METHOD AND SYSTEM FOR MONITORING THE PERFORMANCE OF A HIGH PRESSURE TURBINE OF AN AIRCRAFT ENGINE

Abstract

A method for monitoring a performance of a high pressure turbine (HPT) of an aircraft engine is proposed, comprising: collecting (401) a measured value of an outlet pressure of a high pressure compressor (HPC) of the engine, acquired during a given flight; determining (402) an estimated value of the outlet pressure of the high pressure compressor, using a performance model of the engine and measured values of operating parameters of the engine and of the aircraft, acquired during the given flight, and provided as input to the performance model; calculating (403) a first difference between the measured value and the estimated value; calculating (404) an indicator which is a function of a difference between a reference value and the first difference; and triggering (406) an alert if the indicator is greater than a threshold. Thus, it is possible to generate maintenance alerts sufficiently in advance. Figure to be published with the abstract: Fig. 4

Description

Title of the invention: METHOD AND SYSTEM FOR MONITORING THE PERFORMANCE OF A HIGH PRESSURE TURBINE OF AN AIRCRAFT ENGINE Technical field

[0001] The field of the invention is that of health monitoring and maintenance of aircraft.

[0002] More specifically, the present invention relates to a method for monitoring the performance of a high pressure turbine (HPT) of an aircraft engine.

[0003] When the aircraft comprises several engines, the proposed solution can be implemented for the high pressure turbine of each engine.

[0004] The present invention also relates to: a monitoring system suitable for implementing such a monitoring method; a computer program product and a storage medium enabling the implementation of such a monitoring method; and a maintenance method based on such a monitoring method. STATE OF PRIOR ART

[0005] Aircraft are subjected to extreme conditions when flying, particularly in terms of variations in temperature, pressure and speed. The performance of their components must be regularly checked to ensure their proper functioning.

[0006] Preventive or predictive maintenance consists of carrying out checks and repairs before a breakdown occurs.

[0007] In the field of aeronautics, maintenance makes it possible in particular to improve the availability and performance of an aircraft by avoiding its immobilization on the ground (AOG, for "Aircraft On Ground" in English), and to reduce maintenance costs by making it possible to identify maintenance operations in advance based on the actual performance of the aircraft.

[0008] Monitoring the health status of the aircraft for maintenance purposes includes collecting technical data from the moment the aircraft is powered up, then during the flight and until it is stopped. The data thus collected are used in particular to calculate the various indicators on which maintenance is based, and therefore the scheduling of maintenance operations.

[0009] The use of the data can take place during the flight (this is called in-flight health monitoring) and / or after the flight (for example if the volume of data to be processed requires computing resources). higher). Calculations using the collected data can therefore be carried out in the aircraft and / or in one or more ground devices. In the second case, the ground devices (computers) receive, in real time or delayed, the data collected in the aircraft.

[0010] Observing the health status of an aircraft over multiple flights allows ground personnel to make decisions and plan maintenance operations in advance, saving valuable execution time. Ground personnel can thus make appropriate decisions based on criticality, logistics and upcoming maintenance checks, and prepare repairs and replacements in advance.

[0011] In the context of this maintenance, there is in particular a need to monitor the performance of a high-pressure turbine of an aircraft engine, especially since the high-pressure turbine may be subjected to very high operating temperatures, very high rotational speeds, as well as severe environmental conditions. Currently, this monitoring is carried out during scheduled inspections including endoscope inspections. Given the accessibility conditions of the engine, these inspections can be long and complex to implement. There is therefore a need to have a solution that is reliable and simple to implement, and which makes it possible to anticipate possible operational interruptions ("Operational Interrupts") by raising maintenance alerts sufficiently in advance. Statement of the invention

[0012] A method for monitoring the performance of a high-pressure turbine of an aircraft engine is proposed, the method being implemented by a monitoring system comprising electronic circuitry, the method comprising:

[0013] - collecting at least one measured value of an outlet pressure of a compressor high engine pressure, acquired during a given flight of the aircraft by a sensor included in the aircraft;

[0014] - determine at least one estimated value of the compressor outlet pressure high pressure, using an engine performance model and measured values of engine and aircraft operating parameters, acquired during the given flight of the aircraft by other sensors included in the aircraft, and provided as input to the engine performance model;

[0015] - calculate a first difference between the measured value and the estimated value of the high pressure compressor outlet pressure;

[0016] - calculate an indicator which is a function of a second difference between a value predetermined reference and the first difference; and

[0017] - trigger an alert if the indicator is above a predetermined threshold.

