increases the pressure within the gas mixer 700 so that the pressure drop across the entire gas mixer 700 is zero, very small, or otherwise small. In some implementations, the converging-diverging nozzle 706 may include a threaded or other form of detachable fitting (e.g., a hose clamped around a flange) at the inlet 712, the outlet 710, or both, and this converging-diverging nozzle 706 is attached to the rest of the intake of the engine system 100 and fluidly coupled. Similarly, in some implementations, the cone-converging portion 708a and the cone-diverging portion 708b can be modularly interchangeable with each other and / or gas nozzles 730 of different shapes and configurations to allow the system to be easily modified to suit multiple engine applications.

[0100] The gas mixer 700 includes a gas nozzle 720 and a gas inlet 722. The gas inlet 722 is configured to receive a flow of secondary gas (such as EGR gas) and define a secondary gas flow path 726 via the gas nozzle 720. The gas nozzle 720 is positioned parallel and central to the air flow path 705 and is configured to supply secondary gas (e.g., flowing along the secondary gas flow path 726) to the air flow path 705 in the converging portion 708a of the converging-diverging nozzle 706, upstream from the diverging portion 708b. The gas nozzle is configured to define a secondary gas flow that is complementary (e.g., cooperative and substantially parallel) to the air flow along the air flow path 705.

[0101] In some implementations, the gas nozzle 706 is modularly interchangeable with gas nozzles 706 of different shapes, allowing the system to be easily modified to suit multiple engine applications. For example, the gas nozzle 706 may be equipped with threaded or other form of detachable fittings on the rest of the gas housing 702. The illustrated example shows the conical converging section 708a, the conical diverging section 708b, and the gas nozzle 706 aligned on the same central axis, but in some implementations these elements may not be aligned or parallel. For example, space constraints may necessitate that the gas mixer 700 have an angle between the axes of the converging section 708a and the conical diverging section 708b. In some implementations, the flow path may be curved rather than having a substantially straight flow path, as shown in Figure 7.

[0102] The gas mixer includes a fuel inlet 730 configured to receive fuel (e.g., ammonia) from a fuel supply device such as the exemplary fuel supply device 130 in Figure 1. The fuel inlet 730 is fluidically coupled to a collection of fuel inlet tubes 732a and 732b. The fuel inlet tubes 732a and 732b are configured as fuel nozzles that supply fuel into a second flow path upstream of the converging nozzle, supplying fuel to the secondary gas flow path 726. The fuel inlet tube 732a is positioned parallel to the second flow path and is centrally located. The fuel inlet tube is configured to supply fuel to the secondary gas flow path 726 upstream of the gas nozzle 720. The fuel inlet tube 732b is positioned near the inner circumference of the gas nozzle 720 and is configured to supply fuel to the secondary gas flow path 726 near the outlet of the gas nozzle 720. The fuel inlet tubes 732a and 732b are configured to define a fuel flow that is complementary (e.g., coordinated, substantially parallel) to the secondary gas flow along the secondary gas passage 726. In some implementations, the fuel can be received at high pressure (e.g., liquefied natural gas at 4–12 bar). As the fuel exits the fuel inlet tubes 732a and 732b, the fuel flow facilitates the secondary gas flow.

[0103] In some implementations, the fuel inlet 730 may be a gaseous fuel inlet coupled to a gaseous fuel source, provided that the fuel supplied by the fuel inlet 730 includes a combustible fluid such as natural gas, gasoline, or diesel. Although the fuel inlet 730 is shown as a single tube, it can be configured, for example, as a through-hole intersecting the flow region of the mixer, as a fuel supply hole along the periphery of the flow region, or in other ways. The illustrated example shows fuel inlet tubes 732a, 732b configured to inject fuel upstream of the diverging section 708b, but fuel can also be added using a fuel supply port upstream of the air inlet 712 or the secondary gas inlet 722. Such a port may include a gaseous fuel supply port. In some cases, the fuel can be supplied at high speed, up to a speed including a sonic flow, at the outlet of the fuel inlet tubes 732a, 732b, so as to generate a fuel-gas jet pump, and the fuel can flow into the nozzle 720 and provide additional thrust to the secondary gas flow 726 passing through the nozzle 720. In such examples, higher pressure can generate a supersonic jet that can further enhance the fuel-air mixture. Depending on the implementation, this may reduce the need for a fuel pressure regulator. Furthermore, if the fuel jet is cooled by the Joule-Thomson effect, this cooling effect cools the air / fuel flow and thus can reduce the magnitude and / or need for intake cooling (e.g., intercooler 120).

