System and method for delaying ignition timing

Abstract

To control various variables to prevent undesired vibration caused by spark timing.SOLUTION: A control system is configured to monitor operating conditions of at least a first cylinder (26) of a reciprocating engine (10) and to control the reciprocating engine (10), and includes a first sensor (23, 27, 29, 66) configured to monitor a first type of operating condition of the first cylinder (26), and a controller (25) communicatably coupled with the first sensor (23, 27, 29, 66). The controller (25) is configured to: receive a first signal indicative of a first measurement value of the first type of operating condition from the first sensor (23, 27, 29, 66); analyze the first signal to detect a misfire condition in the first cylinder (26); derive an amount of residual gas in the first cylinder (26) if the misfire condition is detected; and adjust control of the reciprocating engine (10) on the basis of the amount of residual gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The subject matter disclosed herein relates to fuel combustion engines, and more specifically, to systems and methods for delaying ignition timing. [Background technology]

[0002] A combustion engine typically burns a carbonaceous fuel such as natural gas, gasoline, or diesel fuel, and uses the corresponding expansion of the high-temperature, high-pressure gas to exert force on specific components of the engine, such as pistons located within the engine's cylinders, causing these components to operate over a certain distance. (For example, Japanese Patent Publication No. 2016-125494) In operation, for example, during the piston's compression stroke, a spark can ignite the air-fuel mixture in the combustion chamber. The timing of the spark can affect many variables, including engine life, fuel economy, and engine power. For example, a spark that occurs too early or too late in the engine cycle can cause undesirable vibrations. In some cases, delaying spark ignition can be beneficial. [Overview of the project]

[0003] Specific embodiments of the invention claimed at the time of filing are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather to provide an overview of possible forms of the disclosure. In fact, the disclosure may include a variety of forms that are similar to or different from the embodiments described below.

[0004] In the first embodiment, Delay in ignition timingThe system includes a control system configured to monitor the operating conditions in at least a first cylinder of a reciprocating engine and to control the reciprocating engine, the control system including a first sensor configured to monitor a first type of operating condition in the first cylinder, and a controller communicatively coupled to the first sensor. The controller is configured to receive a first signal from the first sensor representing a first measurement of the first type of operating condition, analyze the first signal to detect a misfire in the first cylinder, derive the amount of residual gas in the first cylinder if a misfire is detected, and adjust the control of the reciprocating engine based on the amount of residual gas. .Ko ntrow Ra is , by deriving the residual fraction The first 1 Syringe Inside It is configured to derive the amount of residual gas, Residue The fractionation rate is

number

number

[0005] In the second embodiment, Delay in ignition timing The method includes the step of receiving a first signal representing a first measurement of a first type of operating state from a first sensor configured to monitor a first type of operating state of a first cylinder of a reciprocating engine. The method further includes the step of analyzing the first signal to detect a misfire in the first cylinder, and, if a misfire is detected, deriving the amount of residual gas in the first cylinder. The method further includes adjusting the control of the reciprocating engine based on the amount of residual gas. Inside The step of deriving the amount of residual gas includes applying the residual fraction derivation, The residual percentage is,

number

number

[0006] In the third embodiment, a computer instruction is stored in a tangible, non-temporary computer-readable medium, and the instruction is configured to cause the processor to perform the steps of: receiving a first signal representing a first measurement of a first type of operating state from a first sensor configured to monitor a first type of operating state of a first cylinder of a reciprocating engine; and analyzing the first signal to detect a misfire in the first cylinder. If a misfire is detected, the instruction is further configured to cause the processor to perform the steps of: deriving the amount of residual gas in the first cylinder; and adjusting the control of the reciprocating engine based on the amount of residual gas.

[0007] These features, embodiments, and advantages of the present invention, as well as other features, embodiments, and advantages, will be better understood by considering the following detailed description with reference to the accompanying drawings. In the accompanying drawings, similar reference numerals represent similar parts throughout the drawings. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram of a partial embodiment of a power generation system driven by a reciprocating engine according to some aspects of the present disclosure. [Figure 2] Figure 1 shows a side cross-sectional view of one embodiment of a piston assembly in a cylinder of a reciprocating engine, according to several aspects of the present disclosure. [Figure 3]It is a block diagram of an embodiment of a crankshaft of a drive system of a reciprocating engine system shown in FIG. 1. [Figure 4] It is a schematic diagram of an embodiment of three sensors arranged on a rigid mount around a coupling used for the crankshaft shown in FIG. 3. [Figure 5] It is a flowchart of an embodiment of a process for detecting the state of a drive system during the operation of a reciprocating engine system. [Figure 6] It is a flowchart of an embodiment of a process for determining a baseline for pairing of impulses and responses during a specific engine timing event executed in the process shown in FIG. 5. [Figure 7] It is a flowchart of an embodiment of a process for determining an engine state such as misfire, deriving specific engine parameters such as the amount of residual gas in a cylinder, and adjusting engine control based on the derived engine parameters.

Embodiments for Carrying out the Invention

[0009] Hereinafter, one or more specific embodiments of the present invention will be described. In an effort to provide a concise description of these embodiments, not all features of actual examples may necessarily be described in the specification. In the development of such actual examples, as in any engineering project, it should be understood that numerous decisions specific to each example must be made to achieve the specific goals of the developer, which can vary from example to example, such as compliance with system-related and business-related constraints. Further, although such development efforts may be complex and time-consuming, it should be understood that for those skilled in the art who benefit from this disclosure, it is considered an everyday task in manufacturing and production.

[0010] When describing the components of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there is one or more of those components. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be further components other than those listed.

