WO2009125090A1 - System and method for heating the hydraulic fluid of an aircraft - Google Patents

System and method for heating the hydraulic fluid of an aircraft Download PDF

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Publication number
WO2009125090A1
WO2009125090A1 PCT/FR2009/000306 FR2009000306W WO2009125090A1 WO 2009125090 A1 WO2009125090 A1 WO 2009125090A1 FR 2009000306 W FR2009000306 W FR 2009000306W WO 2009125090 A1 WO2009125090 A1 WO 2009125090A1
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WO
WIPO (PCT)
Prior art keywords
high pressure
hydraulic fluid
hydraulic
aircraft
heating device
Prior art date
Application number
PCT/FR2009/000306
Other languages
French (fr)
Inventor
Cédric LONJON
Roger Morvan
Original Assignee
Airbus France
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Airbus France filed Critical Airbus France
Publication of WO2009125090A1 publication Critical patent/WO2009125090A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C13/00—Control systems or transmitting systems for actuating flying-control surfaces, lift-increasing flaps, air brakes, or spoilers
    • B64C13/24—Transmitting means
    • B64C13/38—Transmitting means with power amplification
    • B64C13/40—Transmitting means with power amplification using fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/04—Special measures taken in connection with the properties of the fluid
    • F15B21/042—Controlling the temperature of the fluid
    • F15B21/0427—Heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6343—Electronic controllers using input signals representing a temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/66—Temperature control methods

Definitions

  • the present invention relates to a system and a method for heating the hydraulic fluid of an aircraft, the reheating of the fluid being controlled so as not to disturb the operation of actuators using this hydraulic fluid as a source of energy.
  • a hydraulic circuit comprises a reservoir 10 of hydraulic fluid, also called a hydraulic cover, in which one or more high-pressure pumps suck hydraulic fluid through a suction pipe 14.
  • These high-pressure pumps can correspond to a pump 12a driven by an engine of the aircraft and / or an electric pump 12b. They make it possible to bring the hydraulic fluid to the nominal pressure required for the operation of the aircraft (for example 200 bars or 350 bars depending on the type of aircraft).
  • hydraulic fluid is sent to a high-pressure line 16 to which are connected the various consumers 18 of hydraulic power supplied by this hydraulic circuit.
  • FIG. 2 represents an example of evolution of the logarithm of the viscosity V of a fluid hydraulic used on aircraft according to the temperature T in degrees Celsius.
  • the external temperature in which an aircraft evolves can frequently drop to values of the order of -50 degrees Celsius.
  • values of the outside temperature have an impact on the temperature of the hydraulic fluid of the aircraft, in particular during flights of long duration.
  • a thermal equilibrium of the hydraulic fluid is established whose temperature can go down to values of the order of -15 degrees Celsius for civil transport aircraft. This results in a significant increase in the viscosity of the hydraulic fluid compared to usual temperature conditions of the order of 20 degrees Celsius.
  • the present invention aims to overcome the aforementioned drawbacks. It relates to a system for heating the hydraulic fluid of an aircraft, said aircraft comprising at least one hydraulic circuit comprising:
  • At least one high pressure pump connected to a tank containing hydraulic fluid by a suction pipe and supplying hydraulic fluid to a high pressure line of said hydraulic circuit; and a set of hydraulic energy consumers connected to said high-pressure pipe.
  • This heating system is remarkable in that it comprises: - a controlled heating device! adapted to be connected to this high pressure pipe, said heating device comprising a flow restrictor; and control means dudi ' t heating device able to control the operation of said heating device so as to ensure a pressure level in said high pressure pipe allowing the operation of said hydraulic energy consumers during the entire operating life of the heater; 'aircraft.
  • the quantity of heat produced is proportional, on the one hand, to the flow rate of the hydraulic fluid in the flow restrictor and, on the other hand, to the the pressure difference between the flow restrictor upstream, connected to the high-pressure pipe, and the downstream flow restrictor, connected to a return pipe to the hydraulic tank.
  • the heated fluid mixes with the hydraulic fluid contained in the hydraulic tank. Therefore, the hydraulic fluid contained in the hydraulic tank is gradually warmed.
  • actuators consume significant amounts of hydraulic energy only for long periods of time. very limited time compared to the duration of the flight of the aircraft. Therefore, being given the thermal inertia of the hydraulic fluid, controlling the operation of the reheating device so as to guarantee a pressure level, in the high-pressure pipe, allowing the operation of the hydraulic energy consumers connected to this high-pressure pipe (which causes the heating device to stop when an increase in the consumption of hydraulic energy by said consumers, while the heating device is operating, causes a pressure drop in the high-pressure pipe, below a predetermined pressure value) is not disadvantageous from the point of view of the heating of the hydraulic fluid.
  • the heating system according to the invention thus makes it possible to heat the hydraulic fluid of the aircraft during the entire operating life of the aircraft. Consequently, it makes it possible to reduce the viscosity of the hydraulic fluid and therefore the pressure drops in the hydraulic circuit considered.
  • This hydraulic circuit can therefore be sized taking into account said reduced viscosity. This makes it possible to reduce the diameter of the pipes and the power of the high-pressure pump or pumps. This is very advantageous because it results in a saving of mass of the hydraulic circuit.
  • control means of the heating device are able to regulate the temperature of the hydraulic fluid in a predetermined temperature range. This avoids overheating of the hydraulic fluid that could be detrimental to the proper functioning of the hydraulic circuit.
  • the flow restrictor is installed at a second end of the high pressure line, opposite a first end of said high pressure line connected to said at least one high pressure pump.
  • hydraulic fluid circulates substantially throughout the high pressure line. Since the high-pressure line is supplied with hydraulic fluid by said at least one high-pressure pump that sucks this hydraulic fluid into the hydraulic tank, heated fluid circulates in the high pressure line.
  • the hydraulic fluid consumers connected to the high-pressure pipe have leaks corresponding to a circulation of hydraulic fluid through said consumers, with a flow rate that we generally try to minimize, from the high-pressure pipe to the return pipes to the hydraulic tank. Since the hydraulic fluid flowing in the high pressure line is heated fluid, said consumers are traversed by heated fluid.
  • the heating system according to the invention comprises means for measuring the temperature and / or the pressure of the hydraulic fluid, connected to said control means, these control means being able to produce signals controlling the heating device according to temperature and / or pressure information received from said measuring means.
  • the pressure measuring means make it possible to measure the pressure of the hydraulic fluid in the high-pressure pipe.
  • Means of temperature measurement can in particular be capable of measuring the fluid temperature in the hydraulic • hydraulic tank and / or the high-pressure pipe.
  • the control means may control the operation of the heating device so as to regulate the temperature of the hydraulic fluid.
  • the flow restrictor is a calibrated flow restrictor whose passage of the hydraulic fluid is controlled by a solenoid valve controlled by said control means.
  • the flow restrictor is a variable flow restrictor whose flow value is controlled by said control means.
  • the invention also relates to an aircraft comprising at least one hydraulic circuit comprising a high pressure line which comprises a plurality of branches respectively corresponding to: hydraulic energy consumers located in a first half-wing of the aircraft; and or
  • hydraulic energy consumers located in a second half-wing of the aircraft located in a second half-wing of the aircraft.
  • hydraulic energy consumers located in the rear part of the fuselage of the aircraft, in which at least one of said branches of the high-pressure pipe comprises a heating system as described above.
  • the invention also relates to a method for heating the hydraulic fluid of an aircraft, said aircraft comprising at least one hydraulic circuit comprising:
  • At least one high pressure pump connected to a tank containing hydraulic fluid by a suction pipe and supplying hydraulic fluid to a high pressure line of said hydraulic circuit; and a set of hydraulic energy consumers connected to said high-pressure pipe.
  • a heating device is controlled comprising a flow restrictor connected to a second end of the high pressure pipe, opposite a first end of said high pressure pipe connected to said at least one high pressure pump. , so as to ensure a pressure level in said high pressure pipe allowing the operation of said hydraulic energy consumers during the entire operating life of the aircraft.
  • the heating device is also controlled so as to regulate the temperature of the hydraulic fluid within a predetermined temperature range.
  • the pressure is measured in said high pressure pipe and when the value of the measured pressure is less than a predetermined threshold, the shutdown of said heating device is controlled.
