Predictive model-based spark control

Abstract

In certain embodiments, a significant improvement in H2-ICE performance can be achieved by a combination of active scavenging pre-combustion chamber technology and predictive model-based spark control to overcome the drawbacks of known combustion technologies. In certain embodiments, advanced combustion modeling and simulation of the ignition process, including spark events, arc movement and elongation, and resulting flame propagation, can be used to predict the relationship between spark energy / output, flow within the electrode gap, and flame growth (SOC) for different engines, different spark plugs, and various conditions. This information can be used to adjust the spark energy / output characteristics during the spark event of the same cycle in order to minimize SOC variations and significantly reduce the tendency of combustion anomalies such as backfire, knocking, and pre-ignition that prevent the achievement of high engine output density and efficiency.

Description

[Technical Field] 【0001】 I. Cross-referencing of related applications This application claims priority to U.S. Patent Application No. 63 / 388,359, filed on 12 July 2022, entitled “Predictive Model-Based Spark Control.” The entirety of the aforementioned patent application is incorporated herein by reference to the extent consistent with this disclosure. 【0002】 II. Field of Invention This disclosure relates, in general, to systems and methods for predictive model-based spark control, and more particularly to methods and systems for adjusting spark energy / power characteristics during the same-cycle spark event in order to minimize state of combustion (SOC) fluctuations and significantly reduce combustion anomaly tendencies such as backfire, knocking, and pre-ignition that hinder the achievement of high engine power density and efficiency. [Background technology] 【0003】 III. Background of the Invention The following references describe prior art problems, which will be discussed in more detail later. These references are incorporated herein by reference to the extent consistent with the present disclosure. [1] “Prechamber Combustion: Enabling the Competitive Carbon-Neutral ICE”, Emmanuella Sotiropoulou, Prometheus Applied Technologies, et al, 23rd CIMAC Congress, June 12-16, 2023. [2] “Ignition Energy and Ignition Probability of Methane-Hydrogen-Air Mixtures”, Hankinson G., Mathurkar H., Lowesmith B.J., Loughborough University, Leicestershire, UK - September 2009 - h2knowledgecentre.com。 [3] “Arc Travel Ignition Technology”, TozziL., Sotiropoulou E., Zhu S., Prometheus Applied Technologies, LLC. Lepley D.T., Altronic, LLC, Hoerbiger Engine Solutions. Yasueda S., GDEC, Inc. 15. Tagung“DER ARBEITSPROZESS DES VERBRENNUNGSMOTORS”September 24-25, 2015。 [4] “Optimizing High-Energy Tunable Ignition Technology: Preventing Electrode Damage while Extending the Lean Flammability Limit of Gas Engines,”Lepley, D.T., et al, GMRC, October 2014。 [5] Tozzi L., Sotiropoulou E. 2017. Active Scavenge Prechamber. U.S. Patent No. 9,850,806. [6] Sotiropoulou, et al, 2020. Prechamber Spark Plugs: The Evolution from Low Emission Natural Gas to Zero Emission H2 Operation, MTZ Worldwide, 6:46-50. 【0004】 Natural gas (NG) internal combustion engines, denoted as NG-ICE, and hydrogen (H2) internal combustion engines, denoted as H2-ICE and defined as engines using any fuel mixture containing at least 10% H2 in addition to NG, ammonia (NH3), and other fuels, are generally affected by large variability in the coefficient of variation of indicated mean effective pressure (COV-IMEP), and a high tendency towards extreme combustion instability, defined as lubricant spontaneous combustion (LOA), misfires, backfires, knocking, and pre-ignition. Due to these constraints, H2-ICEs are particularly limited to relatively low levels of engine power density (IMEP) and indicated thermal efficiency (ITE), as well as relatively high levels of nitrous oxide (NOx) emissions. Currently, the best performance achievable by conventional H2-ICEs is limited to the following: - COV-IMEP > 2% - IMEP ≤ 16 bar - ITE ≤ 41% - NOx ≥ 100 mg / Nm 3 【0005】 On the other hand, for H2-ICE to be considered a competitive and sustainable energy conversion solution suitable to compete with hydrogen fuel cells (H2-FC), it would need to achieve the following parameters: - COV-IMEP ≤ 1% - IMEP ≥ 20 bar - ITE ≥ 49% - NOx ≤ 25 mg / Nm 3 【0006】 These performance levels require ultra-lean hydrogen mixtures with high lambda (λ) values ​​exceeding λ=3, and in some cases exceeding λ=4. These levels of fuel mixture dilution require a high-energy / high-power spark ignition system that reliably ignites the hydrogen mixture at ultra-lean lambda and thus reduces fluctuations in state of combustion (SOC) that can cause combustion abnormalities such as backfire, knocking, and pre-ignition, significantly reducing the maximum achievable engine power density and efficiency. 【0007】 An advanced SOC (State of Charge) can induce fast combustion, which can result in knocking and pre-ignition. In contrast, a retarded SOC can induce slow combustion, which can result in backfire, quelling, and misfire. 【0008】 Figure 1 shows Chart 100, which indicates that the minimum ignition energy required for H2 at λ=4 (φ=0.25)110 is 50 times higher than at the stoichiometric (λ=φ=1.0)120 case. 【0009】 However, proper operation with an adjustable / programmable high-power spark requires an appropriate flow velocity between electrodes that is high enough to prevent high-rate electrode wear and hot spots leading to backfire, knocking, and pre-ignition, but low enough to avoid flame kernel extinguishing leading to engine misfires. 【0010】 The mechanism behind these combustion abnormalities is as follows: 【0011】 If the arc movement of a high-power spark is insufficient, a hot spot will form on the spark plug electrode, resulting in an advance of the state of combustion (SOC), which in turn increases the cylinder combustion pressure and temperature, creating high-temperature regions on the valves, spark plugs, cylinder head, and piston crown. These high-temperature regions then ignite the flow of high-concentration H2 mixture into the intake air, causing combustion abnormalities such as backfire, knocking, and pre-ignition. 