[0011] This disclosure relates to reciprocating engines, and more particularly to delaying ignition timing in combustion engines. Generally, a reciprocating engine has an ignition feature or mechanism (e.g., a spark plug) that ignites the fuel-air mixture in the combustion chamber as the piston moves upward toward the top of the cylinder. For example, a spark plug can ignite the fuel-air mixture when the crank angle of the crankshaft is about 5 to 35 degrees from top dead center (TDC), where TDC is the "highest" position of the piston in the cylinder. The performance of a reciprocating engine can be improved by improving the ignition timing (e.g., so that ignition occurs at a specific moment in the engine cycle). For example, poor ignition timing can lead to premature ignition (e.g., engine knocking, pinching), which refers to a condition in which a small area (pocket) of the fuel-air mixture burns outside the envelope in front of the main combustion. Premature ignition can reduce the amount of work recovered from the expanding combustion gases (e.g., by the piston).

[0012] During normal operation, a certain amount of residual exhaust gas may be present in the cylinder. When a reciprocating engine misfires, the residual exhaust gas is replaced by a fresh fuel-air mixture. Therefore, when the reciprocating engine burns after the fresh mixture, the peak cylinder pressure may rise above a desired level, potentially causing undesirable effects on the cylinder components. By delaying the ignition timing during combustion in a misfired cylinder, the peak cylinder pressure can be reduced. In particular, by delaying spark ignition when the engine is misfired, the cylinder pressure can be advantageously reduced, extending the engine's lifespan. In one embodiment, the technology described herein can first detect the occurrence of a misfire in real time and then delay the ignition timing. After the ignition delay, the ignition timing can be returned to normal operation. It should be understood that the technology described herein is also applicable to reciprocating engines that can use diesel fuel for compression ignition, for example. By detecting misfires in real time and then delaying the ignition timing, the technology described herein can improve engine efficiency and extend engine life.

[0013] Referring to the drawings, Figure 1 shows a block diagram of one embodiment of a part of an engine-driven power generation system 8. As will be described in detail below, the system 8 includes an engine 10 (e.g., a reciprocating internal combustion engine) having one or more combustion chambers 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 18, or 20 or more combustion chambers 12). An air supply source 14 is configured to supply pressurized oxidizer 16, such as air, oxygen, oxygen-rich air, oxygen-depleted air, or any combination thereof, to each combustion chamber 12. Furthermore, the combustion chambers 12 are configured to receive fuel 18 (e.g., liquid and / or gaseous fuel) from a fuel supply source 19, and the fuel-air mixture is ignited and burned in each combustion chamber 12. High-temperature, high-pressure combustion gases move the pistons 20 adjacent to each combustion chamber 12 linearly within the cylinder 26, converting the pressure from the gases into rotational motion to rotate the shaft 22. Furthermore, the shaft 22 can be coupled to a load 24 that operates by the rotation of the shaft 22. For example, the load 24 may be any suitable device capable of generating electricity by the rotational output of the system 10, such as a generator. Furthermore, although air is referred to as the oxidizer 16 in the following description, any suitable oxidizer can be used in the disclosed embodiments. Similarly, the fuel 18 may be any suitable gaseous fuel, such as natural gas, associated petroleum gas, propane, biogas, sewage gas, landfill gas, or coal mine gas.

[0014] The system 8 disclosed herein can be adapted for use in stationary applications (e.g., industrial power generation engines) or mobile applications (e.g., automobiles or aircraft). The engine 10 may be a two-stroke, three-stroke, four-stroke, five-stroke, or six-stroke engine. Furthermore, the engine 10 may comprise any number (e.g., 1 to 24) of combustion chambers 12, pistons 20, and associated cylinders. For example, in certain embodiments, the system 8 may include a large industrial reciprocating engine having four, six, eight, ten, sixteen, or twenty-four or more pistons 20 reciprocating within a cylinder 26. In some such cases, the cylinder 26 and / or pistons 20 may have a diameter of about 13.5 to 34 centimeters (cm). In some embodiments, the cylinder and / or pistons 20 may have a diameter of about 10 to 40 cm, 15 to 25 cm, or about 15 cm. The system 10 can generate power in the range of 10 kW to 10 MW. In some embodiments, the engine 10 can operate at less than approximately 1800 revolutions per minute (RPM). In some embodiments, the engine 10 can operate at less than approximately 2000 RPM, 1900 RPM, 1700 RPM, 1600 RPM, 1500 RPM, 1400 RPM, 1300 RPM, 1200 RPM, 1000 RPM, 900 RPM, or 750 RPM. In some embodiments, the engine 10 can operate at approximately 750-2000 RPM, 900-1800 RPM, or 1000-1600 RPM. In some embodiments, the engine 10 can operate at approximately 1800 RPM, 1500 RPM, 1200 RPM, 1000 RPM, or 900 RPM.Typical engines include, for example, the General Electric Company's Jenbacher engine (e.g., Jenbacher Type 2, Type 3, Type 4, Type 6, or J920 FleXtra) or the Waukesha engine (e.g., Waukesha VGF, VHP, APG, 275GL).

[0015] The driven power generation system 8 may include one or more knock sensors 23 for each cylinder 26 that are suitable for detecting engine "knock". The knock sensors 23 may be any sensors configured to sense sounds or vibrations caused by the engine 10, such as sounds or vibrations within the cylinders 26 of the engine 10 due to detonation, premature ignition, and / or pinging. The knock sensors 23 are shown to be communicatively connected to an engine control unit (ECU) 25. When in operation, signals from the knock sensors 23 are transmitted to the ECU 25 to determine whether a knocking condition (e.g., pinging) is present. The ECU 25 can then adjust certain parameters of the engine 10 to improve or eliminate the knocking condition. For example, the ECU 25 may adjust the ignition timing and / or boost pressure to eliminate knocking. As further described herein, it can be further derived that the knock sensors 23 should further analyze and classify certain sounds or vibrations to detect, for example, engine conditions (e.g., misfire, premature ignition, or pinging).