  • the shutdown of the heating device is "Controlled for a predetermined time after the return of said pressure to a value greater than this predetermined threshold. In this way, it avoids successive stops and restarting and close in time of the heating device, particularly during maneuvering phases of the aircraft during which successive actions on actuators (flaps, flaps ...) may be necessary.
  • Figure 1 is a block diagram of a hydraulic circuit of an aircraft.
  • FIG. 2 already described, represents a curve illustrating the evolution of the viscosity of a hydraulic fluid as a function of temperature.
  • Figure 3 is a block diagram of a hydraulic circuit of an aircraft comprising a heating system according to the invention.
  • FIG. 4 represents an aircraft equipped with heating systems according to the invention.
  • FIG. 3 A system for reheating hydraulic fluid of an aircraft according to the invention is shown in FIG. 3.
  • This reheating system equips a hydraulic circuit of an aircraft similar to that previously described and represented in FIG. 1.
  • This reheat system comprises a heating device 24 connected to the high pressure line 16.
  • this heating device corresponds to a calibrated flow restrictor with which is associated a solenoid valve (not shown) allowing to allow or to prohibit the circulation of the hydraulic fluid in this flow restrictor.
  • This solenoid valve is connected in series with the resistor. of debt.
  • An outlet of the heating device 24 is connected to a pipe 20 allowing the low-pressure return of the heated hydraulic fluid to the reservoir 10.
  • the amount of heat produced is proportional, on the one hand, to the flow rate of the hydraulic fluid in the flow restrictor and, on the other hand, to the difference in pressure between the upstream end of the restrictor flow rate (corresponding to the pressure in the high-pressure pipe 16) and the downstream of the flow restrictor (corresponding to the pressure in the return pipe 20).
  • the flow restrictor is calibrated to allow a flow of hydraulic fluid corresponding to the amount of heat that is desired.
  • Said solenoid valve is controlled by control means 26 through a link 27, so as to allow (open solenoid valve) or to prohibit (solenoid valve closed) the flow of hydraulic fluid in the flow restrictor.
  • the control means 26 are connected, by a link 29, to measuring means 28 of . the pressure of the hydraulic fluid in the high-pressure pipe 16.
  • the means 28 for measuring the pressure are common to both the heating system according to the invention and to other functions such as monitoring. pressure of the high-pressure pipe 16.
  • the control means 26 are also connected by means of a link 31 to means 30 for measuring the temperature of the hydraulic fluid in the high-pressure pipe 16 and / or via a link 33 to measuring means 32 for the temperature of the hydraulic fluid in the reservoir 10.
  • the control means 26 can receive pressure and temperature values measured by said measuring means.
  • the power consumed by the consumers 18 of hydropower represents only a minority of the maximum instantaneous power likely to be consumed by said consumers of hydropower.
  • the power consumed increases significantly only during a few phases which represent a very minor part of the aircraft's operating conditions, in particular during maneuvering phases using hydraulic energy to maneuver control actuators (flaps, ailerons, drifting ...) or while maneuvering the landing gear.
  • the control means 26 control the operation of the heating device 24 (open electromagnetic valve) as long as the pressure in the high pressure pipe 16, measured by the measuring means 28, remains greater than a predetermined pressure threshold.
  • the control means 26 control the opening of the solenoid valve associated with the flow restrictor.
  • the control means 26 control the shutdown of the heating device 24.
  • the control means 26 control the closure of the solenoid valve associated with the flow restrictor.
  • the reaction time between the crossing of said pressure threshold and the effective closing of the solenoid valve is sufficiently short not to affect the operation of the consumers 18. This reaction time may for example be between a few tens of milliseconds and a few hundred milliseconds.
  • the flow restrictor is calibrated in such a way that the flow rate of hydraulic fluid consumed by this flow restrictor is compatible with a pressure value, in the high-pressure pipe, greater than said pressure threshold during said majority part of the operating time of the pump. aircraft during which the power consumed by the consumers 18 of hydraulic energy is only a minor part of the maximum instantaneous power likely to be consumed by said consumers of hydraulic energy.
  • the value of said pressure threshold is chosen so that when the value of the pressure of the hydraulic fluid in the high pressure line 16 is greater than or equal to this threshold, the pressure of the fluid, hydraulic is sufficient to allow operation of the different consumer 18 compatible with the performance and security required for the aircraft.
  • the control means 26 continue to control the stopping of the heating device 24 for a predetermined duration, preferably chosen in a range of 1 minute to 5 minutes. minutes. This duration is chosen so that, during maneuvering phases of the aircraft which generally require successive actuations of one or more control actuators, the heating device 24 is kept at a standstill, avoiding discounts in and successive stops that could be detrimental to the longevity of the system without being of interest from the point of view of the heating of the hydraulic fluid given the thermal inertia thereof.
  • the control means 26 control the shutdown of the heating device 24.
  • the hydraulic circuit needs only to be dimensioned taking into account the various consumers 18 connected to the high-pressure pipe 16, without taking into account the consumption of hydraulic fluid by the heating device 24, since the control means 26 control the shutdown of said heating device when the consumption of hydraulic fluid by it could compete with a significant consumption of hydraulic fluid by consumers 18.
  • the system according to the invention does not lead to an increase in the mass of the hydraulic circuit (apart from the mass of the heating device 24 and the control means 26).
  • this system even has the advantage of allowing a reduction in the weight of the hydraulic circuit.
  • a decrease in the viscosity of the hydraulic fluid is obtained.
  • the mass gain is estimated to be at least 75kg for a long haul civil transport aircraft with a capacity of 250 to 350 passengers.
  • a flow of the hydraulic fluid from the tank 10 to the high-pressure pump (s) 12a, 12b (via the pipe 14) is established, supplying the high-pressure pipe 16 and then the reheating device 24.
  • the heated hydraulic fluid exiting the reheating device 24 returns to the tank 10 via a return line 20. Consequently, as and when said circulation of the hydraulic fluid, the temperature of the hydraulic fluid contained in the reservoir 10 increases and becomes substantially homogeneous.
  • control means 26 control the operation of the heating device 24 so as to regulate the temperature of the hydraulic fluid within a predetermined temperature range, for example between 20 0 C and 50 0 C.
  • the lower value of said temperature range is chosen so as to obtain a sufficiently low viscosity of the hydraulic fluid, allowing a significant weight gain resulting from the smaller dimension of the hydraulic circuit.
  • the upper value of said temperature range is chosen so as not to degrade the characteristics of the hydraulic fluid.
  • the control means 26 use the temperature information provided by the temperature measuring means 30 located on the high-pressure pipe 16 and / or by the temperature measuring means 32 located in the tank 10.
  • the heating device 24 is installed at a second end B of the high-pressure pipe 16, opposite a first end A connected to the high-pressure pump (s) 12a, 12b.
  • the operation of the heating device causes a circulation of hydraulic fluid throughout the length of the high pressure line. Since this high pressure line is fed through the high pressure pump (s) with fluid from the tank (10), the temperature of the hydraulic fluid in the entire high pressure line substantially corresponds to the temperature of the heated fluid contained in said reservoir.
  • Such an arrangement of the heating device 24 is very advantageous because it avoids having areas of the high pressure line containing unheated hydraulic fluid. Since most of the usual consumers have leakage of hydraulic fluid between their part connected to the high pressure line 16 and their part connected to the return line 20, these consumers are permanently traversed by heated fluid. This advantageously results in a heating of said consumers, which may allow a smaller dimension and / or better performance of said consumers.
  • the solenoid valve is open type in the absence of power supply.
  • the solenoid valve is closed type in the absence of power supply.
  • the solenoid valve remains closed and therefore the heating device 24 will not disturb the operation of the consumers 18 of hydraulic energy.
  • the heating device corresponds to a variable flow restrictor controlled by a servo valve controlled by the control means.
  • the flow of the hydraulic fluid in the flow restrictor can then be controlled. proportionally to the difference between the measured temperature of the hydraulic fluid and a predetermined value according to a set temperature. This makes it possible to reduce the variations in the temperature of the hydraulic fluid during the operation of the aircraft while minimizing the energy consumption necessary for reheating the hydraulic fluid.
  • the heating system may comprise several heating devices associated with at least some of said branches respectively.
  • the different heating devices may correspond to separate heating systems, controlled by separate control means. However, in a preferred embodiment, these different heating devices are part of the same heating system and are controlled by common control means.
