Method for managing the output of a specific-consumption mode of an aircraft turbine engine
Patent Information
- Application Number
- EP2023757980
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-08-12
- Filing Date
- 2023-08-08
- Publication Date
- 2025-06-18
AI Technical Summary
Current methods for managing the exit from a standby mode in aircraft turbine engines lack adaptability to varying aircraft conditions, leading to inefficient and potentially damaging reactivation processes.
A method that identifies the need for reactivation of a standby turbine engine and implements three different reactivation durations (normal, accelerated, and rapid) based on specific conditions, including anomalies in the primary engine or flight requirements, to maximize safety and minimize turbine engine impact.
Enables tailored reactivation strategies that balance safety and engine longevity, with normal reactivation preferred for minimal impact, while allowing quicker reactivation when necessary, thus optimizing performance and reducing wear on the turbine engine.
Smart Images
Figure 1.1
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE: Method for managing the exit from a specific consumption mode of an aircraft turboshaft engine
[0003] Technical field
[0004] The present invention relates to the management of aircraft turbomachine activations.
[0005] In particular, the present invention relates to helicopters with twin-engine architecture in which one of the two engines can operate in a deactivated or energy-saving mode, also called sleep mode.
[0006] Generally speaking, the invention applies to all aircraft comprising at least two engines.
[0007] Previous techniques
[0008] A turbomachine, and in particular an aircraft turbomachine, for example a helicopter turboshaft, must be started before it can provide thrust or mechanical power to the rotor. In particular, start-up includes heating the turbomachine components and starting the turbine.
[0009] During a flight phase of an aircraft comprising a twin-turboshaft architecture, a turboshaft engine may sometimes be switched off due to the implementation of a particular flight mode, for example an energy saving mode, also called standby mode.
[0010] In this standby mode, also detailed in document FR2967132A 1, the turbine engine remains rotating at a low speed while being driven by combustion gases or by an assistance device such as an electric machine. In this standby mode, the combustion chamber can be switched off. Alternatively, the combustion chamber is switched on while the turbine engine is or is not assisted in its rotation.
[0011] To exit this standby mode, it is possible to restart the engine using a conventional restart or a fast restart. Document FR3027058A1 mentions in particular that a normal restart takes 30 seconds to 1 minute while a fast restart takes around 10 seconds.
[0012] Statement of the invention
[0013] The present invention therefore aims to overcome the aforementioned drawbacks and to provide management of exit from standby mode adapted to each situation in which the aircraft finds itself.
[0014] The present invention relates to a method for managing the exit from a specific consumption mode of an aircraft equipped with a first turbine engine operating in a nominal mode and a second turbine engine operating in a standby mode or in a consumption mode intermediate to the standby mode and the nominal mode of the second turbine engine. Nominal mode is understood to mean the normal operating mode where a turbine engine provides power. The method comprises a step of identifying a need to reactivate the second turbine engine in the nominal mode of said second turbine engine and a step of:
[0015] - normal reactivation for a first duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine verifies a first condition;
[0016] - accelerated reactivation for a second duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine verifies a second condition;
[0017] - rapid reactivation for a third duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine meets a third condition, normal reactivation being preferred over accelerated reactivation, accelerated reactivation also being preferred over rapid reactivation, the first duration being longer than the second duration, and the second duration being longer than the third duration.
[0018] Thus, the second turbine engine can be reactivated for different durations according to different reactivation stages, which makes it possible to maximize the benefits, and in particular to limit the impacts of a reactivation to the exact safety need. Indeed, the shorter the reactivation, the more it damages the turbine engine but also the safer it is.
[0019] Advantageously, the step of identifying a need to reactivate the second turbine engine in the nominal mode of said second turbine engine comprises a step of detecting an anomaly in at least one operating parameter of the first turbine engine or comprises a step of receiving by the second turbine engine a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
[0020] In one embodiment, the normal reactivation step and / or the accelerated reactivation step and / or the rapid reactivation step comprises a step of assisting the second turbine engine by an electrical machine of the aircraft.
[0021] Advantageously, the normal reactivation step comprises a thermal stabilization step at a predefined temperature of the second turbine engine or a step of progressive powering up of the second turbine engine until a balance of the powers supplied between the first and second turbine engines is reached, the normal reactivation step further comprising the implementation of a fuel flow law allowing a reactivation time of between 1 and 3 minutes.
[0022] Advantageously, the accelerated reactivation step includes the implementation of a fuel flow law allowing a reactivation time of between 25 seconds and 45 seconds.
[0023] In one implementation mode, the rapid reactivation step includes the use of a specific starting system configured to implement an assistance torque and a fuel flow law allowing a reactivation time of between 5 seconds and 15 seconds.