[0016] Furthermore, the driven power generation system 8 may include one or more crankshaft sensors 66 suitable for detecting, monitoring, or tracking the position of the cylinder 26 or the crankshaft of the power generation system 8 for each cylinder 26. For example, the power generation system 8 may include multiple crankshafts, each coupled to one or more cylinders 26, or it may include a single crankshaft coupled to all cylinders 26. Each of the crankshaft sensors 66 may, for example, monitor the position of the crankshaft relative to the ignition timing in each cylinder 26.

[0017] Furthermore, the driven power generation system 8 may include an ionization sensor 27 (or multiple ionization sensors 27) communicably coupled to one or more cylinders 26 (e.g., combustion chambers 12 within cylinders 26) or any other component of the engine 10. The ionization sensor 27 can detect combustion by supplying voltage and detecting when current flows (e.g., combustion) and when no current flows (e.g., no combustion). In addition to or instead of this, a capacitive sensor 29 located in the spark plug system 31 can be used to detect misfires. During ignition, the capacitance of the coil can be measured to detect misfires. However, a knock sensor can detect misfires regardless of the cause (e.g., cause of ignition), as will be described in more detail later. Once a misfire is detected, certain analyses can be performed, for example, to calculate the amount of residual gas already present in cylinder 26. The results of the analysis can then be used by the ECU 25 to adjust the controls. For example, the ECU25 can retard the timing by controlling the ignition of the spark plug, adjust the amount of fuel and / or oxidizer (e.g., air) to account for residual gases, or a combination thereof. Thus, the next combustion after a misfire event can have a peak combustion pressure that falls within the manufacturer's recommended range without falling into the high-pressure side or exceeding the manufacturer's recommended range. In other words, if the techniques described herein are not used, the ECU25 may add fuel without considering residual gases, and / or may not retard the ignition, resulting in a peak combustion pressure that is higher than the desired pressure.

[0018] Figure 2 is a side cross-sectional view of one embodiment of a piston assembly 25 having a piston 20 positioned within a cylinder 26 (e.g., engine cylinder) of a reciprocating engine 10. For example, the reciprocating engine 10 of Figure 1 may include one or more piston assemblies 25 (and associated cylinders 26) as shown in Figure 2. The illustrated cylinder 26 has an inner annular wall 28 that defines a cylindrical cavity 30 (e.g., bore). The piston 20 can be defined by an axial axis or direction 34, a radial axis or direction 36, and a circumferential axis or direction 38. The piston 20 includes an upper part 40 (e.g., top land). The upper part 40 generally prevents the escape of fuel 18 and air 16 or fuel-air mixture 32 from the combustion chamber 12 during the reciprocating motion of the piston 20.

[0019] As shown in the figure, the piston 20 is attached to the crankshaft 54 ​​via a connecting rod 56 and a pin 58. The crankshaft 54 ​​converts the reciprocating linear motion of the piston 24 into rotational motion. As already mentioned, the engine 10 may include one or more crankshafts 54, each crankshaft being coupled to one or more piston assemblies 25 (and associated cylinders 26) of the engine 10. As described above, as the piston 20 moves, the crankshaft 54 ​​rotates, acting on the load 24 (shown in Figure 1). As shown in the figure, the combustion chamber 12 is located adjacent to the top land 40 of the piston 24. An intake valve 62 controls the supply of air 16 to the combustion chamber 12. An exhaust valve 64 controls the discharge of exhaust from the engine 10. However, it should be understood that any suitable elements and / or techniques can be utilized to supply fuel 18 and air 16 to the combustion chamber 12 and / or to discharge exhaust, and in some embodiments fuel injection is used. During operation, the combustion of fuel 18 with air 16 in the combustion chamber 12 causes the piston 20 to move in a reciprocating manner (for example, back and forth) in the axial direction 34 within the cavity 30 of the cylinder 26.

[0020] During operation, when the piston 20 is at its highest point within the cylinder 26, it is in a position called top dead center (TDC). When the piston 20 is at its lowest point within the cylinder 26, it is in a position called bottom dead center (BDC). When the piston 20 moves from the top to the bottom, or from the bottom to the top, the crankshaft 54 ​​rotates by half a revolution. Each movement of the piston 20 from the top to the bottom, or from the bottom to the top, is called a stroke, and embodiments of the engine 10 may include two-stroke, three-stroke, four-stroke, five-stroke, or six-stroke or more engines.

[0021] During the operation of the engine 10, a sequence of processes occurs, including an intake process, a compression process, an output process, and an exhaust process. The intake process allows a combustible mixture, such as fuel and air, to be drawn into the cylinder 26, so that the intake valve 62 is opened and the exhaust valve 64 is closed. The compression process compresses the combustible mixture into a smaller space, so that both the intake valve 62 and the exhaust valve 64 are closed. The output process ignites the compressed fuel-air mixture, which can include spark ignition by a spark plug system and / or compression ignition by compression heat. The resulting pressure from combustion pushes the piston 20 to BDC. The exhaust process typically returns the piston 20 to TDC while keeping the exhaust valve 64 open. Thus, the exhaust process expels the post-combustion fuel-air mixture (e.g., combustion gases) through the exhaust valve 64. It should be noted that two or more intake valves 62 and exhaust valves 64 may be used for each cylinder 26.

[0022] Under certain conditions, the air-fuel mixture may ignite prematurely, before the piston 20 returns to TDC. These conditions may be called “knock” or “pinging” and can be detected by the knock sensor 23, the ionization sensor 27, and / or the capacity sensor 29. Under other conditions, the air-fuel mixture may ignite delayed, after the piston 20 has passed TDC. These conditions may be called “misfire.” Knock or misfire can depend on a number of conditions, including environmental conditions, engine condition, engine load 10, airflow, fuel flow, or fuel composition.