  • FIG. 4 represents an aircraft, in particular a civil or military transport aircraft, comprising a hydraulic circuit whose high-pressure line 16 comprises at least two branches 16a and 16b respectively corresponding to the two half-wings of the aircraft, and possibly a third branch 16c corresponding to the rear part of the aircraft.
  • the aircraft has at least one other hydraulic circuit not shown in the figure.
  • Each of the first two branches 16a and 16b makes it possible to supply the hydraulic energy necessary for the operation of actuators (flaps, flaps, etc.) 18a, 18b of the half-wing in question.
  • the third branch 16c makes it possible to supply the hydraulic energy necessary for operating actuators 18c of the rear part of the aircraft (drift, adjustable horizontal plane ).
  • the high pressure line is fed by at least one high pressure pump 12 which can be a pump driven by an aircraft engine or an electric pump. This high pressure pump 12 draws hydraulic fluid contained in the tank 10, through the suction pipe 14. For clarity of the figure, the low pressure return lines of the hydraulic fluid to the tank 10 are not shown. The first one.
  • branch 16a of the high pressure line comprises a first device 24a for heating the hydraulic fluid, substantially at its end opposite the end of the high pressure line connected to the high pressure pump 12.
  • the second branch 16b of the high pressure line comprises a second device 24b for heating the hydraulic fluid, substantially at its end opposite the end of the high pressure line connected to the high pressure pump 12.
  • the third branch 16c of the high pressure line comprises a third device 24c for heating the fluid hydraulic, substantially at its end opposite the end of the high pressure pipe connected to the high pressure pump 12.
  • the various devices 24a, 24b, 24c for heating the hydraulic fluid are controlled by common control means 26 via respective links 27a, 27b, 27c.
  • the control means 26 and the links 27a, 27b, 27c are not shown: they are similar to.
  • the control means 26 respectively control each of the reheating devices 24a, 24b, 24c as described above with reference to FIG. 3.
  • these control means 26 make it possible to control the other heating devices (which are not out of order) according to specific operating modes.
  • failure modes can in particular correspond to a blockage of said solenoid valve, either in the open position or in the closed position.
  • the hydraulic fluid can not flow in the restrictor of flow corresponding to this heating device and therefore the latter does not heat the hydraulic fluid.
  • this mode of failure is not detrimental to the operation of hydraulic energy consumers since it causes no consumption of hydraulic fluid by the heating device.
  • the control means 26 common to the different heating devices 24a, 24b, 24c control the other heating device (s) whose solenoid valve is not in contact. failure to regulate the temperature of the hydraulic fluid contained in the tank 10, based on the temperature information provided by the temperature measuring means 32.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

System for heating the hydraulic fluid of an aircraft (2) which has at least one hydraulic circuit comprising: at least one high-pressure pump (12) connected to a tank (10) containing hydraulic fluid via a suction line (14) and supplying hydraulic fluid to a high-pressure line (16); and a set of hydraulic energy consumers (18) connected to said high-pressure line. The heating system comprises: a controlled heating device (24) which can be connected to this high-pressure line, said heating device comprising a flow restrictor; and means (26) for controlling said heating device that are designed to control the operation of said heating device so as to guarantee a pressure level in said high-pressure line that allows said hydraulic energy consumers to operate throughout the operating life of the aircraft.

Description

Système et procédé de réchauffage du fluide hydraulique d'un aéronef. System and method for reheating the hydraulic fluid of an aircraft.
La présente invention concerne un système et un procédé permettant de réchauffer le fluide hydraulique d'un aéronef, le réchauffage du fluide étant commandé de façon à ne pas perturber le fonctionnement d'actionneurs utilisant ce fluide hydraulique comme source d'énergie.The present invention relates to a system and a method for heating the hydraulic fluid of an aircraft, the reheating of the fluid being controlled so as not to disturb the operation of actuators using this hydraulic fluid as a source of energy.
La plupart des aéronefs comportent des circuits hydrauliques utilisés pour alimenter en énergie des actionneurs correspondant notamment à des commandes de gouvernes, de volets, d'ailerons, etc. Comme représenté sur la figure 1, un circuit hydraulique comporte un réservoir 10 de fluide hydraulique, encore appelé bâche hydraulique, dans lequel une ou plusieurs pompes haute-pression aspirent du fluide hydraulique par une canalisation d'aspiration 14. Ces pompes haute-pression peuvent correspondre à une pompe 12a entraînée par un moteur de l'aéronef et/ou à une pompe électrique 12b. Elles permettent d'amener le fluide hydraulique à la pression nominale requise pour le fonctionnement de l'aéronef (par exemple 200 bars ou 350 bars selon le type d'aéronef). En sortie desdites pompes, de fluide hydraulique est envoyé vers une canalisation haute-pression 16 à laquelle sont raccordés les différents consommateurs 18 d'énergie hydraulique alimentés par ce circuit hydraulique. Lorsque l'un desdits consommateurs utilise de l'énergie hydraulique, il rejette du fluide hydraulique à basse pression. Le fluide hydraulique à basse pression rejeté par les différents consommateurs est renvoyé vers le réservoir 10 par un ensemble de canalisations de retour 20. La puissance effectivement utilisable par les consommateurs 18 est proportionnelle à la différence des pressions du fluide hydraulique mesurées à l'entrée (haute-pression) et à la sortie (basse- pression) desdits consommateurs. Cette puissance est donc fonction de la pression délivrée par la ou lesdites pompes 12a, 12b, diminuée des pertes de charge dans les canalisations de distribution du fluide hydraulique : canalisation haute-pression 16 et canalisations de retour 20. Ces pertes de charge dépendent notamment de la section de passage du fluide dans les canalisations, du débit du fluide et de la viscosité du fluide. Or, la viscosité du fluide augmente fortement lorsque sa température décroît. La figure 2 représente un exemple d'évolution du logarithme de la viscosité V d'un fluide hydraulique utilisé sur aéronef en fonction de la température T en degrés Celsius.Most aircraft have hydraulic circuits used to supply power to actuators corresponding in particular to control surfaces, flaps, fins, etc. As shown in FIG. 1, a hydraulic circuit comprises a reservoir 10 of hydraulic fluid, also called a hydraulic cover, in which one or more high-pressure pumps suck hydraulic fluid through a suction pipe 14. These high-pressure pumps can correspond to a pump 12a driven by an engine of the aircraft and / or an electric pump 12b. They make it possible to bring the hydraulic fluid to the nominal pressure required for the operation of the aircraft (for example 200 bars or 350 bars depending on the type of aircraft). At the output of said pumps, hydraulic fluid is sent to a high-pressure line 16 to which are connected the various consumers 18 of hydraulic power supplied by this hydraulic circuit. When one of said consumers uses hydraulic energy, it rejects low pressure hydraulic fluid. The low pressure hydraulic fluid rejected by the various consumers is sent back to the tank 10 by a set of return lines 20. The power actually usable by the consumers 18 is proportional to the difference of the hydraulic fluid pressures measured at the inlet ( high pressure) and at the outlet (low pressure) of said consumers. This power is therefore a function of the pressure delivered by the at least one pump 12a, 12b, less the pressure drops in the distribution lines of the hydraulic fluid: high-pressure pipe 16 and return pipes 20. These pressure drops depend in particular on the cross section of the fluid in the pipes, the flow rate of the fluid and the viscosity of the fluid. However, the viscosity of the fluid increases sharply when its temperature decreases. FIG. 2 represents an example of evolution of the logarithm of the viscosity V of a fluid hydraulic used on aircraft according to the temperature T in degrees Celsius.
