A liquid rocket engine turbine disk vibration measurement system

Abstract

The application discloses a liquid rocket engine turbine disk vibration measurement system, which comprises a collection system, a blowing pipeline and an optical fiber sealing pipeline; a laser sensor in the collection system is arranged in the interior of an engine shell, a head of the laser sensor is aligned with a turbine disk, a measurement signal of the laser sensor is transmitted to a collector through an optical fiber, the optical fiber sealing pipeline realizes reliable sealing of the optical fiber from the interior of the engine shell to the exterior, and the blowing pipeline leads external blowing gas to the head of the laser sensor to blow away impurities at the head of the laser sensor. The application can realize turbine disk vibration measurement under the environment of a liquid rocket engine turbine end, high temperature, large vibration, large airflow speed and compact structure. It has been verified that the system can reliably work in a 700 DEG C, 1000g, 1000m / s rich fuel gas environment.

Description

Technical Field

[0001] This invention relates to a vibration measurement system for a liquid rocket engine turbine disk, belonging to the field of vibration measurement of liquid rocket engine turbopump turbine disk. Background Technology

[0002] The turbopump is the core power component of a liquid rocket engine, and the turbine is the power source for the turbopump. In the field of liquid rocket engines, especially high-thrust liquid rocket engines, the turbine disk operates in an environment characterized by high airflow velocity, high temperature, large vibration, and compact structure. Conventional sensors are difficult to adapt to this harsh environment, so turbine disk vibration measurement has always been a challenge, limiting our understanding of the vibration of liquid rocket engine turbine disks. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects and provide a liquid rocket engine turbine disk vibration measurement system, solving the problem of difficult turbine disk vibration measurement under the working environment of the turbine disk. This invention can realize turbine disk vibration measurement under the conditions of liquid rocket engine turbine end, high temperature, large vibration, high gas flow velocity and compact structure. It has been verified that the system can work reliably in a fuel-rich gas environment of 700℃, 1000g, and 1000m / s.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A liquid rocket engine turbine disk vibration measurement system includes a data acquisition system, a purging pipeline, and an optical fiber sealed pipeline; The data acquisition system includes a laser sensor, an optical fiber, and a data acquisition unit. The laser sensor is located inside the engine housing, with its head aligned with the turbine disk. One end of the optical fiber is connected to the tail of the laser sensor, and the other end passes through a sealed optical fiber conduit to the engine housing and connects to the data acquisition unit located outside the engine housing. The number of laser sensors is ≥1. The purging line directs external purging gas to the laser sensor head to remove impurities from the laser sensor head.

[0005] Furthermore, the fiber optic sealed conduit includes a sealed tee assembly and a cable lead-out tube; The sealing tee assembly is fixed to the outside of the engine housing and includes an outer nut, a ball joint, a welded connector, and sealant; the cable outlet is located inside the engine housing. The engine housing is equipped with an external connector. One end of the ball connector is connected to a cable lead-out tube and is fixedly connected to the external connector by an outer nut. The cable passes through the cable lead-out tube and one end of the ball connector in sequence to the other end of the ball connector, and the other end of the ball connector is sealed with sealant. The welding nozzle is welded to the spherical joint, and external ambient temperature gas enters the spherical joint through the welding nozzle; the external ambient temperature gas is nitrogen, hydrogen, argon, or other gases that do not react with the combustion gas.

[0006] Furthermore, the purging pipeline includes a purging gas intake pipe, a purging gas distributor, and purging branch pipes; the purging gas distributor is located inside the engine housing and is coaxial with the turbine disk. External purging gas enters the purging gas distributor through the purging gas intake pipe. The number of purging branch pipes is the same as the number of laser sensors that need to be purged. The purging gas entering the purging gas distributor reaches the corresponding laser sensor head through each purging branch pipe.

[0007] Furthermore, the end of the purging branch line has a flat opening structure, the maximum inner diameter of which is equal to the diameter of the laser sensor. d equal; The velocity of the purging gas ejected from the end of the purging branch line is 0.1~0.5 Ma.

