Electric igniter fault detection structure and method based on optical detection

Abstract

An electric igniter fault detection structure and method based on optical detection relates to the field of electric igniter ignition fault detection and comprises an electric exciter, an ignition cable and an ignition electric nozzle. When the electric igniter works, the ignition electric nozzle breaks down the silicon carbide semiconductor to emit electric sparks, and the working state of the electric igniter is researched based on the characteristic spectrum of the electric sparks. Ignition electric nozzles in the torch igniter are installed in a double-redundancy mode in a mirroring mode, the ignition electric nozzles and optical probes are integrated, the ignition condition of the ignition electric nozzle B is detected through the optical probe on the ignition electric nozzle A in a mutual inspection method, and the ignition condition of the ignition electric nozzle A is detected through the optical probe on the ignition electric nozzle B. The optical probe is used for detecting the spectrum of electric sparks during ignition of the electric igniter, and therefore fault detection of the electric igniter is achieved.

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] At present, most of the cryogenic liquid rocket engines in service in my country use gunpowder igniters. Affected by the assembly layout, they can generally only achieve secondary ignition at most, and cannot achieve multiple repeated ignitions, and cannot be reused, which greatly limits the application space of cryogenic liquid rocket engines. Especially for upper stage engines, the inability to ignite multiple times has severely limited the use of cryogenic liquid rocket engines in the field of deep space exploration. For the new generation of cryogenic liquid rocket engines, gunpowder igniters can no longer meet the use requirements, so torch-type electric igniters are needed as starters for engine ignition. Torch-type electric igniters have been widely used in liquid rocket engines because of their high ignition energy, multiple starts, simple structure, and easy maintenance. As a key component of the torch-type electric igniter, the reliability of the electric igniter is the basis for the successful ignition of the liquid rocket engine. 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 the fault detection of the electric igniter.

[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 enhance the future application space.

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

[0006] In a 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 send it 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, and 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, and is used to detect the spark of the ignition nozzle B, and the second detection component is installed in the second mounting hole, and is used to detect 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 provided with an inner conical hole and a mounting groove in sequence 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 cover. The connection position between 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 between 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 step surface is formed between the inner tapered hole and the mounting groove, the side of the sapphire lens A facing the step surface is a flat surface, and the side of the sapphire lens A facing away from the step 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. 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 other end outlet 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, 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 ignited normally.

[0015] In a second aspect, a detection method of 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 element and the second detection element to the engine fault diagnosis device through 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 in 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 nozzle in the torch igniter is installed in a dual redundant mirrored manner, and the ignition nozzle is integrated with the optical probe. 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 by a mutual checking method.

[0020] In summary, this application at least includes 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 fault detection of the electric igniter;

[0022] 2) Sapphire is embedded in the ignition end of the ignition nozzle as a lens, and a conical hole is set on the ignition end face of the nozzle. After the sapphire is embedded, it is fixed with high-temperature glue, which plays the role of the first seal. A conical groove is set at the tail of the ignition nozzle, and the optical fiber lead-out line is sealed with glue, which plays the role of the second seal.

[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 It is a schematic diagram of the optical measurement system of the electric igniter;

[0026] Figure 2 It 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 rear end of the ignition nozzle.

[0029] Description of the accompanying drawings: 1-torch igniter; 2-ignition nozzle A; 3-ignition nozzle B; 4-ignition cable; 5-electric exciter; 6-optical fiber probe A; 7-optical fiber probe B; 8-connecting optical fiber; 9-engine fault diagnostic device; 10-cooling hydrogen 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 mainly consists of three parts: electric exciter 5, ignition cable 4, and ignition nozzle. The ignition nozzle includes a shell, a semiconductor installed in the first shell, and a center electrode. When the electric igniter is working, a high-voltage pulse electricity is formed between the center electrode and the shell to break down the semiconductor and emit an electric spark. This patent studies the working state of the electric igniter based on the characteristic spectrum of the electric spark.

[0033] like Figure 1 As shown, the embodiment of the present application discloses an optical electric igniter fault detection structure, which is mainly composed of an ignition nozzle A2, an ignition nozzle B3, an ignition cable 4, an electric exciter 5, an optical fiber probe A6, an optical fiber probe B7, a connecting optical fiber 8, and an engine fault diagnostic device 9. When designing the torch igniter 1, a dual nozzle redundant design is adopted, and the two nozzles are installed in a mirror image. During operation, the engine control system powers on the electric exciter 5, and the electric exciter 5 converts low-voltage direct current into high-voltage pulse electricity, which is transmitted to the ignition nozzle A2 and the ignition nozzle B3 by the ignition cable 4. The high-voltage pulse electricity breaks down the semiconductor blocks of the ignition nozzles A2 and B3 to generate electric sparks. A mutual inspection method is adopted, that is, the optical fiber probe A6 on the ignition nozzle A2 detects the ignition condition of the ignition nozzle B3, and the optical fiber probe B7 on the ignition nozzle B3 detects the ignition condition of the ignition nozzle A2. The optical signal is transmitted to the engine fault diagnostic device 9 through the connecting optical fiber 8. 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 integrated ignition nozzle of the patented design 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, the ignition nozzle A2 includes a first housing, and a first semiconductor and a first center electrode installed in the first housing, and the ignition nozzle B3 includes a second housing, and a second semiconductor and a second center electrode installed in the second housing. The first housing is provided with a first mounting hole, and the second housing is provided with a second mounting hole. The first mounting hole is provided with a first detection component, and the second mounting hole is provided with a second detection component.