Lors de vols en ambiance froide, par exemple à haute altitude, la température extérieure dans laquelle évolue un aéronef peut fréquemment descendre à des valeurs de l'ordre de -50 degrés Celsius. De telles valeurs de la température extérieure ont un impact sur la température du fluide hydraulique de l'aéronef, en particulier lors de vols de longue durée. Ainsi, compte tenu des échauffements du fluide hydraulique résultant des fuites dans les pompes et les différents consommateurs, il s'établit un équilibre thermique du fluide hydraulique dont la température peut descendre jusqu'à des valeurs de l'ordre de -15 degrés Celsius pour des avions de transport civil. Il en résulte une importante augmentation de la viscosité du fluide hydraulique par rapport à des conditions de température usuelles de l'ordre de 20 degrés Celsius. Par conséquent, le dimènsionnement des différentes canalisations hydrauliques, des pompes, ainsi que des actionneurs doit être- réalisé en tenant compte de la viscosité du fluide hydraulique utilisé, aux températures précitées. Plus la température du fluide est susceptible d'être basse, plus les diamètres des canalisations doivent être élevés et plus les pompes doivent être puissantes pour obtenir des performances similaires du circuit hydraulique. Outre le surplus de puissance consommée, cela entraîne un surplus de masse de l'aéronef.During flights in a cold environment, for example at high altitude, the external temperature in which an aircraft evolves can frequently drop to values of the order of -50 degrees Celsius. Such values of the outside temperature have an impact on the temperature of the hydraulic fluid of the aircraft, in particular during flights of long duration. Thus, in view of the heating of the hydraulic fluid resulting from leaks in the pumps and the various consumers, a thermal equilibrium of the hydraulic fluid is established whose temperature can go down to values of the order of -15 degrees Celsius for civil transport aircraft. This results in a significant increase in the viscosity of the hydraulic fluid compared to usual temperature conditions of the order of 20 degrees Celsius. Therefore, the dimensioning of the various hydraulic lines, pumps, as well as actuators must be realized taking into account the viscosity of the hydraulic fluid used, at the aforementioned temperatures. The lower the fluid temperature, the higher the pipe diameters must be and the more powerful the pumps are in order to achieve similar hydraulic system performance. In addition to the surplus power consumed, this results in a surplus of mass of the aircraft.
La présente invention a pour objet de remédier aux inconvénients précités. Elle concerne un système de réchauffage du fluide hydraulique d'un aéronef, ledit aéronef comportant au moins un circuit hydraulique comprenant :The present invention aims to overcome the aforementioned drawbacks. It relates to a system for heating the hydraulic fluid of an aircraft, said aircraft comprising at least one hydraulic circuit comprising:
- au moins une pompe haute pression raccordée à une bâche contenant du fluide hydraulique par une canalisation d'aspiration et alimentant en fluide hydraulique une canalisation haute pression dudit circuit hydraulique ; et - un ensemble de consommateurs d'énergie hydraulique raccordés à ladite canalisation haute pression.- At least one high pressure pump connected to a tank containing hydraulic fluid by a suction pipe and supplying hydraulic fluid to a high pressure line of said hydraulic circuit; and a set of hydraulic energy consumers connected to said high-pressure pipe.
Ce système de réchauffage est remarquable en ce qu'il comporte : - un dispositif de réchauffage commandé! apte à être raccordé à cette canalisation haute pression, ledit dispositif de réchauffage comprenant un restricteur de débit ; et - des moyens de commande dudi't dispositif de réchauffage aptes à commander le fonctionnement dudit dispositif de réchauffage de façon à garantir un niveau de pression dans ladite canalisation haute pression permettant le fonctionnement desdits consommateurs d'énergie hydraulique pendant toute la durée de fonctionnement de l'aéronef.This heating system is remarkable in that it comprises: - a controlled heating device! adapted to be connected to this high pressure pipe, said heating device comprising a flow restrictor; and control means dudi ' t heating device able to control the operation of said heating device so as to ensure a pressure level in said high pressure pipe allowing the operation of said hydraulic energy consumers during the entire operating life of the heater; 'aircraft.
Lorsque du fluide hydraulique traverse le restricteur de débit, l'énergie transportée par ce fluide hydraulique est transformée en chaleur : la quantité de chaleur produite est proportionnelle d'une part au débit du fluide hydraulique dans le restricteur de débit et d'autre part à la différence de pression entre l'amont du restricteur de débit, raccordé à la canalisation haute-pression, et l'aval du restricteur de débit, raccordé à une canalisation de retour vers la bâche hydraulique. Le fluide réchauffé se mélange avec le fluide hydraulique contenu dans la bâche hydraulique. Par conséquent, le fluide hydraulique contenu dans la bâche hydraulique est progressivement réchauffé.When hydraulic fluid passes through the flow restrictor, the energy transported by this hydraulic fluid is transformed into heat: the quantity of heat produced is proportional, on the one hand, to the flow rate of the hydraulic fluid in the flow restrictor and, on the other hand, to the the pressure difference between the flow restrictor upstream, connected to the high-pressure pipe, and the downstream flow restrictor, connected to a return pipe to the hydraulic tank. The heated fluid mixes with the hydraulic fluid contained in the hydraulic tank. Therefore, the hydraulic fluid contained in the hydraulic tank is gradually warmed.
Lorsque le dispositif de réchauffage est commandé pour fonctionner, du fluide hydraulique provenant de la canalisation haute-pression circule de l'amont vers l'aval du restricteur de débit. Etant donné que les moyens de commande du dispositif de réchauffage commandent son fonctionnement de façon à garantir un niveau de pression, dans la canalisation haute pression, permettant le fonctionnement des consommateurs d'énergie hydraulique raccordés à cette canalisation haute pression pendant toute la durée de fonctionnement de l'aéronef, l'utilisation de fluide hydraulique provenant de ladite canalisation haute-pression pour faire fonctionner le dispositif de réchauffage n'est pas pénalisante pour le fonctionnement desdits consommateurs d'énergie hydraulique. Il n'est donc pas nécessaire de tenir compte du débit de fluide hydraulique dans ce dispositif de réchauffage lors du dimensionnement du circuit hydraulique (puissance des pompes, diamètres des canalisations...). Cela est très avantageux, puisque le système de réchauffage objet de l'invention n'entraîne pas d'augmentation de la masse du circuit hydraulique. De plus, les consommateurs d'énergie hydraulique raccordés à la canalisation haute-pression (actionneurs de gouvernes, de volets, d'ailerons, de trains d'atterrissage:..) ne consomment de l'énergie hydraulique de façon significative que pendant des durées très limitées par rapport à la durée du vol de l'aéronef. Par conséquent, étant donné l'inertie thermique du fluide hydraulique, le fait de commander le fonctionnement du dispositif dé réchauffage de façon à garantir un niveau de pression, dans la canalisation haute pression, permettant le fonctionnement des consommateurs d'énergie hydraulique raccordés à cette canalisation haute pression (ce qui entraîne l'arrêt du dispositif de réchauffage lorsqu'un accroissement de la consommation d'énergie hydraulique par lesdits consommateurs, pendant que le dispositif de réchauffage est en fonctionnement, provoque une baisse de la pression dans la canalisation haute pression, en dessous d'une valeur de pression prédéterminée) n'est pas pénalisant du point de vue du réchauffage du fluide hydraulique.When the reheat device is controlled to operate, hydraulic fluid from the high pressure line flows from upstream to downstream of the flow restrictor. Since the control means of the heating device control its operation so as to ensure a pressure level in the high pressure line, allowing the operation of the hydraulic energy consumers connected to this high pressure line for the entire operating period of the aircraft, the use of hydraulic fluid from said high-pressure pipe to operate the heating device is not detrimental to the operation of said hydraulic energy consumers. It is therefore not necessary to take into account the flow of hydraulic fluid in the heating device during the design of the hydraulic circuit (power pumps, pipe diameters ...). This is very advantageous, since the heating system object of the invention does not cause an increase in the mass of the hydraulic circuit. In addition, the hydraulic power consumers connected to the high-pressure line (control, flap, fin, landing gear: ... actuators) consume significant amounts of hydraulic energy only for long periods of time. very limited time compared to the duration of the flight of the aircraft. Therefore, being given the thermal inertia of the hydraulic fluid, controlling the operation of the reheating device so as to guarantee a pressure level, in the high-pressure pipe, allowing the operation of the hydraulic energy consumers connected to this high-pressure pipe ( which causes the heating device to stop when an increase in the consumption of hydraulic energy by said consumers, while the heating device is operating, causes a pressure drop in the high-pressure pipe, below a predetermined pressure value) is not disadvantageous from the point of view of the heating of the hydraulic fluid.