[0023] The illustrated engine 10 also includes a crankshaft sensor 66, a knock sensor 23, and an engine control unit (ECU) 25 from Figure 1, which includes a processor 72 and memory 74. The crankshaft sensor 66 can detect the position and / or rotational speed of the crankshaft 54. Thus, in certain embodiments, crank angle or crank timing information can be derived. That is, when monitoring a combustion engine, timing is often expressed in terms of the angle of the crankshaft 54, which is correlated with time. For example, one cycle of a four-stroke engine 10 can be measured as a 720° cycle over a certain period of time. In some embodiments, the crankshaft sensor 66 can also detect the operating angular velocity of the crankshaft 54. A change in the operating angular velocity of the crankshaft 54 ​​(e.g., the operating angular velocity exceeds a baseline, threshold, or desired value of angular velocity) can indicate a change in peak combustion pressure (e.g., an increase), as will be detailed below with reference to later figures.

[0024] The knock sensor 23 may include one or more of the following: a piezoelectric accelerometer, a microelectromechanical system (MEMS) sensor, a Hall effect sensor, a magnetostrictive sensor, etc. Sensor 23 may also include any other sensor designed to sense vibration, acceleration, sound, and / or motion. In other embodiments, sensor 23 does not have to be a knock sensor in the traditional sense and may be any sensor capable of sensing vibration, pressure, acceleration, deflection, or motion, and does not have to be used to detect engine "knock".

[0025] The ionization sensor 27 can provide a voltage suitable for generating plasma during combustion, and can also provide a current. Therefore, a current passing through the generated plasma can represent combustion, while the absence of current can represent the absence of combustion. In certain embodiments, the ionization sensor can be placed in the spark plug system 31. The capacitance sensor 29 can also detect misfires through changes in capacitance when the ignition coil generates a high voltage to produce a spark via the spark plug system 31. For example, the baseline capacitance may change during a misfire.

[0026] Due to the percussive nature of the engine 10, the knock sensor 23 can detect features even if it is mounted outside the cylinder 26. However, the knock sensor 23 may be located in various places inside or around each cylinder 26. Furthermore, in some embodiments, a single knock sensor 23 may be shared, for example, by one or more adjacent cylinders 26. In other embodiments, each cylinder 26 may contain one or more knock sensors 23. The crankshaft sensor 66 and the knock sensor 23 are shown as communicating electronically with the engine control unit (ECU) 25. The ECU 25 comprises a processor 72 and a memory 74. The memory 74 can store computer instructions that can be executed by the processor 72. The ECU 25 monitors and controls the operation of the engine 10, for example, by adjusting the combustion timing (e.g., delaying the ignition timing), adjusting the timing of valves 62, 64, adjusting the supply of fuel and oxidizer (e.g., air), etc.

[0027] Each of the sensors 23, 27, 29, and 66 can transmit a signal to the controller 25 indicating the operating status of the respective monitored object, and the controller 25 can analyze the signals to detect changes in operating peak combustion pressure and diagnose the cause of the change in peak combustion pressure, as described below. That is, the technology described herein can use the ECU 25 to receive data from the knock sensor 23 of each cylinder 26 (or group of cylinders 26), the crankshaft sensor 66 of each cylinder 26 (or group of cylinders 26), the ionization sensor 27 of each cylinder 26 (or group of cylinders 26), and / or the capacitive sensor 29 of each cylinder 26 (or group of cylinders 26). The ECU 25 can then perform a process to analyze the data to determine the operating status of the engine 10 and diagnose the cause of any abnormal or undesirable operating conditions. For example, the ECU25 can analyze one or more signals to detect a change (e.g., an increase) in the operating peak combustion pressure in one or more cylinders, and then analyze one or more further signals to diagnose the cause of the change (e.g., an increase) in the operating peak combustion pressure in one or more cylinders.

[0028] While the embodiments described herein may utilize a variety of techniques for detecting misfires in real time (e.g., substantially instantaneously), it may be useful to describe the real-time misfire detection techniques applicable to the use of the knock sensor 23, as will be shown in more detail with respect to Figure 3.

[0029] Figure 3 is a block diagram of one embodiment of the crankshaft 22 of the drive system 132 of the reciprocating engine system 10 of Figure 1. As shown, the crankshaft 22 may include a flywheel 142, a plurality of crankpins 144, and a hub 146 connected to the shaft 148. The crankpins 144 can be connected to the "big" end of the connecting rod of each cylinder. The crankshaft 22 can be used to convert the reciprocating motion of the piston 24 into rotational motion. The flywheel 142 is used to move the piston from bottom dead center (BDC) to top dead center (TDC) using power stored from other pistons connected to the crankshaft 22, or by the same process acting on the other side of the piston. For example, the flywheel 142 can be used to run the non-powered portion of the engine cycle of the engine 12. Furthermore, the flywheel 142 provides smooth rotation of the crankshaft 22, and the hub 46 can be used, among other things, to dampen torsional vibrations of the crankshaft 22. In some embodiments, the crankshaft 22 may include a coupling for connecting the crankpin 144, the hub 146, and / or the flywheel 142 to the shaft 148. Furthermore, the crankshaft 22 may rotate on bearings or journals that restrain the displacement of the crankshaft 22 due to forces generated by the piston 24 and transmitted to the crankshaft 22 by the connecting rod. It should be understood that the disclosed state-based monitoring technique can monitor all components of the drive system 132, including the components described above (e.g., the crankshaft 22, couplings, bearings, journals, base frame, mounting points, and other related components).

[0030] Figure 4 is a schematic diagram of an embodiment of three sensors 23 positioned on a rigid mount 50 around the coupling 52 used for the crankshaft 22 in Figure 1. The three sensors 23 are arranged in a circle with a 120° interval between them, enabling measurements in the X, Y, and Z axes. The three sensors 23 can measure local vibrations of the crankshaft 22 and send the measurements to the processor 72 for analysis. For example, the measurements from the three sensors 23 can be used to evaluate whether the detected vibration response of the crankshaft 22 is appropriate based on the input to the system 10 (e.g., torsional acceleration, peak combustion pressure).

