An acoustic feedback aerospace methane engine electric ignition system

Abstract

The present application relates to the technical field of aerospace engine, and specifically discloses an acoustic feedback type aerospace methane engine electric ignition system.The present application collects the sound signal generated by electric spark through integrating an audio frequency sensor at the ignition electrode, cooperates with the signal amplification and filtering circuit to carry out signal amplification and filtering processing, and carries out frequency analysis and amplitude analysis by the host computer, solves the technical problems that the existing exciter cannot judge the spark working state due to the absence of feedback circuit, and the signal clutter interference of the transformer voltage acquisition scheme is serious and it is difficult to accurately feedback the ignition condition, improves the accuracy of spark frequency and spark energy size determination in the ignition process, and meets the stringent requirements of aerospace methane engine on ignition reliability and state measurability.

Description

Technical Field

[0001] This invention relates to the field of aerospace engine technology, and in particular to an acoustic feedback type electric ignition system for aerospace methane engines. Background Technology

[0002] In the field of aerospace liquid rocket engines, the reliability of the electric ignition system directly affects the success or failure of engine startup and flight safety. Existing electric ignition systems mainly consist of an ignition nozzle, ignition cable, and exciter. The exciter adopts a single-socket dual-power supply structure and internally incorporates filtering, protection, control, and energy storage circuits. Existing technologies have two significant drawbacks: first, the exciter, lacking a feedback circuit, cannot accurately determine whether a spark has been generated normally and the spark's operating status; second, while the feedback scheme using transformer voltage acquisition can achieve ignition status monitoring, the actual measurement signal suffers from severe noise interference, making it difficult to accurately report the ignition status and spark condition. These deficiencies result in a lack of effective closed-loop monitoring of the ignition process, making it difficult to meet the stringent requirements of aerospace methane engines for ignition reliability and status measurability.

[0003] Therefore, there is an urgent need to provide a technical solution to address the above problems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an acoustic feedback-based electric ignition system for aerospace methane engines. The technical solution of this acoustic feedback-based electric ignition system for aerospace methane engines is as follows: Includes: exciter, ignition cable, ignition nozzle, audio sensor, audio signal amplification and filtering circuit, and main control computer; The actuator is connected to the ignition nozzle via the ignition cable. The actuator is used to generate a high-voltage electric pulse and transmit the high-voltage electric pulse to the ignition nozzle via the ignition cable, so that the ignition nozzle generates an electric spark. The audio sensor is integrated with the ignition nozzle as a single component, and the audio sensor is used to collect the sound signal when the ignition nozzle generates an electric spark. The input terminal of the audio signal amplification and filtering circuit is connected to the output terminal of the audio sensor, and the audio signal amplification and filtering circuit is used to amplify and filter the sound signal. The input terminal of the main control computer is connected to the output terminal of the audio signal amplification and filtering circuit. The main control computer is used to perform frequency analysis and amplitude analysis on the amplified and filtered audio signal, and to determine the spark frequency and spark energy of the electric spark based on the analysis results.

[0005] The beneficial effects of the acoustic feedback-type electric ignition system for aerospace methane engines of the present invention are as follows: The system of this invention integrates an audio sensor at the ignition nozzle to collect the sound signal generated by the electric spark. It then uses an audio signal amplification and filtering circuit to amplify and filter the signal, and the main control computer performs frequency and amplitude analysis. This solves the technical problems of existing exciters lacking feedback circuits, which makes it impossible to determine the spark working status, and transformer voltage acquisition schemes, which suffer from severe signal noise interference and difficulty in accurately feeding back the ignition status. The system improves the accuracy of spark frequency and spark energy determination during the ignition process, meeting the stringent requirements of aerospace methane engines for ignition reliability and status measurability.

[0006] Based on the above scheme, the acoustic feedback type electric ignition system for aerospace methane engines of the present invention can be further improved as follows.

[0007] In one alternative embodiment, the audio sensor is disposed outside the ignition part and is used to collect the sound signal when the ignition nozzle generates an electric spark. The ignition nozzle is disposed inside the ignition part and is used to generate an electric spark.

[0008] The beneficial effects of adopting the above-mentioned optional method are as follows: by further setting the audio sensor outside the ignition part and setting the ignition nozzle inside the ignition part, the audio sensor avoids the high-temperature combustion environment while the ignition nozzle penetrates into the combustion area, which solves the technical problems of sensor damage due to high temperature and insufficient ignition position of the nozzle, and improves the sensor protection effect and ignition position accuracy.