Le système, de réchauffage selon l'invention permet donc de réchauffer le fluide hydraulique de l'aéronef pendant toute la durée de fonctionnement de l'aéronef. Par conséquent, il permet de diminuer la viscosité du fluide hydraulique et donc les pertes de charge dans le circuit hydraulique considéré. Ce circuit hydraulique peut donc être dimensionné en tenant compte de ladite viscosité réduite. Cela permet de réduire le diamètre des canalisations et la puissance de la ou des pompes haute-pression. Cela est très avantageux car il en résulte un gain de masse du circuit hydraulique.The heating system according to the invention thus makes it possible to heat the hydraulic fluid of the aircraft during the entire operating life of the aircraft. Consequently, it makes it possible to reduce the viscosity of the hydraulic fluid and therefore the pressure drops in the hydraulic circuit considered. This hydraulic circuit can therefore be sized taking into account said reduced viscosity. This makes it possible to reduce the diameter of the pipes and the power of the high-pressure pump or pumps. This is very advantageous because it results in a saving of mass of the hydraulic circuit.
De façon avantageuse, les moyens de commande du dispositif de réchauffage sont aptes à réguler la température du fluide hydraulique dans une plage de température prédéterminée. Cela permet d'éviter une surchauffe du fluide hydraulique qui pourrait être préjudiciable au bon fonctionnement du circuit hydraulique.Advantageously, the control means of the heating device are able to regulate the temperature of the hydraulic fluid in a predetermined temperature range. This avoids overheating of the hydraulic fluid that could be detrimental to the proper functioning of the hydraulic circuit.
Dans un mode préféré de réalisation, le restricteur de débit est installé à une seconde extrémité de la canalisation haute pression, opposée à une première extrémité de ladite canalisation haute pression raccordée à ladite au moins une pompe haute pression. Ainsi, lorsque le dispositif de réchauffage est commandé pour fonctionner, du fluide hydraulique circule sensiblement dans l'ensemble de la canalisation haute-pression. Etant donné que la canalisation haute-pression est alimentée en fluide hydraulique par ladite au moins une pompe haute-pression qui aspire ce fluide hydraulique dans la bâche hydraulique, du fluide réchauffé circule dans la canalisation haute pression. De façon usuelle, les consommateurs de fluide hydraulique raccordés à la canalisation haute-pression présentent des fuites correspondant à une circulation de fluide hydraulique à travers lesdits consommateurs, avec un débit que l'on essaie généralement de minimiser, de la canalisation haute-pression vers les canalisations de retour à la bâche hydraulique. Etant donné que le fluide hydraulique circulant dans la canalisation haute-pression est du fluide réchauffé, lesdits consommateurs sont traversés par du fluide réchauffé. Il en résulte avantageusement un réchauffage desdits consommateurs. Par conséquent, ceux-ci peuvent être dimensionnés pour fonctionner à des températures plus élevées qu'en l'absence d'un système de réchauffage selon l'invention, ce qui peut permettre un gain de masse et/ou de meilleures performances. Dans un mode avantageux de réalisation, le système de réchauffage selon l'invention comporte des moyens de mesure de la température et/ou de la pression du fluide hydraulique, raccordés aux dits moyens de commande, ces moyens de commande étant aptes à élaborer des signaux de commande du dispositif de réchauffage en fonction d'informations de température et/ou de pression reçues desdits moyens de mesure. En particulier, les moyens de mesure de pression permettent de mesurer la pression du fluide hydraulique dans la canalisation haute-pression. Ainsi, lorsque les moyens de commande reçoivent une information de pression dans la canalisation haute-pression inférieure à une valeur prédéterminée correspondant à la pression nécessaire au bon fonctionnement des actionneurs, ils commandent l'arrêt du dispositif de réchauffage. Les moyens de mesure de température peuvent en particulier permettre de mesurer la température du fluide •hydraulique dans la bâche hydraulique et/ou dans la canalisation haute-pression. En fonction des informations fournies par lesdits moyens de mesure de température, les moyens de commande peuvent commander le fonctionnement du dispositif de réchauffage de façon à réguler la température du fluide hydraulique.In a preferred embodiment, the flow restrictor is installed at a second end of the high pressure line, opposite a first end of said high pressure line connected to said at least one high pressure pump. Thus, when the heating device is controlled to operate, hydraulic fluid circulates substantially throughout the high pressure line. Since the high-pressure line is supplied with hydraulic fluid by said at least one high-pressure pump that sucks this hydraulic fluid into the hydraulic tank, heated fluid circulates in the high pressure line. In the usual way, the hydraulic fluid consumers connected to the high-pressure pipe have leaks corresponding to a circulation of hydraulic fluid through said consumers, with a flow rate that we generally try to minimize, from the high-pressure pipe to the return pipes to the hydraulic tank. Since the hydraulic fluid flowing in the high pressure line is heated fluid, said consumers are traversed by heated fluid. This advantageously results in a heating of said consumers. Therefore, these can be sized to operate at higher temperatures than in the absence of a heating system according to the invention, which can allow a gain in mass and / or better performance. In an advantageous embodiment, the heating system according to the invention comprises means for measuring the temperature and / or the pressure of the hydraulic fluid, connected to said control means, these control means being able to produce signals controlling the heating device according to temperature and / or pressure information received from said measuring means. In particular, the pressure measuring means make it possible to measure the pressure of the hydraulic fluid in the high-pressure pipe. Thus, when the control means receive pressure information in the high-pressure pipe lower than a predetermined value corresponding to the pressure necessary for the proper operation of the actuators, they control the shutdown of the heating device. Means of temperature measurement can in particular be capable of measuring the fluid temperature in the hydraulic • hydraulic tank and / or the high-pressure pipe. Depending on the information provided by said temperature measuring means, the control means may control the operation of the heating device so as to regulate the temperature of the hydraulic fluid.
Dans un premier mode de réalisation, le restricteur de débit est un restricteur de débit calibré dont le passage du fluide hydraulique est contrôlé par une électrovanne commandée par lesdits moyens de commande.In a first embodiment, the flow restrictor is a calibrated flow restrictor whose passage of the hydraulic fluid is controlled by a solenoid valve controlled by said control means.
Dans un second mode de réalisation, le restricteur de débit est un restricteur de débit variable dont la valeur du débit est commandée par lesdits moyens de commande. L'invention est aussi relative à un aéronef comportant au moins un circuit hydraulique comprenant une canalisation haute pression qui comporte une pluralité de branches correspondant respectivement : - à des consommateurs d'énergie hydraulique situés dans une première demi-voilure de l'aéronef ; et/ouIn a second embodiment, the flow restrictor is a variable flow restrictor whose flow value is controlled by said control means. The invention also relates to an aircraft comprising at least one hydraulic circuit comprising a high pressure line which comprises a plurality of branches respectively corresponding to: hydraulic energy consumers located in a first half-wing of the aircraft; and or
- à des consommateurs d'énergie hydraulique situés dans une deuxième demi-voilure de l'aéronef ; et/ouhydraulic energy consumers located in a second half-wing of the aircraft; and or
- à des consommateurs d'énergie hydraulique situés dans la partie arrière du fuselage de l'aéronef, dans lequel au moins une desdites branches de la canalisation haute pression comporte un système de réchauffage tel que décrit précédemment.hydraulic energy consumers located in the rear part of the fuselage of the aircraft, in which at least one of said branches of the high-pressure pipe comprises a heating system as described above.
L'invention est également relative à un procédé de réchauffage du fluide hydraulique d'un aéronef, ledit aéronef comportant au moins un circuit hydraulique comprenant : .The invention also relates to a method for heating the hydraulic fluid of an aircraft, said aircraft comprising at least one hydraulic circuit comprising:
- au moins une pompe haute pression raccordée à une bâche contenant du fluide hydraulique par une canalisation d'aspiration et alimentant en fluide hydraulique une canalisation haute pression dudit circuit hydraulique ; et - un ensemble de consommateurs d'énergie hydraulique raccordés à ladite canalisation haute pression.- At least one high pressure pump connected to a tank containing hydraulic fluid by a suction pipe and supplying hydraulic fluid to a high pressure line of said hydraulic circuit; and a set of hydraulic energy consumers connected to said high-pressure pipe.
Ce procédé est remarquable en ce que l'on commande un dispositif de réchauffage comprenant un restricteur de débit raccordé à une seconde extrémité de la canalisation haute pression, opposée à une première extrémité de ladite canalisation haute pression raccordée à ladite au moins une pompe haute pression, de façon à garantir un niveau de pression dans ladite canalisation haute pression permettant le fonctionnement desdits consommateurs d'énergie hydraulique pendant toute la durée de fonctionnement de l'aéronef.This method is remarkable in that a heating device is controlled comprising a flow restrictor connected to a second end of the high pressure pipe, opposite a first end of said high pressure pipe connected to said at least one high pressure pump. , so as to ensure a pressure level in said high pressure pipe allowing the operation of said hydraulic energy consumers during the entire operating life of the aircraft.