[0104] In some embodiments, the fuel inlet 730 may be a high-pressure fuel inlet. For example, a high-pressure gaseous fuel (e.g., NH3, H2, methanol, or other low-carbon fuel at a gas pressure of 10 to 500 bar) can be supplied through the fuel inlet tubes 762a, 762b to help accelerate the airflow. In another embodiment, a liquefied gaseous fuel (e.g., NH3, liquefied natural gas, H2) can be heated under liquid conditions and then supplied through the fuel inlet tubes 762a, 762b, and the heat addition increases the pumping effect, as the liquefied gaseous fuel can be injected into the air or EGR flow and "flashed" to form a very high-speed (e.g., supersonic) jet.

[0105] Depending on the implementation, the gas mixer 700 can be used in an alternative configuration. For example, EGR is not typically used in diesel engine applications. However, other gases, such as ammonia, can be supplied as a secondary gas at the gas inlet 722 and combined with the diesel fuel flowing through the fuel inlet tubes 732a and 732b to facilitate air intake. In a specific example, ammonia could be supplied at 50 bar and mixed in the gas mixer 700 to create a stoichiometric mixture (e.g., 15% ammonia and 85% air).

[0106] The gas mixer 700 also includes a check valve 760 with two gas inlets. The check valve 760 includes gas inlets 762a and 762b. Gas inlet 762a is configured to receive secondary gas (e.g., EGR) from a first source, such as an exemplary EGR passage 108a. Gas inlet 762b is configured to receive secondary gas (e.g., EGR) from a different second source, such as an exemplary EGR passage 108b. In some implementations, gas inlets 762a, 762b, gas inlet 722, or any of these may include threaded or other form of detachable fittings (e.g., hoses clamped around a flange) to mount the check valve 760 and allow fluid coupling to the rest of the EGR system of the engine system 100.

[0107] In some implementations, the gas mixer 760 can be fluidically coupled to an engine system configured such that a secondary gas (e.g., EGR) flows as pulses alternating between gas inlets 762a and 762b. For example, gas inlet 762a is fluidically connected to a first cylinder, and gas inlet 762b is fluidically connected to a different second cylinder, configured to discharge the first cylinder and not discharge the second cylinder, or vice versa.

[0108] The check valve 760 also includes a valve 764. Valve 764 is configured as a flapper valve in which a pivot valve, which allows the gas flow through one of the gas inlets 762a and 762b to push open the valve body relative to the flowing gas inlet and shut off the other, prevents backflow from gas inlet 762a to gas inlet 762b and from gas inlet 762b to gas inlet 762a. Valve 764 is a flapper valve as illustrated in the example, but other types of backflow prevention valves, such as check valves, may also be used.

[0109] The gas nozzle 720 is configured to provide a high-speed gas path. The second gas passage 726 is aerodynamically efficient to maintain high speed (e.g., from exhaust manifolds 106a, 106b). This allows for full total pressure (e.g., static pressure + dynamic pressure due to velocity) of the secondary gas flow. The fuel flow through the fuel inlet tubes 732a, 732b adds additional thrust to the secondary gas flow along the secondary gas passage 726. The secondary gas (e.g., EGR) and fuel combine to form a coupled primary jet, causing an intake of air flowing along the air passage 705. This is the reverse of a conventional jet pump where air and fuel are coupled as a primary flow to guide the secondary (e.g., EGR) gas flow. The advantage of the illustrated example is that the pulsating motion of the secondary gas along the secondary gas passage 726 accelerates the intake of air from the air inlet 712. In implementations where the airflow is also pumped at its own high speed, such as by the exemplary compressor 122 in Figure 1, the airflow can also provide a complementary reduction in suction pressure, as seen in the gas path, and both flows can help to promote the other flow.