[0009] In one optional embodiment, the audio signal amplification and filtering circuit includes a signal amplification circuit and a filtering circuit; the signal amplification circuit is used to amplify the amplitude of the sound signal to obtain an amplified sound signal; the filtering circuit is used to filter the amplified sound signal to obtain an amplified and filtered audio signal.

[0010] The advantages of adopting the above-mentioned optional method are as follows: the hierarchical processing method of further amplifying the amplitude of the sound signal through the signal amplification circuit and filtering the amplified sound signal through the filtering circuit enhances the ability to extract weak sound signals and suppresses environmental noise interference. It solves the technical problem of inaccurate analysis caused by the low signal-to-noise ratio of the original signal and improves the signal quality and reliability of subsequent analysis.

[0011] In one alternative embodiment, the filtering circuit is a bandpass filter circuit, the passband frequency range of which matches the frequency range of the electrical spark sound, and the filtering circuit is also used to filter out frequency components of ambient noise.

[0012] The beneficial effects of adopting the above-mentioned optional method are as follows: by further using a bandpass filter circuit whose passband frequency range matches the frequency spectrum range of the electric spark sound, the characteristic frequency of the electric spark sound is accurately preserved and irrelevant environmental noise is filtered out, which solves the technical problem of signal recognition difficulties caused by noise spectrum overlap and improves the purity and frequency resolution accuracy of the electric spark sound signal.

[0013] In one alternative approach, the analysis results include spark frequency and spark energy level; The main control computer is specifically used to: perform a fast Fourier transform on the amplified and filtered audio signal and extract the spark frequency, and detect the peak amplitude of the amplified and filtered audio signal and map it to the spark energy level.

[0014] The beneficial effects of adopting the above-mentioned optional method are as follows: by further performing fast Fourier transform on the amplified and filtered audio signal to extract the spark frequency, and detecting the peak amplitude and mapping it to the spark energy level, a quantitative correspondence between the sound signal and the ignition parameters is established, which solves the technical problem of the lack of objective evaluation standards for spark frequency and energy, and improves the quantitative evaluation capability and analysis accuracy of ignition status.

[0015] In one alternative embodiment, the exciter internally includes a filter protection circuit, a control circuit, and an energy storage circuit; the input terminal of the filter protection circuit is connected to an external power source, and the output terminal of the filter protection circuit is connected to the control circuit; the output terminal of the control circuit is connected to the energy storage circuit; and the output terminal of the energy storage circuit is connected to the ignition cable.

[0016] The advantages of adopting the above-mentioned optional method are as follows: by further setting up a modular structure of filtering protection circuit, control circuit and energy storage circuit inside the exciter, the connection relationship and signal flow of each functional circuit are clarified, the problems of chaotic circuit layout and electromagnetic compatibility are solved, and the electromagnetic anti-interference capability and ignition pulse output stability of the exciter are improved.

[0017] In one alternative embodiment, the ignition nozzle is installed in the combustion chamber of an aerospace methane engine. The combustion chamber is provided with an oxygen line interface and a methane line interface. The oxygen line interface is used to connect to an oxygen line, and the methane line interface is used to connect to a methane line.

[0018] The advantages of adopting the above-mentioned optional method are as follows: by further installing the ignition nozzle in the combustion chamber which is equipped with oxygen pipeline interface and methane pipeline interface, the interface adaptation between the ignition system and the engine combustion chamber is completed, the technical problem of insufficient coordination between ignition position and fuel delivery path is solved, and the integration between the ignition system and the methane engine combustion chamber is improved.

[0019] In an alternative embodiment, the master computer is further configured to: After determining that both the spark frequency and the spark energy level have reached preset thresholds, the oxygen pipeline is controlled to supply oxygen to the combustion chamber, and the methane pipeline is controlled to supply methane to the combustion chamber.

[0020] The beneficial effects of adopting the above-mentioned optional method are as follows: by further controlling the oxygen pipeline and methane pipeline to deliver fuel after judging that the spark frequency and spark energy level have both reached the preset threshold, the sequential logic of ignition status confirmation and fuel supply is established, which solves the technical problem of ignition failure or detonation risk caused by premature fuel injection, and improves the safety of ignition timing and the reliability of engine starting.

[0021] In one alternative embodiment, the audio sensor and the ignition nozzle are integrated into the same component via a mounting flange fixed to the outer wall of the combustion chamber. The audio sensor is located outside the combustion chamber, and the ignition nozzle extends through the mounting flange into the interior of the combustion chamber. A sealing structure is provided between the mounting flange and the outer wall of the combustion chamber.

[0022] The advantages of adopting the above-mentioned optional method are as follows: by further integrating the audio sensor and the ignition nozzle into the same component through the mounting flange, and fixing the mounting flange to the outer wall of the combustion chamber and setting a sealing structure, a compact layout of external sensor monitoring and internal nozzle ignition is formed, which solves the technical problems of loose split installation structure and combustion chamber sealing failure, and improves the system's structural compactness and combustion chamber airtightness reliability.

