Automatic diagnosis method and system for failure of grouped thermocouples in aircraft engines

Abstract

This invention discloses an automatic diagnosis method and system for group thermocouple failure in aero-engines, belonging to the field of aero-engine technology. The method includes numbering each thermocouple in the thermocouple group and locating the thermocouples based on their numbers. By combining the judgment of individual thermocouples and the group of thermocouples, the failure status of thermocouples can be automatically detected. When a thermocouple fails, an average temperature expression is obtained based on the temperature data of a reference thermocouple and the difference expression between the temperature data of the remaining numbered thermocouples and the temperature data of the reference thermocouple. The failure thermocouple can then be quickly located based on changes in the average temperature expression.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, specifically relating to an automatic diagnosis method and system for group thermocouple failure in aero-engines. Background Art

[0002] A typical aero engine consists of components such as an air intake, compressor, combustion chamber, gas turbine, and power turbine. To monitor the engine's operating status, sensors are placed on different components. Among these, the power turbine inlet temperature is a crucial parameter characterizing the engine's operating status. During flight, to ensure the engine's lifespan and reliability, the inlet temperature must be maintained within the operating limits. Pilots adjust the operating conditions based on the inlet temperature: if the inlet temperature is close to the limit, the operating conditions must be lowered to reduce the inlet temperature and maintain it at a healthy level, thus preserving the engine's lifespan; if the inlet temperature is low, the operating conditions can be increased to meet the pilot's demand for higher power.

[0003] Aero engines are highly complex machines. The turbine inlet section is characterized by high temperature, high pressure, and an unsteady, non-uniform flow field. The temperature varies at different locations along the 45° section. Therefore, to objectively understand the engine's condition and accurately measure temperature, the primary method currently used is to measure the turbine inlet temperature using a group of thermocouples. The average temperature output by the group of thermocouples is taken as the measured temperature. However, because thermocouples operate under high temperature, high pressure, and an unsteady, non-uniform flow field for extended periods, they are subjected to the combined effects of high temperature and alternating stress. Therefore, a single T45 thermocouple is at high risk of ablation or breakage. When one thermocouple ablates or breaks, the average value of the remaining thermocouples is used as the output temperature. However, if a thermocouple fails, the average output value will inevitably change. For example, if the thermocouple is damaged... The temperature measured by the thermocouple is the maximum value. When it fails, the average temperature output by the system decreases, indicating an increase in the pilot's available power. However, once the pilot pushes up the engine status, the actual temperature will be higher than the displayed temperature, potentially causing the engine to overheat, damaging engine life and flight safety. Conversely, if the measured value of the failed thermocouple is lower, the average output temperature will increase, indicating an increase in engine status and a decrease in the pilot's available power. However, the actual temperature will be lower than the displayed temperature. During the process of pushing up the engine status, the limit value will be triggered prematurely, limiting the engine's power output. This could lead to a situation where more power is needed in some emergency situations but is unavailable, which also endangers flight safety. Based on this, it is necessary to design a scheme that can quickly locate the failed thermocouple when it fails, and formulate a strategy in a timely manner. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic diagnostic method and system for group thermocouple failure in aero-engines, so as to solve the problem of locating failed thermocouples mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an automatic diagnosis method for group thermocouple failure in an aero-engine, comprising:

[0006] Number each thermocouple in the thermocouple group and obtain the temperature data of all numbered thermocouples;

[0007] Calculate the first average of the temperature data of all numbered thermocouples in the thermocouple group and the second average of the thermocouple group after removing the temperature data of any numbered thermocouple.

[0008] The failure status of the thermocouple assembly is determined based on the difference between the second average value and the first average value, as well as the rate of change of the first average value. When the thermocouple assembly fails, the failed thermocouple in the thermocouple assembly is located, including:

[0009] The temperature data of each thermocouple is expressed based on its number.

[0010] Select any numbered thermocouple from the thermocouple group as the reference thermocouple, and obtain the difference expression between the temperature data of the other thermocouples and the temperature data of the reference thermocouple;

[0011] The average temperature expression of the thermocouple group is obtained based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of the other numbered thermocouples and the temperature data expression of the reference thermocouple; and the failure thermocouple in the thermocouple group is located based on the average temperature expression.