[0110] Depending on the implementation, the gas mixer 700 can improve engine performance. For example, by using the fuel flow and secondary gas flow to accelerate, pressurize, or otherwise enhance the airflow, the amount of compressor work required from the turbine 122 to move the same amount of air can be reduced. Reducing the amount of work required by the turbine 122 reduces the amount of back pressure in the exhaust manifolds 106a, 106b, thereby reducing power loss due to the pumping work performed by the pistons during the exhaust stroke. The gas mixer 700 enables the use of high levels of EGR up to approximately 30%. Using the gas mixer 700 allows the efficiency of an EGR engine at a stoichiometric mixture ratio to approach that of a lean engine, while enabling the use of TWC, resulting in near-zero emissions.

[0111] During use, the gas nozzle 720 and the conical convergence section 708a increase in velocity and decrease in air pressure along the air passage 705 within the gas mixer 700. Air is drawn into the gas mixer 700 along the air passage 705 through the air inlet 712 in response to (for example, due to) the pressure drop in the secondary gas ejection flow leaving the gas nozzle 720. The secondary gas is guided along the secondary gas passage 726 (for example, from the exhaust manifolds 106a and 106b) to a point downstream of the conical convergence section 708a. The airflow, secondary gas flow, and fuel flow are mixed to form a combustion mixture. The pressure of the combustion mixture increases, and the velocity of the combustion mixture decreases in the conical divergence section 708b.

[0112] Figure 8 shows Chart 800, an example of gas concentrations resulting from the in-cylinder combustion of ammonia. In some implementations, Chart 800 may be a chart of gas concentrations resulting from combustion in the exemplary engine system 100 shown in Figure 1.

[0113] Chart 800 shows gas concentrations by weight relative to the engine crank angle. The illustrated gas concentrations include NH3 (ammonia) represented by line 810, nitric oxide (NO) represented by line 820, and nitrogen dioxide (NO2) represented by line 830. As Chart 800 shows, when ammonia is used as fuel, NH3 levels start at high pre-combustion levels (e.g., 0.001 kg), while NO and NO2 levels are close to zero. At the start of combustion, around -8°TDC in the illustrated example, as indicated by arrow 850, NH3 levels begin to decrease as they burn with oxygen, and as a result, the levels of the combustion byproduct NO simultaneously increase.

[0114] As combustion continues, the available oxygen is depleted, the combustion rate slows down, and the rate of change in the amounts of NH3 and NO in the cylinder also slows down, eventually stabilizing at approximately 0.0003 kg of NO and 0.0008 kg of NH3. These gases, at the resulting concentrations, are ultimately released from the cylinder as exhaust gas during the exhaust stroke. The remaining NH3 in the exhaust gas is commonly called "ammonia slip." Both NO and NH3 are generally considered pollutants, and many jurisdictions have regulations that limit the amount of these gases that can be allowed as exhaust gases (tailpipe emissions).

[0115] Figure 9 is a schematic cross-sectional view showing an example of a diesel aftertreatment system 900. In some embodiments, the exhaust aftertreatment system 900 may be an example of the exhaust aftertreatment system 150 shown in Figure 1. In some embodiments, the exhaust aftertreatment system 900 may be a catalytic converter system.

[0116] The illustrated exhaust aftertreatment system 900 is configured to receive exhaust 901 from the engine (for example, gases expelled from the engine cylinders during the exhaust stroke) and reduce the amount of various pollutant gases before they exit as exhaust gas 902. The exhaust 901 from the engine contains gases such as carbon monoxide (CO), hydrocarbons (HC), NOx, particulate matter (PM), carbon dioxide (CO2), water (H2O), and diatomaceous nitrogen (N2). The purpose of the operation of the exhaust aftertreatment system 900 is to substantially remove everything except CO2, H2O, and N2 before it exits as exhaust gas 902.