[0031] Furthermore, the knock sensor 23 can be locally positioned in the engine 12 in the same plane as the crankshaft 22 (e.g., the xy plane). By positioning the knock sensor in the same plane as the crankshaft 22, it becomes possible to detect vibrations when the movement of the piston 24 is obstructed (e.g., gets stuck) and / or when the piston 24 overheats. When the piston gets stuck, there may be vertical linear motion within the cylinder 26 that affects the rotational motion on the rod journal and main journal that are in contact with the crankshaft 22. That is, resistance in the motion of the crankshaft 22 may manifest as pulses from the knock sensor 23. The knock sensor 23 can be positioned at 90° to the center of the crankshaft 22 (e.g., perpendicular to the crankshaft 22). In some embodiments, the knock sensor can be positioned on a bearing cap, which provides a clearer reading of the resonance of the crankshaft 22 at a closer position.

[0032] Figure 5 is a flowchart of one embodiment of a process 160 for detecting the state of the reciprocating engine system 10, such as a misfire, while the system 10 is operating, using a knock sensor 23. Process 160 can be implemented as a computer instruction stored in a non-temporary computer-readable medium (e.g., memory 74) and executable by a processor 72. The following description of process 160 is given with respect to the processor 72 of the controller or ECU 25, but it should be noted that process 160 may also be executed by other processors located on the controller or ECU 25 and / or other devices that may be capable of communicating with sensors 23, 27, 29, and 66. Furthermore, while the following description of process 160 describes several operations that may be performed, it should be noted that process 160 may be executed in various appropriate orders, and not all operations may be performed. It should be understood that the entire process 160 may be executed by the ECU 25, or its execution may be distributed between the ECU 25 and another device (e.g., a workstation).

[0033] Referring here to process 160, the processor 72 can receive data from one or more sensors 23, 27, 29, and / or 66 (block 162). For example, the processor 72 can receive velocity data from a crankshaft 22 velocity sensor, which the processor can use to determine the torsional acceleration / deceleration of the crankshaft 22; vibration data from a knock sensor 23 local to the engine 12 (e.g., located in the head) indicating misfire events and / or peak combustion pressure per cycle; crankshaft angle indicating the position of the piston 20; an index of the crankshaft position at TDC (e.g., position in the ignition sequence) used to determine the ignition timing; and / or vibration frequencies of the crankshaft 22 from the knock sensor 23 and sensors 27, 29, 66 local to the crankshaft 22. In some embodiments, the processor 72 can use information to determine the ignition sequence of the cylinders 26 (e.g., to determine which cylinder 26 is immediately igniting) and vibration responses resulting from ignition events. Therefore, the processor 72 can determine a baseline for impulse-response pairings during a particular engine event (block 164). The impulses may include torsional acceleration applied to the crankshaft 22, peak combustion pressure, etc., and the impulses may vary depending on which engine event (e.g., intake, combustion, power, exhaust) is occurring. Therefore, the vibration response to the impulses may also vary for each engine event. The baseline can be determined when the engine 12 is first started or brought online. In addition to this, or instead, the baseline may be determined by the manufacturer in a test facility. It should be noted that the baseline may also be determined periodically, such as each time the engine 12 is started. The baseline for impulse-response pairings can be stored in memory 74 for later access.

[0034] The processor 72 can determine the pairing of subsequent impulses and responses based on subsequent data received from one or more sensors 23 (block 166). Next, the processor 72 can determine whether the subsequent vibration response is substantially different from the baseline response for similar impulses in a particular engine event. That is, the processor 72 can, for example, use a multidimensional model to determine whether the subsequent vibration response deviates from the baseline vibration response for the same input. It should be noted that "multidimensional" can refer to at least multiple inputs considered by the model. As already mentioned, inputs that can be combined may include torsional acceleration / deceleration applied to the crankshaft 22 received from the sensor 23, piston position at crank angle (or position in the cylinder, e.g., relative to TDC), timing of the engine event (e.g., cylinder position in the firing sequence), whether the cylinder 26 was misfiring, estimated intra-cylinder pressure, and / or electrical load.

[0035] It can be understood that various aspects of cylinder combustion can exist. For example, a cylinder may be able to burn normally for a given speed and mode, or it may ignite abnormally due to violent ignition (e.g., higher pressure for a particular engine event), misfire, or quiet ignition (e.g., lower pressure or torque). Multidimensional models can distinguish between various aspects of cylinder combustion and accurately evaluate the vibration response because the vibration response is related to the individual aspects of cylinder combustion (e.g., inputs related to combustion pressure, torsional acceleration, specific ignition timing, etc.).

[0036] Furthermore, baseline vibration response characteristics can be stored for specific events. For example, when the engine is operating normally and a specific amount of torsional acceleration is applied to the crankshaft 22, the resulting vibration response characteristics may have a specific frequency. In the case of engine misfire or when peak combustion pressure is present in the cylinder, the resulting vibration characteristics may have a different frequency. Moreover, each engine event in the cycle, such as intake, compression, output, and exhaust, may include different inputs (e.g., torsional acceleration, peak combustion pressure) that may result in similar or different vibration response characteristics. Therefore, when an engine event occurs again with inputs similar to the baseline input, the processor 72 can compare the resulting vibration response characteristics with the baseline vibration response characteristics to determine whether a certain state of the drive system 132 exists.

