Turbine engine particle monitoring

Abstract

The present invention relates to a method for monitoring a turbine engine (1), the turbine engine (1) comprising: - at least one rotating shaft (6, 7, 8) supported by at least one bearing (12a, 12b, 12c, 13a, 13b, 13c); - at least one motor (M1, M2) configured to supply electrical energy to the turbine engine (1), the motor (M1, M2) comprising at least one roller bearing (23); the motor (M1, M2) and the bearings (12a, 12b, 12c, 13a, 13b, 13c) arranged in a lubrication enclosure (A1, A2); and - a lubrication system (S) adapted to lubricate the bearings (12a, 12b, 12c, 13a, 13b, 13c). The lubrication system (S) includes a particle detector (104) for lubricating the roller bearings (23) and for recovering oil present in the enclosures (A1, A2). The particle detector is adapted to count particles present in the lubrication system (S). The method includes performing the following steps after a time period A following motor stop, and when the oil flow rate circulating in the lubrication system is greater than a given threshold (B): - stopping the motor for a duration T1 to release particles from the roller bearings (23) so that the particles circulate in the lubrication system; - counting the particles circulating in the lubrication system for a duration T2; and - triggering a maintenance alarm for the motor when the number of counted particles is greater than the threshold.

Description

Technical Field

[0001] This application relates generally to the field of turbines, and more specifically to the monitoring of turbines equipped with sensors designed to retain metal particles entrained by lubricating oil generated by bearings. Background Technology

[0002] Turbines typically have rotating components driven by shafts supported by bearings. These bearings ensure the shaft rotates correctly and are lubricated via a closed-loop lubrication circuit. Bearings are subject to wear, which results in particles of varying sizes appearing in the lubrication circuit. To monitor bearing wear, particle sensors are installed in the lubrication circuit to prevent engine failure. To meet energy demands, turbines include one or more motors to provide electricity, specifically driving the high-pressure shaft. These motors also have bearings that must be lubricated and monitored in the same manner as the bearings supporting the rotating shaft. Summary of the Invention

[0003] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, countries have already implemented, are implementing, or will implement various restrictions on carbon emissions. In particular, an ambitious standard, applicable to both new aircraft and currently in circulation, requires the implementation of technological solutions to comply with existing regulations. The civil aviation industry has been committed to contributing to addressing climate change for many years.

[0004] Technological research has significantly improved the environmental performance of aircraft. The applicant considered influencing factors at all stages of design and development to obtain more energy-efficient and environmentally friendly aviation components and products. The integration and use of these components and products in civil aviation have a moderate environmental impact, with the aim of improving the energy efficiency of aircraft.

[0005] Therefore, the applicant has been committed to reducing its climate impact by using benign development and manufacturing methods and processes that minimize greenhouse gas emissions, thereby reducing the environmental impact of its activities.

[0006] This ongoing research and development effort focuses on next-generation aircraft engines that will make aircraft lighter, particularly through the use of materials and lighter onboard equipment, the development of propulsion using electric technology, and the development of aviation biofuels as an important complement to technological advancements.

[0007] This application is the result of technical research aimed at significantly improving aircraft performance and, in this sense, contributing to reducing the environmental impact of aircraft.

[0008] In particular, one object of this application is to monitor a turbine that includes at least one motor, which is preferably integrated into the turbine and as close as possible to the shaft.

[0009] The electric motor is integrated inside the turbine, rather than in a nacelle of limited size.

[0010] In view of the ever-increasing demand for electricity, this invention makes the use of electric motors possible. More specifically, electricity is cleaner and easier to maintain.

[0011] Therefore, a first aspect of the present invention relates to a method for monitoring a turbine, the turbine comprising: at least one rotating shaft supported by at least one bearing; at least one motor configured to supply power to the turbine, the motor including at least one roller bearing; the motor and bearing disposed in a lubrication enclosure; a lubrication system adapted to lubricate the bearing and the roller bearing and for recovering oil present in the enclosure, the lubrication system including a particle detector adapted to count particles present in the lubrication system, the method comprising the following steps after a time period A following a motor stop:

[0012] -a) Stop the motor and hold for a duration of T1 to release particles originating from the roller bearings, allowing the particles to circulate in the lubrication system;

[0013] -b) Count the particles circulating in the lubrication system for a duration of time T2;

[0014] -c) When the number of counted particles exceeds the threshold, trigger a maintenance alarm for the motor.