[0008] Furthermore, the purging gas is positioned at a distance of 0.5 meters from the laser sensor head. d ~1 d An airflow curtain is formed at the location; specifically, along the sensor detection direction, the distance between the center line of the flat opening at the end of the blowout branch pipe and the sensor head is 0.5. d ~1 d， The airflow curtain blown out from the flat nozzle is perpendicular to the sensor's detection direction.

[0009] Furthermore, the aforementioned liquid rocket engine turbine disk vibration measurement system also includes a pipeline support structure; The pipeline support structure includes annular reinforcing ribs and multiple support rods; one end of the support rod is fixedly connected to the engine housing, and the other end is fixedly connected to the outer surface of the blow-off gas distributor to support the blow-off gas distributor; The center of the annular reinforcing rib is located on the axis of the blow-off gas distributor, and the annular reinforcing rib is fixedly connected to multiple support rods at the same time. The purging branch line is fixed to the support rod at multiple points.

[0010] Furthermore, the aforementioned liquid rocket engine turbine disk vibration measurement system also includes a sensor mounting bracket; The sensor mounting bracket is a cylindrical shape with one open end; the sensor mounting bracket is located outside the turbine disk mandrel head and is coaxial with the turbine disk; the liquid rocket engine turbine disk vibration measurement system includes ≥1 surface laser sensor with its tail fixed to the inner wall of the sensor mounting bracket and its head aligned with the outer surface of the turbine disk mandrel head.

[0011] Furthermore, the purge gas splitter is a cylindrical shape with one open end. The closed end of the purge gas splitter is connected to the purge gas inlet pipe. The inner surface of the open end of the purge gas splitter is fixedly connected to the outer surface of the closed end of the sensor mounting bracket by threads. A cavity for accommodating purge gas is formed between the closed end of the sensor mounting bracket and the closed end of the purge gas splitter.

[0012] Furthermore, the laser sensor head is aligned with the edge of the turbine disk, the turbine disk's spindle head, or any position on the turbine disk surface.

[0013] Furthermore, the laser sensor head is aligned with the edge of the turbine disk, the disk head, or any position on the surface of the turbine disk; the surface of the turbine disk is the part between the edge of the turbine disk and the disk head. When the laser sensor head is aligned with the edge of the turbine disk, the laser sensor tail is fixed to the engine housing, and the laser sensor points parallel to the turbine disk axis. When the laser sensor head is aligned with the turbine disk's spindle head, the laser sensor tail is fixed to the sensor mounting bracket, and the laser sensor's direction is parallel to the turbine disk's radial direction. When the laser sensor head is aligned with any position on the turbine disk surface, the laser sensor tail is fixed to the pipeline support structure, and the laser sensor points perpendicular to the disk surface.

[0014] Compared with the prior art, the present invention has at least one of the following advantages: (1) The present invention provides a liquid rocket engine turbine disk vibration measurement system, which places the sensor inside the engine housing and uses an optical fiber sealed pipeline to achieve reliable sealing of the optical fiber lead-out. At the same time, purge gas is introduced to purge the sensor, which can realize the measurement of turbine disk vibration signal. At the same time, it effectively avoids the leakage of high temperature and rich combustion gas and improves the reliability of the sensor under harsh working conditions. (2) The sensor of the present invention has a flexible installation position and can obtain vibration signals at different positions of the turbine disk, thereby obtaining the spatial distribution characteristics of the turbine disk vibration; (3) The present invention has designed an optical fiber sealing pipeline. By using ordinary sealant and room temperature gas introduction, a reliable sealing of the fuel-rich gas under high airflow velocity, high temperature and large vibration environment can be achieved through a simple sealing structure. This ensures that the optical signal inside the test fixture is transmitted to the outside of the test fixture, while sealing the fuel-rich gas inside the test fixture to prevent the fuel-rich gas from leaking out. (4) The present invention designs a structure for the blow-off pipeline, which can form an airflow curtain at the sensor head position to blow off and protect the sensor head, avoiding dust accumulation and obstruction of the sensor during the equipment start-up process. At the same time, the head can be cleaned as needed during the test process to ensure that the sensor can work stably and reliably. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the principle of a liquid rocket engine turbine disk vibration measurement system according to the present invention; Figure 2 This is a schematic diagram of the structure of a liquid rocket engine turbine disk vibration measurement system according to the present invention; Figure 3 for Figure 2 Sectional view in the EE direction; Figure 4 for Figure 2 Sectional view in the FF direction; Figure 5 This is a schematic diagram of the sealing tee assembly of the present invention; Figure 6 This is a schematic diagram showing the location of the blow-off branch pipeline and corresponding sensors of the present invention. Detailed Implementation

