A monitoring method for a turbine pump non-compatible rub failure

Abstract

The application provides a monitoring method for a turbine pump in an inadmissible rub fault, which comprises the following steps: firstly, collecting output signals of vibration sensors at each monitoring position of the turbine pump during the working process of the turbine pump; secondly, obtaining multi-dimensional judgment elements according to the vibration sensor signals; and finally, comprehensively scoring according to three-dimensional judgment elements, judging the rub level of the turbine pump, and determining whether the turbine pump appears in the inadmissible rub fault. The application evaluates the rub level of the turbine pump by means of the multi-dimensional evaluation idea, and refines and divides the rub level of the turbine pump. After judging that the rub phenomenon appears, the method is no longer directly adopted to stop the machine, but is adopted to judge whether the rub phenomenon is admissible or not by means of the scoring evaluation mode. For the admissible slight rub, the method is adopted to keep monitoring, and for the inadmissible rub fault, the method is adopted to stop the machine. The method can reduce the waste of manpower and material resources, and improve the repeatability of the rocket turbine pump.

Description

Technical Field

[0001] This invention relates to the field of turbopump health management, specifically to a monitoring method for non-tolerant rubbing faults in turbopumps. Background Technology

[0002] Friction is a common malfunction occurring in various mechanical equipment. The degree of friction varies depending on the situation; some may be just slight contact with relatively minor consequences, while others may be a strong impact, causing serious damage to the equipment. This difference makes the hazards of friction malfunctions also vary. Slight friction may only affect the operating efficiency of the equipment or produce some noise and vibration, but strong friction may lead to damage to equipment parts or even cause safety accidents, resulting in injuries or fatalities.

[0003] A search revealed that existing technologies for rotor rubbing faults primarily focus on methods for fault diagnosis and identification. For example, invention publication CN112858485A discloses a rubbing fault diagnosis method based on acoustic emission technology. This method collects the emitted sound signal of rotor rubbing, performs empirical mode decomposition on the signal, reconstructs the intrinsic mode components, and finally performs Teager energy spectrum analysis on the reconstructed signal to diagnose rotor rubbing faults. This method avoids the problems of multiple vibration sources and inaccurate information, as it does not rely on traditional vibration signals for diagnosis. Another example is invention publication CN114812989A, which discloses a rotor rubbing identification method based on state parameter analysis. This method analyzes the amplitude of vibration data jumps and predicts the trend of these jumps to determine whether a rubbing fault has occurred. This method can effectively identify rubbing faults based on the relative rate of change of active power, area deviation rate, and relative rate of change of displacement.

[0004] However, the above methods can only identify whether a friction failure has occurred, but cannot differentiate the degree of friction. In other words, current friction monitoring methods are limited to the stage of whether friction exists, and cannot distinguish the strength, frequency, and potential damage of friction. This leads to the common practice in engineering practice of shutting down the machine as soon as a friction failure is detected to avoid accidents. However, shutting down the machine for all friction failures is unreasonable. Some minor friction failures may only require simple adjustments or maintenance to resolve the problem, without needing to shut down the machine. Only for severe friction failures should timely shutdown be carried out to prevent greater harm. Therefore, it is necessary to research more advanced and detailed friction monitoring technologies and analyze the tolerability of friction failures. Summary of the Invention

[0005] As a core component of rocket engines, the turbopump's operating condition directly affects the rocket's thrust and performance. During operation, due to the high speed and harsh working environment of the turbopump, rubbing failures are difficult to avoid. However, some minor rubbing has little or no impact on the turbopump. If even these tolerable rubbing failures are addressed with shutdown measures, it would result in significant resource waste. Current technologies lack tolerance analysis for rubbing failures. Therefore, this invention proposes a monitoring method for intolerable rubbing failures in turbopumps based on a multi-dimensional evaluation approach.

[0006] The technical solution of this invention is as follows:

[0007] The aforementioned monitoring method for non-tolerant rubbing faults in turbopumps includes the following steps:

[0008] Step 1: Install vibration sensors at multiple monitoring locations on the turbopump and collect the output signals of each vibration sensor during the operation of the turbopump;

[0009] Step 2: Based on the vibration sensor signals acquired in Step 1, obtain multi-dimensional judgment elements:

[0010] First dimension: Based on the output signal of the vibration sensor, determine the degree of single-point contact at each monitoring location;

[0011] The second dimension: Based on the output signals of all vibration sensors, determine the number of locations where rubbing occurs;

[0012] The third dimension: Based on the output signals of all vibration sensors, determine the duration of the rubbing phenomenon in the turbine pump;

[0013] Step 3: Perform a comprehensive score on the three dimensions of judgment elements obtained in Step 2 to determine the impact level of the turbopump and whether the turbopump has an intolerable impact failure.