[0015] The method according to the first aspect is supplemented by the following features, which are employed individually or in any possible combination of techniques:

[0016] - When the flow rate of oil circulating in the lubrication system is greater than a given threshold (B), proceed with steps a), b), and c);

[0017] -The turbine includes a first motor and a second motor. The first motor stops, and the method includes: reconfiguring the second motor to supply power in place of the stopped first motor;

[0018] - The motor is based on winding technology and does not have permanent magnets that can attract particles;

[0019] - The motor is configured to convert torque from the rotating shaft into electricity;

[0020] - Each step that stops the motor is performed at the end of time period A, which is between 1 flight and 50 flights of the turbine.

[0021] - This method includes authorizing the motor to acquire torque after a time period T2 has elapsed.

[0022] - The time period T1 is between 0.1 seconds and 90 minutes, including the end value.

[0023] - The time period T2 is between 1 second and 10 minutes, including the end value.

[0024] In a second aspect, the invention also relates to a turbine comprising: at least one rotating shaft supported by at least one bearing; at least one motor configured to supply power to the turbine, the motor including at least one roller bearing; the motor and bearing disposed in a lubrication enclosure; a lubrication system adapted to lubricate the bearing and the roller bearing and for recovering oil present in the enclosure, said lubrication system including a particle detector adapted to count particles present in the lubrication system, the turbine including a processing unit connected to said detector and configured to perform a method for monitoring a turbine according to the first aspect.

[0025] In a third aspect, the present invention proposes an aircraft comprising at least one turbine according to the second aspect. Attached Figure Description

[0026] Other features, objects, and advantages of the invention will become apparent from the following description, which is given entirely in an illustrative and non-limiting manner and should be read with reference to the accompanying drawings, in which:

[0027] - Figure 1 An embodiment of an aircraft including a turbine according to this application is shown;

[0028] - Figure 2 An embodiment of the turbine according to this application is shown;

[0029] - Figure 3 The steps of the monitoring method according to this application are shown;

[0030] In all the accompanying drawings, similar elements have the same reference numerals. Detailed Implementation

[0031] Figure 1 An aircraft 100 comprising two turbines 1 is shown, and Figure 2 Turbine 1 is schematically shown. Turbine 1 has a main direction extending along the longitudinal axis X, and includes a fan 2, a low-pressure compressor 3a, a high-pressure compressor 3b, a combustion chamber 4, a high-pressure turbine 5a, a low-pressure turbine 5b, and an exhaust nozzle (not shown) from upstream to downstream along the gas flow direction.

[0032] The high-pressure turbine 5a rotates the high-pressure compressor 5a via a first shaft 8, called the high-pressure shaft, while the low-pressure turbine 5b rotates the low-pressure compressor 3a and the fan 2 via a second shaft 6, called the low-pressure shaft. The low-pressure shaft 6 is typically housed inside the high-pressure shaft 7. Advantageously, the fan 2 is rotated by the low-pressure shaft 6 via a gear reduction mechanism 10 and a third shaft, called the fan shaft 7, which is fixed between the reduction mechanism 10 and the fan 2. The reduction mechanism 10 enables the use of a large-diameter fan 2, while simultaneously having a high-speed operating low-pressure compressor 3a and a low-pressure turbine 5b.

[0033] The fan shaft 7, high-pressure shaft 8, and low-pressure shaft 6 are centered on the axis X of the turbine 1 via a series of bearings.

[0034] Specifically, the high-pressure shaft 7 and the low-pressure shaft 6 are fixed to the turbine 1 housing 9 by means of bearings 12a, 12b, 12c, 13a, 13b, and 13c. The bearings indicated by reference numerals 12a, 12b, and 12c are arranged at the rear of the turbine 1, while bearings 13a, 13b, and 13c are arranged at the front of the turbine 1. The fan shaft 7 is also supported by structural components by means of bearings not shown.

[0035] To lubricate various bearings 12a, 12b, 12c, 13a, 13b, 13c, the turbine 1 includes a lubrication system S supplying a closed oil passage and enclosures A1 and A2 housing the bearings 12a, 12b, 12c, 13a, 13b, 13c. These enclosures A1 and A2 define a sealed environment in which oil jets are sprayed onto the bearings. The bearings 12a, 12b, 12c, 13a, 13b, 13c are lubricated and cooled by oil sprayed into the enclosures via nozzles G1 and G2 (e.g., at pressures between 2 and 10 bar).

