An electric igniter fault detection structure and method based on optical detection

Abstract

An optically inspected electric igniter fault detection structure and method relate to the field of electric igniter ignition fault detection. The structure and method comprise three components: an electric exciter, an ignition cable, and an ignition nozzle. When the electric igniter is operating, the ignition nozzle emits a spark when it breaks down in the silicon carbide semiconductor. The operating state of the electric igniter is studied based on the characteristic spectrum of the spark. The ignition nozzles within the torch igniter are mirror-mounted in a dual-redundant manner, integrating the ignition nozzles with optical probes. Using a mutual inspection method, the optical probe on ignition nozzle A detects the ignition status of ignition nozzle B, and the optical probe on ignition nozzle B detects the ignition status of ignition nozzle A. The optical probe is used to detect the spectrum of the spark when the electric igniter ignites, thereby enabling electric igniter fault detection.

Description

Technical Field

[0001] The electric igniter fault detection method based on optical detection of the present invention can be applied to the ignition fault detection of the electric igniter of liquid oxygen-methane engine and liquid hydrogen-liquid oxygen engine. Background Art

[0002] Currently, most of my country's cryogenic liquid rocket engines in service use proton igniters. Due to their assembly layout, these engines typically only support a second ignition, preventing multiple re-ignitions and, consequently, reuse. This significantly limits the application of cryogenic liquid rocket engines. This inability to re-ignite upper stage engines, in particular, severely restricts their use in deep space exploration. For the new generation of cryogenic liquid rocket engines, proton igniters are no longer sufficient, necessitating the use of torch-type electric igniters as starters for engine ignition. Torch-type electric igniters are widely used in liquid rocket engines due to their high ignition energy, multiple start capabilities, simple structure, and ease of maintenance. As a key component of the torch-type electric igniter, its reliability is fundamental to the successful ignition of liquid rocket engines. Summary of the Invention

[0003] The technical problem solved by the present application is to overcome the deficiencies of the prior art and provide an electric igniter fault detection method based on optical detection, which uses an optical probe to detect the spectrum of the electric spark when the electric igniter is ignited, thereby realizing electric igniter fault detection.

[0004] This patent realizes the integration and miniaturization of optical probes and ignition nozzles through integrated design according to the working conditions of the thrust chamber, and realizes real-time monitoring and diagnosis of the ignition status of the electric igniter; it is conducive to the intelligent control of the engine, and lays the foundation for the engineering application and productization of the torch electric igniter. It is of great significance to improve the working reliability of the engine, realize multiple reuse, and expand future application space.

[0005] The technical solutions provided in this application are as follows:

[0006] In the first aspect, an electric igniter fault detection structure based on optical detection is provided, comprising a detection component, a connecting optical fiber and an engine fault diagnostic device, wherein the detection component is connected to the electric igniter and is used to collect the electric spark of the electric igniter to obtain a discharge spectrum, and transmit the spectrum to the engine fault diagnostic device through the connecting optical fiber, and the engine fault diagnostic device analyzes the discharge spectrum to diagnose the ignition condition of the electric igniter; the electric igniter comprises a torch igniter, an ignition nozzle A and an ignition nozzle B, the torch igniter is provided with a combustion channel, the ignition nozzle A and the ignition nozzle B are relatively installed on the torch igniter, and the ignition nozzle A and One end of the ignition nozzle B is located in the combustion channel. The ignition nozzle A includes a first shell, and a first semiconductor and a first center electrode installed in the first shell. The ignition nozzle B includes a second shell, and a second semiconductor and a second center electrode installed in the second shell. The detection component includes a first detection component and a second detection component. The first shell is provided with a first mounting hole, and the second shell is provided with a second mounting hole. The first detection component is installed in the first mounting hole for detecting the spark of the ignition nozzle B. The second detection component is installed in the second mounting hole for detecting the spark of the ignition nozzle A.