De façon avantageuse, on commande également le dispositif de réchauffage de façon à réguler la température du fluide hydraulique dans une plage de température prédéterminée.Advantageously, the heating device is also controlled so as to regulate the temperature of the hydraulic fluid within a predetermined temperature range.
Dans un . mode préféré de réalisation, on mesure la pression dans ladite canalisation haute pression et lorsque la valeur de la pression mesurée est inférieure à un seuil prédéterminé, on commande l'arrêt dudit dispositif de réchauffage. Avantageusement, l'arrêt du dispositif de réchauffage est „ commandé pendant une durée prédéterminée après le retour de ladite pression à une valeur supérieure à ce seuil prédéterminé. De cette façon, on évite des arrêts et remises en marche successifs et rapprochés dans le temps du dispositif de réchauffage, en particulier lors de phases de manœuvre de l'aéronef pendant lesquelles des actions successives sur des actionneurs (ailerons, volets...) peuvent être nécessaires.In one . preferred embodiment, the pressure is measured in said high pressure pipe and when the value of the measured pressure is less than a predetermined threshold, the shutdown of said heating device is controlled. Advantageously, the shutdown of the heating device is "Controlled for a predetermined time after the return of said pressure to a value greater than this predetermined threshold. In this way, it avoids successive stops and restarting and close in time of the heating device, particularly during maneuvering phases of the aircraft during which successive actions on actuators (flaps, flaps ...) may be necessary.
L'invention sera mieux comprise à la lecture de la description qui suit et à l'examen des figures annexées. La figure 1, déjà décrite, est un schéma fonctionnel d'un circuit hydraulique d'un aéronef.The invention will be better understood on reading the description which follows and on examining the appended figures. Figure 1, already described, is a block diagram of a hydraulic circuit of an aircraft.
La figure 2, déjà décrite, représente une courbe illustrant l'évolution de la viscosité d'un fluide hydraulique en fonction de la température.FIG. 2, already described, represents a curve illustrating the evolution of the viscosity of a hydraulic fluid as a function of temperature.
La figure 3 est un schéma fonctionnel d'un circuit hydraulique d'un aéronef comportant un système de réchauffage selon l'invention.Figure 3 is a block diagram of a hydraulic circuit of an aircraft comprising a heating system according to the invention.
La figure 4 représente un aéronef équipé de systèmes de réchauffage selon l'invention.FIG. 4 represents an aircraft equipped with heating systems according to the invention.
Un système de réchauffage de fluide hydraulique d'un aéronef conforme à l'invention est représenté sur la figure 3. Ce système de réchauffage équipe un circuit hydraulique d'un aéronef similaire à celui précédemment décrit et représenté en figure 1. Ce système de réchauffage comporte un dispositif de réchauffage 24 raccordé à la canalisation haute pression 16. Dans un premier mode de réalisation de l'invention, ce dispositif de réchauffage correspond à un réstricteur de débit calibré auquel est associée une électrovanne (non représentée) permettant d'autoriser ou d'interdire la circulation du fluide hydraulique dans ce réstricteur de débit. Cette électrovanne est montée en série avec le réstricteur. de débit. Une sortie du dispositif de réchauffage 24 est raccordée à une canalisation 20 permettant le retour à basse pression du fluide hydraulique réchauffé vers le réservoir 10. Lorsque du fluide hydraulique traverse ce réstricteur de débit, l'énergie transportée par ce fluide hydraulique est transformée en chaleur du fait de sa baisse de pression : la quantité de chaleur produite est proportionnelle d'une part au débit du fluide hydraulique dans le réstricteur de débit et d'autre part à la différence de pression entre l'amont du réstricteur de débit (correspondant à la pression dans la canalisation haute pression 16) et l'aval du restricteur de débit (correspondant à la pression dans là canalisatioji de retour 20). Le restricteur de débit est calibré de façon à permettre un débit de fluide hydraulique correspondant à la quantité de chaleur que l'on souhaite obtenir. Ladite électrovanne est commandée par des moyens de commande 26 à travers une liaison 27, de façon à autoriser (électrovanne ouverte) ou à interdire (électrovanne fermée) la circulation du fluide hydraulique dans le restricteur de débit.A system for reheating hydraulic fluid of an aircraft according to the invention is shown in FIG. 3. This reheating system equips a hydraulic circuit of an aircraft similar to that previously described and represented in FIG. 1. This reheat system comprises a heating device 24 connected to the high pressure line 16. In a first embodiment of the invention, this heating device corresponds to a calibrated flow restrictor with which is associated a solenoid valve (not shown) allowing to allow or to prohibit the circulation of the hydraulic fluid in this flow restrictor. This solenoid valve is connected in series with the resistor. of debt. An outlet of the heating device 24 is connected to a pipe 20 allowing the low-pressure return of the heated hydraulic fluid to the reservoir 10. When hydraulic fluid passes through this flow restrictor, the energy transported by this hydraulic fluid is converted into heat because of its pressure drop: the amount of heat produced is proportional, on the one hand, to the flow rate of the hydraulic fluid in the flow restrictor and, on the other hand, to the difference in pressure between the upstream end of the restrictor flow rate (corresponding to the pressure in the high-pressure pipe 16) and the downstream of the flow restrictor (corresponding to the pressure in the return pipe 20). The flow restrictor is calibrated to allow a flow of hydraulic fluid corresponding to the amount of heat that is desired. Said solenoid valve is controlled by control means 26 through a link 27, so as to allow (open solenoid valve) or to prohibit (solenoid valve closed) the flow of hydraulic fluid in the flow restrictor.
Les moyens de commande 26 sont reliés, par une liaison 29, à des moyens de mesure 28 de . la pression du fluide hydraulique dans la canalisation haute pression 16. Dans un mode particulier de réalisation, les moyens de mesure 28 de la pression sont communs à la fois au système de réchauffage selon l'invention et à d'autres fonctions telles que la surveillance de la pression dans la canalisation haute pression 16. Les moyens de commande 26 sont aussi reliés, par une liaison 31 à des moyens 30 de mesure de la température du fluide hydraulique dans la canalisation haute pression 16 et/ou par une liaison 33 à des moyens de mesure 32 de la température du fluide hydraulique dans le réservoir 10. Ainsi, les moyens de commande 26 peuvent recevoir des valeurs de pression et de température mesurées par lesdits moyens de mesure.The control means 26 are connected, by a link 29, to measuring means 28 of . the pressure of the hydraulic fluid in the high-pressure pipe 16. In a particular embodiment, the means 28 for measuring the pressure are common to both the heating system according to the invention and to other functions such as monitoring. pressure of the high-pressure pipe 16. The control means 26 are also connected by means of a link 31 to means 30 for measuring the temperature of the hydraulic fluid in the high-pressure pipe 16 and / or via a link 33 to measuring means 32 for the temperature of the hydraulic fluid in the reservoir 10. Thus, the control means 26 can receive pressure and temperature values measured by said measuring means.
Pendant une part majoritaire du temps de fonctionnement de l'aéronef, la puissance consommée par les consommateurs 18 d'énergie hydraulique ne représente qu'une part minoritaire de la puissance instantanée maximale susceptible d'être consommée par lesdits consommateurs d'énergie hydraulique. La puissance consommée n'augmente de façon significative que pendant quelques phases représentant une part très minoritaire du tenips fonctionnement de l'aéronef, en particulier lors de phases de manœuvres utilisant de l'énergie hydraulique pour manœuvrer des actionneurs de gouvernes (volets, ailerons, dérive...) ou lors de la manœuvre du train d'atterrissage.During a majority of the operating time of the aircraft, the power consumed by the consumers 18 of hydropower represents only a minority of the maximum instantaneous power likely to be consumed by said consumers of hydropower. The power consumed increases significantly only during a few phases which represent a very minor part of the aircraft's operating conditions, in particular during maneuvering phases using hydraulic energy to maneuver control actuators (flaps, ailerons, drifting ...) or while maneuvering the landing gear.