【0012】 Figure 2 illustrates a series of phenomena leading to combustion abnormalities caused by improper arc movement of a high-power spark following a hot spot on the electrode. 【0013】 When a hot spot is formed on the electrode, the SOC advances, and the cylinder pressure and combustion chamber temperature can increase (see the 83rd cycle 210 in Figure 2). These conditions increase the combustion rate of heat release (HRR) in the next cycle and further increase the cylinder pressure and combustion chamber temperature (see the 84th cycle 220 in Figure 2). As a result, knocking (see the 85th cycle 230 in Figure 2) and intake backfire (also known as front fire) / pre-ignition (see the 86th cycle 240 in Figure 2) may occur in subsequent cycles. 【0014】 Due to the occurrence of these combustion abnormalities, the H2-ICE is prevented from reaching an output density (IMEP) exceeding approximately 16 bar, and the H2-ICE is regarded as a sustainable energy conversion solution. Therefore, achieving the levels of engine efficiency (ITE) and exhaust gas (NOx) necessary to compete with H2-FC is limited. Summary of the Invention Problems to be Solved by the Invention 【0015】 It is necessary to address the aforementioned drawbacks in the art. Brief Description of the Drawings 【0016】 IV. Brief Description of the Drawings [Figure 1] Shows a graph of the minimum ignition energy required for CH4 and H2 according to a specific embodiment. [Figure 2] Shows consecutive events leading to combustion abnormalities in a H2-ICE according to a specific embodiment. [Figure 3] Shows the spark gap of electrode 310 and the corresponding spark current curve 320 according to a specific embodiment. [Figure 4] Shows the spark gap of electrode 410 and the corresponding spark current curve 420 according to a specific embodiment. [Figure 5] Shows the spark gap of electrode 510 and the corresponding spark current curve 520 according to a specific embodiment. [Figure 6] The spark gap of electrode 610 and the corresponding spark current curve 620 according to a specific embodiment are shown. [Figure 7] This document describes an active scavenging pre-combustion chamber design for operation with H2-ICE according to a specific embodiment. [Figure 8] The electrode gap and four typical spark positions are shown according to a specific embodiment. [Figure 9] This shows a typical range of spark voltage and current fluctuations obtained during engine operation using an active scavenging pre-combustion chamber and a high-energy programmable open-loop ignition system according to a specific embodiment. [Figure 10] This shows an ignition system with a spark voltage sensor, a spark current sensor, and a smart spark control module added, according to a specific embodiment. [Figure 11] A flowchart of a predictive model-based spark control system according to a specific embodiment is shown. [Figure 12] A flowchart of a predictive model-based spark control method according to a specific embodiment is shown. [Figure 13] This shows a steep increase in arc voltage following spark breakdown, according to a specific embodiment. [Figure 14] This shows a gradual increase in arc voltage following spark breakdown, according to a specific embodiment. [Figure 15] This shows a flat arc voltage following spark breakdown, including a steep rise at a later point in time, according to a specific embodiment. [Figure 16] This shows the decrease in arc voltage following spark breakdown in a specific embodiment. [Figure 17] This shows a combustion CFD simulation of a leading-edge spark generated at a low speed position according to a specific embodiment. [Figure 18] A lookup table is shown that correlates the initial position of the spark with the spark waveform required to achieve the target SOC value, according to a specific embodiment. [Figure 19] A conventional spark ignition system according to a specific embodiment is shown. [Modes for carrying out the invention] 【0017】 V. Detailed explanation In certain embodiments, the spark current profile (i.e., spark output) can be adjusted to match the flow velocity and spark generation location in the electrode gap. This allows for smaller fluctuations in state of charge (SOC) and thus makes it possible to achieve the above engine performance targets with ultra-dilute hydrogen fuel mixtures. 【0018】 In certain embodiments, the above drawbacks can be mitigated by a) detecting the spark location and associated flow velocity based on the trend of the spark voltage after voltage breakdown, b) predicting the SOC based on simulations that correlate the spark location, flow velocity, spark output, and SOC, and c) adjusting the spark waveform / output during the same spark event to minimize SOC fluctuations. 【0019】 In a particular embodiment, a method for controlling the start of combustion in an internal combustion engine, comprising providing a pre-combustion chamber, the pre-combustion chamber comprising an outer and inner surface sealing a pre-combustion chamber volume, one or more exhaust ports communicating between the outer and inner surfaces for introducing a fuel-air mixture into the pre-combustion chamber volume, and a spark gap electrode assembly comprising a primary electrode disposed within the pre-combustion chamber volume and one or more ground electrodes disposed within the pre-combustion chamber volume and offset from the primary electrode to form one or more electrode gaps, and one or more A method is disclosed that includes introducing a spark across at least one electrode gap to ignite a fuel-air mixture; measuring the initial trend of the spark voltage or spark current of the spark; determining whether the spark was initiated at the leading or trailing edge of the electrode gap; determining whether the flow at the spark's location is high or low; and controlling the initial rate of flame propagation by adjusting the ignition delay to maintain a substantially constant combustion start, based on whether the spark was initiated at the leading or trailing edge and whether the spark flow is high or low. One or more electrode gaps are approximately 2 mm-1 ~about 4mm -1 It may have a surface area-to-volume ratio of approximately 2 mm for an engine power density of approximately 10 bar BMEP. The surface area-to-volume ratio of one or more electrode gaps is approximately 2 mm for an engine power density of approximately 10 bar BMEP. -1 ~Approximately 4mm of engine power density for BMEP of about 20 bar -1 The BMEP may change in proportion to the BMEP. The fuel-air mixture may have a uniform velocity distribution that changes by less than 50% per cycle in the pre-combustion chamber volume and electrode gap. 