[0007] The first detection component includes a sapphire lens A and a high-temperature resistant optical fiber B. The first shell is sequentially provided with an inner conical hole and a mounting groove at one end of the first mounting hole close to the combustion channel. The diameter of the inner conical hole gradually increases in the direction away from the center of the first mounting hole. The diameter of the mounting groove is larger than the diameter of the large-diameter end of the inner conical hole. The high-temperature resistant optical fiber B is installed in the inner conical hole and the first mounting hole. The sapphire lens A is installed in the mounting groove. The sapphire lens A contacts the end of the high-temperature resistant optical fiber B. High-temperature sealant is provided between the conical wall of the inner conical hole and the high-temperature resistant optical fiber B, and between the sapphire lens A and the circumferential wall of the mounting groove.

[0008] The first shell is provided with an outer tapered hole and a glue injection hole in sequence at the end of the first mounting hole away from the combustion channel. The diameter of the outer tapered hole gradually increases in the direction away from the center of the first mounting hole. The diameter of the glue injection hole is the same as the diameter of the large diameter end of the outer tapered hole. The connecting optical fiber is an optical fiber with a protective sleeve. The connection position of the connecting optical fiber and the high-temperature resistant optical fiber B is located in the glue injection hole, and high-temperature sealant is poured into the outer tapered hole and the glue injection hole.

[0009] The installation method of the first detection component in the first mounting hole includes: installing the high-temperature resistant optical fiber B in the first mounting hole and the inner tapered hole, pouring high-temperature sealant between the tapered wall of the inner tapered hole and the high-temperature resistant optical fiber B, and then installing the sapphire lens A in the mounting groove, and pouring high-temperature sealant between the sapphire lens A and the circumferential wall of the mounting groove; the length of the high-temperature resistant optical fiber B is greater than the total length of the inner tapered hole, the first mounting hole, the outer tapered hole and the glue injection hole. After the end of the high-temperature resistant optical fiber B and the high-temperature resistant optical fiber B are connected outside the glue injection hole, the connection position of the connecting optical fiber and the high-temperature resistant optical fiber B is installed in the glue injection hole, and high-temperature sealant is poured into the outer tapered hole and the glue injection hole.

[0010] A stepped surface is formed between the inner tapered hole and the mounting groove. The side of the sapphire lens A facing the stepped surface is a flat surface, and the side of the sapphire lens A facing away from the stepped surface is a spherical surface.

[0011] The axes of the ignition nozzle A and the ignition nozzle B are collinear.

[0012] The torch igniter is provided with an air inlet and a cooling hydrogen channel 10. The outer circumferential surface of the first shell is provided with a first connecting groove, and the outer circumferential surface of the second shell is provided with a second connecting groove. The first connecting groove and the second connecting groove are connected to the combustion channel. The air inlet is used to cool the hydrogen intake. The cooling hydrogen channel 10 includes at least two, one end of the cooling hydrogen channel 10 is connected to the air inlet, and the outlet of the other end is opposite to the first connecting groove and the second connecting groove.

[0013] The maximum operating temperature of the sapphire lens A is 2000° C., and the light transmission band of the sapphire lens A (12) is 300-350 nm.

[0014] The engine fault diagnostic device analyzes the discharge spectrum to diagnose the ignition condition of the electric igniter, including: the characteristic spectrum wavelength range of the electric spark is 300nm-320nm, and when the light intensity of the electric spark within the characteristic spectrum range is greater than a set threshold, it is determined that the electric igniter is igniting normally.

[0015] In a second aspect, a detection method for an electric igniter fault detection structure based on optical detection is provided, comprising:

[0016] S1: Install the first detection member in the first mounting hole, and install the second detection member in the second mounting hole;

[0017] S2: connecting the first detection component and the second detection component to the engine fault diagnosis device via connecting optical fibers;

[0018] S3: After the electric igniter ignites, the first detection component and the second detection component collect the electric spark to obtain a discharge spectrum, and send it to the engine fault diagnosis device through the connecting optical fiber. The engine fault diagnosis device analyzes the discharge spectrum. When the light intensity of the electric spark within the characteristic spectrum range in the discharge spectrum is greater than the set threshold, it is determined that the electric igniter ignites normally.