[0023] In one alternative approach, the main control computer is specifically used for: The amplified and filtered audio signal is sampled and stored in the time domain, and each waveform peak in the time domain waveform corresponds to a sound pulse emitted by an electric spark. The spark frequency is obtained by counting the number of waveform tips per unit time, and the spark energy level is obtained by measuring the amplitude of the waveform tips.

[0024] The advantages of adopting the above-mentioned optional method are as follows: by further performing time-domain waveform sampling and storage on the amplified and filtered audio signal, counting the number of waveform peaks per unit time to obtain the spark frequency, and measuring the amplitude of the waveform peaks to obtain the spark energy level, the calculation process of spark parameters is simplified and the processing delay is reduced. This solves the technical problem of insufficient real-time performance caused by the complexity of frequency domain transformation calculation, and improves the speed of spark parameter acquisition and the real-time monitoring capability of ignition status.

[0025] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of an embodiment of an acoustic feedback type electric ignition system for aerospace methane engines according to the present invention; Figure 2 A schematic diagram of the installation structure of the electric ignition system for a space methane engine. Figure 3 A flowchart illustrating the workflow of the electric ignition system for aerospace methane engines; Figure 4 This is a flowchart of the signal processing for the electric ignition system of a space methane engine. Figure 5 This is a schematic diagram of the measured ignition sound waveform. Detailed Implementation

[0027] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0028] Figure 1 A schematic diagram of an embodiment of an acoustic feedback-based electric ignition system for aerospace methane engines provided by the present invention is shown. Figure 1 As shown, the acoustic feedback aerospace methane engine electric ignition system includes: an exciter, an ignition cable, an ignition nozzle, an audio sensor, an audio signal amplification and filtering circuit, and a main control computer.

[0029] The actuator is connected to the ignition nozzle via the ignition cable. The actuator is used to generate a high-voltage electrical pulse and transmit the high-voltage electrical pulse to the ignition nozzle via the ignition cable, so that the ignition nozzle generates an electrical spark.

[0030] An exciter is a device that generates high-voltage electrical pulses and has internal filtering and protection circuits, control circuits, and energy storage circuits. For example, in a space methane engine ignition test, an exciter of model A generated a high-voltage electrical pulse with an amplitude of 3.5kV after receiving power from an external power source.

[0031] The ignition cable refers to the cable that connects the exciter and the ignition nozzle and transmits high-voltage electrical pulses; for example, a shielded cable with a withstand voltage rating of 10kV serves as the ignition cable, transmitting the high-voltage electrical pulses generated by the exciter to the ignition nozzle. The ignition nozzle is an actuator that receives high-voltage electrical pulses and generates an electric spark within the ignition area; for example, the ignition nozzle is installed inside the combustion chamber, and its ignition end generates a continuous electric spark under the action of the high-voltage electrical pulse.

[0032] High-voltage electrical pulse refers to a high-voltage, short-duration transient electrical signal generated by the exciter; for example, the high-voltage electrical pulse output by the exciter has an amplitude of 3.5kV and a pulse width of 5μs. Electrical spark refers to the instantaneous discharge phenomenon generated when the ignition nozzle breaks down the gas-fuel mixture under the action of a high-voltage electrical pulse; for example, a bright blue electrical spark is generated at the ignition end of the ignition nozzle when the high-voltage electrical pulse arrives, accompanied by a crisp popping sound.

[0033] The audio sensor is integrated with the ignition nozzle as a single component, and the audio sensor is used to collect the sound signal when the ignition nozzle generates an electric spark.

[0034] The audio sensor refers to a sensing element that collects the sound signal generated when an electric spark is produced, integrated into the same component as the ignition nozzle. For example, a condenser microphone is installed outside the combustion chamber as an audio sensor, with the microphone diaphragm facing the ignition nozzle to collect the sound signal. The sound signal refers to the sound wave signal accompanying the generation of the electric spark, the frequency and amplitude of which are related to the frequency and energy of the electric spark. For example, each discharge of an electric spark produces a spike-shaped sound pulse, the frequency range of which is 100Hz to 200Hz, and the original amplitude of the sound signal is approximately 50mV.

[0035] The input terminal of the audio signal amplification and filtering circuit is connected to the output terminal of the audio sensor, and the audio signal amplification and filtering circuit is used to amplify and filter the sound signal.