[0024] Advantageously, the first condition includes the receipt by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
[0025] Advantageously, the second condition comprises the detection of a failure on the first turbine engine, for example among the loss of redundancy of a sensor, an excessive oil temperature, the loss of an energy source of the aircraft, or comprises the detection of flight conditions requiring operation in nominal mode of the second turbine engine, or comprises the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
[0026] Advantageously, the third condition comprises the detection of a failure on the first turbine engine, for example the detection of an anomaly among the values of fuel flow rate, and / or of the temperature and / or of the rotational speed at the outlet of a high-pressure turbine of the turbine engine, and / or of the pressure at the outlet of a compressor of the turbine engine, and / or of the torque, and / or the detection of the extinction of a combustion chamber of the turbine engine, and / or of a leak on an oil circuit, and / or of a leak on a fuel circuit, and / or a detection of filings, and / or of an inability to regulate the performance of the turbine engine, and / or of an inconsistency between the power demand and the power supplied, and / or comprises the detection of flight conditions requiring operation in nominal mode of the second turbine engine, or comprises the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
[0027] In one embodiment, the method is implemented continuously by a computer of the first and / or second turboshaft engine as long as the second turboshaft engine is not in its nominal operating mode, the first, second and third conditions also comprising a condition of maintaining the flight altitude of the aircraft for the time necessary for the reactivation of the second turboshaft engine.
[0028] Brief description of the drawings
[0029] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:
[0030] [Fig 1] is a block diagram of the different states of a second turbine engine during the implementation of the method according to the invention; and
[0031] [Fig 2] illustrates the steps of the method according to the invention.
[0032] Detailed description of at least one embodiment
[0033] In one embodiment, the method according to the invention is implemented in an aircraft, for example a helicopter, comprising a first turbine engine and a second turbine engine supplying power to a main gearbox of the aircraft.
[0034] The first and second turboshaft engines each comprise a compressor which raises the pressure of a gas entering the turboshaft engines, a combustion chamber which raises the temperature of the compressed gas, and an expansion turbine which also drives the compressor.
[0035] In particular, the first and second turbine engines are, for example, free turbine turbine engines, the expansion turbine being divided into a high pressure turbine, also called a gas generator turbine, and a power turbine, also called a free turbine.
[0036] The method according to the invention is in particular implemented when the aircraft operates with a specific consumption mode such as the energy saving mode, in particular when one of the two turbine engines, for example the first turbine engine, operates in a nominal mode, in other words in an operating mode offering standard performances and allowing the aircraft to move in the atmosphere, and when the second turbine engine operates in a deactivated mode. In particular, deactivated mode means a standby mode of the second turbine engine, or a consumption mode intermediate between the standby mode and the nominal mode of the second turbine engine.
[0037] The first and second turbine engines can be interchanged when implementing the method according to the invention.
[0038] The intermediate consumption mode is, for example, an operating mode of the second turbine engine when the latter switches from its nominal mode to its standby mode, or from its standby mode to its nominal mode.
[0039] Standby mode is a consumption mode allowing the aircraft's second turbine engine to have low fuel consumption, while allowing reactivation which can be rapid, for a situation where the aircraft would need both turbine engines or in the event that the first turbine engine had a failure.
[0040] Figure 1 schematically shows a block diagram of the different states of a second turbine engine during the implementation of the method according to the invention, in other words during steps of reactivation of the second turbine engine.
[0041] In particular, Figure 1 shows a nominal consumption mode 2 of the second turbine engine, a standby mode 4, and an intermediate consumption mode 6 in standby mode 4 and in nominal mode 2. The method according to the invention applies to the second turbine engine in particular when the latter is in an operating mode such as standby mode 4 or intermediate consumption mode 6. In these latter modes, the combustion chamber can be switched off, while the turbine of the gas generator is weakly driven in rotation, for example using an electric machine. Alternatively, the combustion chamber is switched on and the turbine of the gas generator includes or does not include rotational drive assistance. Figure 2 shows schematically the different steps of the method for managing the exit from a specific consumption mode of the aircraft.
[0042] The method comprises a step 8 of identifying a need to reactivate the second turbine engine in nominal mode 2 of said second turbine engine.
[0043] Step 8 of identifying a need to reactivate the second turbine engine comprises in particular a step (not shown) of detecting an anomaly in at least one operating parameter of the first turbine engine and / or of the aircraft. In particular, if the detected anomaly, for example representative of a leak in a circuit or more broadly of a loss of performance, reflects a failure which makes the use of the first turbine engine alone insufficient for the flight of the aircraft, a need to reactivate the second turbine engine is identified.