[0036] The lubrication system S includes a supply pump 101 that pumps oil from an oil reservoir 102 to deliver it through conduits 91 formed in the housing 9 to bearings 12a, 12b, 12c, 13a, 13b, 13c housed in enclosures A1, A2. During operation, the lubricating oil is centrifuged by the bearings and accumulates at the low points of enclosures A1, A2. To prevent oil from escaping from enclosures E1, E2, dynamic seals 10, such as labyrinth seals or servo-controlled radial seals (JRS), are provided. The lubrication system S is a closed loop because the oil volume is limited. As a result, the centrifuged oil is recovered by a recovery pump 103, which can recirculate the recovered oil. Each enclosure A1, A2 is provided with an oil recovery pump 103 to discharge an oil volume equivalent to the oil injected into the enclosure. Pump 103 pumps oil from conduits 92 formed in the housing 9. It should be noted that centrifugal oil can generate oil clouds / mist in the enclosure.

[0037] To detect wear on the bearings, a particle detector 104 is installed in the oil passage before the recovered oil is reinjected into the reservoir 101. This particle detector 104 is, for example, an electromagnetic sensor configured to collect particles present in the lubrication system. This detector is connected to the turbine's processing unit 200, which analyzes the signal from the detector to count the particles.

[0038] As noted in the introduction, turbine 1 includes one or more motors M1, M2 for supplying electricity to turbine 1. Motors M1, M2 obtain torque from the turbine shaft, for example, and convert it into electricity to supply power to turbine 1 (e.g., to an accessory).

[0039] Motors M1 and M2 typically include a stator 21, a rotor 22, and roller bearings 23 (or bearings) to minimize the air gap between the rotor 22 and the stator 21. To lubricate the roller bearings 23 of motors M1 and M2, the motors are housed in oil enclosures A1 and A2 to utilize the oil supplied by the bearings supporting the shaft of the turbine 1 described above. Here, the oil accumulated from the roller bearings 23 of motors M1 and M2 is also centrifuged to accumulate at the lowest point of the enclosures A1 and A2.

[0040] like Figure 2 As shown, two motors, M1 and M2, are installed, with each motor M1 and M2 located within oil containment components A1 and A2. Of course, different numbers of motors are possible.

[0041] It has been observed that, during operation, motors M1 and M2 emit magnetic fields that retain particles generated by the wear of their roller bearings and potentially attract magnetic particles generated by the wear of bearings housed within the enclosure. Advantageously, the motors are based on a winding technique, and there are no permanent magnets capable of attracting particles other than the magnetic field.

[0042] The trapped particles can damage the motors M1 and M2 themselves, but they can also interfere with bearing monitoring because these particles are not counted.

[0043] In order to monitor the turbine, taking into account the presence of the motor, the monitoring process described below is performed.

[0044] The motors M1 and M2 to be monitored stop after a certain period of time A following a previous shutdown also intended for their monitoring, and advantageously stop when the oil flow rate in the lubrication system is greater than a threshold B (steps E1, E2). Both conditions must be met simultaneously, if applicable. In the description given here, it is assumed that machine M1 is stopped. The oil flow rate B is set on the test bench, and is selected such that it can be obtained during the flight phase. The flight phase of interest is, for example, takeoff. Furthermore, the oil flow rate B ensures that detection must be performed when particles are accurately delivered by the oil flow (e.g., not when the turbine is idling), and this flow rate must be low enough to ensure that it is achieved under any flight conditions.

[0045] The time interval A between each stop of motor M1 is also defined by testing and depends on the rate of bearing degradation. Such duration corresponds to 1 to 50 flights of turbine 1.

[0046] In a complementary manner, when motor M1 stops, another motor M2 present in turbine 1 can then be reconfigured to take over the stopped motor (step E3) so that the turbine operation is unaffected and power is continuously supplied. Alternatively, an external power source (e.g., a battery) can take over the stopped motor.

[0047] After a time period T1 following the stop of motor M1 (step E4), particle counting begins (step E5). This time period T1 is also set on the test bench, and counting is avoided between the moment of particle release and the moment the fastest particle arrives at the particle detector. This duration takes into account the speed at which particles move in the oil flow at a flow rate greater than value B. Of course, the duration will depend on the flow rate B. The time period T1 can be between 100 ms and 90 seconds, including the extreme values. As an example, considering a pipe length between 1 m and 10 m, and a flow rate between 200 L / h and 10,000 L / h through a pipe between 0.75 inches and 1 inch, a range between 0.1 seconds and 90 seconds was obtained.