[0036] The input terminal of the main control computer is connected to the output terminal of the audio signal amplification and filtering circuit. The main control computer is used to perform frequency analysis and amplitude analysis on the amplified and filtered audio signal, and to determine the spark frequency and spark energy of the electric spark based on the analysis results.

[0037] The amplified and filtered audio signal refers to the electrical signal obtained after the original sound signal has been amplified and filtered in sequence. For example, the original 50mV sound signal is amplified 40 times to 2V, and then filtered by a bandpass filter with a passband frequency of 80Hz to 300Hz to remove low-frequency environmental vibration noise and high-frequency electromagnetic interference noise, thus obtaining the amplified and filtered audio signal.

[0038] The analysis results refer to the conclusions about the electrical spark state obtained by the main control computer after performing frequency and amplitude analysis on the amplified and filtered audio signal; for example, the analysis results include a spark frequency of 120Hz and a spark energy level of 3, where the spark energy level is divided into 5 levels.

[0039] Spark frequency refers to the number of electric sparks generated by the ignition nozzle per unit time; for example, if the main control computer calculates that 120 electric sparks are generated per second, the spark frequency is 120Hz. Spark energy refers to the amount of energy released during each electric spark discharge. Spark energy is positively correlated with the amplitude of the sound signal; for example, a sound pulse with an amplitude of 1.2V corresponds to a spark energy of approximately 50mJ, and a sound pulse with an amplitude of 0.6V corresponds to a spark energy of approximately 20mJ.

[0040] The technical solution of this embodiment integrates an audio sensor at the ignition nozzle to collect the sound signal generated by the electric spark. The audio signal amplification and filtering circuit is used to amplify and filter the signal, and the main control computer performs frequency and amplitude analysis. This solves the technical problems of existing exciters not having a feedback circuit, which makes it impossible to determine the spark working status, and transformer voltage acquisition schemes having serious signal noise interference, making it difficult to accurately report the ignition status. This improves the accuracy of determining the spark frequency and spark energy during the ignition process, and meets the stringent requirements of aerospace methane engines for ignition reliability and status measurability.

[0041] In one alternative embodiment, the audio sensor is disposed outside the ignition part and is used to collect the sound signal when the ignition nozzle generates an electric spark. The ignition nozzle is disposed inside the ignition part and is used to generate an electric spark.

[0042] The exterior of the ignition point refers to the external space of the ignition area of ​​the ignition nozzle. The exterior of the ignition point does not need to withstand the high temperature and pressure environment of the combustion chamber. For example, the audio sensor is installed on the mounting flange on the outer wall of the combustion chamber, and the temperature at the location of the audio sensor is below 100℃. The interior of the ignition point refers to the enclosed space where the ignition area of ​​the ignition nozzle is located. The interior of the ignition point is in direct contact with the gas mixture and the combustion flame. For example, the ignition nozzle extends 15mm into the combustion chamber, and the ignition end withstands temperatures as high as 2000℃.

[0043] In the above-mentioned optional methods, by further arranging the audio sensor outside the ignition part and the ignition nozzle inside the ignition part, the audio sensor avoids the high-temperature combustion environment while the ignition nozzle penetrates deep into the combustion area. This solves the technical problems of sensor damage due to high temperature and insufficient ignition position of the nozzle, and improves the sensor protection effect and ignition position accuracy.

[0044] In one optional embodiment, the audio signal amplification and filtering circuit includes a signal amplification circuit and a filtering circuit; the signal amplification circuit is used to amplify the amplitude of the sound signal to obtain an amplified sound signal; the filtering circuit is used to filter the amplified sound signal to obtain an amplified and filtered audio signal.

[0045] The amplified sound signal refers to the signal obtained after the original sound signal has been amplified by a signal amplification circuit. The amplified sound signal has not yet been filtered. For example, the original 50mV sound signal is amplified 40 times by the amplification circuit to become a 2V amplified sound signal.

[0046] Among the above-mentioned optional methods, the graded processing method of amplifying the sound signal amplitude through a signal amplification circuit and filtering the amplified sound signal through a filtering circuit enhances the ability to extract weak sound signals and suppresses environmental noise interference. This solves the technical problem of inaccurate analysis caused by the low signal-to-noise ratio of the original signal, and improves signal quality and the reliability of subsequent analysis.

[0047] In one alternative embodiment, the filtering circuit is a bandpass filter circuit, the passband frequency range of which matches the frequency range of the electrical spark sound, and the filtering circuit is also used to filter out frequency components of ambient noise.