Selon l'invention, les moyens de commande 26 commandent le fonctionnement du dispositif de réchauffage 24 (éléctrovanne ouverte) tant que la pression dans la canalisation haute pression 16, mesurée par les moyens de mesure 28, reste supérieure à un seuil de pression prédéterminé. Pour cela, les moyens de commande 26 commandent l'ouverture de l'électrovanne associée au restricteur de débit. Lorsque la valeur de la pression mesurée dans la canalisation haute pression devient inférieure à ce seuil de pression, les moyens de commande 26 commandent l'arrêt du dispositif de réchauffage 24. Pour cela, les moyens de commande 26 commandent la fermeture de l'électrovanne associée au restricteur de débit. Le temps de réaction entre le franchissement dudit seuil de pression et la fermeture effective de l'électrovanne est suffisamment court pour ne pas affecter le fonctionnement des consommateurs 18. Ce temps de réaction peut par exemple être compris entre quelques dizaines de millisecondes et quelques centaines de millisecondes. Le restricteur de débit est calibré de telle façon que le débit de fluide hydraulique consommé par ce restricteur de débit soit compatible avec une valeur de pression, dans la canalisation haute pression, supérieure audit seuil de pression pendant ladite part majoritaire du temps de fonctionnement de l'aéronef au cours de laquelle la puissance consommée par les consommateurs 18 d'énergie hydraulique ne représente qu'une part minoritaire de la puissance instantanée maximale susceptible d'être consommée par lesdits consommateurs d'énergie hydraulique. La valeur dudit seuil de pression est choisie de façon à ce que lorsque la valeur de la pression du fluide hydraulique dans la canalisation haute pression 16 est supérieure ou égale à ce seuil, la pression du fluide, hydraulique soit suffisante pour permettre un fonctionnement des différents consommateurs 18 compatible avec les performances et la sécurité requises pour l'aéronef.According to the invention, the control means 26 control the operation of the heating device 24 (open electromagnetic valve) as long as the pressure in the high pressure pipe 16, measured by the measuring means 28, remains greater than a predetermined pressure threshold. For this, the control means 26 control the opening of the solenoid valve associated with the flow restrictor. When the value of the pressure measured in the high pressure line becomes lower than this pressure threshold, the control means 26 control the shutdown of the heating device 24. For this, the control means 26 control the closure of the solenoid valve associated with the flow restrictor. The reaction time between the crossing of said pressure threshold and the effective closing of the solenoid valve is sufficiently short not to affect the operation of the consumers 18. This reaction time may for example be between a few tens of milliseconds and a few hundred milliseconds. The flow restrictor is calibrated in such a way that the flow rate of hydraulic fluid consumed by this flow restrictor is compatible with a pressure value, in the high-pressure pipe, greater than said pressure threshold during said majority part of the operating time of the pump. aircraft during which the power consumed by the consumers 18 of hydraulic energy is only a minor part of the maximum instantaneous power likely to be consumed by said consumers of hydraulic energy. The value of said pressure threshold is chosen so that when the value of the pressure of the hydraulic fluid in the high pressure line 16 is greater than or equal to this threshold, the pressure of the fluid, hydraulic is sufficient to allow operation of the different consumer 18 compatible with the performance and security required for the aircraft.
Après une baisse du niveau de pression dans la canalisation haute pression 16 en dessous dudit seuil prédéterminé, les moyens de commande 26 continuent à commander l'arrêt du dispositif de réchauffage 24 pendant une duréeφrédéterminée, de préférence choisie dans une plage de 1 minute à 5 minutes. Cette durée est choisie de façon à ce que, lors de phases de manœuvre de l'aéronef qui nécessitent généralement des actionnements successifs d'un ou plusieurs actionneurs de gouvernes, on maintienne le dispositif de réchauffage 24 à l'arrêt en évitant des remises en marche et des arrêts successifs qui pourraient être préjudiciables à la longévité du système sans pour autant présenter d'intérêt du point de vue du réchauffage du fluide hydraulique étant donné l'inertie thermique de celui-ci.After a lowering of the pressure level in the high-pressure pipe 16 below said predetermined threshold, the control means 26 continue to control the stopping of the heating device 24 for a predetermined duration, preferably chosen in a range of 1 minute to 5 minutes. minutes. This duration is chosen so that, during maneuvering phases of the aircraft which generally require successive actuations of one or more control actuators, the heating device 24 is kept at a standstill, avoiding discounts in and successive stops that could be detrimental to the longevity of the system without being of interest from the point of view of the heating of the hydraulic fluid given the thermal inertia thereof.
Lorsque le fonctionnement du dispositif de réchauffage 24 est commandé par les moyens de commande 26 et qu'un ou plusieurs consommateurs 18 doivent consommer de l'énergie hydraulique pour manœuvrer des actionneurs de gouvernes lors de phases de manœuvre de l'aéronef, si l'activation desdits consommateurs entraîne une' baisse du niveau de pression (du fait de la demande supplémentaire de débit de fluide hydraulique) dans la canalisation haute pression 16 en dessous dudit seuil de pression prédéterminé, les moyens de commande 26 commandent l'arrêt du dispositif de réchauffage 24. Il en résulte une remontée de la pression dans la canalisation haute pression, ce qui permet un fonctionnement correct desdits consommateurs. Du fait d'un tel fonctionnement, le circuit hydraulique n'a besoin d'être dimensionné qu'en tenant compte des différents consommateurs 18 raccordés à la canalisation haute pression 16, sans tenir compte de la consommation de fluide hydraulique par le dispositif de réchauffage 24, puisque les moyens de commande 26 commandent l'arrêt dudit dispositif de réchauffage lorsque la consommation de fluide hydraulique par celui-ci risquerait d'entrer en concurrence avec une consommation importante de fluide hydraulique par les consommateurs 18. Cela est très avantageux, puisque, en conséquence, le système selon l'invention n'entraîne pas d'augmentation de la masse du circuit hydraulique (hormis la masse du dispositif de réchauffage 24 et des moyens de commande 26). A contrario, ce système présente même l'avantage de permettre une réduction de la masse du circuit hydraulique. En effet, étant donné une température du fluide hydraulique supérieure à celle que l'on obtiendrait en l'absence d'un tel système de réchauffage, on obtient une diminution de la viscosité du fluide hydraulique. Il en résulte une diminution significative des pertes de charges, ce qui permet un moindre dirηensionnement du circuit hydraulique (pompe(s) haute pression 12a, 12b, diamètre de canalisations...) et donc une diminution de la masse. Le gain de masse est estimé au moins à 75kg pour un avion de transport civil long courrier d'une capacité de 250 à 350 passagers. Lors du fonctionnement du dispositif de réchauffage 24, il s'établit une circulation du fluide hydraulique du réservoir 10 vers la (les) pompe(s) haute pression 12a, 12b (via la canalisation 14), alimentant la canalisation haute pression 16 puis le dispositif de réchauffage 24. Le fluide hydraulique réchauffé sortant du dispositif de réchauffage 24 retourne au réservoir 10 par une canalisation de retour 20. Par conséquent, au fur et à mesure de ladite circulation du fluide hydraulique, la température du fluide hydraulique contenu dans le réservoir 10 augmente et devient sensiblement homogène.When the operation of the heating device 24 is controlled by the control means 26 and one or more Consumer 18 must consume energy to operate hydraulic actuators control surfaces when operating phases of the aircraft, if the activation of said consumer causes a "lower pressure level (due to the additional demand for fluid flow hydraulic) in the high pressure line 16 below said predetermined pressure threshold, the control means 26 control the shutdown of the heating device 24. This results in a rise in pressure in the high pressure pipe, which allows operation correct said consumers. Due to such an operation, the hydraulic circuit needs only to be dimensioned taking into account the various consumers 18 connected to the high-pressure pipe 16, without taking into account the consumption of hydraulic fluid by the heating device 24, since the control means 26 control the shutdown of said heating device when the consumption of hydraulic fluid by it could compete with a significant consumption of hydraulic fluid by consumers 18. This is very advantageous, since consequently, the system according to the invention does not lead to an increase in the mass of the hydraulic circuit (apart from the mass of the heating device 24 and the control means 26). On the contrary, this system even has the advantage of allowing a reduction in the weight of the hydraulic circuit. In fact, given a higher hydraulic fluid temperature than that which would be obtained in the absence of such a heating system, a decrease in the viscosity of the hydraulic fluid is obtained. This results in a significant decrease in the pressure losses, which allows a lower management of the hydraulic circuit (pump (s) high pressure 12a, 12b, diameter of pipes ...) and therefore a decrease in mass. The mass gain is estimated to be at least 75kg for a long haul civil transport aircraft with a capacity of 250 to 350 passengers. During operation of the heating device 24, a flow of the hydraulic fluid from the tank 10 to the high-pressure pump (s) 12a, 12b (via the pipe 14) is established, supplying the high-pressure pipe 16 and then the reheating device 24. The heated hydraulic fluid exiting the reheating device 24 returns to the tank 10 via a return line 20. Consequently, as and when said circulation of the hydraulic fluid, the temperature of the hydraulic fluid contained in the reservoir 10 increases and becomes substantially homogeneous.