[0019] The ignition nozzles in the torch igniter are installed in a dual-redundant mirrored manner, integrating the ignition nozzles with the optical probes. A mutual inspection method is adopted in which the optical probe on ignition nozzle A detects the ignition status of ignition nozzle B, and the optical probe on ignition nozzle B detects the ignition status of ignition nozzle A.

[0020] In summary, this application has at least the following beneficial technical effects:

[0021] 1) Conventional electric igniters cannot accurately detect the ignition status of the ignition nozzle during operation. Using optical measurement methods and analyzing the electric spark through characteristic spectra can accurately determine the ignition status of the electric igniter, which is conducive to the realization of electric igniter fault detection;

[0022] 2) A sapphire is embedded in the ignition end of the ignition nozzle as a lens. A tapered hole is set on the ignition end face of the nozzle. After the sapphire is embedded, it is fixed with high-temperature glue, which serves as the first sealing function. A tapered groove is set at the tail of the ignition nozzle to fill the optical fiber lead wire with glue and seal it, which serves as the second sealing function.

[0023] 3) On the torch igniter, the A and B nozzles are installed in a mirror image, and the A and B ignition nozzles are used to detect each other to ensure that there will be no errors during measurement due to the small size of the optical fiber probe.

[0024] 4) A cooling hydrogen channel is added to the torch igniter to ensure that the end surface temperature of the ignition nozzle is below 400K. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the optical measurement system for electric igniter;

[0026] Figure 2 This is a structural diagram of the integrated ignition nozzle;

[0027] Figure 3 This is a partial enlarged view of the ignition end of the nozzle;

[0028] Figure 4 This is a partial enlarged view of the tail end of the ignition nozzle.

[0029] Explanation of the accompanying reference numerals: 1-torch igniter; 2-ignition nozzle A; 3-ignition nozzle B; 4-ignition cable; 5-electric actuator; 6-fiber optic probe A; 7-fiber optic probe B; 8-connecting optical fiber; 9-engine fault diagnostic device; 10-hydrogen cooling channel;

[0030] 11- ignition nozzle ignition end face; 12- sapphire lens A; 13- high temperature resistant optical fiber B; 14- high temperature sealant; 15- ignition nozzle tail. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] The electric igniter primarily consists of an electric exciter 5, an ignition cable 4, and an ignition nozzle. The ignition nozzle includes a housing, a semiconductor mounted within a first housing, and a center electrode. When the electric igniter is operating, a high-voltage pulse of electricity is generated between the center electrode and the housing, breaking down the semiconductor and emitting an electric spark. This patent studies the operating state of the electric igniter based on the characteristic spectrum of the electric spark.

[0033] like Figure 1 As shown, the present embodiment discloses an optical electric igniter fault detection structure, primarily comprising an ignition nozzle A2, an ignition nozzle B3, an ignition cable 4, an electric actuator 5, a fiber optic probe A6, a fiber optic probe B7, a connecting optical fiber 8, and an engine fault diagnostic device 9. The torch igniter 1 is designed with dual nozzles for redundancy, with the two nozzles mounted in mirrored configuration. During operation, the engine control system powers the electric actuator 5, which converts low-voltage direct current into high-voltage pulsed electricity, which is transmitted via the ignition cable 4 to the ignition nozzles A2 and B3. The high-voltage pulsed electricity breaks down the semiconductor blocks of ignition nozzles A2 and B3, generating sparks. A mutual checking mechanism is employed: the fiber optic probe A6 on ignition nozzle A2 detects the ignition status of ignition nozzle B3, while the fiber optic probe B7 on ignition nozzle B3 detects the ignition status of ignition nozzle A2. The optical signal is transmitted via the connecting optical fiber 8 to the engine fault diagnostic device 9. The engine fault diagnostic device 9 analyzes the discharge spectrum of the ignition nozzle. The characteristic spectrum wavelength range of the electric spark is 300nm-320nm (this range is set as the threshold). When the light intensity of the electric spark within the characteristic spectrum range is greater than the set threshold, it is judged that the electric igniter is igniting normally, thereby diagnosing the ignition condition of the electric igniter.