【0020】 The spark output is determined using combustion simulations to achieve the target combustion start value and stable engine operation, and can be adjusted by a predetermined amount stored in one or more ignition control module lookup tables. The spark output can be increased if the spark is initiated at the leading edge. The spark output can be increased inversely proportional to the flow velocity at the spark's position. The spark output can be decreased if the spark is initiated at the trailing edge. The spark output can be decreased inversely proportional to the flow velocity at the spark's position. 【0021】 The determination step may include comparing the initial trend of the spark voltage or spark current of the spark with a predetermined spark waveform. The predetermined spark waveform may be determined by considering at least one of the following: whether the spark is initially located between the leading and trailing edges, and whether the spark initially has a flow velocity between the average leading edge velocity and the average trailing edge velocity. The step of adjusting the spark output may be performed in the same cycle in which the spark was introduced in order to achieve the target combustion initiation. 【0022】 The method may further include determining that an arc extinction condition exists if a steep and short rise in the spark voltage is detected as exponential or sinusoidal ringing. The method may further include determining that a stable flame condition exists if either (1) a flat trend in the spark voltage after a voltage breakdown event, followed by a subsequent rate of increase exceeding a predetermined value, or (2) an immediate rise in the spark voltage after a voltage breakdown event that is not exponential or sinusoidal ringing and has a rate of increase below a predetermined value is detected. The method may further include determining that a flame extinction or slow combustion condition exists if either (1) a decrease in the spark voltage after a voltage breakdown event indicating insufficient arc movement and extension from the leading edge of the electrode, or (2) a rise in the spark voltage after a voltage breakdown event at a rate exceeding a predetermined value indicating that arc extinction from the trailing or leading edge of the electrode is expected. The method may further include determining that a fast combustion or knocking condition exists if a rise in the spark voltage within a predetermined range is detected after a voltage breakdown event. The method may further include predicting combustion onset based on engine design, fuel characteristics, and one or more operating conditions, using at least one of the trends in spark voltage or spark current after a voltage breakdown event. 【0023】 In certain embodiments, a high-energy programmable ignition system for an internal combustion engine is disclosed, comprising at least one of a spark voltage sensor for detecting a spark voltage from one or more spark gap electrodes in a pre-combustion chamber and a spark current sensor for detecting a spark current from one or more spark gap electrodes in a pre-combustion chamber; and an ignition control module configured to receive at least one of a spark voltage and a spark current from one or more spark gap electrodes, measure the initial trend of the spark voltage or spark current of one or more spark gap electrodes, determine whether the spark was initiated at the leading or trailing edge of one or more spark gap electrodes, determine whether the flow at the spark location is fast or slow, and control the initial rate of flame growth by adjusting the output to the spark to maintain a substantially constant combustion start by adjusting the ignition delay based on whether the spark was initiated at the leading or trailing edge and whether the spark flow is fast or slow. 【0024】 The ignition control module may be configured to adjust the spark output by a predetermined amount, determined using combustion simulations and stored in one or more ignition control module lookup tables, in order to achieve a target combustion start value and stable engine operation. The ignition control module may be configured to increase the output to the spark if the spark is initiated at the leading edge. The ignition control module may be configured to increase the spark output inversely proportional to the flow velocity at the spark's position. The ignition control module may be configured to decrease the output to the spark if the spark is initiated at the trailing edge. The ignition control module may be configured to decrease the spark output inversely proportional to the flow velocity at the spark's position. 【0025】 The ignition control module may be configured to compare the initial trend of the spark voltage or spark current of a spark with a predetermined spark waveform. The predetermined spark waveform may be determined by considering at least one of the following: whether the spark is initially located between the leading and trailing edges, and whether the spark initially has a flow velocity between the average leading edge velocity and the average trailing edge velocity. The ignition control module may be configured to adjust the spark output in the same cycle in which the spark was introduced in order to achieve a target combustion start. The ignition control module may be configured to determine that an arc extinction condition exists if a steep and short rise in the spark voltage is detected as exponential or sinusoidal ringing. 