[0117] The exhaust aftertreatment system 900 includes several treatment sections. A diesel oxidation catalyst (DOC) filter 910 is provided to reduce CO, HC, and PM emissions. For example: 2CO2 + O2 → 2CO2 [HC] + O2 → CO2 + H2O 2NO2 + O2 → NO2

[0118] A catalytic soot filter (CSF) 920 is provided to collect PM and suppress CO emissions during the combustion of the collected PM. Cleaning of carbon PM from the SCF 920 (e.g., regeneration of a diesel particulate filter (DPF)) can be performed actively and / or passively. For example: (active)C+O2→CO2 (passive)C+2NO2→CO2+2NO

[0119] The selective catalytic reduction (SCR) filter 930 uses a reducing agent (e.g., ammonia) and a catalyst to trigger a chemical reaction that converts NOx into nitrogen, water, and a small amount of CO2. For example: 4NH3 + 4NO + O2 → 4N2 + 6H2O 4NH3 + 2NO + 2NO2 → 4N2 + 6H2O 8NH3 + 6NO2 → 7N2 + 12H2O

[0120] An ammonia slip catalyst (ASC) filter 940 is provided to convert residual ammonia (e.g., ammonia slip) into nitrogen and water. For example: [NH3]→N2+H2O NOx + NH3 → N2 + H2O

[0121] In typical diesel applications (e.g., non-dual-fuel), the reducing agent used in the SCR filter 930 is high-grade urea, commonly known as diesel exhaust flow (DEF), which needs to be supplied to the SCR filter 930. When heated by the high-temperature exhaust gas, DEF vaporizes and decomposes into ammonia and carbon dioxide. Ammonia acts as a reducing agent to reduce NO and NO2 levels. However, excess ammonia (e.g., ammonia slip) is also commonly regulated as a pollutant. The excess ammonia provided by DEF is then reduced by the ASC filter 940. For example: 4NH3 + 3O2 → 2N2 + 6H2O

[0122] Of note in the illustrated example of the diesel aftertreatment system 900 is the omission of the urea (e.g., DEF) mixer at position 950. Since the ammonia required for the SCR filter 930 can be obtained from the exhaust gas 901 from the engine, the diesel aftertreatment system 900 is configured without the urea mixer 950. In a dual-fuel ammonia-diesel engine, such as the example of engine system 100 in Figure 1, when ammonia is used as fuel, an ammonia slip may inherently remain in the exhaust gas, as described in the explanation of Figure 8. Such inherent ammonia slip can be used as part or all of the reducing agent required for the SCR filter 930, reducing or eliminating the need for the DEF and / or urea mixer in the diesel aftertreatment system 900. Any excess ammonia remaining after treatment by the SCR filter 930 is reduced by the ASC filter 940. The ASC filter is included to reduce or remove NH3 remaining after use in the NOx reaction and is appropriately sized.

[0123] Furthermore, combustion can be controlled (e.g., by the ECU 202 and / or air / fuel module 204 illustrated in Figure 2) to generate a predetermined amount of ammonia slip so that the SCR can reduce NOx levels to below a target amount (e.g., as established by government regulations). For example, in some cases, the amount of ammonia slip in the exhaust 901 from the engine may be insufficient for the full functioning of the SCR filter 930. This may result in excess exhaust gas of NO and NO2. In such cases, the mixing and combustion of ammonia and diesel can be intentionally controlled to increase the amount of ammonia slip, if necessary to provide a sufficient amount of ammonia for use in the SCR filter 930. In other words, ammonia fuel can also be used as a reducing agent in the catalytic process, reducing or eliminating the need for the DEF and / or urea mixer in the diesel aftertreatment system 900. Any excess ammonia remaining after processing by the SCR filter 930 is reduced by the ASC filter 940. The ASC filter is included to reduce or remove any NH3 remaining after use in the NOx reaction and can be appropriately sized.

[0124] Figure 10 is a chart showing an example of NOx formation due to fuel combustion in air (e.g., NOx in an example exhaust 901 from an exemplary engine in Figure 9, from an example engine 201 in Figure 2). NOx generation by combustion is a function of both lambda (e.g., excess air ratio) and temperature. NOx concentration is represented by the line 10¹⁰ and temperature by the line 10²⁰.

[0125] It is possible to directly control NOx levels in at least two ways. For example, lambda can be controlled by controlling the air-fuel ratio (AFR) supplied to the combustion process. In another example, the combustion phase can be controlled (e.g., advancing it results in more NOx, while delaying it results in less NOx).