[0016] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0017] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0018] This invention addresses the challenge of measuring turbine disk vibration under the operating environment of liquid rocket engine turbine disks by proposing a liquid rocket engine turbine disk vibration measurement system to solve the problem of turbine disk vibration measurement under hot test conditions. The liquid rocket engine turbine disk vibration measurement system includes a data acquisition system, a purging pipeline, and a fiber optic sealed pipeline. The data acquisition system includes a laser sensor, an optical fiber, and a data acquisition unit. The laser sensor measures turbine disk vibration; the optical signal passes through the optical fiber to the data acquisition unit for processing to obtain vibration data. During the measurement process, the purging pipeline protects the laser sensor head by purging, ensuring stable and reliable operation of the laser sensor under harsh conditions. The fiber optic sealed pipeline reliably seals the optical fiber from the inside of the test fixture to the outside, preventing leakage of high-temperature, fuel-rich gases. Specifically, the purging pipeline includes a purging gas inlet pipe, a purging gas distributor, and purging branch pipes; the sealing system includes a sealed tee assembly and a cable outlet pipe.

[0019] By effectively combining the acquisition system, purging pipeline, and fiber optic sealed pipeline, turbine disk vibration measurement can be achieved in liquid rocket engine turbine end environments with high temperature, high vibration, high gas flow velocity, and compact structure. The system has been verified to operate reliably in fuel-rich gas environments at 700℃, 1000g, and 1000m / s.

[0020] Example 1: This embodiment will combine Figures 1-6 The technical solution is described in detail.

[0021] This invention provides a liquid rocket engine turbine disk vibration measurement system, including a data acquisition system, a purging pipeline, and an optical fiber sealed pipeline. The laser sensor in the data acquisition system is located inside the engine casing with its head aligned with the turbine disk. The measurement signal from the laser sensor is transmitted to the data acquisition unit via optical fiber. The optical fiber sealed pipeline ensures a reliable seal when the optical fiber is led out from inside the engine casing to the outside. The purging pipeline leads external purging gas to the head of the laser sensor to remove impurities at the laser sensor head.

[0022] Specifically, the present invention provides a liquid rocket engine turbine disk vibration measurement system, such as... Figure 1 As shown, it includes three parts: acquisition system 1, purging pipeline 2, and fiber optic sealed pipeline 3.

[0023] like Figure 2 and Figure 3 The acquisition system 1 includes a laser sensor 4, an optical fiber 5, and a data acquisition unit 6. The optical fiber 5 passes through an optical fiber sealed conduit 3 to complete the lead wire and gas sealing. The laser sensor 4 is fixed to the vicinity of the turbine disk to be measured by welding or threaded connection. Figure 2 As shown, the installation positions of the laser sensor 4 include, but are not limited to, measurement position 16, measurement position 17, measurement position 18, or measurement position 19. Measurement position 16 is aligned with the edge of the turbine disk 21, measurement position 17 is aligned with the surface of the turbine disk, and measurement positions 18 and 19 are aligned with the outer surface of the disk core head of the turbine disk 21. When the laser sensor 4 is located at measurement position 16 or measurement position 17, the sensor's direction is parallel to the turbine disk axis; when the laser sensor 4 is located at measurement position 18 or measurement position 19, the sensor's direction is parallel to the turbine disk radial direction. The turbine disk 21 is measured by the laser sensor 4 arranged inside the engine housing 14. The measurement signal is transmitted to the acquisition unit 6 through the laser sensor 4 and optical fiber 5. After signal processing, the vibration signals at different positions of the turbine disk are obtained, thereby obtaining the spatial distribution characteristics of the turbine disk vibration.