【0026】 The ignition control module may be further configured to determine that a stable flame state exists if either (1) a flat trend in the spark voltage after a voltage breakdown event, followed by a subsequent rate of increase exceeding a predetermined value, or (2) an immediate increase in the spark voltage after a voltage breakdown event that is not exponential or sinusoidal ringing and has a rate of increase below a predetermined value. The ignition control module may be further configured to determine that a quenching or slow combustion state exists if either (1) a decrease in the spark voltage after a voltage breakdown event indicating insufficient arc movement and extension from the leading edge of the electrode, or (2) an increase in the spark voltage after a voltage breakdown event at a rate exceeding a predetermined value indicating that arc extinction from the trailing or leading edge of the electrode is expected. The ignition control module may be further configured to determine that a fast combustion or knocking state exists if an increase in the spark voltage within a predetermined range is detected after a voltage breakdown event. The ignition control module may be further configured to predict combustion onset based on engine design, fuel characteristics, and one or more of one or more operating conditions, using at least one of the trends in spark voltage or spark current after a voltage breakdown event. 【0027】 In certain embodiments, advanced 3D combustion CFD (Computational Fluid Dynamics) and ID modeling and simulation of ignition nucleus dynamics, defined as arc movement and arc extension occurring at the spark gap electrode, can be used to create correlations between arc voltage and current waveforms, ignition nucleus dynamics, and predicted SOC and flame characteristics. These correlations can then be used to derive spark control methods for each engine and spark plug design. This can then be used to obtain predictive model-based spark control with the following capabilities: 【0028】 In a specific embodiment as shown in Figure 3, if sufficient arc movement and arc extension 310 are predicted from the leading edge of the spark gap electrode to achieve a proper SOC and a stable flame, the spark can be terminated to avoid electrode hot spots that cause premature SOC and high electrode wear. 【0029】 In a particular embodiment as shown in Figure 4, if insufficient arc movement and extension 410 that would result in extinction or a hot spot is predicted from the leading edge of the electrode, an enhancement of the spark waveform or a subsequent enhanced spark can be triggered within the same cycle, which is predicted to achieve a proper SOC and a stable flame. 【0030】 In a specific embodiment as shown in Figure 5, if sufficient arc extension 510 is predicted from the trailing edge of the electrode to achieve a proper SOC and a stable flame, the spark can be terminated to avoid electrode hot spots that cause premature SOC and high electrode wear. 【0031】 In a particular embodiment as shown in Figure 6, if an arc extinction 610 resulting in flame quenching is predicted from the trailing or leading edge of the electrode, a subsequent spark with enhanced spark or waveform enhancement can be triggered within the same cycle, which is predicted to achieve a proper SOC and a stable flame. 【0032】 In certain embodiments, such as those shown in FIG. 7, the active scavenging pre - combustion chamber design 700 can have electrodes 710 that are radially arranged and have a large surface area and a small gap designed to achieve high durability, and one or more scavenging ports 720. In certain embodiments having an engine output density of 20 bar BMEP or more, a typical electrode surface area can be 9 mm 2 or more, and the gap size can be 0.25 mm or less. Thus, the resulting gap surface area to volume ratio can be 9 mm 2 / (9 mm 2 ×0.25 mm)=4 mm -1 or more. In certain embodiments having an engine output density less than 20 bar BMEP, the electrode gap surface area to volume ratio can be less than 4 mm -1 . In certain embodiments, for applications having an output density of about 10 bar BMEP, the electrode surface area can be about 1 mm 2 , and the gap size can be about 0.5 mm. In these embodiments, the resulting gap surface area to volume ratio can be about 1 mm 2 / (1 mm 2 ×0.5 mm)=2 mm -1 . In certain embodiments, for applications having an output density of 10 bar BMEP to 20 bar BMEP, an electrode surface area to volume ratio that is approximately proportional to the output density ratio can be used. For example, an application having an output density of 15 bar BMEP can use an electrode surface area to volume ratio of about 3 mm -1 (15 / 10×2 = 15 / 20×4 = 3). 【0033】 In certain embodiments, the flow velocity in the gap between the electrodes and four typical spark positions at the edges of the electrodes of the active scavenging pre - combustion chamber plug 800 having a radial gap can be as shown in FIG. 8. In these embodiments, the flow velocity distribution of the fuel - air mixture within the pre - combustion chamber volume portion, and the direction and magnitude of the flow within the electrode gap, can be extremely uniform and reproducible with cycle - to - cycle variations of less than 50%. 【0034】 In a particular embodiment, the four positions can be characterized as follows: • Position (810): Leading edge / low speed • Position (820): Leading edge / High speed ·Position (830): Trailing edge / low speed ·Position (840): Trailing edge / high speed 【0035】 Depending on the initial spark location and local flow velocity, the State of Charge (SOC) can fluctuate significantly due to arc movement and flame kernel formation. This can lead to significant combustion instability, particularly in H2-TCEs operating in ultra-lean fuel mixtures, which hinders operation at high engine power density (BMEP) and efficiency (BTE). 【0036】 In certain embodiments, the range of spark voltage and current fluctuations obtained during engine operation using an active scavenging pre-combustion chamber and a high-energy programmable open-loop ignition system may be as shown in Figure 9. Analysis of these waveforms can enable the determination of the degree of arc extension fluctuation 910 and the occurrence of arc extinction 920, which is identified when a steep, short rise in spark voltage is detected as exponential or sinusoidal ringing. 【0037】 In certain embodiments, it may be possible to determine the approximate location where the spark first occurred, for example, position (810): leading edge / low speed or position (840): trailing edge / high speed, by appropriately analyzing the spark voltage and current waveform. 