[0126] In the illustrated example, it can be seen that there is a region 1050 where the minimum NOx production 1010 occurs when the mixture is rich (e.g., lambda < approximately 1.0). In the second region 1060, the maximum NOx production 1010 occurs at or near lambda of approximately 1.25, with a high temperature 1020 and excess oxygen due to the lean AFR mixture. In the third region 1070, the effect of excess air reduces the effect of temperature faster than the effect of excess O2, and NOx production from lambdas above approximately 1.25 decreases exponentially. In the region where lambda is greater than approximately 1.75, lean combustion reduces NOx production 1010 to below the stoichiometric mixture ratio.

[0127] Depending on the implementation, control strategies can be implemented to control the combustion phase. For example, in the example of engine system 100, in-cylinder pressure sensing, real-time combustion, diagnostic control (such as active combustion control), and air-fuel ratio control can be used to adjust NOx generation. In some embodiments, the control strategy can be configured to maintain the NH3 to NOx ratio within the high-efficiency range of the exhaust aftertreatment system (e.g., lambda from approximately 1.0 to approximately 1.2).

[0128] In some implementations, NOx and NH3 sensors can be used at the inlet and / or outlet of the engine exhaust aftertreatment system 900 (e.g., engine exhaust aftertreatment system 900) as controller feedback in a closed-loop control strategy to adjust in-cylinder NOx production to manage the effectiveness of the engine exhaust aftertreatment system. For example, the ECU 202 and / or air / fuel module 204 can be configured to receive sensor feedback from the engine exhaust aftertreatment system 900 to measure the efficiency and effectiveness of the engine exhaust aftertreatment system 900 and to adjust engine operation to reduce NOx production (e.g., about 90% or more) and / or NH3 consumption (e.g., to reduce the requirements of the ASC filter 940). In some implementations, the strategy can be configured to control in-cylinder combustion to produce an NH3 to NOx ratio between about 1.0 and about 1.2 so that both are reduced without the use of a urea doser (e.g., without a DEF system) by a combination of the SCR filter 930 and the ASC filter 940.

[0129] Figure 11 is a flowchart of an example of process 1100 for controlling an internal combustion engine system. Process 1110 is performed in relation to an internal combustion engine having a body sealed in a combustion chamber, the body being movable from the center position by moving to a point position for compressing gases in the compression phase and expanding combustion gases in the expansion phase. Each position of the body defines the volume of the combustion chamber. In some embodiments, an example of process 1100 can be performed by the front or part of an example of engine system 100 in Figure 1 and / or an example of engine system 200 in Figure 2.

[0130] In the 1110, a pressure signal is received from the combustion chamber pressure sensor while the volume is within a first range, the first range corresponding to a portion of the compression phase, and the received pressure is a first pressure. For example, an example of an ECU 202 can receive an in-cylinder pressure feedback signal from an example of a high-speed pressure sensor 272 during a first range of crank angle and / or piston position.

[0131] In the 1120, a first pulse of fuel is supplied at a first position in the body during the compression phase, based on the received pressure signal. For example, the air / fuel module 204 and / or the ignition module 206 may supply a first pulse of fuel to the engine cylinder 208 based on pressure feedback from the high-speed pressure sensor 272. In some embodiments, a pressure signal may be received during a previous combustion cycle and used to configure the first pulse during a subsequent (e.g., next) combustion cycle. In some embodiments, a pressure signal may be received and used within the same combustion cycle. In some embodiments, the first pulse of fuel may be further configured to prepare an air / fuel mixture close to autoignition in the combustion chamber. For example, the first pulse of fuel may be configured such that the amount of fuel is almost insufficient to cause autoignition during the compression stroke. In some embodiments, the first pulse may be supplied in the example of points 442 and / or 542 in Figures 4 and 5.