[0014] Furthermore, in step 1, the monitoring locations include at least the inducer wheel, centrifugal wheel, turbine, and shaft.

[0015] Furthermore, in step 2, the degree of rubbing at each monitoring location is determined using the following process:

[0016] The degree of single-point contact friction is divided into three levels: no contact friction, slight friction, and severe friction.

[0017] If the output signal of the vibration sensor at a certain monitoring location is only the fundamental frequency signal, the corresponding single-point friction level is no friction.

[0018] If the output signal of the vibration sensor at a certain monitoring location shows high and low harmonics, the corresponding single point of contact and friction is at the slight level.

[0019] If the output signal of the vibration sensor at a certain monitoring location shows a low frequency exceeding the set amplitude, the corresponding single-point rubbing severity level is considered severe.

[0020] Furthermore, in step 2, if any monitoring location detects a rubbing phenomenon, the turbine pump is considered to have a rubbing phenomenon. Only when the rubbing phenomenon disappears at all monitoring locations is the turbine pump considered to have disappeared. The duration of the turbine pump rubbing phenomenon is obtained by using the time when the turbine pump rubbing phenomenon disappears and the time when the turbine pump rubbing phenomenon occurs.

[0021] Furthermore, in step 2, the following process is used to determine whether rubbing occurs at a certain monitoring location:

[0022] If the output signal of the vibration sensor at a certain monitoring location shows high and low harmonics and / or low frequency values ​​exceeding the set amplitude, it is considered that a rubbing phenomenon has occurred at that monitoring location.

[0023] Furthermore, in step 3, the comprehensive score is obtained by multiplying the scores of the three dimensions, where the first dimension score is the highest value of the first dimension score corresponding to all monitoring locations.

[0024] Furthermore, in step 3, for a certain monitoring location, its first dimension score is assigned different values ​​according to three levels, where the first level score is 0, the second level score is 1, and the third level score is 10.

[0025] Furthermore, in step 3, the second dimension uses the number of monitoring locations where rubbing occurs as the scoring value. If the number of monitoring locations where rubbing occurs exceeds 4, it is directly determined that the turbo pump has an intolerable rubbing failure.

[0026] Furthermore, in step 3, the third dimension is divided into the following 5 levels:

[0027] level Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ illustrate T≤0.1s 0.1s < T ≤ 0.2s 0.2s < T ≤ 0.3s 0.3s < T ≤ 0.4s T > 0.4s

[0028] Where T represents the duration of the rubbing phenomenon in the turbopump; the five levels of rating are: 1, 2, 3, 4, and 5.

[0029] Furthermore, in step 3, if the overall score reaches 10, it is determined that the turbopump has an unacceptable rubbing failure.

[0030] Beneficial effects

[0031] This invention utilizes a multi-dimensional evaluation approach to assess the wear and tear levels of turbopumps. It refines the classification of wear and tear levels and, upon detecting wear and tear, instead of immediately shutting down the pump, uses a scoring system to determine the tolerance of the wear and tear. For tolerable minor wear and tear, monitoring is maintained; for intolerable wear and tear, shutdown is implemented. This method reduces waste of human and material resources and improves the repeatability of rocket turbopumps.

[0032] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0034] Figure 1 Monitoring method flowchart;

[0035] Figure 2 Turbopump structural diagram;

[0036] Figure 3 Centrifugal impeller analog disk signal spectrum diagram. Detailed Implementation

[0037] This invention addresses the problem of significant resource waste caused by the current method of directly shutting down turbopumps to handle rubbing failures. It proposes a monitoring method for turbopumps with intolerable rubbing failures. By using a multi-dimensional evaluation approach, the rubbing level of the turbopump is assessed. Only when the assessment reaches the level of intolerable rubbing failure is shutdown implemented, thereby reducing the waste of human and material resources and improving the repeatability of rocket turbopumps.