[0012] Furthermore, based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of the other numbered thermocouples and the temperature data expression of the reference thermocouple, the average temperature expression of the thermocouple group is obtained; and the location of the failed thermocouple in the thermocouple group based on the average temperature expression includes:

[0013] Based on the temperature data expression of the reference thermocouple and the difference expression between the temperature expressions of the other numbered thermocouples and the temperature data expression of the reference thermocouple, we obtain the first expression for the average temperature of the thermocouple group under all numbered thermocouples and the second expression for the average temperature of the thermocouple group after removing any numbered thermocouple.

[0014] The difference between the first and second expressions yields the expression for the average temperature change of the thermocouple assembly.

[0015] The faulty thermocouple in the thermocouple group is located based on the expression of average temperature change.

[0016] Furthermore, the method of locating the failed thermocouple in the thermocouple assembly based on the average temperature change expression includes:

[0017] The thermocouple temperature data is substituted into the average temperature change expression to calculate the value. When the calculated value is greater than the third set value, the thermocouple with the removed number is identified as the failed thermocouple.

[0018] Furthermore, the determination of the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value, includes:

[0019] The difference is compared with the set value. If the difference is less than the first set value, the thermocouple assembly is determined to be not faulty.

[0020] Furthermore, the determination of the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value, also includes:

[0021] When the difference is greater than the first set value, the absolute value of the rate of change of the first average value is compared with the set value. When the absolute value of the rate of change of the first average value is greater than the second set value, the thermocouple assembly is determined to be faulty.

[0022] Furthermore, the thermocouple with the minimum temperature data of the thermocouples in the thermocouple group is selected as the reference thermocouple.

[0023] Furthermore, the temperature data for each thermocouple is expressed as T45. -n , where n is the thermocouple number, and n is an integer greater than or equal to 1.

[0024] Furthermore, the third setting value is 4.

[0025] Furthermore, the first setting is 6°C, and the second setting is 20%.

[0026] Another aspect of this application discloses an automatic diagnostic system for group thermocouple failures in an aero-engine, comprising:

[0027] The acquisition module is configured to number each thermocouple in the thermocouple group and acquire the temperature data of all numbered thermocouples.

[0028] The calculation module is configured to calculate the first average value of the temperature data of all numbered thermocouples in the thermocouple group and the second average value of the thermocouple group after removing the temperature data of any numbered thermocouple.

[0029] The positioning module is configured to determine the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value. When the thermocouple assembly fails, it locates the number of the failed thermocouple in the thermocouple assembly and includes:

[0030] The temperature data of each thermocouple is expressed based on its number.

[0031] Select any numbered thermocouple from the thermocouple group as the reference thermocouple, and obtain the difference expression between the temperature data of the other thermocouples and the temperature data of the reference thermocouple;

[0032] The average temperature expression of the thermocouple group is obtained based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expression of the other numbered thermocouples and the temperature expression of the reference thermocouple; and the failure thermocouple number in the thermocouple group is located based on the average temperature expression.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This application uses a combination of single thermocouples and thermocouple groups to automatically detect thermocouple failure. When a thermocouple fails, it obtains an average temperature expression based on the temperature data of a reference thermocouple and the difference between the temperature data of other numbered thermocouples and the temperature data of the reference thermocouple. Based on the change in the average temperature expression, it can quickly locate the failed thermocouple. Attached Figure Description

[0035] Figure 1 This is a flowchart of the method in this application;

[0036] Figure 2 A schematic diagram of the engine structure and the power turbine inlet;

[0037] Figure 3 This is a schematic diagram of the measurement system. Detailed Implementation