[0048] A bandpass filter circuit refers to a filter circuit that allows signals within a specific frequency range to pass through while filtering out signals below the lower limit and above the upper limit. For example, a bandpass filter circuit with a passband frequency of 80Hz to 300Hz allows the sound of electric sparks from 100Hz to 200Hz to pass through, while filtering out low-frequency vibration noise below 80Hz and high-frequency electromagnetic interference above 300Hz. The frequency spectrum range refers to the distribution range of the electric spark sound signal in the frequency domain. For example, the measured frequency spectrum range of an electric spark sound is concentrated between 100Hz and 200Hz, with the main energy peak located around 150Hz.

[0049] In the above-mentioned optional methods, by further employing a bandpass filter circuit whose passband frequency range matches the frequency spectrum range of the electric spark sound, the characteristic frequencies of the electric spark sound are accurately preserved and irrelevant environmental noise is filtered out. This solves the technical problem of signal recognition difficulties caused by noise spectrum overlap and improves the purity and frequency resolution accuracy of the electric spark sound signal.

[0050] In one alternative approach, the analysis results include spark frequency and spark energy level; The main control computer is specifically used to: perform a fast Fourier transform on the amplified and filtered audio signal and extract the spark frequency, and detect the peak amplitude of the amplified and filtered audio signal and map it to the spark energy level.

[0051] Spark energy level refers to dividing the spark energy into several discrete levels to simplify the determination of ignition status. For example, the main control computer divides spark energy into 5 levels: in the amplified and filtered audio signal, an amplitude greater than 1.5V corresponds to level 5, 1.0V to 1.5V corresponds to level 4, 0.5V to 1.0V corresponds to level 3, below 0.5V corresponds to level 2, and no signal corresponds to level 1. Peak amplitude refers to the maximum amplitude of each pulse peak in the sound signal waveform. Peak amplitude is used to characterize the energy of a single electric spark. For example, a peak amplitude of 1.2V at the tip of a waveform in the time domain corresponds to spark energy level 4.

[0052] Among the above-mentioned optional methods, a further analysis method is used to extract the spark frequency by performing a fast Fourier transform on the amplified and filtered audio signal, detect the peak amplitude, and map it to the spark energy level. This establishes a quantitative correspondence between the sound signal and the ignition parameters, solves the technical problem of the lack of objective evaluation standards for spark frequency and energy, and improves the quantitative evaluation capability and analysis accuracy of the ignition status.

[0053] In one alternative embodiment, the exciter internally includes a filter protection circuit, a control circuit, and an energy storage circuit; the input terminal of the filter protection circuit is connected to an external power source, and the output terminal of the filter protection circuit is connected to the control circuit; the output terminal of the control circuit is connected to the energy storage circuit; and the output terminal of the energy storage circuit is connected to the ignition cable.

[0054] The filtering and protection circuit refers to a circuit installed inside the exciter for electromagnetic compatibility protection of the input power supply. For example, the filtering and protection circuit includes a common-mode choke and a transient voltage suppressor; the common-mode choke suppresses conducted interference on the power line, and the transient voltage suppressor absorbs surge voltage. The control circuit refers to a circuit installed inside the exciter for controlling the charging and discharging sequence of the energy storage circuit. For example, after receiving an external trigger signal, the control circuit first controls the energy storage circuit to charge for 100μs according to a set sequence, and then controls the discharge switch to turn on. The energy storage circuit refers to a circuit installed inside the exciter for storing electrical energy and releasing it under the control of the control circuit to generate a high-voltage electrical pulse. For example, the energy storage circuit includes a 0.47μF capacitor, which charges to 500V and then instantly discharges to the primary winding of the ignition transformer.

[0055] External power supply refers to a DC power supply that provides operating power to the exciter; for example, a power supply with an output of 28V DC voltage serves as an external power supply, providing the exciter with a stable voltage and a maximum current of 2A.

[0056] In the above-mentioned optional methods, by further setting up a modular structure of filtering protection circuit, control circuit and energy storage circuit inside the exciter, the connection relationship and signal flow of each functional circuit are clarified, the problems of chaotic circuit layout and electromagnetic compatibility are solved, and the electromagnetic anti-interference capability and ignition pulse output stability of the exciter are improved.

[0057] In one alternative embodiment, the ignition nozzle is installed in the combustion chamber of an aerospace methane engine. The combustion chamber is provided with an oxygen line interface and a methane line interface. The oxygen line interface is used to connect to an oxygen line, and the methane line interface is used to connect to a methane line.

[0058] In this context, "space methane engine" refers to a liquid rocket engine that uses methane and oxygen as propellants. For example, a 10-ton thrust space methane engine, using gaseous oxygen and methane as propellants, is used in the upper stage of a launch vehicle. "Combustion chamber" refers to the cavity in a space methane engine used to mix oxygen and methane and perform a combustion reaction to generate thrust. For example, a combustion chamber has a cylindrical structure with an inner diameter of 150 mm, a length of 200 mm, and an operating pressure of 5 MPa.