[0034] like Figure 2 As shown, the patented integrated ignition nozzle of the present invention integrates the ignition nozzle and the optical probe to ensure that the integrated ignition nozzle does not leak during the test run.

[0035] like Figure 3As shown, ignition nozzle A2 includes a first housing, a first semiconductor, and a first center electrode mounted therein. Ignition nozzle B3 includes a second housing, a second semiconductor, and a second center electrode mounted therein. The first housing has a first mounting hole, while the second housing has a second mounting hole. A first detection assembly is mounted in the first mounting hole, while a second detection assembly is mounted in the second mounting hole.

[0036] like Figure 3 As shown, taking the ignition nozzle A2 as an example, the first detection assembly includes a sapphire lens A12 and a high-temperature resistant optical fiber B13. A tapered hole is provided on the ignition nozzle's ignition end face 11. Specifically, an inner tapered hole and a mounting groove are sequentially provided on the first housing at the end of the first mounting hole near the combustion channel. The inner tapered hole gradually increases in diameter as it moves away from the center of the first mounting hole. The mounting groove has a larger diameter than the larger diameter end of the inner tapered hole. The high-temperature resistant optical fiber B13 is installed in the inner tapered hole and the first mounting hole. The sapphire lens A12 is installed in the mounting groove, and the high-temperature resistant optical fiber B13 is connected to the sapphire lens A12. First, high-temperature sealant is poured between the tapered wall of the inner tapered hole and the high-temperature resistant optical fiber B13. Then, the sapphire lens 12 is installed and high-temperature sealant 14 is poured around the edge of the sapphire lens 12 to fix the sapphire lens 12, which serves as the first sealing function. During this process, the sapphire lens 12 presses the high-temperature sealant in the inner tapered hole and, at the same time, combines with the high-temperature sealant on the edge of the sapphire lens 12 to ensure sealing.

[0037] like Figure 4 As shown, a conical groove is opened at the tail end 15 of the ignition nozzle, that is, the first shell is provided with an outer conical hole and a glue injection hole in sequence at the end of the first mounting hole away from the combustion channel. The diameter of the outer conical hole gradually increases in the direction away from the center of the first mounting hole. The diameter of the glue injection hole is the same as the diameter of the large diameter end of the outer conical hole. The connecting optical fiber 8 is an optical fiber with a protective sleeve. After the high-temperature resistant optical fiber 13 is connected to the connecting optical fiber 8, high-temperature sealant 14 is poured into the outer conical hole and the glue injection hole to fix the optical fiber connection point and serve as a second seal. The two seals jointly ensure the high-pressure resistance of the integrated ignition nozzle.

[0038] The optical probe utilizes a flexible, high-temperature-resistant fiber optic sensor. A sapphire block is embedded in the spark plug-side electrode. To achieve total reflection, the surface is coated, and the end of the sapphire block is connected to a high-temperature-resistant fiber optic. Sapphire's higher temperature resistance ensures its ability to detect sparks. The sapphire lens A12 has a flat surface facing the stepped surface, while the sapphire lens A12 has a spherical surface facing away from the stepped surface. This increases the light-collecting surface of the sapphire lens A12, allowing detection with a diameter of 1-2 mm. This combination significantly reduces the size of the detection device.

[0039] The structure of the second detection assembly is the same as that of the first detection assembly. The installation structure of the second detection assembly in the second installation hole of the ignition nozzle B3 is the same as that of the first detection assembly in the first installation hole.