[0018] Thus, it is possible to monitor the performance of a high-pressure turbine of an aircraft engine, using a solution that is reliable and simple to implement, and which makes it possible to anticipate possible interruptions in operation by raising maintenance alerts sufficiently in advance.

[0019] According to a particular embodiment, the measured values of the outlet pressure of the high pressure compressor and of the operating parameters of the engine and of the aircraft are acquired during a cruise phase of the given flight of the aircraft.

[0020] According to a particular embodiment, the alert is triggered if the indicator is greater than the predetermined threshold for at least X of the last Y flights of the aircraft up to and including the given flight, with X and Y predetermined integers and X <Y.

[0021] According to a particular embodiment, the predetermined reference value is an average value of the first differences, each between the measured value and the estimated value of the outlet pressure of the high pressure compressor, calculated for a predetermined number of flights of the aircraft after an initial assembly of the engine on the aircraft or after an operation to restore initial performance of the engine.

[0022] According to a particular embodiment, the engine performance model is implemented in the form of a neural network trained to provide an estimated value of the outlet pressure of the high pressure compressor, as a function of measured values of said operating parameters of the engine and of the aircraft.

[0023] A computer program product is also provided, comprising instructions causing the execution, by a processor, of the method mentioned above according to any one of its embodiments, when said instructions are executed by the processor.

[0024] Also provided is a storage medium storing such instructions.

[0025] A system for monitoring the performance of a turbine is also proposed. high pressure of an aircraft engine, the monitoring system comprising electronic circuitry configured to implement:

[0026] - collecting at least one measured value of an outlet pressure of a compressor high engine pressure, acquired during a given flight of the aircraft by a sensor included in the aircraft;

[0027] - determine at least one estimated value of the compressor outlet pressure high pressure, using an engine performance model and measured values of engine and aircraft operating parameters, acquired during the given flight of the aircraft by other sensors included in the aircraft, and provided as input to the engine performance model;

[0028] - calculate a first difference between the measured value and the estimated value of the high pressure compressor outlet pressure;

[0029] - calculate an indicator which is a function of a second difference between a value predetermined reference and the first difference; and

[0030] - trigger an alert if the indicator is above a predetermined threshold.

[0031] A method of maintaining a high-pressure turbine of an aircraft engine is also proposed, the method comprising:

[0032] - carry out the method mentioned above according to any of its modes of implementation, to monitor the performance of the high pressure turbine; and

[0033] - in the event of triggering an alert relating to the performance of the high turbine pressure, carry out at least one maintenance operation on the high pressure turbine. Brief description of the drawings

[0034] The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of at least one exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0035] [Fig-1] schematically illustrates, in side view, an aircraft equipped with a system of monitoring the performance of a high pressure turbine of an aircraft engine;

[0036] [Fig.2] schematically illustrates an example of hardware architecture of the system of monitoring the performance of a high pressure turbine of an aircraft engine;

[0037] [Fig.3] schematically illustrates an example of implementation of an aircraft engine, comprising various components and in particular a high pressure turbine;

[0038] [Fig.4] schematically illustrates an example of a monitoring algorithm for the performance of a high-pressure turbine of an aircraft engine; and

[0039] [Fig.5] schematically illustrates an example of a maintenance algorithm for a high-pressure turbine of an aircraft engine.

[0040] DETAILED DESCRIPTION OF EMBODIMENTS

[0041] [Fig.l] schematically illustrates, in side view, an aircraft 100 equipped with two engines (only the one on the left, referenced 101, is visible in [Fig.l]) and a system 200 for monitoring the performance of a high-pressure turbine included in each of the engines.

[0042] Since the proposed solution can be implemented for the high-pressure turbine of each of the engines, a single engine (and therefore a single high-pressure turbine) is referred to generically in the remainder of the description.

[0043] As detailed below, the system 200 for monitoring the performance of a high-pressure turbine of an engine 101 of an aircraft 100 makes it possible to trigger an alert (for example the display of information and / or the sending of a message to a maintenance service) if a trigger condition is verified. In addition, as also detailed below, the triggering of an alert relating to a high-pressure turbine may be followed by at least one maintenance operation on this high-pressure turbine (for example, the repair or replacement of one or more elements thereof).

[0044] In a particular implementation, the system 200 for monitoring the performance of a high-pressure turbine of an engine 101 is an on-board electronic device. For example, it is part of an electronic circuit of the avionics of the aircraft 100. Preferably, it is integrated into a computer of the aircraft 100.

[0045] In a variant, the system 200 for monitoring the performance of a high-pressure turbine of an engine 101 is not on board the aircraft 100 but is present on the ground.