[0048] The particles are counted for a duration of time T2 (step E6). This time period T2 is, for example, between 1 second and 10 minutes, including the end value. As an example, considering a transmission efficiency of 0.25 and rounding, T2 is obtained as 1 second to 6 minutes. This time period T2 takes into account the slowest particle speed that still allows the motor M1 to be released, ensuring that the particles reach the particle detector 104. At the end of this time period T2, particle counting stops (step E7). Therefore, the time period T2 sets the counting window, enabling the counting of a large number of particles (from fastest to slowest). Stopping the motor in the enclosure allows particles from the shaft bearing and the motor's roller bearings to circulate well in the lubrication system.

[0049] Detection of particles originating from motor bearings is achieved by considering any particles detected between T1 and T2 as originating from the motor. More specifically, statistically, the probability of particles originating from turbine bearings being released during this window is negligible compared to the entire observation period, meaning that the source of particulate emission can be reliably located.

[0050] In this way, the amount of particles originating from the motor can be determined.

[0051] The counted number of particles is compared with the maintenance threshold SM (step E8), and if the number is greater than the threshold, a maintenance alarm is generated (step E9). Otherwise, if the number is less than the threshold, the motor is restarted (step E10), allowing the motor to be authorized to acquire torque.

[0052] It should be noted that this alarm can take the form of a user-facing alert, such as a visual alarm. The stopped motor is then restarted (step E10), alerting the user to perform maintenance and enabling restart. Specifically, the motor is once again authorized to acquire torque to convert it into electricity.

Claims

1. A method for monitoring a turbine (1), The turbine (1) includes: - At least one rotating shaft (6, 7, 8) supported by at least one bearing (12a, 12b, 12c, 13a, 13b, 13c); - At least one motor (M1, M2) is configured to supply power to the turbine (1), the motor (M1, M2) including at least one roller bearing (23); the motor (M1, M2) and the bearing (12a, 12b, 12c, 13a, 13b, 13c) are arranged in a lubrication enclosure (A1, A2); - A lubrication system (S), configured to lubricate the bearings (12a, 12b, 12c, 13a, 13b, 13c) and the roller bearing (23), and configured to recover oil present in the lubrication enclosures (A1, A2), the lubrication system (S) including a particle detector (104) adapted to count particles present in the lubrication system (S). The method includes (E1) performing the following steps after a time period A following the motor stops: a) Stop the motor (E2) and hold for a duration of T1 (E4) to release particles originating from the roller bearing (23) so that the particles circulate in the lubrication system; b) Count the particles circulating in the lubrication system for duration T2 (E5, E6); c) When the number of counted particles exceeds the threshold (SM), a maintenance alarm (E8, E9) for the motor is triggered. Specifically, when the flow rate of the oil circulating in the lubrication system is greater than a given threshold (B), steps a), b), and c) are performed. Each step (E2) that stops the motor is performed at the end of time period A, which falls between 1 to 50 flights of the turbine (1). The time period T1 is between 0.1 seconds and 90 seconds, including the endpoints. The time period T2 is between 1 second and 10 minutes, including the end value.

2. The method according to claim 1, wherein the turbine (1) comprises a first motor (M1) and a second motor (M2), wherein the first motor (M1) is stopped, the method comprising: Reconfigure (E3) the second motor (M2) so that the second motor (M2) supplies power instead of the stopped first motor (M1).

3. The method according to claim 1 or 2, wherein, The motors (M1, M2) are based on winding technology and do not have permanent magnets that can attract particles.

4. The method according to claim 1 or 2, wherein, The motors (M1, M2) are configured to convert torque from the rotating shaft into electricity.

5. The method according to claim 1 or 2, wherein after the time period T2 has elapsed, the method includes authorizing (E10) the motor to acquire torque.

6. A turbine (1) comprising at least one rotating shaft (6, 7, 8) supported by at least one bearing (12a, 12b, 12c, 13a, 13b, 13c), at least one motor (M1, M2), and a lubrication system (S), the at least one motor being configured to supply power to the turbine (1), the motor (M1, M2) comprising at least one roller bearing (23); the motor (M1, M2) and the bearing (12a, 12b, 12c, 13a, 13b, 13c) being disposed in lubrication enclosures (A1, A2); the lubrication system Suitable for lubricating the bearings (12a, 12b, 12c, 13a, 13b, 13c) and the roller bearings (23) and for recovering oil present in the lubrication enclosures (A1, A2), the lubrication system (S) includes a particle detector (104) adapted to count particles present in the lubrication system (S), and the turbine (1) includes a processing unit (200) connected to the particle detector (104) and configured to perform the method for monitoring the turbine (1) according to any one of claims 1 to 5.

7. An aircraft comprising a turbine (1) according to claim 6.

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