[0038] As shown in Table 1, based on the different dangers that rubbing may cause, rubbing is divided into three levels: no rubbing, tolerable rubbing, and intolerable rubbing. When the turbopump is in a no-rubbing state, there is no contact between the turbopump rotor and stator, and no rubbing traces are found after disassembly. When the turbopump is in a tolerable rubbing state, rubbing occurs but is minor, with little impact on the turbopump's structure and performance, and no action is required. When the turbopump is in an intolerable rubbing state, the turbopump has experienced a highly dangerous rubbing, which has a significant impact on the turbopump's structural integrity and performance, and the machine should be shut down to prevent further danger.

[0039] Table 1 Classification of Turbine Pump Friction Levels

[0040]

[0041] like Figure 1As shown, the monitoring method specifically includes the following steps:

[0042] Step 1: Install vibration sensors at multiple monitoring locations on the turbopump and collect the output signals of each sensor during the turbopump's operation. Since the turbopump commonly experiences rubbing at the inducer wheel, centrifugal wheel, turbine, and shaft, etc. Figure 2 As shown, at least these four locations are designated as monitoring locations. In addition, other monitoring locations can be set depending on the specific circumstances. For each monitoring location, one or more vibration sensors can be installed for monitoring.

[0043] Step 2: Based on the vibration sensor signals acquired in Step 1, obtain multi-dimensional judgment elements:

[0044] The first dimension: Based on the vibration sensor signal, determine the degree of contact at each monitoring location.

[0045] In this invention, we use the following process to determine whether a rubbing phenomenon occurs at a certain monitoring location:

[0046] By using vibration displacement sensors installed at the corresponding structures of the turbine pump, when rubbing characteristics are found in the vibration signal at a certain monitoring location, such as high and low harmonics and / or low-frequency quantities with large amplitude, it can be considered that rubbing has occurred at that location.

[0047] And further determine the degree of friction at each monitoring location:

[0048] In this invention, the degree of single-point contact friction is divided into three levels: no contact friction, slight friction, and severe friction. For a given monitoring location, the first dimension score is assigned different values ​​according to the three levels, with level 1 having a score of 0, level 2 having a score of 1, and level 3 having a score of 10. Vibration signals indicating no contact friction consist only of the fundamental frequency signal, which is the no-contact friction level. The presence of high and low harmonics indicates slight friction, which can be considered a minor contact friction, also known as the slight level. The presence of large-amplitude low-frequency signals indicates a large radial force, resulting in a significant impact on the turbine pump shaft system, which is the severe level. (See attached diagram.) Figure 3 The signal shown contains both subharmonics and low-frequency components, indicating a severe level.

[0049] The second dimension: Based on the output signals of all vibration sensors, determine the number of monitoring locations where rubbing occurs; using the aforementioned method, we have already determined whether rubbing occurs at each monitoring location, thus enabling us to count the number of monitoring locations where rubbing occurs.

[0050] In this invention, the second dimension score uses the number of locations where rubbing occurs as the score value. If the number of locations where rubbing occurs exceeds 4, it is directly determined that the turbopump has an intolerable rubbing failure.

[0051] The third dimension: Based on the output signals of all vibration sensors, determine the duration of the rubbing phenomenon in the turbine pump.

[0052] For the entire turbopump, if any monitoring point detects rubbing, then the turbopump is considered to have rubbing. The rubbing is considered to have disappeared only when all monitoring points show the disappearance of rubbing. The duration of the rubbing is determined by using the times when the rubbing disappears and when it first appears. We divide the third dimension into the following five levels:

[0053] level Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ illustrate T≤0.1s 0.1s < T ≤ 0.2s 0.2s < T ≤ 0.3s 0.3s < T ≤ 0.4s T > 0.4s

[0054] Where T represents the duration of the rubbing phenomenon in the turbopump; the five levels of rating are: 1, 2, 3, 4, and 5.

[0055] Step 3: Perform a comprehensive score on the three dimensions of judgment elements obtained in Step 2 to determine the impact level of the turbopump and whether the turbopump has an intolerable impact failure.

[0056] In this invention, a comprehensive score is obtained by multiplying the scores from three dimensions, where the first dimension score is the highest value corresponding to all monitoring locations in the first dimension. If the comprehensive score reaches 10, it is determined that the turbopump has an intolerable contact / rubbing fault.