[0024] like Figure 2 and Figure 4The bleed-out pipeline 2 includes a bleed-out gas intake pipe 7, a bleed-out gas distributor 8, a #1 bleed-out branch pipe 9, and a #2 bleed-out branch pipe 10. The bleed-out pipeline 2 is welded and fixed to the engine housing 14 via a pipeline support structure 15. The bleed-out pipeline 2 should be fixed at multiple points to increase the vibration frequency of the pipeline system. The pipeline support structure 15 should be designed to avoid creating pitch diameter vibration excitation on the turbine disk. By setting up the bleed-out pipeline 2, bleed-out gas is introduced into the bleed-out gas distributor 8 via the bleed-out gas intake pipe 7, enabling simultaneous bleed-out protection for multiple laser sensors 4 through a single bleed-out gas path. This also reduces the complexity of the bleed-out process and mitigates the strength reduction problem caused by openings in the housing. The gas in the purge gas distributor 8 is guided through purge branch pipes 1# 9 and 2# 10 to the head of the laser sensor 4 located at measurement position 1# 16 or measurement position 2# 17. A flat-mouth structure with the same diameter as the sensor at the end of the purge branch pipe forms a localized airflow curtain of 0.1~0.5Ma, protecting the head of the laser sensor 4 from dust accumulation during equipment startup and preventing it from obstructing the sensor. Simultaneously, the head can be cleaned as needed during testing, ensuring stable and reliable sensor operation. Figure 6 As shown, the airflow curtain is perpendicular to the sensor detection direction, that is, the flat opening is perpendicular to the sensor detection direction.

[0025] The fiber optic sealed conduit 3 includes a sealed tee assembly 11, a #1 cable outlet pipe 12, and a #2 cable outlet pipe 13. The sealed tee assembly 11 includes an outer nut 111, a ball joint 112, a welded connector 113, and sealant 114. Figure 5 In the sealing tee assembly 11, one end of the ball joint 112 is connected to the outer connector of the engine housing 14 via the outer nut 111. The other end of the ball joint 112 has a stepped section for placing the sealant 114. The optical fiber 5 enters one end of the ball joint 112 via the No. 1 cable lead-out pipe 12 or the No. 2 cable lead-out pipe 13 from the outer connector of the engine housing 14 and exits from the other end of the ball joint 112. The stepped section at the other end of the ball joint 112 is sealed with ordinary sealant 114 to prevent gas leakage from the sealing tee. At the same time, room temperature gas is introduced into the welded connector 113 to isolate the sealant 114 and cool the sealing tee. Through this combination, the use of high-temperature resistant materials and high-temperature resistant sealants can be avoided in high airflow velocity, high temperature, and high vibration environments. At the same time, reliable sealing of fuel-rich gas can be achieved, reducing the difficulty of processing and manufacturing the structure and raw materials.

[0026] The present invention 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 invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0027] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A vibration measurement system for a liquid rocket engine turbine disk, characterized in that, This includes the acquisition system, purging lines, and fiber optic sealing lines; The acquisition system includes a laser sensor (4), an optical fiber (5), and a collector (6); the laser sensor (4) is located inside the engine housing, with the head of the laser sensor (4) aligned with the turbine disk, one end of the optical fiber (5) is connected to the tail of the laser sensor (4), and the other end passes through the optical fiber sealed tube to the engine housing and connects to the collector (6) located outside the engine housing; the number of laser sensors (4) is ≥1; The purging pipeline leads external purging gas to the head of the laser sensor (4) to remove impurities at the head of the laser sensor (4); The fiber optic sealed conduit includes a sealed tee assembly (11) and a cable lead-out pipe; The sealing tee assembly (11) is fixed to the outside of the engine housing and includes an outer nut (111), a ball joint (112), a welded connector (113), and sealant (114); the cable outlet is located inside the engine housing; An external connector is provided on the engine housing. One end of the ball connector (112) is connected to the cable lead-out pipe and is fixedly connected to the external connector through the outer nut (111). The optical fiber (5) passes through the cable lead-out pipe and one end of the ball connector (112) to the other end of the ball connector (112). The other end of the ball connector (112) is sealed with sealant (114). The welding nozzle (113) is welded to the ball joint (112), and the external ambient temperature gas enters the ball joint (112) through the welding nozzle (113); the external ambient temperature gas is a gas that does not react with the combustion gas; the external ambient temperature gas is nitrogen, hydrogen or argon.