[0044] Alternatively, step 8 of identifying a need to reactivate the second turbine engine comprises a step (not shown) of receiving a reactivation instruction issued by an on-board computer and / or by a pilot of the aircraft. Indeed, the on-board computer of the aircraft can at any time provide an instruction indicating that the second turbine engine must be used in nominal mode. Similarly, a pilot of the aircraft may wish to request the reactivation of the second turbine engine, for example by pressing a button, in order to carry out a particular maneuver.
[0045] Once a need to reactivate the second turbine engine has been identified, the method comprises the implementation of a reactivation step which can take three different forms, the three types of reactivation being able to impact the aging of the second turbine engine differently.
[0046] A normal reactivation step 10 is carried out for a first duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine and / or the pilot verifies a first condition C1. This is the longest possible reactivation step; in particular, it allows the mechanical integrity of the second turbine engine to be preserved.
[0047] In one embodiment, the first condition C1 comprises the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or by a pilot of the aircraft.
[0048] This normal reactivation step 10 includes a thermal stabilization step at a predefined temperature of the second turbine engine. Alternatively, this step 10 includes a step of progressive powering up of the second turbine engine until the power supplied between the first and second turbine engines is balanced.
[0049] Normal reactivation step 10 further includes the implementation of a fuel flow law and torque optimization allowing a reactivation time of between 1 and 3 minutes.
[0050] Step 10 thus allows the temperature of the components of the second turboshaft engine to gradually increase.
[0051] This normal reactivation step 10 is the most commonly used reactivation step since it is often a non-urgent reactivation. It is the step with the least impact on the aging of the turboshaft engine and is therefore preferred.
[0052] The second type of reactivation is the implementation of a step 12 accelerated reactivation for a second duration of the second turbine engine in the nominal mode of said second turbine engine, and this when the aircraft and / or the first turbine engine and / or the second turbine engine verifies a second condition C2.
[0053] The second condition C2 includes, for example, the detection of a failure, and more broadly of an anomaly reflecting a failure of the first turbine engine, for example the loss of redundancy of a sensor, excessive oil temperature, or the loss of an aircraft energy source.
[0054] Alternatively, the second condition C2 comprises the detection of flight conditions requiring operation in nominal mode of the second turbine engine. For example, the measured atmospheric pressure is not compatible with the use of a single turbine engine in nominal mode, and it is therefore necessary to reactivate the second turbine engine. Alternatively, the second condition C2 comprises the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
[0055] Accelerated reactivation step 12 is substantially similar to normal reactivation step 10, but includes the implementation of a fuel flow law allowing a reactivation time of between 25 seconds and 45 seconds. This accelerated reactivation step 12 is therefore shorter, in particular thanks to the absence of a thermal stabilization step, and allows the second turbine engine to be reactivated more quickly. This reactivation nevertheless involves an impact on the aging of the second turbine engine.
[0056] The third type of reactivation is the implementation of a step 14 of rapid reactivation for a third duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine verifies a third condition C3.
[0057] The third condition C3 also includes the detection of a failure of the first turbine engine, or more broadly of an anomaly among the values of fuel flow, and / or of the temperature and / or of the rotational speed at the outlet of a high-pressure turbine of the turbine engine, and / or of the pressure at the outlet of a compressor of the turbine engine, and / or of the torque, and / or the detection of the flameout of a combustion chamber of the turbine engine, and / or of a leak in an oil circuit, and / or of a leak in a fuel circuit, and / or a detection of filings, and / or of an inability to regulate the performance of the turbine engine, and / or of an inconsistency between the power demand and the power supplied. These potential anomalies reflect failures of the first turbine engine which generally require rapid reactivation of the second turbine engine because they can be symptomatic of a significant loss of power of the first turbine engine.Alternatively, the third condition C3 comprises the detection of flight conditions requiring rapid operation in nominal mode 2 of the second turbine engine, or comprises the receipt by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
[0058] Rapid reactivation step 14 is different from the two previous types of reactivation. In particular, rapid reactivation step 14 involves the use of a specific starting system configured and sized to provide high torque assistance and to implement a fuel flow law allowing a reactivation time of between 5 and 15 seconds, around 10 seconds.
[0059] However, rapid reactivation step 14 has a significant impact on the aging of the second turbine engine and is only used in an emergency.
[0060] Among the three types of reactivation, normal reactivation step 10 is preferred over accelerated reactivation step 12, and accelerated reactivation step 12 is also preferred over rapid reactivation step 14. Indeed, a reactivation with low impact on aging is preferred, although the first duration is longer than the second duration, and the second duration is longer than the third duration.
[0061] Optionally, the second turbine engine comprises an electric assist machine and each of the normal reactivation, accelerated reactivation, or rapid reactivation stages comprises a stage of assistance of the second turbine engine by the aircraft's electric assist machine.
[0062] In other words, the electric assistance machine participates in the rotational drive of the second turbine engine during its reactivation in order to accelerate said reactivation.