[0046] In another variant, the system 200 for monitoring the performance of a high-pressure turbine of an engine 101 comprises a first part which is on board the aircraft 100 and a second part which is present on the ground. Thus, the calculations and the triggering of alerts can be distributed between the two parts of the system.

[0047] In another variant, at least one system 200 for monitoring the performance of a high pressure turbine of an engine 101 is on board the aircraft and at least one system 200 for monitoring the performance of a high pressure turbine of an engine 101 is installed on the ground.

[0048] [Fig. 2] schematically illustrates an example of hardware architecture of the system 200 for monitoring the performance of a high-pressure turbine of an aircraft engine, which then comprises, connected by a communication bus 210: a processor or CPU (“Central Processing Unit” in English) 201; a RAM (“Random Access Memory” in English) 202; a ROM (“Read Only Memory” in English) 203, for example a Flash memory; a data storage device, such as a hard disk drive (HDD) or a storage media reader, such as an SD (“Secure Digital” in English) card reader 204; at least one communication interface 205 allowing the monitoring system 200 to interact in the avionics of the aircraft 100.

[0049] The processor 201 is capable of executing instructions loaded into the RAM 202 from the ROM 203, from an external memory (not shown), from a storage medium, such as an SD card, or from a communication network (not shown). When the monitoring system 200 is powered on, the processor 201 is capable of reading instructions from the RAM 202 and executing them. These instructions form a computer program causing the processor 201 to implement the behaviors, steps and algorithm described herein.

[0050] All or part of the behaviors, steps and algorithm described herein may thus be implemented in software form by executing a set of instructions by a programmable machine, such as a DSP (Digital Signal Processor) or a microcontroller, or be implemented in hardware form by a machine or a dedicated component (chip) or a set of components (chipset), such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specified Integrated Circuit). Generally speaking, the monitoring system 200 comprises electronic circuitry arranged and configured to implement the behaviors, steps and algorithms described herein.

[0051] [Fig. 3] schematically illustrates an example of implementation of an aircraft engine 101, comprising various components (group referenced II) and in particular: - an air inlet (“Inlet” in English), referenced 301; - a blower (“Fan” in English), referenced 302; - a bypass duct, referenced 303; - a low pressure compressor, referenced LPC (for “Low Pressure Compressor” in English); - a high pressure compressor, referenced HPC (for “High Pressure Compressor” in English); - a combustion chamber (“Bumer” in English), referenced 304; - a high pressure turbine, referenced HPT (for “High Pressure Turbine” in English); and - a low pressure turbine, referenced LPT (for “Low Pressure Turbine” in English.

[0052] Conventionally, various “stations” of the engine (group referenced I) are also indicated and referenced 0, 2, 15, 25, 30, 40, 48 and 50.

[0053] Furthermore, the engine 101 is equipped with a plurality of sensors (group referenced III) making it possible to acquire measured values of different operating parameters of the engine. [Fig. 3] shows the locations of the sensors referenced P2, T2, NI, N2, P25, T25, P30, T30, Wf and EGT. In particular: - the P2 sensor allows the acquisition of measured values of the inlet pressure of the turbomachine (engine); - the T2 sensor allows the acquisition of measured values of the inlet temperature of the turbomachine (engine); - the NI sensor allows the acquisition of measured values of the rotation speed of the low pressure shaft of the engine; - the N2 sensor allows the acquisition of measured values of the rotation speed of the high pressure shaft of the engine; - the P25 sensor allows the acquisition of measured values of the inlet pressure of the high pressure compressor (HPC); - the T25 sensor allows the acquisition of measured values of the inlet temperature of the high pressure compressor (HPC); - the P30 sensor allows the acquisition of measured values of the high pressure compressor (HPC) outlet pressure; - the T30 sensor allows the acquisition of measured values of the high pressure compressor (HPC) outlet temperature; - the Wf sensor allows the acquisition of measured values of the fuel flow; and - the EGT sensor allows the acquisition of measured values of the exhaust gas temperature.

[0054] As described in more detail below, the aircraft comprises other sensors for acquiring measured values of different operating parameters of the aircraft (altitude, temperature, etc.).

[0055] [Fig. 4] schematically illustrates an exemplary algorithm for monitoring the performance of a high pressure turbine (HPT) of an aircraft engine. The algorithm (method) is implemented by the monitoring system 200 discussed above in connection with [Fig. 1] and 2.

[0056] As already mentioned above, the aircraft is equipped with a P30 sensor for acquiring measured values of the outlet pressure of the high pressure compressor (HPC).

[0057] The algorithm is for example executed for each of the successive flights of the aircraft. We now detail the steps of the algorithm, considering an execution for a given flight of the aircraft.