[0037] If the characteristics of a subsequent vibration response differ from the characteristics of a baseline vibration response for a similar input, the processor 72 can determine that there is a problem with a component of the drive system 132 and perform preventive actions, predictions, and / or diagnoses (block 170). In some embodiments, the processor 72 can determine that a general problem exists in the drive system 132 without precisely identifying what that problem might be. In such cases, the processor 72 can perform preventive actions depending on the magnitude of the discrepancy between the characteristics of the subsequent vibration response and the characteristics of the baseline vibration response, as described above. For example, if the discrepancy exceeds a threshold amount or threshold percentage, the processor 72 can shut down the engine 12. In some embodiments, if the discrepancy is relatively small, the processor 72 can send an alarm to be displayed on a user interface screen included with the controller 25, send an alarm to be displayed on a workstation, transmit the alarm via the CAN and / or OBDII interface, issue an audible alarm, or any combination thereof. Furthermore, the processor 72 can plan maintenance when the characteristic discrepancy is below a threshold amount to reduce customer downtime. Furthermore, the controller 25's display or an accompanying human-machine interface (HMI) can display the degradation rate of the drive system 132, which can provide the user with insight into when maintenance should be scheduled. In another embodiment, the controller 25 can display the remaining lifespan so that parts can be replaced at a better time. Thus, the technology disclosed herein makes it possible to plan maintenance based on the condition of the drive system 132, as opposed to fixed time intervals determined by planned monitoring.

[0038] In some embodiments, the processor 72 can diagnose which component is experiencing a problem based on data from the sensors 23. For example, because numerous sensors 23 are located throughout the engine 12 (e.g., some are localized to the engine 12, and some are in the same plane as the crankshaft 22), acoustic resonance and / or vibration characteristics may be stronger in certain parts of the engine 12. For example, if a bearing rather than a coupling has a certain condition, the acoustic resonance and / or vibration characteristics may be stronger in the crankcase than in the couplings of the drive system. However, if the coupling has a certain condition, a fourth set of sensors (e.g., three sensors 23 on a rigid mount around the coupling) is likely to result in stronger acoustic resonance and / or vibration characteristics (e.g., amplitude increases at a faster rate than in the localized engine 12). In this way, the processor 72 can identify regions of the drive system 132 that have a certain condition, which can allow the user to refine their investigation and save time.

[0039] In some embodiments, to perform prediction or diagnosis, the processor 72 can accumulate a knowledge base about what state a particular impulse-response pairing indicates. In some embodiments, to enable this, a test can be performed by using a multidimensional model in a simulation to change specific inputs and / or characteristics of the components of the drive system 132 and reveal the associated vibration response characteristics. For example, in one simulation, the thickness of the rubber element of the coupling was reduced by about 20%, resulting in a frequency increase of about 5% in the subsequent vibration response characteristics. Therefore, when the same input is used and a subsequent vibration response characteristic that is about 5% higher is obtained, the processor 72 can perform a diagnosis and determine that the thickness of the rubber element of the coupling has been reduced. By performing the test in this way, impulse-response pairings that indicate a particular state can be obtained, and problems can be diagnosed when impulse-response pairings are observed during operation.

[0040] Furthermore, as mentioned above, the processor 72 can make predictions about what states may occur in the future based on historical data. That is, the processor 72 can remember the trends in impulse-response pairings that lead to certain states over time. For example, by analyzing historical data (e.g., impulse-response pairings), the processor 72 can determine the degradation rate of components of the drive system 132 (e.g., couplings), and based on this, if the engine 12 behaves similarly in the future (e.g., showing similar trends in impulse-response pairings), the processor 72 can determine that the coupling is expected to progress to a specific state within a given time frame. However, it should be noted that other factors, such as fuel degradation or other factors that can accelerate component degradation, may affect the prediction. Thus, the prediction may be constrained by time frames to account for further factors.

[0041] Figure 6 is a flowchart of one embodiment of process 180 for determining a baseline of impulse-response pairings during a specific engine event performed in process 160 (e.g., block 164) of Figure 5. Process 180 can be implemented as a computer instruction that can be stored in a non-temporary computer-readable medium (e.g., memory 74) and executed by processor 72. The following description of process 180 is given with respect to processor 72 of controller 25, but it should be noted that process 180 may be executed by other processors located on other devices that may be capable of communicating with controller 25 and / or sensor 23. Furthermore, while the following process 180 describes several operations that may be performed, it should be noted that process 180 may be executed in various appropriate orders, and not all operations may be performed. It should be understood that the entire process 180 may be executed by controller 25, or the execution may be distributed between controller 25 and another device (e.g., workstation). Process 180 demonstrates a method of combining various inputs to provide a robust and powerful state-based monitoring system.

[0042] Referring here to process 180, the processor 72 can determine the torsional acceleration / deceleration on the crankshaft 22 based on velocity (block 182) and time. As previously mentioned, a first set of sensors 23 (e.g., crankshaft velocity / position sensors) can be used to provide a pulse each time a tooth passes the ring gear, and the processor 72 can determine the velocity based on the pulse. The acceleration / deceleration is then the derivative of velocity with respect to time. Thus, the processor 72 can determine the acceleration of the crankshaft 22 by finding the derivative of velocity with respect to time, which can then be quantified as torsional acceleration / deceleration. Furthermore, in some embodiments, the pulse can be used to determine the angular position of the crankshaft based on which tooth of the ring gear it passes over (e.g., degree of rotation). In addition, the processor 72 can determine whether vibrations from a second set of sensors 23 located in the engine 12 (e.g., the head of the cylinder 26) indicate a misfire event, and further / or estimate the peak combustion pressure to supplement the quantification of the amplitude of torsional stress (block 184). In other words, data from a second set of sensors 23 (e.g., knock sensors) can be used to provide the processor 72 with a more comprehensive view of the torsional stresses that occur under various engine conditions (e.g., misfire, peak combustion pressure).