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] Reference Figure 3 This is a schematic diagram of the measurement system, in which thermocouple sensors are arranged at... Figure 2The thermocouples are arranged in a ring array on the 45-degree section of the turbine. The average temperature output by the thermocouples is used as the output temperature for temperature monitoring. However, because the thermocouples operate under high temperature, high pressure, and non-uniform flow field conditions, they are subjected to the combined effects of high temperature and alternating stress. Therefore, the risk of a single thermocouple burning or breaking is relatively high. When a thermocouple burns or breaks, it fails. The T45 junction box transmits the average value of the remaining intact thermocouples as the output temperature to the engine testing system. However, the failure of a single thermocouple inevitably leads to a change in the output temperature. In some examples, if the temperature measured by the faulty thermocouple is higher (i.e., the output temperature of that thermocouple is higher), the average temperature output by the thermocouple group will decrease after that thermocouple fails. The parameters may appear to indicate a decreased engine status and increased pilot-available power. However, if the pilot pushes the engine status up, the actual temperature will be higher than the displayed temperature, potentially causing engine overheating, damaging engine life, and jeopardizing flight safety. In other cases, if a faulty thermocouple measures a lower temperature (i.e., the output temperature of that thermocouple is lower), and that thermocouple fails, the average temperature output by the thermocouple group will rise, indicating an increased engine status and reduced pilot-available power. The actual temperature will be lower than the displayed temperature, and during the engine status push-up process, the T45 limit will be triggered prematurely, limiting engine power output. This could lead to a situation where higher power is needed in certain emergencies but is unavailable, similarly jeopardizing flight safety. Based on these problems, this application provides an automatic diagnostic method for group thermocouple failures in aero-engines, referring to... Figure 1 The above methods include:

[0040] S100: Number each thermocouple in the thermocouple group and obtain the temperature data of all numbered thermocouples;

[0041] S200: Calculate the first average value of the temperature data of all numbered thermocouples in the thermocouple group and the second average value of the thermocouple group after removing the temperature data of any numbered thermocouple.

[0042] S300: The failure status of the thermocouple assembly is determined based on the difference between the second average value and the first average value, as well as the rate of change of the first average value. When the thermocouple assembly fails, the number of the failed thermocouple in the thermocouple assembly is located and included:

[0043] The temperature data of each thermocouple is expressed based on its number.

[0044] Select any numbered thermocouple from the thermocouple group as the reference thermocouple, and obtain the difference expression between the temperature data of the other thermocouples and the temperature data of the reference thermocouple;

[0045] The average temperature expression of the thermocouple group is obtained based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of the other numbered thermocouples and the temperature expression of the reference thermocouple; and

[0046] The failure thermocouple number in the thermocouple group is located based on the average temperature expression.

[0047] In some embodiments, determining the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, and the rate of change of the first average value, includes:

[0048] The difference is compared with the set value. If the difference is less than the first set value, the thermocouple assembly is determined to be not faulty.

[0049] Furthermore, determining the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value, also includes:

[0050] When the difference is greater than the first set value, the absolute value of the rate of change of the first average value is compared with the set value. When the absolute value of the rate of change of the first average value is greater than the second set value, the thermocouple assembly is determined to be faulty.

[0051] In some embodiments, in step S300, the temperature data representation of each thermocouple is obtained based on the thermocouples, that is, each thermocouple's temperature data is assigned a code. For example, the temperature data representation of each thermocouple is T45. -n Where n is the thermocouple number, and n is an integer greater than or equal to 1. Correspondingly, taking thermocouple number 1 as the reference thermocouple as an example, the difference expression between the temperature data of any other thermocouple and the temperature data of the reference thermocouple is T45. -n -T45 -1 Correspondingly, the average temperature expression of the thermocouple group is obtained by using the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of the other numbered thermocouples and the temperature expression of the reference thermocouple; and

[0052] Locating the number of failed thermocouples in a thermocouple group based on the average temperature expression specifically includes:

[0053] Locating the failed thermocouple in a thermocouple group based on the average temperature expression includes:

[0054] Based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expression of the other numbered thermocouples and the temperature expression of the reference thermocouple, we obtain the first expression for the average temperature of the thermocouple group under all numbered thermocouples and the second expression for the average temperature of the thermocouple group after removing any numbered thermocouple.

[0055] The difference between the first and second expressions yields the expression for the average temperature change of the thermocouple assembly.

[0056] The faulty thermocouple in the thermocouple group is located based on the expression of average temperature change.

[0057] Furthermore, locating the failed thermocouple in the thermocouple assembly based on the average temperature change expression includes:

[0058] The thermocouple temperature data is substituted into the average temperature change expression to calculate the value. When the calculated value is greater than the third set value, the thermocouple with the removed number is identified as the failed thermocouple.