[0132] In the 1130, a second pulse of fuel is supplied at a second position in the body during the compression phase, based on the received pressure signal. For example, the air / fuel module 204 and / or the ignition module 206 can supply a second pulse of fuel to the engine cylinder 208 based on pressure feedback from the high-speed pressure sensor 272. In some implementations, the pressure signal can be received during the previous combustion cycle and used to construct the second pulse during a subsequent (e.g., next) combustion cycle. In some implementations, the pressure signal can be received and used within the same combustion cycle. In some implementations, this process can be operated by monitoring the previous cycle with pressure sensing and crank angle position (e.g., converted to volume), and looking for key combustion indicators such as "combustion start" (e.g., CA10 or 10% MFB or 10% of combustion) and the center of combustion (e.g., CA50, 50% MFB (mass percentage of combustion)). From the previous cycle, this cycle can be adjusted to control these parameters to target values. The target values ​​can be set by good combustion phase, safe operation, and / or NH3 to NOx ratio.

[0133] Several implementations of the RCCI method (e.g., High-Temperature Combustion Method - also known as Reactivity Controlled Compression Ignition) can utilize the following: (a) supply of air and primary fuel (e.g., NH3), (b) compression to a certain level after occlusion of the intake valve, (c) direct injection of secondary fuel (e.g., diesel fuel) early in the cycle (e.g., if the temperature is too low to ignite the diesel fuel), (d) further compression occurs, causing the diesel fuel droplets to disperse, vaporize, and mix with the primary fuel, (e) further compression reaches the autoignition temperature of the diesel vapor, which is mixed close to the stoichiometric mixture range (e.g., lambda is approximately 1.0), and (f) volumetric autoignition occurs, igniting the mixture volumetrically. Heat release spreads via a precursor wave of autoignition (e.g., rather than in front of a conventional flame). In some implementations, volumetric ignition can be triggered using a second injection of secondary fuel to assist or fix the autoignition event (e.g., "ignition-assisted HCCI / RCCI").

[0134] In some embodiments, process 1100 may also include initiating combustion in the combustion chamber based on a second pulse of fuel. For example, the second pulse of fuel may be configured such that an additional amount of fuel triggers automatic ignition during the compression stroke. In some embodiments, the second pulse may be supplied at points 444 and / or 544 as illustrated in Figures 4 and 5.

[0135] Depending on the implementation, process 1100 may also include controlling CA50 using at least one of a first or second pulse of fuel. For example, ECU 202 may be configured to supply fuel at a timing and in an amount that allows 50% of the fuel to burn before the piston reaches a predetermined position or the crankshaft reaches a predetermined crank angle.

[0136] In some implementations, process 1100 may include controlling the NH3 / NOx ratio resulting from the combustion of diesel fuel, ammonia fuel, and air during the expansion phase using at least one of a first or second fuel pulse. For example, as shown in Figures 4, 5, 8, and 10, the timing and amount of multiple fuel pulses can be selected to control the amount of NOx and NH3 remaining in the exhaust gas from the engine. In some implementations, the NH3 / NOx ratio may be selected to be greater than 1. In some implementations, the NH3 / NOx ratio may be selected to be less than approximately 1.2.

[0137] Depending on the implementation, process 1100 may include receiving free ammonia present in the exhaust gas by an exhaust aftertreatment system, and catalyzing NOx based on the free ammonia by the exhaust aftertreatment system (for example, this is common in current SCR (Selective Catalytic Reaction) systems). For example, one example of engine system 100 may include an exhaust aftertreatment system 150 for treating the exhaust gas before it exits the exhaust pipe 160. In another example, using one example of exhaust aftertreatment system 900 in Figure 9, the exhaust gas can be catalytically treated as it passes from the exhaust 901 from the engine to the exhaust pipe 902.

[0138] Depending on the implementation, process 1100 may include controlling the amount of free ammonia present in the exhaust gas based on at least one of a first pulse of fuel or a second pulse of fuel. In particular, by adjusting the combustion center (CA50) to an advanced phase, NOx may be increased and NH3 slip may be reduced, thereby lowering the NH3 / NOx ratio, or by delaying the CA50 setpoint, the NH3 to NOx ratio may be increased. For example, an example of ECU 202 may control one or more of the air / diesel fuel ratio, air / ammonia fuel ratio, diesel fuel / ammonia ratio, first pulse fuel amount, second pulse fuel amount, first pulse fuel timing, and / or second pulse fuel timing to induce a predetermined amount of ammonia slip at the end of combustion. The free ammonia from the ammonia slip can then be used by an example of an SCR filter 930 to reduce NOx exhaust gas, and an ASC filter 940 can be used to reduce the amount of free ammonia remaining after the catalytic reaction.