[0043] Furthermore, the processor 72 can use data from a third set of sensors 23 to determine the timing of engine events related to torsional acceleration based on the crankshaft position 22 (block 186). Engine event timing information for ignition can be provided by the processor 72 to the third set of sensors 23, so that the sensors can indicate the crankshaft position when the piston 24 is at TDC. This information can be used by the processor 72 to determine which ignition events are on in the engine 12 and to derive the ignition sequence of the cylinders 26. Furthermore, the processor 72 can determine the characteristics of the vibration response to inputs (block 188). As previously mentioned, a fourth set of sensors 23 on a rigid mount around the coupling attached to the crankshaft 22 can provide this data. As a result, the processor 72 can determine whether or not there is an undesirable condition in the drivetrain 132 by using inputs such as the cylinder firing order, which cylinder was ignited immediately before, the combustion state of the cylinder (e.g., peak combustion pressure), the amount of torsional acceleration applied to the crankshaft 22, and the response including the characteristics of the vibration response resulting from the combined impulses.

[0044] Figure 7 is a flowchart of one embodiment of a process 200 suitable for improving engine life by detecting in real time the state of the engine 10, such as misfire in cylinder 26, deriving specific parameters such as the amount of residual gas in cylinder 26, and then taking specific measures such as delaying the ignition timing and / or reducing the fuel supply, thereby bringing the combustion pressure within the manufacturer's recommended range for the cycle following the detected state. The process 200 can be implemented as computer instructions that can be stored in a non-temporary computer-readable medium (e.g., memory 74) and executed by the processor 72. The following description of the process 200 is given with respect to the processor 72 of the controller 25, but it should be noted that the process 200 may be executed by other processors located on other devices that may be capable of communicating with the controller 25 and / or the sensor 23. Furthermore, the following description of the process 200 describes several operations that may be performed, but it should be noted that the process 200 may be performed in various appropriate orders, and not all operations may be performed. It should be understood that the entire process 200 may be executed by the controller 25, or the execution may be distributed between the controller 25 and another device (e.g., a workstation).

[0045] In the illustrated embodiment, process 200 can first determine whether the target engine condition has occurred (block 202). For example, misfires in one or more cylinders 26 can be detected using the techniques described above with respect to the use of the knock sensor 23. Similarly, an ionization sensor 27 can detect misfires by supplying a voltage and detecting whether a current flow occurs (e.g., combustion) or whether no current flow occurs (e.g., no combustion). That is, the current flow based on ionization during combustion may differ at the time of a misfire compared to the baseline current flow in a non-misfire state. Similarly, a capacitance sensor 29 can measure the coil capacitance at ignition and use the coil capacitance to detect misfires. In certain embodiments, sensors 23, 27, and 29 can detect misfires in real time.

[0046] Once an engine condition such as a misfire is detected, the techniques described herein can apply specific analyses, such as the derivation of one or more engine parameters (block 204). The derived engine parameters may include the derivation of the amount of residual gas in the misfired cylinder 26. In certain embodiments, a Haywood residual gas analysis can be applied as follows:

[0047] Composition of the unburned mixture The mass of the mixture confined in cylinder 26 is m c It can be expressed as, where m c The introduced mass (m) for each cycle is i ) the residual mass (m) carried over from the previous cycle (e.g., the combustion cycle) r This is the result of adding (x). r The following applies:

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[0053] It can be determined using the following assumptions.

[0054] 1. For lean and stoichiometric mixtures (φ ≤ 1), CO and H2 can be ignored.

[0055] 2. For rich and stoichiometric mixtures (φ ≥ 1), O2 can be ignored.

[0056] In a particular embodiment, the residual gas mass fraction x r and / or combustion gas fraction x b This can be derived, for example, by measuring the CO2 concentration in a gas sample sensed from the misfired cylinder 26 during the compression stroke. The CO2 concentration can be used in the following formula.

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[0061] In yet another embodiment, adjustment (block 208) can be applied based on the derivation of an ignition delay time based on one or more equations that take the residual gas in the derived cylinder 26 as input and produce an ignition timing delay time as output. The equations can be derived to take into account, for example, the size of the cylinder 26, the operating RPM, the temperature, pressure, flow rate (e.g., exhaust flow rate, fuel flow rate), etc. The equations may include an equation relating to the time required to fill the potentially misfiring cylinder 26 with fuel and / or oxidizer based on the residual gas already present. Other equations may be based on physics (e.g., the law of ideal gases, Boyle's law, Dalton's law, Charles's law, Avogadro's law, etc.). Thus, after deriving that a misfire has occurred (block 204) and then deriving the residual gas present in the misfiring cylinder 26 (block 206), the technique described herein can adjust the control of the engine 10 (block 208) so that the post-misfire combustion event results in a cylinder pressure within a range as if no misfire had occurred.

[0062] The technical benefits include detecting cylinder misfires in real time via one or more different types of sensors (e.g., knock sensors, capacity sensors, ionization sensors, or a combination thereof), and then deriving, for example, the amount of residual gas after the misfire. Furthermore, the technical benefits include adjusting engine control based on the amount of residual gas in the misfired cylinder, for example, by delaying spark ignition, adjusting fuel flow rate, adjusting oxidizer flow rate, or a combination thereof. By performing this adjustment so that the peak pressure in the combustion following the misfire is within the manufacturer's specifications rather than being an excessively high peak pressure, engine performance can be improved and engine life extended.