[0058] In a step 401, the monitoring system 200 collects a measured value (denoted P30actuai) of an outlet pressure of the high pressure compressor (HPC) of the engine (101), acquired during the given flight of the aircraft by the sensor P30. In one embodiment, this acquisition is carried out during the cruise phase of the given flight.

[0059] In one embodiment, the monitoring system 200 collects several measured values P30actuai (all acquired during the given flight) and uses the average of these measured values for the following steps.

[0060] In a step 402, the monitoring system 200 determines an estimated value (denoted P30estim) of the outlet pressure of the high pressure compressor (HPC), using a performance model of the engine and measured values of a set of engine and aircraft operating parameters, these values being provided as input to the engine performance model. These measured values are acquired during the given flight of the aircraft, by other sensors included in the aircraft (other than the P30 sensor). In one embodiment, these measured values are acquired during the cruise phase of the given flight of the aircraft.

[0061] In one embodiment, the monitoring system 200 determines several estimated values P30estim and uses the average of these estimated values for the following steps.

[0062] In one embodiment, the engine performance model is implemented as a neural network, trained to provide an estimated value (P30estim) of the high pressure compressor (HPC) outlet pressure, based on measured values of the set of engine and aircraft operating parameters. This set of parameters comprises, for example, a subset of engine operating parameter(s) and a subset of aircraft operating parameter(s).

[0063] The subset of engine operating parameters includes, for example, engine shaft speeds (e.g., the engine low pressure shaft speed).

[0064] The subset of operating parameters of the aircraft comprises for example one or more of the parameters belonging to the group comprising (non-exhaustive list): - altitudes; - temperatures (e.g., the total temperature upstream of the aircraft); - pressures (e.g., total pressure upstream of the aircraft); - a Mach number of the aircraft; - a condition of a wing anti-icing valve; - a condition of a nacelle anti-icing valve; - a condition of a purge pressure regulating valve; - etc.

[0065] In one embodiment, the neural network is trained to provide an estimated value for various internal parameters of the engine, based on the measured values of the set of operating parameters of the engine and the aircraft. For example, in addition to the outlet pressure of the high pressure compressor (the estimated value of which is denoted P30estim), the various internal parameters of the engine (for each of which a value is estimated) include: - the rotation speed of the high pressure shaft of the engine; - the output pressure of the engine's high pressure compressor (LPC); - the engine's low pressure compressor (LPC) outlet temperature; - the outlet temperature of the engine's high pressure compressor (HPC); - the engine exhaust gas temperature; - the engine fuel flow; - etc.

[0066] In a step 403, the monitoring system 200 calculates a first difference (denoted Delta_P30) between the measured value P30actuai (collected in step 401) and the estimated value P30estim (determined in step 402) of the outlet pressure of the high pressure compressor (HPC). In other words, the monitoring system 200 calculates:

[0067] Delta_P30 = P30actual - P30estim

[0068] In a step 404, the monitoring system 200 calculates a health indicator (denoted HI, for “Health Indicator” in English) which is a function of a second difference between a predetermined reference value (denoted Delta_P30_initial) and the first difference Delta_P30. In one embodiment, the monitoring system 200 calculates:

[0069] HI = Delta_P30_initial - Delta_P30

[0070] In one embodiment, the predetermined reference value Delta_P30_initial is an average value of the first differences, each between the measured value P30actuai and the estimated value P30estim of the outlet pressure of the high pressure compressor, calculated for a predetermined number (for example 50) of flights of the aircraft after an initial assembly of the engine on the aircraft or after an operation (workshop visit) to restore initial performance of the engine.

[0071] In one embodiment, the monitoring system 200 calculates a normalized value of the health indicator HI (for example a normalized value expressed as a percentage), to facilitate its interpretation.

[0072] In a step 405, the monitoring system 200 checks whether the health indicator HI is greater than a predetermined threshold S (for example, S = 1 in the case of a normalized health indicator HI).

[0073] Indeed, due to thermal degradation, the efficiency of the high pressure turbine (HPT) of the engine decreases over time, the outlet pressure of the high pressure compressor (HPC) also decreases over time, and consequently the health indicator HI increases.

[0074] In a variant, the monitoring system 200 checks in step 405 whether the indicator HI is greater than the predetermined threshold S for at least X of the last Y flights of the aircraft up to and including the given flight, with X and Y predetermined integers and X <Y. Par exemple, X=40 et Y=50.

[0075] In the event of a “yes” response to the test of step 405, the monitoring system 200 goes to step 406 in which it triggers an alert (for example the display of information and / or the sending of a message to a maintenance service, for example for recommend an endoscope inspection of the hot parts of the engine), then it moves on to the end step 407.