[0059] The above method will be explained below using a measurement system comprising four thermocouples, and the measured temperatures of the four thermocouples will be denoted as T45. -1 T45 -2 T45 -3 T45 -4 That is, T45 -1 T45 -2 T45 -3 T45 -4 These correspond to the temperatures measured by thermocouples 1 through 4, and T45 -1 To be the minimum value, and satisfying T45 -1 <T45 -2 <T45 -3 <T45 -4 And calculate T45 accordingly. -2 T45 -3 and T45 -4 With T45 -1 The difference:

[0060]

[0061]

[0062]

[0063] When one thermocouple fails, the remaining three of the four thermocouples in the group will automatically average their signals and output a signal. At this time, T45 exhibits a sudden jump and subsequent maintenance characteristic. Assuming that under normal conditions, the average value of the four thermocouples in the group is T45... AVG ,at this time

[0064] ,

[0065] After one thermocouple fails, the average value of the remaining three thermocouples is T45. （AVG） , with T45 -1 Taking failure as an example, at this time

[0066] ,

[0067] Thermocouple failure detection logic includes two aspects: absolute value change of T45 and slope change. Thermocouple failure is only determined when both conditions are met, as detailed below:

[0068] when At this time, regardless of T45 AVG The system determines that the T45 thermocouple is normal and does not take any action based on how the slope changes.

[0069] when And T45 AVG When the absolute value of the slope change is greater than 20%, it is determined that the thermocouple assembly is damaged, and the subsequent steps of locating the failed thermocouple are initiated.

[0070] The steps for locating a failed thermocouple are as follows:

[0071] Firstly, based on the above calculations, T45 -2 T45 -3 T45 -4 With T45 -1 The difference is used to rewrite the formula for calculating the average temperature TAVG of the above thermocouple group, where T45 is... -1 +T45 -2 +T45 -3 +T45 -4 =Δ 2-1 +Δ 3-1 +Δ 4-1 +4T45 -1 Substituting the above formula into T45 AVG The calculation formula yields T45. AVG The new calculation formula is as follows:

[0072]

[0073] The failure detection logic for thermocouple No. 1 at this time is as follows:

[0074] Assuming thermocouple #1 fails, at this time

[0075] At this time, when T45 （AVG） Compared to the T45 AVG The absolute value of the change is greater than the set value (e.g., 4°C) and continues for a set time (e.g., 2 seconds), that is... If the failure is observed for 2 seconds, then thermocouple No. 1 can be determined to be faulty.

[0076] The failure detection logic for thermocouple #2 is similar to that for thermocouple #1:

[0077] When thermocouple #2 fails, T45 （AVG） Compared to T45 AVG The change is At this time If the failure persists for 2 seconds, then thermocouple No. 2 can be determined to be faulty.

[0078] The failure detection logic for thermocouple #3 is similar to that for thermocouple #1:

[0079] When thermocouple #3 fails, T45 （AVG） Compared to T45 AVG The change is At this time If the failure persists for 2 seconds, then thermocouple No. 3 can be determined to be faulty.

[0080] The failure detection logic for thermocouple #4 is similar to that for thermocouple #1:

[0081] When thermocouple #4 fails, T45 （AVG） Compared to T45 AVG The change is At this time If the failure persists for 2 seconds, then thermocouple No. 3 can be determined to be faulty.

[0082] Another aspect of this application discloses an automatic diagnostic system for group thermocouple failures in an aero-engine, comprising:

[0083] The acquisition module is configured to number each thermocouple in the thermocouple group and acquire the temperature data of all numbered thermocouples.

[0084] The calculation module is configured to calculate the first average value of the temperature data of all numbered thermocouples in the thermocouple group and the second average value of the thermocouple group after removing the temperature data of any numbered thermocouple.

[0085] The positioning module is configured to determine the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value. When the thermocouple assembly fails, it locates the number of the failed thermocouple in the thermocouple assembly and includes:

[0086] The temperature data of each thermocouple is expressed based on its number.

[0087] Select any numbered thermocouple from the thermocouple group as the reference thermocouple, and obtain the difference expression between the temperature data of the other thermocouples and the temperature data of the reference thermocouple;

[0088] The average temperature expression of the thermocouple group is obtained based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of the other numbered thermocouples and the temperature expression of the reference thermocouple; and

[0089] The failure thermocouple number in the thermocouple group is located based on the average temperature expression.