【0038】 In certain embodiments, the approximate location where the spark first occurred can be used to generate predictions of the flame growth rate and the resulting state of charge (SOC) using a verified combustion CFD. The spark location values ​​and corresponding SOC predictions can be edited in a lookup table. 【0039】 In a particular embodiment as shown in Figure 10, predictive model-based spark control may include a programmable high-energy closed-loop ignition system 1000 in which a spark voltage sensor 1010 and a current sensor 1020 of the spark plug 1030 are added to the ignition coil secondary winding constituting the ignition coil 1040. These sensors can provide a spark waveform feedback signal 1050 to a smart spark control module 1060 (also known as the ignition control module), which generates a spark waveform control signal 1070 and a spark trigger control signal 1080 to the ignition driver 1090, which in turn adjusts the ongoing (i.e., nominal) spark current waveform to a predetermined current waveform stored in the ignition control module lookup table as needed to achieve a SOC sufficiently close to the target value during the same ignition event, thus reducing fluctuations between combustion cycles and the occurrence of combustion anomalies such as backfire, knocking, and pre-ignition. 【0040】 In certain embodiments, the spark voltage sensor 1010, the spark current sensor 1020, and the smart spark control module 1060 may be incorporated into a high-energy programmable spark ignition system. In certain embodiments, the high-energy programmable spark ignition system may be such as that described in the above reference [4]. 【0041】 In certain embodiments, the overall functionality of a predictive model-based spark control system (also known as an adaptive control pre-combustion chamber ignition system) may be as shown in Figure 11. 【0042】 In certain embodiments, the smart spark control module can use the spark waveform feedback signal from the ignition coil to predict the State of Combustion (SOC) based on combustion simulation results stored in a lookup table, and issue the following three main commands to the ignition driver: a. If the predicted SOC is as targeted, no adjustments to ongoing sparks are necessary. b. If the predicted SOC occurs later than the target, increase the ongoing spark energy / power up to a predetermined spark waveform stored in the lookup table. c. If the predicted SOC occurs earlier than the target, the ongoing spark energy / power is reduced to a predetermined spark waveform stored in the lookup table. 【0043】 In certain embodiments, based on the above input command, the ignition driver 1090 can generate a primary pulse to the ignition coil necessary to obtain a predetermined spark waveform stored in a lookup table, which is required to achieve a SOC close to the target value, and thus reduce inter-cycle fluctuations of the SOC. 【0044】 In a particular embodiment as shown in Figure 12, a predictive model-based spark control method may include the following steps: Step 1210 allows raw voltage and / or current feedback signals from the ignition coil secondary to be supplied to the signal conditioning and processing circuit of the smart spark control module. Step 1220 allows the spark waveform feedback signal to be converted into signal data by the signal conditioning and processing circuit. 【0045】 In certain embodiments, such as those shown in step 1230, the signal data from the adjustment and processing circuits may have a predetermined trend that provides a basis for determining the approximate initial spark location and associated flow velocity. Exemplary trends are shown in Figures 13 to 16. Figure 13 shows an example of a steep arc voltage rise 1310 of about 20 volts / μs or more following spark breakdown. Figure 14 shows an example of a gradual arc voltage rise 1410 in the range of about 10 volts / μs following spark breakdown. Figure 15 shows an example of a flat arc voltage 1510 following spark breakdown, including a steep rise 1520 at a later point in time. Figure 16 shows an example of an arc voltage drop 1610 following spark breakdown. 【0046】 In certain embodiments, such as those shown in step 1240, signal data can be derived from the spark voltage after a voltage breakdown event and used in conjunction with a method for predicting the approximate initial spark location and associated flow velocity based on a predetermined trend of the signal. The following are some exemplary predictions. The trend shown in Figure 13 may indicate that the trailing edge spark occurs at a high-speed location (e.g., location 840 with a velocity of about 20 m / s), which may result in fast combustion or knocking. The trend shown in Figure 14 may indicate that the trailing edge spark occurs at a low-speed location (e.g., location 830 with a velocity of about 10 m / s), which may result in a stable flame that produces normal combustion with a SOC close to the target. The trend shown in Figure 15 may indicate that the leading edge spark occurs at a high-speed location (e.g., location 820 with a velocity of about 15 m / s), which may result in a stable flame that produces normal combustion with a SOC close to the target. The trend shown in Figure 16 may indicate that leading-edge sparks occur at low-speed positions (e.g., position 810 with a velocity of approximately 10 m / s), which can lead to slow combustion or flame extinction. 【0047】 In certain embodiments, such as those shown in step 1250, approximate initial spark location and associated velocity information can be used in a lookup table, which provides a correlation between the approximate initial spark location and associated velocity, the spark waveform, and the target SOC value, based on combustion CFD simulation predictions. In certain embodiments, a combustion CFD simulation for a leading-edge spark occurring at a low-velocity location (e.g., location 810) may be as shown in Figure 17. At location 810, it can be seen that the initial flame front can be achieved after approximately 4.8 crank angles (CAD) (11.70 - 6.90 = 4.8). This initial flame front can be used, for example, to define the SOC. In certain embodiments, the CFD image shown in Figure 17 shows that the velocity field within the spark gap is uniform and has a magnitude of approximately 10 m / s. Image 1710 shows that the initial spark 1720 occurs at the leading edge at a timing of -11.70 CAD. Image 1730 shows that at a timing of -10.09 CAD, the arc has moved approximately 0.6 mm within the gap due to the force acting on the arc by the flow field. Image 1740 shows that a flame kernel is generated within the electrode gap at -8.50 CAD. Image 1770 shows that the front of the initial flame is formed outside the gap at -6.90 CAD. This state is defined as the state of combustion (SOC). The total time from spark generation (-11.70 CAD) to SOC (-6.90 CAD) defines an ignition delay of 4.8 CAD. For a given engine operating state, predictive model-based spark control can achieve consistent ignition delay (or SOC), thereby preventing the occurrence of abnormal combustion that limits the achievement of higher engine power density and efficiency. 