[0076] In the event of a “no” response to the test of step 405, the monitoring system 200 goes directly to the end step 407.

[0077] [Fig.5] schematically illustrates an example of a maintenance algorithm for a high-pressure turbine of an aircraft engine.

[0078] In a step 501, the monitoring system 200 executes an algorithm for monitoring the performance of a high-pressure turbine of an aircraft engine, for example in the particular embodiment described above (see the description of [Fig.4]).

[0079] If an alert has been triggered at the end of step 501 (result “yes” in test step 502), at least one maintenance operation, on the high-pressure turbine of the aircraft engine, is carried out (step 503), then it is the end step 504. Otherwise (result “no” in test step 502), it is directly the end step 504.

[0080] In one embodiment, the maintenance operation comprises an endoscope inspection of the hot parts of the engine, in order to detect a possible structural weakness of the high pressure turbine. If such a weakness is detected, the engine will be replaced in order to avoid an in-flight engine shutdown.

Claims

Claims

1. A method for monitoring a performance of a high pressure turbine (HPT) of an engine (101) of an aircraft (100), the method being implemented by a monitoring system (200) comprising electronic circuitry, the method comprising: - collecting (401) at least one measured value (P30actuai) of an outlet pressure of a high pressure compressor (HPC) of the engine (101), acquired during a given flight of the aircraft by a sensor (P30) included in the aircraft; - determining (402) at least one estimated value (P30estim) of the outlet pressure of the high pressure compressor (HPC), using an engine performance model and measured values of operating parameters of the engine and the aircraft, acquired during the given flight of the aircraft by other sensors included in the aircraft, and provided as input to the engine performance model;- calculate (403) a first difference (Delta_P30) between the measured value (P30actuai) and the estimated value (P30estim) of the outlet pressure of the high pressure compressor (HPC); - calculate (404) an indicator (HI) which is a function of a second difference between a predetermined reference value (Delta_P30_initial) and the first difference (Delta_P30); and - trigger (406) an alert if the indicator (HI) is greater than a predetermined threshold (S).;

2. A method according to claim 1, wherein the measured values of the high pressure compressor outlet pressure and the engine and aircraft operating parameters are acquired during a cruise phase of the given flight of the aircraft.

3. A method according to any one of claims 1 and 2, wherein the alert is triggered (406) if the indicator is greater than the predetermined threshold for at least X of the last Y flights of the aircraft up to and including the given flight, with X and Y predetermined integers and X <Y.

4. A method according to any one of claims 1 to 3, wherein the predetermined reference value is an average value of the first differences, each between the measured value and the estimated value of the outlet pressure of the high pressure compressor, calculated for a predetermined number of flights of the aircraft after initial assembly of the engine on the aircraft or after an operation to restore initial engine performance.

5. A method according to any one of claims 1 to 4, wherein the engine performance model is implemented as a neural network trained to provide an estimated value of the high pressure compressor outlet pressure, based on measured values of said engine and aircraft operating parameters.

6. Computer program product, comprising instructions causing the execution, by a processor (201), of the method according to any one of claims 1 to 5, when said instructions are executed by the processor.

7. A storage medium (203) storing a computer program comprising instructions causing a processor (201) to execute the method of any one of claims 1 to 5 when said instructions are read and executed by the processor.

8. System (200) for monitoring a performance of a high pressure turbine (HPT) of an engine (101) of an aircraft (100), the monitoring system comprising electronic circuitry configured to implement: - collecting at least one measured value (P30actuai) of an outlet pressure of a high pressure compressor (HPC) of the engine (101), acquired during a given flight of the aircraft by a sensor (P30) included in the aircraft; - determining at least one estimated value (P30estim) of the outlet pressure of the high pressure compressor (HPC), using an engine performance model and measured values of operating parameters of the engine and the aircraft, acquired during the given flight of the aircraft by other sensors included in the aircraft, and provided as input to the engine performance model;- calculate a first difference (Delta_P30) between the measured value (P30actuai) and the estimated value (P30estim) of the outlet pressure of the high pressure compressor; - calculate an indicator (HI) which is a function of a second difference between a predetermined reference value (Delta_P30_initial) and the first difference (Delta_P30); and; - trigger an alert if the indicator (HI) is higher than a predetermined threshold (S).

9. A method of maintaining a high pressure turbine (HPT) of an engine (101) of an aircraft (100), the method comprising: - executing (501) the method according to any one of claims 1 to 5, to monitor the performance of the high pressure turbine; and - in the event of triggering (502) of an alert relating to the performance of the high pressure turbine, carrying out (503) at least one maintenance operation on the high pressure turbine.

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