[0036] like Figure 3 As shown, taking the ignition nozzle A2 as an example, the first detection component includes a sapphire lens A12 and a high temperature resistant optical fiber B13. A conical hole is set on the ignition end face 11 of the ignition nozzle, that is, an inner conical hole and a mounting groove are sequentially set at one end of the first mounting hole of the first housing close to the combustion channel, the inner conical hole gradually increases in diameter along 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 B13 is installed in the inner conical 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 conical wall of the inner conical hole and the high-temperature resistant optical fiber B13, and then the sapphire lens 12 is installed and high-temperature sealant 14 is poured into the edge of the sapphire lens 12 to fix the sapphire lens 12, which plays the first sealing role. In this process, the sapphire lens 12 presses the high-temperature sealant in the inner conical hole, and at the same time combines with the high-temperature sealant on the edge of the sapphire lens 12 to ensure the sealing.

[0037] like Figure 4 As shown, a conical groove is opened at the tail 15 of the ignition nozzle, that is, the first shell is sequentially provided with an outer conical hole and a glue injection hole at the end of the first mounting hole away from the combustion channel, the diameter of the outer conical hole gradually increases along 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, and 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 play a second sealing role at the same time, and the two seals jointly ensure the high-pressure resistance of the integrated ignition nozzle.

[0038] The optical probe uses a flexible high-temperature resistant optical fiber sensor. A sapphire is embedded in the electrode on the spark plug side. In order to achieve total reflection and light transmission, a film is coated on its surface. The end of the sapphire block is connected to a high-temperature resistant optical fiber. Sapphire has a higher temperature resistance, which ensures that it can detect electric sparks. The side of the sapphire lens A12 facing the step surface is a flat surface, and the side of the sapphire lens A12 away from the step surface is a spherical surface, which makes the light collection surface of the sapphire lens A12 larger. Therefore, the size of the sapphire lens A12 can achieve detection with a diameter of 1-2mm. Combined, the size of the detection device is greatly reduced.

[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 other end outlet is opposite to the first connecting groove and the second connecting groove.

[0041] This embodiment also provides a detection method of 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 element and the second detection element to the engine fault diagnosis device through 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 in 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 belong to the common knowledge of those skilled in the art.

[0046] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached 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 diagnostic device (9). The detection component is connected to an electric igniter and is used to collect electric sparks of the electric igniter to obtain a discharge spectrum, and transmit the spectrum to the engine fault diagnostic device (9) through the connecting optical fiber (8). The engine fault diagnostic 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 component comprises 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 and is used to detect the electric spark of the ignition nozzle B (3). The second detection component is installed in the second mounting hole and is used to detect the electric spark of the ignition nozzle A (2).

2. The electric igniter fault detection structure based on optical detection according to claim 1, characterized in that: The first detection component comprises a sapphire lens A (12) and a high temperature resistant optical fiber B (13); an inner conical hole and a mounting groove are sequentially arranged at one end of the first mounting hole close to the combustion channel; the inner conical hole gradually increases in diameter 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 conical hole; the high temperature resistant optical fiber B (13) is installed in the inner conical 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 conical wall of the inner conical 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.

3. The electric igniter fault detection structure based on optical detection according to claim 2, characterized in that: The first shell 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 between 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.

4. The electric igniter fault detection structure based on optical detection according to claim 3 is characterized in that: The method for installing the first detection component in the first installation hole comprises: installing a high temperature resistant optical fiber B (13) in the first installation hole and the inner tapered hole, injecting high temperature sealant between the tapered wall surface 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 injecting high temperature sealant between the sapphire lens A (12) and the circumferential wall surface 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.

5. The electric igniter fault detection structure based on optical detection according to claim 2, 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 flat surface, and the side of the sapphire lens A (12) away from the stepped surface is a spherical surface.

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

7. The electric igniter fault detection structure based on optical detection 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 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 other end outlet is directly opposite to the first connecting groove and the second connecting groove.

8. 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.

9. The electric igniter fault detection structure based on optical detection 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, when the light intensity of the electric spark within the characteristic spectrum range is greater than a set threshold value, it is judged that the electric igniter is ignited normally.

10. A detection method for an electric igniter fault detection structure based on optical detection as claimed in 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 element and the second detection element to the engine fault diagnosis device (9) via a connecting optical fiber (8); 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 (9) through the connecting optical fiber (8). The engine fault diagnosis device (9) analyzes the discharge spectrum. When the light intensity of the electric spark in the characteristic spectrum range in the discharge spectrum is greater than the set threshold value, it is determined that the electric igniter ignites normally.

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