2. The liquid rocket engine turbine disk vibration measurement system according to claim 1, characterized in that, The purging pipeline includes a purging gas inlet pipe (7), a purging gas splitter (8), and purging branch pipes. The purging gas splitter (8) is located inside the engine housing and is coaxial with the turbine disk. External purging gas enters the purging gas splitter (8) through the purging gas inlet pipe (7). The number of purging branch pipes is the same as the number of laser sensors (4) that need to be purged. The purging gas entering the purging gas splitter (8) reaches the head of the corresponding laser sensor (4) through each purging branch pipe.

3. The liquid rocket engine turbine disk vibration measurement system according to claim 2, characterized in that, The end of the purging branch line has a flat opening structure, and the maximum inner diameter of the flat opening structure is the same as the diameter of the laser sensor (4). d equal.

4. The liquid rocket engine turbine disk vibration measurement system according to claim 3, characterized in that, The purging gas is 0.5 meters away from the head of the laser sensor (4). d ~1 d An airflow curtain is formed at the location.

5. The liquid rocket engine turbine disk vibration measurement system according to claim 2, characterized in that, It also includes pipeline support structures (15); The pipeline support structure (15) includes annular reinforcing ribs and multiple support rods; one end of the support rod is fixedly connected to the engine housing, and the other end is fixedly connected to the outer surface of the blow-off gas distributor (8) to support the blow-off gas distributor (8); The center of the annular reinforcing rib is located on the axis of the blow-off gas distributor (8), and the annular reinforcing rib is fixedly connected to multiple support rods at the same time; The purging branch line is fixed to the support rod at multiple points.

6. The liquid rocket engine turbine disk vibration measurement system according to claim 5, characterized in that, It also includes a sensor mounting bracket (20); The sensor mounting bracket (20) is a cylindrical shape with one open end; the sensor mounting bracket (20) is located outside the turbine disk spindle head, and the sensor mounting bracket (20) is coaxial with the turbine disk; the liquid rocket engine turbine disk vibration measurement system includes ≥1 laser sensor (4) with its tail fixed to the inner wall of the sensor mounting bracket and its head aligned with the outer surface of the turbine disk spindle head.

7. The liquid rocket engine turbine disk vibration measurement system according to claim 6, characterized in that, The blow-off gas splitter (8) is a cylindrical shape with one open end. The closed end of the blow-off gas splitter (8) is connected to the blow-off gas inlet pipe (7). The inner surface of the open end of the blow-off gas splitter (8) is fixedly connected to the outer surface of the closed end of the sensor mounting bracket by threads. A cavity for accommodating blow-off gas is formed between the closed end of the sensor mounting bracket and the closed end of the blow-off gas splitter (8).

8. The liquid rocket engine turbine disk vibration measurement system according to claim 1, characterized in that, The laser sensor (4) head is aligned with the edge of the turbine disk, the disk spindle head of the turbine disk, or any position on the surface of the turbine disk.

9. The liquid rocket engine turbine disk vibration measurement system according to claim 6, characterized in that, The laser sensor (4) head is aligned with the edge of the turbine disk, the disk spindle head of the turbine disk, or any position on the surface of the turbine disk; When the head of the laser sensor (4) is aligned with the edge of the turbine disk, the tail of the laser sensor (4) is fixed to the engine housing, and the direction of the laser sensor (4) is parallel to the axis of the turbine disk. When the head of the laser sensor (4) is aligned with the spindle head of the turbine disk, the tail of the laser sensor (4) is fixed on the sensor mounting bracket, and the direction of the laser sensor (4) is parallel to the radial direction of the turbine disk. When the head of the laser sensor (4) is aligned with any position on the turbine disk surface, the tail of the laser sensor (4) is fixed on the pipeline support structure (15), and the direction of the laser sensor (4) is perpendicular to the turbine disk surface.

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