[0059] The oxygen line interface refers to the connection port on the combustion chamber wall used to connect to an external oxygen line; for example, a 10mm diameter threaded interface is provided on the side wall of the combustion chamber as an oxygen line interface, and a metal sealing gasket is used at the interface. The methane line interface refers to the connection port on the combustion chamber wall used to connect to an external methane line; for example, a 12mm diameter threaded interface is provided on the side wall of the combustion chamber as a methane line interface, and a conical sealing structure is used at the interface.

[0060] The oxygen pipeline refers to the piping system that delivers oxygen to the combustion chamber. For example, an 8mm inner diameter stainless steel pipe serves as the oxygen pipeline, extending from the oxygen storage tank and passing through a solenoid valve before connecting to the oxygen pipeline interface in the combustion chamber. The methane pipeline refers to the piping system that delivers methane to the combustion chamber. For example, a 10mm inner diameter stainless steel pipe serves as the methane pipeline, extending from the methane storage tank and passing through a solenoid valve before connecting to the methane pipeline interface in the combustion chamber.

[0061] In the above-mentioned optional methods, by further installing the ignition nozzle into the combustion chamber which is equipped with oxygen line interface and methane line interface, the interface adaptation between the ignition system and the engine combustion chamber is completed, the technical problem of insufficient coordination between ignition position and fuel delivery path is solved, and the integration between the ignition system and the methane engine combustion chamber is improved.

[0062] In an alternative embodiment, the master computer is further configured to: After determining that both the spark frequency and the spark energy level have reached preset thresholds, the oxygen pipeline is controlled to supply oxygen to the combustion chamber, and the methane pipeline is controlled to supply methane to the combustion chamber.

[0063] The preset threshold refers to the critical value set in advance by the main control computer when judging whether the spark frequency and spark energy level meet the ignition requirements. For example, the preset threshold is set to a spark frequency of not less than 100Hz and a spark energy level of not less than level 3 (which can be adjusted according to the actual situation, and no restriction is set here). The main control computer determines that ignition is successful only when both conditions are met at the same time.

[0064] Among the above-mentioned optional methods, a linkage control method is further established by controlling the oxygen pipeline and methane pipeline to deliver fuel after determining that the spark frequency and spark energy level have both reached the preset threshold. This establishes the sequential logic of ignition status confirmation and fuel supply, solves the technical problem of ignition failure or detonation risk caused by premature fuel injection, and improves the safety of ignition timing and the reliability of engine starting.

[0065] In one alternative embodiment, the audio sensor and the ignition nozzle are integrated into the same component via a mounting flange fixed to the outer wall of the combustion chamber. The audio sensor is located outside the combustion chamber, and the ignition nozzle extends through the mounting flange into the interior of the combustion chamber. A sealing structure is provided between the mounting flange and the outer wall of the combustion chamber.

[0066] The mounting flange refers to the mechanical connector that integrates the audio sensor and the ignition nozzle and fixes them to the outer wall of the combustion chamber. For example, a disc-shaped mounting flange with an outer diameter of 80mm has a center hole for mounting the ignition nozzle and a side opening for mounting the audio sensor. The sealing structure refers to the sealing element placed between the mounting flange and the outer wall of the combustion chamber to prevent gas leakage. For example, a copper gasket serves as the sealing structure, compressed between the mounting flange and the outer wall of the combustion chamber to form a hard metal seal.

[0067] Among the above-mentioned optional methods, the audio sensor and the ignition nozzle are further integrated into the same component via a mounting flange. The mounting flange is fixed to the outer wall of the combustion chamber and a sealing structure is set. This creates a compact layout with external sensor monitoring and internal nozzle ignition, which solves the technical problems of loose split installation structure and combustion chamber sealing failure, and improves the system's structural compactness and combustion chamber airtightness reliability.

[0068] In one alternative approach, the main control computer is specifically used for: The amplified and filtered audio signal is sampled and stored in the time domain. Each peak of the time domain waveform corresponds to a sound pulse emitted by an electric spark.

[0069] Time-domain waveform sampling refers to the process by which the main control computer discretely acquires the amplified and filtered audio signal at fixed time intervals. For example, the main control computer samples the amplified and filtered audio signal at a sampling rate of 100k times per second, recording the voltage value at each sampling point. A waveform tip refers to the sharp peak shape formed by the electrical spark sound pulse in the time-domain waveform. For example, if an upward-protruding peak appears approximately every 8.3ms (corresponding to 120Hz) in the sampled time-domain waveform, this peak is the waveform tip. A sound pulse refers to a transient sound wave signal generated during a single electrical spark discharge. A sound pulse appears as a waveform tip in the time-domain waveform. For example, a single electrical spark discharge generates a sound pulse lasting 0.5ms, which appears as a sharp pulse with an amplitude of 1.2V in the time-domain waveform.