[0139] Figure 12 is a schematic diagram of an example of a typical computer system 1200. According to one embodiment, system 1200 can be used for the operation described in relation to an example of method 1100 in Figure 11. For example, system 1200 may be included in any or all of the ECU 202, air / fuel module 204, ignition module 206, RT-CDC 611, or ECU 602.

[0140] System 1200 includes a processor 1210, memory 1220, storage device 1230, and input / output device 1240. Each of these components 1210, 1220, 1230, and 1240 is interconnected using a system bus 1250. The processor 1210 can process procedures to be executed within System 1200. In one implementation, the processor 1210 is a single-threaded processor. In another implementation, the processor 1210 is a multi-threaded processor. The processor 1210 can process procedures stored in memory 1220 or storage device 1230 to display graphical information of a user interface on the input / output device 1240.

[0141] Memory 1220 stores information within system 1200. In one embodiment, memory 1220 is a computer-readable medium. In one embodiment, memory 1220 is a volatile memory unit. In another embodiment, memory 1220 is a non-volatile memory unit.

[0142] The storage device 1230 can provide a large amount of storage to the system 1200. In one embodiment, the storage device 1230 is a computer-readable medium. In various different embodiments, the storage device 1230 may be a floppy disk device, a hard disk device, an optical disk device, or a tape device.

[0143] The input / output device 1240 provides input / output operation for the system 1200. In one embodiment, the input / output device 1240 includes a keyboard and / or a pointing device. In another embodiment, the input / output device 1240 includes a display unit for displaying a graphical user interface.

[0144] The described features can be implemented in digital electronic circuits, computer hardware, firmware, software, or a combination thereof. The device can be implemented in a computer program product explicitly embodied in an information carrier, such as a machine-readable memory device, for execution by a programmable processor, and the steps of the method can be executed by a programmable processor executing a program of instructions that perform the functions of the described implementation by acting on input data and producing an output. The described features can be advantageously implemented in one or more computer programs executable on a programmable system including at least one programmable processor coupled to receive data and instructions from a data storage system, at least one input device, and at least one output device, and to transmit data and instructions to the data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used directly or indirectly by a computer to perform a particular activity or to produce a particular result. Computer programs can be written in any form of programming language, including compiled languages ​​and interpreted languages, and can be deployed in any form, such as a standalone program, or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0145] Processors suitable for executing instruction programs include, for example, both general-purpose and special-purpose microprocessors, a single processor, or one of several processors in any type of computer. Generally, a processor receives instructions and data from read-only memory, random-access memory, or both. Essential elements of a computer are the processor for executing instructions and one or more memories for storing instructions and data. Generally, a computer includes one or more mass storage devices for storing data files, or communicates operationally with such devices. Such devices include internal hard disks and removable disks, magneto-optical disks, and magnetic disks. Storage devices suitable for explicitly embodying the instructions and data of a computer program include, for example, all forms of non-volatile memory: semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks. Processors and memory may be complemented or integrated by ASICs (Application-Specific Integrated Circuits).

[0146] To provide interaction with the user, these features can be implemented in a computer that has display devices such as CRT (cathoderay tube) and LCD (liquid crystal display) monitors for displaying information to the user, as well as a keyboard and pointing devices such as a mouse or trackball that allow the user to provide input to the computer.

[0147] This feature can be implemented in computer systems including backend components such as data servers, or in computer systems including middleware components such as application servers and internet servers, or in computer systems including frontend components such as client computers equipped with a graphical user interface, an internet browser, or any combination thereof. The components of the system can be connected by any form or medium of digital data communication, such as a communication network. Examples of communication networks include, for example, computers and networks that form a LAN, WAN, and the Internet.

[0148] A computer system can include clients and servers. Clients and servers are generally remote to each other and typically interact over a network, such as the one described. The client-server relationship arises from computer programs running on each computer that have a client-server relationship with one another.