[0090] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An automatic diagnostic method for group thermocouple failure in an aero-engine, characterized in that, include: Number each thermocouple in the thermocouple group and obtain the temperature data of all numbered thermocouples; Calculate the first average of the temperature data of all numbered thermocouples in the thermocouple group and the second average of the thermocouple group after removing the temperature data of any numbered thermocouple. The failure status of the thermocouple assembly is determined based on the difference between the second average value and the first average value, as well as the rate of change of the first average value. When the thermocouple assembly fails, the failed thermocouple in the thermocouple assembly is located, including: The temperature data of each thermocouple is expressed based on its number. Select any numbered thermocouple from the thermocouple group as the reference thermocouple, and obtain the difference expression between the temperature data of the other numbered thermocouples and the temperature expression of the reference thermocouple; Based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of other numbered thermocouples and the temperature data expression of the reference thermocouple, the average temperature expression of the thermocouple group is obtained. Based on the average temperature expression, the location of the failed thermocouple in the thermocouple group is determined, including: Based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expression of the other numbered thermocouples and the temperature expression of the reference thermocouple, we obtain the first expression for the average temperature of the thermocouple group under all numbered thermocouples and the second expression for the average temperature of the thermocouple group after removing any numbered thermocouple. The difference between the first and second expressions yields the expression for the average temperature change of the thermocouple assembly. The faulty thermocouple in the thermocouple group is located based on the expression of average temperature change.

2. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 1, characterized in that: The method of locating the failed thermocouple in the thermocouple group based on the average temperature change expression includes: The thermocouple temperature data is substituted into the average temperature change expression to calculate the value. When the calculated value is greater than the third set value, the thermocouple with the removed number is identified as the failed thermocouple.

3. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 1, characterized in that: The method of determining the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value, includes: The difference is compared with a first set value. If the difference is less than the first set value, the thermocouple assembly is determined to be not faulty.

4. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 3, characterized in that: The method of determining the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value, further includes: When the difference is greater than the first set value, the absolute value of the rate of change of the first average value is compared with the second set value. When the absolute value of the rate of change of the first average value is greater than the second set value, the thermocouple assembly is determined to be faulty.

5. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 1, characterized in that: The thermocouple with the minimum temperature data value in the thermocouple group is selected as the reference thermocouple.

6. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 1, characterized in that: The temperature data for each thermocouple is expressed as T45. -n , where n is the thermocouple number and n is an integer greater than or equal to 1.

7. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 2, characterized in that: The third setting value is 4.

8. The automatic diagnosis method for group thermocouple failure in an aero-engine according to claim 4, characterized in that: The first setting is 6°C, and the second setting is 20%.

9. An automatic diagnostic system for the failure of group thermocouples in an aero-engine, characterized in that: include: The acquisition module is configured to number each thermocouple in the thermocouple group and acquire the temperature data of all numbered thermocouples. The calculation module is configured to calculate the first average value of the temperature data of all numbered thermocouples in the thermocouple group and the second average value of the thermocouple group after removing the temperature data of any numbered thermocouple. The positioning module is configured to determine the failure status of the thermocouple assembly based on the difference between the second average value and the first average value, as well as the rate of change of the first average value. When the thermocouple assembly fails, it locates the number of the failed thermocouple in the thermocouple assembly and includes: The temperature data of each thermocouple is expressed based on its number. Select any numbered thermocouple from the thermocouple group as the reference thermocouple, and obtain the difference expression between the temperature data of the other numbered thermocouples and the temperature expression of the reference thermocouple; The average temperature expression of the thermocouple group is obtained based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expressions of the other numbered thermocouples and the temperature expression of the reference thermocouple; and the location of the failed thermocouple number in the thermocouple group is determined based on the average temperature expression, including: Based on the temperature data expression of the reference thermocouple and the difference expression between the temperature data expression of the other numbered thermocouples and the temperature expression of the reference thermocouple, we obtain the first expression for the average temperature of the thermocouple group under all numbered thermocouples and the second expression for the average temperature of the thermocouple group after removing any numbered thermocouple. The difference between the first and second expressions yields the expression for the average temperature change of the thermocouple assembly. The faulty thermocouple in the thermocouple group is located based on the expression of average temperature change.

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