[0040] The torch igniter 1 is provided with an air inlet and a cooling hydrogen channel 10. A first connecting groove is provided on the outer circumferential surface of the first shell, and a second connecting groove is provided on the outer circumferential surface of the second shell. The first connecting groove and the second connecting groove are connected to the combustion channel. The air inlet is used to cool the hydrogen intake. The cooling hydrogen channel 10 includes at least two cooling hydrogen channels, one end of which is connected to the air inlet, and the outlet of the other end is opposite to the first connecting groove and the second connecting groove.

[0041] This embodiment also provides a detection method for an electric igniter fault detection structure based on optical detection, comprising:

[0042] S1: Install the first detection member in the first mounting hole, and install the second detection member in the second mounting hole;

[0043] S2: connecting the first detection component and the second detection component to the engine fault diagnosis device via connecting optical fibers;

[0044] S3: After the electric igniter ignites, the first detection component and the second detection component collect the electric spark to obtain a discharge spectrum, and send it to the engine fault diagnosis device through the connecting optical fiber. The engine fault diagnosis device analyzes the discharge spectrum. When the light intensity of the electric spark within the characteristic spectrum range in the discharge spectrum is greater than the set threshold, it is determined that the electric igniter ignites normally.

[0045] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0046] The present application has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present application. Those skilled in the art will appreciate that, without departing from the spirit and scope of the present application, various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present application, all of which fall within the scope of the present application. The scope of protection of the present application shall be determined by the appended claims.

Claims

1. An electric igniter fault detection structure based on optical detection, characterized in that: The invention comprises a detection component, a connecting optical fiber (8) and an engine fault diagnosis device (9). The detection component is connected to the electric igniter and is used to collect the electric spark of the electric igniter to obtain a discharge spectrum, and transmit the spectrum to the engine fault diagnosis device (9) through the connecting optical fiber (8). The engine fault diagnosis device (9) analyzes the discharge spectrum to diagnose the ignition condition of the electric igniter. The electric igniter comprises a torch igniter (1), an ignition nozzle A (2) and an ignition nozzle B (3), wherein the torch igniter (1) is provided with a combustion channel, the ignition nozzle A (2) and the ignition nozzle B (3) are mounted on the torch igniter (1) opposite to each other, one end of the ignition nozzle A (2) and the ignition nozzle B (3) are located in the combustion channel, the ignition nozzle A (2) comprises a first shell, and a first semiconductor and a first center electrode mounted in the first shell, and the ignition nozzle B (3) comprises a second shell, and a second semiconductor and a second center electrode mounted in the second shell; The detection assembly comprises a first detection assembly and a second detection assembly, the first housing is provided with a first mounting hole, the second housing is provided with a second mounting hole, the first detection assembly is installed in the first mounting hole and is used to detect the electric spark of the ignition nozzle B (3), and the second detection assembly is installed in the second mounting hole and is used to detect the electric spark of the ignition nozzle A (2); The first detection component includes a sapphire lens A (12) and a high-temperature resistant optical fiber B (13). The first shell is sequentially provided with an inner tapered hole and a mounting groove at one end of the first mounting hole close to the combustion channel. The diameter of the inner tapered hole gradually increases in a direction away from the center of the first mounting hole. The diameter of the mounting groove is larger than the diameter of the large-diameter end of the inner tapered hole. The high-temperature resistant optical fiber B (13) is installed in the inner tapered hole and the first mounting hole. The sapphire lens A (12) is installed in the mounting groove. The sapphire lens A (12) contacts the end of the high-temperature resistant optical fiber B (13). High-temperature sealant is provided between the tapered wall of the inner tapered hole and the high-temperature resistant optical fiber B (13), and between the sapphire lens A (12) and the circumferential wall of the mounting groove.