[0070] The spark frequency is obtained by counting the number of waveform tips per unit time, and the spark energy level is obtained by measuring the amplitude of the waveform tips.

[0071] The number of waveform peaks refers to the number of waveform peaks appearing in the time-domain waveform per unit time; for example, if 120 waveform peaks are counted in a 1-second sampled waveform, the number of waveform peaks is 120. The amplitude of a waveform peak refers to the voltage difference from the baseline to the peak of each waveform peak. The amplitude of a waveform peak is used to characterize the energy of the corresponding electric spark; for example, the amplitude of the first waveform peak is 1.2V, the amplitude of the second waveform peak is 1.1V, and the amplitude of the third waveform peak is 1.3V.

[0072] Among the above optional methods, a time-domain analysis method is further adopted, which involves sampling and storing the amplified and filtered audio signal in the time domain, counting the number of waveform peaks per unit time to obtain the spark frequency, and measuring the amplitude of the waveform peaks to obtain the spark energy level. This simplifies the calculation process of spark parameters and reduces processing latency, solves the technical problem of insufficient real-time performance caused by the complexity of frequency domain transformation calculation, and improves the speed of spark parameter acquisition and the real-time monitoring capability of ignition status.

[0073] In aerospace engine ignition systems, acoustic detection technology converts sound signals into electrical signals, then filters other frequency waveforms in the sound wave signal to extract the desired sound frequency and intensity information. This embodiment applies acoustic detection technology to an engine ignition system, using sound as a medium to measure the spark frequency and sound intensity of the electric ignition system.

[0074] like Figure 1As shown, the exciter is connected to the ignition nozzle via an ignition cable. The exciter contains a high-voltage circuit that generates high-voltage pulses, which are transmitted to the ignition nozzle via the ignition cable. An audio sensor is connected to an audio signal amplification and filtering circuit located inside the exciter via a signal line. The audio sensor collects the sound signal generated when the electric spark is produced. This sound signal is transmitted to the exciter via the signal line, amplified and filtered by the audio signal amplification and filtering circuit, and then transmitted to the main control computer. The main control computer performs frequency and amplitude acquisition on the received audio signal. It determines the spark frequency based on the frequency and the spark energy based on the amplitude; a louder sound indicates a greater spark energy.

[0075] like Figure 2 As shown, the oxygen and methane lines are connected to the combustion chamber, where methane and oxygen are transported and mixed. The ignition nozzle extends into the combustion chamber, while the audio sensor is integrated with it as a single component, located outside the combustion chamber. The ignition nozzle generates an electric spark under a high-voltage electrical pulse, igniting the gas-fuel mixture. The audio sensor, located outside the combustion chamber, collects the sound signal generated by the ignition nozzle during ignition, eliminating the need to penetrate the combustion chamber, avoids extreme high-temperature operating conditions, and does not damage the combustion chamber's sealing structure.

[0076] like Figure 3 As shown, the system workflow of this embodiment begins with the issuance of an ignition command. The exciter starts working, the ignition nozzle generates an electric spark, and simultaneously, audio signals are acquired. The acquired spark sound is used to determine whether an electric spark has been generated. Once an electric spark is confirmed, fuel is delivered to the combustion chamber, and the engine ignites successfully. The acquisition of spark sound is used to determine whether the electric ignition system is working properly. When an electric spark is generated normally, the air-fuel mixture is ignited.

[0077] like Figure 4 As shown, the audio signal processing flow is as follows: The audio signal first enters the signal amplification circuit, which amplifies the amplitude of the audio signal to obtain an amplified sound signal. The amplified sound signal then enters the filtering circuit, which filters out the frequency components of ambient noise, resulting in an amplified and filtered audio signal. The amplified and filtered audio signal then enters the data acquisition circuit, which converts the analog signal into a digital signal. The digital signal then enters the signal processing circuit, which performs frequency and amplitude analysis on the signal, outputting the spark frequency and spark energy. Through this signal processing flow, the characteristic parameters of the electric spark can be accurately extracted from the audio signal, eliminating the influence of ambient noise.

[0078] Figure 5 A schematic diagram of the measured ignition sound waveform is shown. For example... Figure 5As shown, each waveform peak corresponds to a sound pulse emitted by an electric spark, the time interval between adjacent peaks corresponds to the spark frequency, and the peak amplitude corresponds to the spark energy. Normal ambient noise amplitude is low, and spark characteristics can be accurately extracted after filtering.