【0048】 Other examples of combustion simulations for different sparks occurring at different locations are provided in the above reference [1]. In a particular embodiment, as shown in Figure 18, the example lookup table can correlate the approximate initial position of the spark to the spark waveform required to achieve the target SOC value. In a particular embodiment, the spark current profile 1810 can be correlated to the low-speed leading edge at position 810, the spark current profile 1820 can be correlated to the high-speed leading edge at position 820, the spark current profile 1830 can be correlated to the low-speed trailing edge at position 830, and the spark current profile 1840 can be correlated to the high-speed trailing edge at position 840. 【0049】 In certain embodiments, if the approximate initial spark position is at the leading edge for any given target SOC, a higher energy / power spark may be required, and the spark's energy / power may be inversely proportional to the flow velocity at the spark position. Conversely, if the approximate initial spark position is at the trailing edge, a lower energy / power spark may be required. The target SOC may be determined by the ignition timing (IT) and may be defined to be approximately in the middle of the range of SOC variation. 【0050】 In certain embodiments, such as those shown in step 1260, the ongoing spark waveform can be adjusted to match a predetermined spark waveform from a lookup table 1250 that corresponds to a predicted approximate initial spark position and may be required to achieve the target SOC. For example, if the preceding cycle has a spark position 810 (low-speed leading edge) and the prediction for the current cycle is position 830 (low-speed trailing edge), the spark waveform should be adjusted from waveform 1810 to waveform 1830. 【0051】 In certain embodiments, such as those shown in step 1270, the smart spark control module can perform continuous loop control for each combustion cycle as needed to match a predetermined spark waveform from a lookup table that corresponds to the predicted approximate initial spark position and may be required to achieve the target SOC, thereby performing same-cycle adjustments to the ongoing spark waveform. 【0052】 Predictive model-based spark control in certain embodiments represents an improvement over the prior art. Combustion instability in hydrogen engines, primarily but not limited to (backfire, knocking, and pre-ignition shown in Figure 2), can be mitigated by improving the homogeneity of the air-fuel mixture and reducing engine power that reduces engine efficiency. No known ignition system features adaptive spark control capable of mitigating the degree of combustion instability as defined in this disclosure. Neither high-energy / power ignition systems nor low-energy / power ignition systems can mitigate combustion instability, particularly in hydrogen engines, to any significant degree. 【0053】 In certain embodiments, a conventional spark ignition system may include an ignition driver 1910, an ignition coil 1920, and a spark plug 1930, as shown in Figure 19. Compared to a conventional system (Figure 19), a predictive model-based spark control system (also known as an adaptive control pre-combustion chamber ignition system 1000, for example, as shown in Figures 10 and 11) may feature a voltage sensor 1010 and / or current sensor 1020 on the secondary side of a coil winding 1040, as shown in Figure 10, a smart spark control module 1060, as shown in Figures 10 and 11, and a communication path that supplies a spark waveform control signal 1070 and a spark trigger control signal 1080 from the smart spark control module to the ignition driver 1090, as shown in Figure 10. 【0054】 In certain embodiments, a significant improvement in H2-ICE performance can be achieved by combining active scavenging pre-combustion chamber technology with predictive model-based spark control. 【0055】 In certain embodiments, advanced combustion modeling and simulation of the ignition process, including spark events, arc movement and extension, and the resulting flame propagation, can be used to predict the relationship between spark energy / power, flow within the electrode gap, and initial flame growth that defines the State of Composite (SOC) for different engines and under various conditions. This information can be used to adjust the spark energy / power characteristics during spark events in the same cycle to minimize SOC fluctuations and significantly reduce the tendency for combustion anomalies such as backfire, knocking, and pre-ignition, which hinder the achievement of high engine power density and efficiency. 【0056】 In certain embodiments, the spark voltage and / or current from the secondary side of the coil winding may be used as a feedback signal 1050 by a smart spark control module 1060 (Figure 11) that controls the ignition driver 1090 (Figure 10) and enables necessary adjustments to the spark current waveform to minimize SOC fluctuations. 【0057】 In certain embodiments, the initial trend of the spark voltage signal after a voltage breakdown event can be used to determine the location where the spark first occurs and the flow velocity at that location. This information can then be used to predict the time of SOC occurrence. Subsequently, the ongoing spark output can be adjusted to match the target SOC using the correlation between spark output and SOC, which can be stored in a lookup table. This method of controlling the spark output during spark events in the same cycle may be necessary to reduce SOC fluctuations, thereby improving engine combustion performance and exhaust emissions. Furthermore, controlling the spark output during spark events in the same cycle can minimize the rate of electrode corrosion caused by high-energy ignition systems, thus significantly improving the durability of the spark plug electrodes. 