[0063] Optionally, the first, second and third conditions also each include an additional condition of maintaining the flight altitude of the aircraft for the time required to reactivate the second turbine engine. Indeed, although step 10 of normal reactivation is preferred because it has little impact on the aging of the second turbine engine, if this does not guarantee that the flight altitude of the aircraft will be maintained, a faster reactivation step will be preferred. The same reasoning applies to step 12 of accelerated reactivation.
[0064] Additionally, a reactivation step may be interrupted in favor of another reactivation step when the conditions for the other reactivation step are met.
[0065] For example, when a normal reactivation step 10 is in progress, but an anomaly indicating a significant failure is detected, a rapid reactivation step 14 is performed. However, if the specific starting system has a failure 16, an accelerated reactivation step 12 is finally performed.
[0066] In one embodiment, the method is implemented continuously by a computer of the second turbine engine as long as the second turbine engine is not in its nominal operating mode 2. Thus, the search for identifying a need to reactivate the second turbine engine only stops when the second turbine engine is in its nominal operating mode 2.
Claims
CLAIMS 1. Method for managing the exit from a specific consumption mode of an aircraft equipped with a first turbine engine operating in a nominal mode and a second turbine engine operating in a standby mode (4) or in an intermediate consumption mode (6) to the standby mode (4) and to the nominal mode (2) of the second turbine engine, characterized in that it comprises a step (8) of identifying a need to reactivate the second turbine engine in the nominal mode of said second turbine engine and a step of: normal reactivation for a first duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine verifies a first condition (C l ) (step 10); - accelerated reactivation for a second duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine meets a second condition (C2) (step 12); rapid reactivation for a third duration of the second turbine engine in the nominal mode of said second turbine engine when the aircraft and / or the first turbine engine meets a third condition (C3) (step 14), normal reactivation being preferred over accelerated reactivation, accelerated reactivation also being preferred over rapid reactivation, the first duration being longer than the second duration, and the second duration being longer than the third duration.
2. Method according to claim 1, in which the step (8) of identifying a need to reactivate the second turbine engine in the nominal mode of said second turbine engine comprises a step of detecting an anomaly of at least one operating parameter of the first turbine engine or comprises a step of receiving a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
3. Method according to one of claims 1 and 2, in which the step (10) of normal reactivation and / or the step of accelerated reactivation and / or the step of rapid reactivation comprises a step of assisting the second turbine engine by an electrical machine of the aircraft.
4. Method according to any one of claims 1 to 3, in which the normal reactivation step (10) comprises a step of thermal stabilization at a predefined temperature of the second turbine engine or a step of progressive powering up of the second turbine engine until a balance of the powers supplied between the first and second turbine engines is reached, the normal reactivation step further comprising the implementation of a fuel flow law allowing a reactivation time of between 1 and 3 minutes.
5. Method according to any one of claims 1 to 4, in which the accelerated reactivation step (12) comprises the implementation of a fuel flow law allowing a reactivation time of between 25 seconds and 45 seconds.
6. Method according to any one of claims 1 to 5, in which the rapid reactivation step (14) comprises the use of a specific starting system configured to implement an assistance torque and a fuel flow law allowing a reactivation time of between 5 seconds and 15 seconds.
7. Method according to any one of claims 1 to 6, in which the first condition (C l ) comprises the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft.
8. Method according to any one of claims 1 to 7, in which the second condition (C2) comprises the detection of a failure on the first, for example among the loss of redundancy of a sensor, an excessive oil temperature, the loss of an energy source of the aircraft, or comprises the detection of flight conditions requiring operation in nominal mode of the second turbine engine, or comprises the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or an aircraft pilot.
9. Method according to any one of claims 1 to 8, in which the third condition (C3) comprises the detection of a failure of the first turbine engine, for example the detection of an anomaly among the values of fuel flow rate, and / or of the temperature and / or of the rotational speed at the outlet of a high-pressure turbine of the turbine engine, and / or of the pressure at the outlet of a compressor of the turbine engine, and / or of the torque, and / or the detection of the extinction of a combustion chamber of the turbine engine, and / or of a leak on an oil circuit, and / or of a leak on a fuel circuit, and / or a detection of filings, and / or of an inability to regulate the performance of the turbine engine, and / or of an inconsistency between the power demand and the power supplied, and / or comprises the detection of flight conditions requiring operation in nominal mode of the second turbine engine,or includes the reception by the second turbine engine of a reactivation instruction issued by an on-board computer and / or a pilot of the aircraft., 10. Method according to any one of claims 1 to 9, implemented continuously by a computer of the first and / or second turboshaft engine as long as the second turboshaft engine is not in its nominal operating mode (2), the first, second and third conditions also comprising a condition of maintaining the flight altitude of the aircraft for the time necessary for the reactivation of the second turboshaft engine.