[0057] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0058] This embodiment uses data from a turbine pump collision simulation tester to monitor non-compliance collisions. Figure 3 This is the vibration signal of the simulated centrifugal impeller of the turbine pump. The low-frequency components in the graph indicate a relatively severe collision, resulting in a large radial force. The graph also shows high-order harmonic components, indicating friction within the simulated impeller. Therefore, the first dimension of the simulated centrifugal impeller is rated as level 3, with a score of 10 (based on the table). The simulated friction only occurred at the centrifugal impeller; therefore, the second dimension shows friction at monitoring location 1, with a score of 1. Data recording from the experimental apparatus shows that the duration of this friction was 0.27 seconds; therefore, the third dimension is rated as level 3, with a score of 3 (based on the table). The total score is 30 points, indicating an intolerable friction level, requiring shutdown.

[0059] 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 without departing from the principles and spirit of the present invention.

Claims

1. A monitoring method for non-tolerant rubbing faults in turbine pumps, characterized in that: It includes the following steps: Step 1: Arrange vibration sensors at multiple monitoring positions of the turbo pump, and collect the output signals of each vibration sensor during the operation of the turbo pump; the monitoring positions at least include the inducer, centrifugal impeller, turbine, and the seal position in front of the turbine; Step 2: Obtain multi-dimensional judgment elements based on the vibration sensor signals collected in Step 1: The first dimension: According to the output signal of the vibration sensor, judge the single-point rubbing degree of each monitoring position; the single-point rubbing degree is divided into three levels: no rubbing, slight, and severe; if the output signal of the vibration sensor at a certain monitoring position only has a fundamental frequency signal, the corresponding single-point rubbing degree is no rubbing; if the output signal of the vibration sensor at a certain monitoring position shows high and low harmonics, the corresponding single-point rubbing degree is at the slight level; if the output signal of the vibration sensor at a certain monitoring position shows a low-frequency quantity exceeding the set amplitude, the corresponding single-point rubbing degree is at the severe level; The second dimension: According to the output signals of all vibration sensors, judge the number of positions where rubbing occurs; Take the number of monitoring positions where rubbing occurs as the score value. If the number of monitoring positions where rubbing occurs exceeds 4, directly determine that the turbo pump has an unacceptable rubbing fault; The third dimension: According to the output signals of all vibration sensors, judge the duration of the rubbing phenomenon of the turbo pump; the third dimension is divided into the following 5 levels: Level I indicates that T≤0.1s, Level II indicates that 0.1s<T≤0.2s, Level III indicates that 0.2s<T≤0.3s, Level IV indicates that 0.3s<T≤0.4s, Level V indicates that T>0.4s, where T is the duration of the rubbing phenomenon of the turbo pump; The scores for the 5 levels are in sequence: 1, 2, 3, 4, 5; Step 3: Conduct a comprehensive score on the three-dimensional judgment elements obtained in Step 2 to judge the rubbing level of the turbo pump and determine whether the turbo pump has an unacceptable rubbing fault; among them, the comprehensive score is the product of the scores of the three dimensions, and the score of the first dimension takes the highest value of the scores of the first dimension corresponding to all monitoring positions; for a certain monitoring position, its score of the first dimension takes different values according to 3 levels. Among them, the score of the first level is 0, the score of the second level is 1, and the score of the third level is 10; if the comprehensive score reaches 10, it is determined that the turbo pump has an unacceptable rubbing fault.

2. The monitoring method for non-tolerant rubbing faults in turbine pumps according to claim 1, characterized in that: In Step 2, if it is judged that rubbing occurs at any monitoring position, it is considered that the turbo pump has a rubbing phenomenon. When the rubbing phenomena at all monitoring positions disappear, it is considered that the rubbing phenomenon of the turbo pump disappears; use the moment when the rubbing phenomenon of the turbo pump disappears and the moment when the rubbing phenomenon of the turbo pump appears to obtain the duration of the rubbing phenomenon of the turbo pump.

3. The monitoring method for non-tolerant rubbing faults in turbine pumps according to claim 2, characterized in that: In Step 2, use the following process to judge whether rubbing occurs at a certain monitoring position: If the output signal of the vibration sensor at a certain monitoring position shows high and low harmonics and / or a low-frequency quantity exceeding the set amplitude, it is considered that rubbing occurs at this monitoring position.

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