【0058】 Therefore, certain embodiments offer the unique advantage that an engine fueled by a hydrogen mixture can operate with higher efficiency and lower exhaust emissions at higher power densities. This means that, as a result of the present invention, hydrogen engines can compete with fuel cells and thus provide a viable alternative for accelerating global decarbonization. 【0059】 While specific embodiments of the present invention have been described, it will be understood by those skilled in the art that various modifications can be made and replaced by equivalents without departing from the true spirit and scope of the invention as defined by the appended claims. In addition, many modifications can be made to adapt specific situations, materials, compositions, methods, or one or more operations to the purpose, spirit and scope of the invention. All such modifications are intended to fall within the scope of the appended claims. In particular, while the methods disclosed herein describe specific operations performed in a specific order, it will be understood that these operations can be combined, subdivided, or rearranged to form equivalent methods without departing from the teachings of the invention. Therefore, unless otherwise indicated herein, the order and grouping of operations does not limit the invention.

Claims

[Claim 1] A method for controlling the start of combustion in an internal combustion engine, To provide a pre-combustion chamber, the pre-combustion chamber is The outer and inner surfaces that seal the volume section of the pre-combustion chamber, In order to introduce a fuel-air mixture into the pre-combustion chamber volume, one or more discharge ports are provided that communicate between the outer surface and the inner surface. A spark gap electrode assembly, A primary electrode arranged within the pre-combustion chamber volume section, Displaced within the pre-combustion chamber volume and offset from the primary electrode to form one or more electrode gaps, Spark gap electrode assembly including Including providing, The spark gap electrode assembly generates a spark across at least one of the one or more electrode gaps to ignite the fuel-air mixture. To measure the initial trend of the spark voltage or spark current of the spark, The determination of whether the spark started at the leading edge or trailing edge of the electrode gap is made based on the initial trend of the spark voltage. To determine whether the flow at the spark location is high-speed or low-speed, based on the initial trend of the spark voltage, The initial speed of flame propagation is controlled by adjusting the ignition delay to achieve stable engine operation by adjusting the output of the spark based on whether the spark was initiated at the leading edge or trailing edge and whether the flow of the spark is high speed or low speed. A method that includes this. [Claim 2] The gap between one or more electrodes is approximately 2 mm. -1 ~about 4mm -1 The method according to claim 1, having a surface area to volume ratio. [Claim 3] The surface area to volume ratio of the one or more electrode gaps is approximately 2 mm for an engine power density of approximately 10 bar BMEP. -1 ~Approximately 20 bar BMEP engine power density of approximately 4 mm -1 The method according to claim 2, wherein the value changes in proportion to BMEP. [Claim 4] The method according to claim 1, wherein the fuel-air mixture has a uniform flow velocity distribution that changes by less than 50% per cycle in the pre-combustion chamber volume and electrode gap. [Claim 5] The method according to claim 1, wherein the output of the spark is adjusted by a predetermined amount determined from the target combustion initiation value using a combustion simulation and one or more ignition control module lookup tables that store the correlation between the spark output and the target combustion initiation value, in order to achieve the target combustion initiation value and to achieve stable engine operation. [Claim 6] The method according to claim 1, wherein the output to the spark is increased when the spark is initiated at the leading edge. [Claim 7] The method according to claim 6, wherein the output of the spark is increased inversely proportional to the flow velocity at the position of the spark. [Claim 8] The method according to claim 1, wherein the output to the spark is reduced when the spark is initiated at the trailing edge. [Claim 9] The method according to claim 8, wherein the output of the spark is reduced in inverse proportion to the flow velocity at the position of the spark. [Claim 10] The method according to claim 1, wherein determining whether the spark was initiated at the leading or trailing edge of the electrode gap and whether the flow at the spark location is high speed or low speed includes comparing the initial trend of the spark voltage or spark current of the spark with a predetermined spark waveform. [Claim 11] The method according to claim 10, wherein the predetermined spark waveform is determined according to whether the spark is initially located between the leading edge and the trailing edge, and whether the spark initially has a flow velocity between the average leading edge velocity and the average trailing edge velocity. [Claim 12] The method according to claim 1, wherein the output of the spark is adjusted to the same combustion cycle in which the spark was generated in order to achieve a target combustion start. [Claim 13] The method according to claim 1, further comprising triggering a subsequent spark with an enhanced waveform in response to determining that an arc extinction condition exists when a steep and short rise in the spark voltage is detected to be exponential or sinusoidal ringing. [Claim 14] The method according to claim 1, further comprising terminating the spark in response to determining that a stable flame state exists when either (1) a flat trend in the spark voltage after a voltage breakdown event, followed by a subsequent rate