2. The optical detection-based electric igniter fault detection structure according to claim 1, characterized in that: The first housing is provided with an outer tapered hole and a glue injection hole in sequence at one end of the first mounting hole away from the combustion channel. The outer tapered hole gradually increases in diameter in a direction away from the center of the first mounting hole. The diameter of the glue injection hole is the same as the diameter of the large-diameter end of the outer tapered hole. The connecting optical fiber (8) is an optical fiber with a protective sleeve. The connection position of the connecting optical fiber (8) and the high-temperature resistant optical fiber B (13) is located in the glue injection hole, and high-temperature sealant is poured into the outer tapered hole and the glue injection hole.

3. The electric igniter fault detection structure based on optical detection according to claim 2, characterized in that: The method for installing the first detection component in the first installation hole comprises: installing the high-temperature resistant optical fiber B (13) in the first installation hole and the inner tapered hole, pouring high-temperature sealant between the tapered wall of the inner tapered hole and the high-temperature resistant optical fiber B (13), then installing the sapphire lens A (12) in the installation groove, and pouring high-temperature sealant between the sapphire lens A (12) and the circumferential wall of the installation groove; The length of the high-temperature resistant optical fiber B (13) is greater than the total length of the inner tapered hole, the first mounting hole, the outer tapered hole and the glue injection hole. After the end of the high-temperature resistant optical fiber B (13) and the high-temperature resistant optical fiber B (13) are connected outside the glue injection hole, the connection position of the connecting optical fiber (8) and the high-temperature resistant optical fiber B (13) is installed in the glue injection hole, and high-temperature sealant is poured into the outer tapered hole and the glue injection hole.

4. The optical detection-based electric igniter fault detection structure according to claim 1, characterized in that: A stepped surface is formed between the inner conical hole and the mounting groove, the side of the sapphire lens A (12) facing the stepped surface is a plane, and the side of the sapphire lens A (12) facing away from the stepped surface is a spherical surface.

5. The optical detection-based electric igniter fault detection structure according to claim 1, characterized in that: The axes of the ignition nozzle A (2) and the ignition nozzle B (3) are collinear.

6. The optical detection-based electric igniter fault detection structure according to claim 1, characterized in that: The torch igniter (1) is provided with an air inlet and a cooling hydrogen channel (10), a first outer shell outer circumferential surface is provided with a first connecting groove, a second outer shell outer circumferential surface is provided with a second connecting groove, the first connecting groove and the second connecting groove are connected to the combustion channel, the air inlet is used for cooling the hydrogen intake, the cooling hydrogen channel (10) includes at least two, one end of the cooling hydrogen channel (10) is connected to the air inlet, and the outlet of the other end is directly opposite to the first connecting groove and the second connecting groove.

7. The electric igniter fault detection structure based on optical detection according to claim 1, characterized in that: The maximum operating temperature of the sapphire lens A (12) is 2000° C., and the light transmission band of the sapphire lens A (12) is 300-350 nm.

8. The optical detection-based electric igniter fault detection structure according to claim 1, characterized in that: The engine fault diagnostic device (9) analyzes the discharge spectrum to diagnose the ignition condition of the electric igniter, including: the characteristic spectrum wavelength range of the electric spark is 300nm-320nm, and when the light intensity of the electric spark within the characteristic spectrum range is greater than a set threshold, it is judged that the electric igniter is ignited normally.

9. A detection method for an electric igniter fault detection structure based on optical detection according to any one of claims 1 to 8, characterized in that: include: S1: Install the first detection member in the first mounting hole, and install the second detection member in the second mounting hole; S2: connecting the first detection member and the second detection member to the engine fault diagnosis device (9) via the connecting optical fiber (8); S3: after the electric igniter ignites, the first detection member and the second detection member collect the electric spark to obtain a discharge spectrum, and send the spectrum to the engine fault diagnosis device (9) via the connecting optical fiber (8). The engine fault diagnosis device (9) analyzes the discharge spectrum. When the light intensity of the electric spark within the characteristic spectrum range in the discharge spectrum is greater than a set threshold value, it is determined that the electric igniter ignites normally.

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