[0079] It should be understood that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0080] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

[0081] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and represent a limitation on a specific order or sequence. Where appropriate, the order of use for similar objects can be interchanged so that the embodiments of this application described herein can be implemented in an order other than that shown or described.

[0082] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An acoustic feedback-based electric ignition system for aerospace methane engines, characterized in that, include: Exciter, ignition cable, ignition nozzle, audio sensor, audio signal amplification and filtering circuit, and main control computer; The actuator is connected to the ignition nozzle via the ignition cable. The actuator is used to generate a high-voltage electric pulse and transmit the high-voltage electric pulse to the ignition nozzle via the ignition cable, so that the ignition nozzle generates an electric spark. The audio sensor is integrated with the ignition nozzle as a single component, and the audio sensor is used to collect the sound signal when the ignition nozzle generates an electric spark. The input terminal of the audio signal amplification and filtering circuit is connected to the output terminal of the audio sensor, and the audio signal amplification and filtering circuit is used to amplify and filter the sound signal. The input terminal of the main control computer is connected to the output terminal of the audio signal amplification and filtering circuit. The main control computer is used to perform frequency analysis and amplitude analysis on the amplified and filtered audio signal, and to determine the spark frequency and spark energy of the electric spark based on the analysis results.

2. The acoustic feedback type aerospace methane engine electric ignition system according to claim 1, characterized in that, The audio sensor is located outside the ignition part and is used to collect the sound signal when the ignition nozzle generates an electric spark. The ignition nozzle is located inside the ignition part and is used to generate an electric spark.

3. The acoustic feedback type aerospace methane engine electric ignition system according to claim 1, characterized in that, The audio signal amplification and filtering circuit includes a signal amplification circuit and a filtering circuit; the signal amplification circuit is used to amplify the amplitude of the sound signal to obtain an amplified sound signal; the filtering circuit is used to filter the amplified sound signal to obtain an amplified and filtered audio signal.

4. The acoustic feedback type aerospace methane engine electric ignition system according to claim 3, characterized in that, The filtering circuit is a bandpass filter circuit, and the passband frequency range of the bandpass filter circuit matches the frequency range of the electric spark sound. The filtering circuit is also used to filter out the frequency components of environmental noise.

5. The acoustic feedback type electric ignition system for aerospace methane engines according to claim 1, characterized in that, The analysis results include spark frequency and spark energy level; The main control computer is specifically used to: perform a fast Fourier transform on the amplified and filtered audio signal and extract the spark frequency, and detect the peak amplitude of the amplified and filtered audio signal and map it to the spark energy level.

6. The acoustic feedback type aerospace methane engine electric ignition system according to claim 1, characterized in that, The exciter is internally equipped with a filter protection circuit, a control circuit, and an energy storage circuit; the input terminal of the filter protection circuit is connected to an external power supply, and the output terminal of the filter protection circuit is connected to the control circuit; the output terminal of the control circuit is connected to the energy storage circuit; the output terminal of the energy storage circuit is connected to the ignition cable.

7. The acoustic feedback type aerospace methane engine electric ignition system according to claim 5, characterized in that, The ignition nozzle is installed in the combustion chamber of the aerospace methane engine. The combustion chamber is equipped with an oxygen pipeline interface and a methane pipeline interface. The oxygen pipeline interface is used to connect to the oxygen pipeline, and the methane pipeline interface is used to connect to the methane pipeline.

8. The acoustic feedback type aerospace methane engine electric ignition system according to claim 7, characterized in that, The main control computer is also used for: After determining that both the spark frequency and the spark energy level have reached preset thresholds, the oxygen pipeline is controlled to supply oxygen to the combustion chamber, and the methane pipeline is controlled to supply methane to the combustion chamber.

9. The acoustic feedback type aerospace methane engine electric ignition system according to claim 7, characterized in that, The audio sensor and the ignition nozzle are integrated into the same component via a mounting flange. The mounting flange is fixed to the outer wall of the combustion chamber. The audio sensor is located outside the combustion chamber. The ignition nozzle extends into the interior of the combustion chamber through the mounting flange. A sealing structure is provided between the mounting flange and the outer wall of the combustion chamber.

10. The acoustic feedback type aerospace methane engine electric ignition system according to claim 5, characterized in that, The main control computer is specifically used for: The amplified and filtered audio signal is sampled and stored in the time domain, and each waveform peak in the time domain waveform corresponds to a sound pulse emitted by an electric spark. The spark frequency is obtained by counting the number of waveform tips per unit time, and the spark energy level is obtained by measuring the amplitude of the waveform tips.

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