of increase exceeding a predetermined value, or (2) an immediate increase in the spark voltage after a voltage breakdown event having a rate of increase that is not exponential or sinusoidal and is below a predetermined value is detected. [Claim 15] The method according to claim 1, further comprising triggering a subsequent spark with an enhanced spark or a strengthened waveform in response to determining that a quenching or slow combustion state exists when either (1) a decrease in spark voltage after a voltage breakdown event indicating insufficient arc movement and extension from the leading edge of the electrode gap, or (2) an increase in spark voltage after a voltage breakdown event at a rate exceeding a predetermined value, indicating that arc extinction from the trailing or leading edge of the electrode gap is expected. [Claim 16] The method according to claim 1, further comprising adjusting the output of the spark in response to determining that a high-speed combustion or knocking condition exists when an increase in spark voltage within a predetermined range is detected after a voltage breakdown event. [Claim 17] A high-energy programmable ignition system for an internal combustion engine, At least one of a spark voltage sensor for detecting the spark voltage from one or more spark gap electrodes in the pre-combustion chamber and a spark current sensor for detecting the spark current from one or more spark gap electrodes in the pre-combustion chamber, It is an ignition control module, Receiving at least one of the spark voltage and spark current from the one or more spark gap electrodes, To measure the initial trend of the spark voltage or spark current of one or more spark gap electrodes, To determine whether the spark originated at the leading edge or trailing edge of the one or more spark gap electrodes, based on the initial trend of the spark voltage. To determine whether the flow at the location of the spark is high speed or low speed, based on the initial trend of the spark voltage. The initial rate of flame growth is controlled by adjusting the ignition delay to achieve stable engine operation by adjusting the output to the spark based on whether the spark was initiated at the leading edge or trailing edge and whether the flow of the spark is high speed or low speed. An ignition control module configured to perform the following: A high-energy programmable ignition system including a high-energy programmable ignition system. [Claim 18] The system according to claim 17, wherein the ignition control module is configured to adjust the spark output by a predetermined amount determined from the target combustion start value, using one or more ignition control module lookup tables that store a combustion simulation and a correlation between the spark output and the target combustion start value, in order to achieve a target combustion start value and to achieve stable engine operation. [Claim 19] The system according to claim 17, wherein the ignition control module is configured to increase the output to the spark when the spark is initiated at the leading edge. [Claim 20] The system according to claim 19, wherein the ignition control module is configured to increase the output of the spark in inverse proportion to the flow velocity of the spark at the position of the spark. [Claim 21] The system according to claim 17, wherein the ignition control module is configured to reduce the output to the spark when the spark is started at the trailing edge. [Claim 22] The system according to claim 21, wherein the ignition control module is configured to reduce the output of the spark in inverse proportion to the flow velocity of the spark at the position of the spark. [Claim 23] The system according to claim 17, wherein the ignition control module is configured to compare the initial trend of the spark voltage or spark current of the spark with a predetermined spark waveform. [Claim 24] The system according to claim 23, wherein the predetermined spark waveform is determined depending on whether the spark is initially located between the leading edge and the trailing edge, and whether the spark initially has a flow velocity between the average leading edge velocity and the average trailing edge velocity. [Claim 25] The system according to claim 17, wherein the ignition control module is configured to adjust the output of the spark in the same combustion cycle in which the spark was generated in order to achieve a target combustion start. [Claim 26] The system according to claim 17, wherein the ignition control module is configured to trigger a spark enhancement or a subsequent spark with an enhanced waveform in response to determining that an arc extinction condition exists when it detects that the steep and short rise in the spark voltage is exponential or sinusoidal ringing. [Claim 27] The system according to claim 17, wherein the ignition control module is further configured to terminate the spark in response to determining that a stable flame state exists when either (1) a flat trend in the spark voltage after a voltage breakdown event, followed by a subsequent rate of increase exceeding a predetermined value, or (2) an immediate increase in the spark voltage after a voltage breakdown event having a rate of increase that is not exponential or sinusoidal ringing and is less than a predetermined value. [Claim 28] The system according to claim 17, wherein the ignition control module is further configured to trigger a subsequent spark with an enhanced spark or a strengthened waveform in response to determining that a quenching or slow combustion state exists when either (1) a decrease in spark voltage after a voltage breakdown event indicating insufficient arc movement and extension from the leading edge of the electrode, or (2) an increase in spark voltage after a voltage breakdown event at a rate exceeding a predetermined value indicating that arc extinction from the trailing or leading edge of the electrode is expected. [Claim 29] The system according to claim 17, wherein the ignition control module is further configured to adjust the output of the spark in response to determining that a high-speed combustion or knocking condition exists when an increase in spark voltage within a predetermined range is detected after a voltage breakdown event.