[0063] This specification discloses the disclosure in its best mode and uses several examples to enable those skilled in the art to carry out the disclosure, including the manufacture and use of any apparatus or system and the execution of any related methods. The patentable scope of the disclosure is defined by the claims and may include other embodiments that a person skilled in the art could conceive. Such other embodiments are included in the technical scope of the claims if they have structural elements that do not differ from the language of the claims, or include equivalent structural elements that do not substantially differ from the language of the claims. [Embodiment 1] A control system configured to monitor the operating state in at least the first cylinder (26) of the reciprocating engine (10) and to control the reciprocating engine (10). It is equipped with, The control system is A first sensor (23, 27, 29, 66) configured to monitor a first type of operating state of the first cylinder (26), A controller (25) is communicatively coupled to the first sensors (23, 27, 29, 66) and Equipped with, The controller (25) is A first signal representing a first measured value of the first type of operating state is received from the first sensor (23, 27, 29, 66), The first signal is analyzed to detect a misfire in the first cylinder (26). If a misfire is detected, the amount of residual gas in the first cylinder (26) is derived. The control of the reciprocating engine (10) is adjusted based on the amount of residual gas. System (8) is configured as follows. [Embodiment 2] The system (8) according to Embodiment 1 comprises a first knock sensor (23). [Embodiment 3] The controller (25) is Reading out baseline impulse and baseline response characteristics related to engine events, Receiving subsequent data from multiple sensors located on the engine, To derive subsequent impulse and subsequent response characteristics related to engine events based on the aforementioned subsequent data, and For each engine event, determine whether the subsequent response characteristics differ from the baseline response characteristics of the subsequent impulse and baseline impulse. The system (8) according to Embodiment 2, configured to analyze the first signal to detect the misfire condition. [Embodiment 4] The system (8) according to Embodiment 1 comprises a capacitive sensor (29) calibrated to detect misfires through changes in ignition coil capacity, an ionization sensor (27) configured to detect changes in current during combustion due to ionization, or a combination thereof. [Embodiment 5] The system (8) according to Embodiment 1, wherein the controller (25) is configured to derive the amount of residual gas in the first cylinder (26) by residual fraction deriving. [Embodiment 6] The aforementioned residual fraction is

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[0072] 8 Power generation system 10 Engines 12 Combustion chamber 14. Air supply source 16. Oxidizing agent, air 18 Fuel 19 Fuel supply source 20 pistons 22 Crankshaft, Crankshaft position 23 Knock Sensor 24 pistons, load 25 Piston Assembly, Controller, ECU 26 cylinders, misfiring cylinders 27 Ionization Sensor 28 Inner ring wall 29 Capacitive Sensor 30 Cavity 31 Spark plug system 32 Air mixture 34 Axis 36 directions 38 directions 40 Top, Topland 46 Hubs 50 Rigid Mount 52 Coupling 54 Crankshaft 56 Connecting Rods 58 pins 62 Intake valve 64 Exhaust valve 66 Crankshaft Sensor 72 processors 74 memory 132 Drivetrain 142 Flywheel 144 Crankpin 146 Hub 148 shaft 160 processes 162 blocks 164 blocks 166 blocks 170 blocks 180 processes 182 blocks 184 blocks 186 blocks 188 blocks 200 processes 202 blocks 204 blocks 206 blocks 208 blocks H moles H average mole Type I K correction factor K correction factor N moles c subscript xb Combustion gas fraction xr Residual gas mass fraction

Claims

1. A control system configured to monitor the operating state in at least the first cylinder (26) of the reciprocating engine (10) and to control the reciprocating engine (10). It is equipped with, The control system is A first sensor (23, 27, 29, 66) configured to monitor a first type of operating state of the first cylinder (26), A controller (25) is communicatively coupled to the first sensors (23, 27, 29, 66) and Equipped with, The controller (25) is A first signal representing a first measured value of the first type of operating state is received from the first sensor (23, 27, 29, 66), The first signal is analyzed to detect a misfire in the first cylinder (26) by reading out baseline impulses and baseline response characteristics related to a reciprocating engine event, receiving subsequent data from a plurality of first sensors arranged on the reciprocating engine, deriving subsequent impulses and subsequent response characteristics related to the reciprocating engine event based on the subsequent data, and determining whether the subsequent response characteristics differ from the baseline response characteristics for each subsequent impulse and baseline impulse in the reciprocating engine event. The first sensor is a first knock sensor (23), If a misfire is detected, the amount of residual gas in the first cylinder (26) is derived. A system (8) for delaying ignition timing is configured to adjust the control of the reciprocating engine (10) so that the combustion pressure remains within a desired pressure range in the cycle following the detected condition, by taking measures to delay the ignition timing based on the amount of residual gas.

2. The system (8) according to claim 1, wherein, in addition to the first knock sensor, the first sensor comprises a capacitive sensor (29) configured to detect misfires through changes in ignition coil capacity, an ionization sensor (27) configured to detect changes in current during combustion due to ionization, or a combination thereof.

3. The system (8) according to claim 1, wherein the controller (25) is configured to adjust the control of the reciprocating engine by delaying spark ignition.

4. The system (8) according to claim 2, wherein the controller (25) is configured to adjust the control of the reciprocating engine by adjusting the flow rate of fuel, the flow rate of oxidizer, or a combination thereof.

5. A method for controlling a reciprocating engine (10), The steps include receiving a first signal representing a first measured value of the first type of operating state from a first sensor (23, 27, 29, 66) configured to monitor a first type of operating state of a first cylinder (26) of a reciprocating engine (10), A step of analyzing the first signal to detect a misfire in the first cylinder (26), comprising: reading out a baseline impulse and baseline response characteristics relating to a reciprocating engine event; receiving subsequent data from a plurality of first sensors arranged on the reciprocating engine; deriving subsequent impulses and subsequent response characteristics relating to a reciprocating engine event based on the subsequent data; and determining whether the subsequent response characteristics differ from the baseline response characteristics for each subsequent impulse and baseline impulse in a reciprocating engine event, wherein the first sensor is a first knock sensor (23), When a misfire is detected, the process involves determining the amount of residual gas in the first cylinder (26), A method for delaying ignition timing, comprising the step of adjusting the control of the reciprocating engine (10) so that the combustion pressure is kept within a desired pressure range in the cycle following the detected condition, by taking measures to delay the ignition timing based on the amount of residual gas.

6. The method according to claim 5, further comprising the steps of detecting a misfire through a change in ignition coil capacity, detecting a change in current during combustion due to ionization, and wherein the reciprocating engine (10) comprises, in addition to the first knock sensor, a capacity sensor (29), an ionization sensor (27), or a combination thereof, as the first sensor.

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