[0149] While several implementations are described in detail above, other modifications are possible. For example, the logic flow depicted in the diagram does not require a specific order or sequence shown to achieve the desired result. Furthermore, other steps may be provided or steps may be removed from the described flow, and other components may be added to or removed from the described system. Thus, other implementations are within the scope of the following claims.

Claims

1. A device for controlling the operation of an internal combustion engine, wherein the internal combustion engine comprises a body sealed in a combustion chamber, the body being movable to a top dead center position to compress gas or at least one of a gas / liquid mixture in the compression phase, and being movable from the top dead center position to expand combustion gases in the expansion phase, and each position of the body defining the volume of the combustion chamber, The system includes a processor that receives input from a position sensor configured to sense the position of the main body corresponding to the volume of the combustion chamber, and input from a combustion chamber pressure sensor, and the processor is configured to receive input from a position sensor that senses the position of the main body corresponding to the volume of the combustion chamber, While the volume is within a first range, a pressure signal is received from the combustion chamber pressure sensor, the first range corresponds to a part of the compression phase, and the received pressure is a first pressure. Based on the received pressure signal, a first signal is supplied, configured to supply a first pulse of fuel at a first position of the main body during the compression phase. Based on the received pressure signal, a second signal is supplied, configured to supply a second pulse of fuel at a second position of the main body during the compression phase. A device for controlling the operation of an internal combustion engine.

2. The first signal is further configured to prepare an air / fuel mixture that is close to automatic ignition during compression. The apparatus according to claim 1.

3. The second signal is further configured to initiate combustion in the combustion chamber. The apparatus according to claim 1.

4. The second signal is further configured to control at least one of CA50 or CA10. The apparatus according to claim 1.

5. The second signal is NH generated from the combustion of diesel fuel, ammonia fuel, and air. ３ Further configured to control the NOx ratio, The apparatus according to claim 1.

6. The aforementioned ratio is approximately 1. The apparatus according to claim 5.

7. The aforementioned ratio is less than approximately 1.

2. The apparatus according to claim 6.

8. The exhaust aftertreatment system further comprises receiving free ammonia present in the exhaust gas and being further configured to catalyze NOx based on the ammonia. The apparatus according to claim 1.

9. A method performed in relation to an internal combustion engine having a body sealed in a combustion chamber, wherein the body is movable to a top dead center position to compress gas or at least one of a gas / liquid mixture in the compression phase, and is movable from the top dead center position by expanding combustion gases in the expansion phase, and each position of the body defines the volume of the combustion chamber. A step of receiving a pressure signal from a combustion chamber pressure sensor while the volume is within a first range, wherein the first range corresponds to a portion of the compression phase, and the received pressure is a first pressure. The steps include supplying a first pulse of fuel at a first position of the main body during the compression phase based on the received pressure signal, The step of supplying a second pulse of fuel at a second position of the main body during the compression phase based on the received pressure signal, method.

10. The first pulse of the fuel is further configured to prepare an air / fuel mixture that is close to automatic ignition. The method according to claim 9.

11. The step further comprises initiating combustion in the combustion chamber based on a second pulse of the fuel. The method according to claim 9.

12. The step further comprises controlling at least one of CA50 or CA10 based on at least one of the first pulse of the fuel or the second pulse of the fuel. The method according to claim 9.

13. Based on at least one of the first pulse of the fuel or the second pulse of the fuel, NH produced from the combustion of diesel fuel, ammonia fuel and air ３ Further includes a step to control the NOx ratio, The method according to claim 9.

14. The aforementioned ratio is approximately 1. The method according to claim 13.

15. The aforementioned ratio is less than approximately 1.

2. The method according to claim 14.

16. The exhaust aftertreatment system includes the step of receiving free ammonia present in the exhaust gas, The exhaust gas aftertreatment system further comprises the step of catalyzing NOx based on free ammonia, The method according to claim 9.

17. The method further comprises the step of controlling the amount of free ammonia present in the exhaust gas based on at least one of a first pulse of the fuel or a second pulse of the fuel. The method according to claim 16.

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