Avantageusement, les moyens de commande 26 commandent le fonctionnement du dispositif de réchauffage 24 de façon à réguler la température du fluide hydraulique à l'intérieur d'une plage de température prédéterminée, par exemple entre 200C et 500C. La valeur inférieure de ladite plage de température est choisie de façon à obtenir une viscosité du fluide hydraulique suffisamment faible, permettant un gain de masse significatif résultant du moindre dimensionnément du circuit hydraulique. La valeur supérieure de ladite plage de température est choisie de façon à ne pas dégrader les caractéristiques du fluide hydraulique. Pour réguler la température, les moyens de commande 26 utilisent les informations de température fournies par les moyens de mesure de température 30 situés sur la canalisation haute pression 16 et/ou par les moyens de mesure de température 32 situés dans le réservoir 10.Advantageously, the control means 26 control the operation of the heating device 24 so as to regulate the temperature of the hydraulic fluid within a predetermined temperature range, for example between 20 0 C and 50 0 C. The lower value of said temperature range is chosen so as to obtain a sufficiently low viscosity of the hydraulic fluid, allowing a significant weight gain resulting from the smaller dimension of the hydraulic circuit. The upper value of said temperature range is chosen so as not to degrade the characteristics of the hydraulic fluid. To regulate the temperature, the control means 26 use the temperature information provided by the temperature measuring means 30 located on the high-pressure pipe 16 and / or by the temperature measuring means 32 located in the tank 10.
De préférence, le dispositif de réchauffage 24 est installé à une seconde extrémité B de la canalisation haute pression 16, opposée à une première extrémité A raccordée à la (aux) pompe(s) haute pression 12a, 12b. Ainsi, le fonctionnement du dispositif de réchauffage entraîne une circulation de fluide hydraulique dans toute la longueur de la canalisation haute pression. Etant donné que cette canalisation haute pression est alimentée, à travers la (les) pompe(s) haute pression avec du fluide provenant du réservoir 10, la température du fluide hydraulique dans l'ensemble de la canalisation haute pression correspond sensiblement à la température du fluide réchauffé contenu dans ledit réservoir. Une telle disposition du dispositif de réchauffage 24 est très avantageuse car elle permet d'éviter d'avoir des zones de la canalisation haute pression contenant du fluide hydraulique non réchauffé. Etant donné que la plupart des consommateurs 18 usuels présentent des fuites de fluide hydraulique entre leur partie raccordée à la canalisation haute pression 16 et leur partie raccordée à la canalisation de retour 20, ces consommateurs sont traversés en permanence par du fluide réchauffé. Il en résulte avantageusement un réchauffage desdits consommateurs, ce qui peut permettre un moindre dimensionnément et/ou de meilleures performances desdits consommateurs. Dans une première variante, l'électrovanne est du type ouverte en l'absence d'alimentation électrique.Preferably, the heating device 24 is installed at a second end B of the high-pressure pipe 16, opposite a first end A connected to the high-pressure pump (s) 12a, 12b. Thus, the operation of the heating device causes a circulation of hydraulic fluid throughout the length of the high pressure line. Since this high pressure line is fed through the high pressure pump (s) with fluid from the tank (10), the temperature of the hydraulic fluid in the entire high pressure line substantially corresponds to the temperature of the heated fluid contained in said reservoir. Such an arrangement of the heating device 24 is very advantageous because it avoids having areas of the high pressure line containing unheated hydraulic fluid. Since most of the usual consumers have leakage of hydraulic fluid between their part connected to the high pressure line 16 and their part connected to the return line 20, these consumers are permanently traversed by heated fluid. This advantageously results in a heating of said consumers, which may allow a smaller dimension and / or better performance of said consumers. In a first variant, the solenoid valve is open type in the absence of power supply.
Dans une deuxième variante, l'électrovanne est du type fermée en l'absence d'alimentation électrique. Ainsi, en cas de panne électrique, l'électrovanne reste fermée et par conséquent, le dispositif de réchauffage 24 ne risque pas de perturber le fonctionnement des consommateurs 18 d'énergie hydraulique.In a second variant, the solenoid valve is closed type in the absence of power supply. Thus, in the event of a power failure, the solenoid valve remains closed and therefore the heating device 24 will not disturb the operation of the consumers 18 of hydraulic energy.
Dans un deuxième mode de réalisation de l'invention, le dispositif de réchauffage correspond à un restricteur de débit variable piloté par une servo-valve commandée par les moyens de commande 26. Le débit du fluide hydraulique dans le restricteur de débit peut alors être commandé de façon proportionnelle à l'écart entre la température mesurée du fluide hydraulique et une valeur prédéterminée fonction d'une température de consigne. Cela permet de réduire les variations de température du fluide hydraulique au cours du fonctionnement de l'aéronef tout en minimisant la consommation d'énergie nécessaire au réchauffage du fluide hydraulique.In a second embodiment of the invention, the heating device corresponds to a variable flow restrictor controlled by a servo valve controlled by the control means. The flow of the hydraulic fluid in the flow restrictor can then be controlled. proportionally to the difference between the measured temperature of the hydraulic fluid and a predetermined value according to a set temperature. This makes it possible to reduce the variations in the temperature of the hydraulic fluid during the operation of the aircraft while minimizing the energy consumption necessary for reheating the hydraulic fluid.
Dans le cas où la canalisation haute pression 16 comporte plusieurs branches, le système de réchauffage selon l'invention peut comporter plusieurs dispositifs de réchauffage associés respectivement à au moins certaines desdites branches. Les différents dispositifs de réchauffage peuvent correspondre à des systèmes de réchauffage distincts, commandés par des moyens de commande distincts. Toutefois, dans un mode préféré de réalisation, ces différents dispositifs de réchauffage font partie d'un même système de réchauffage et sont commandés par des moyens de commande communs. La figure 4 représente un aéronef, en particulier un avion de transport civil ou militaire, comportant un circuit hydraulique dont la canalisation haute pression 16 comporte au moins deux branches 16a et 16b correspondant respectivement aux deux demi-voilures de l'avion, et éventuellement une troisième branche 16c correspondant à la partie arrière de l'avion. En pratique, pour des raisons de redondance liées à la sûreté de fonctionnement, l'avion comporte au moins un autre circuit hydraulique non représenté sur la figure. Chacune des deux premières branches 16a et 16b permet de fournir l'énergie hydraulique nécessaire au fonctionnement d'actionneurs (ailerons, volets...) 18a, 18b de la demi-voilure considérée. La troisième branche 16c permet de fournir l'énergie hydraulique nécessaire au fonctionnement d'actionneurs 18c de la partie arrière de l'aéronef (dérive, plan horizontal réglable...). La canalisation haute pression est alimentée par au moins une pompe haute pression 12 pouvant être une pompe entraînée par un moteur de l'aéronef ou une pompe électrique. Cette pompe haute pression 12. aspire du fluide hydraulique contenu dans le réservoir 10, par la canalisation d'aspiration 14. Pour la clarté de la figure, les canalisations de retour basse pression du fluide hydraulique vers le réservoir 10 ne sont pas représentées. La première. branche 16a de la canalisation haute pression comporte un premier dispositif 24a de réchauffage du fluide hydraulique, sensiblement à son extrémité opposée à l'extrémité de la canalisation haute pression raccordée à la pompe haute pression 12. La deuxième branche 16b de la canalisation haute pression comporte un deuxième dispositif 24b de réchauffage du fluide hydraulique, sensiblement à son extrémité opposée à l'extrémité de la canalisation haute pression raccordée à la pompe haute pression 12. La troisième branche 16c de la canalisation haute pression comporte un troisième dispositif 24c de réchauffage du fluide hydraulique, sensiblement à son extrémité opposée à l'extrémité de la canalisation haute pression raccordée à la pompe haute pression 12. Les différents dispositifs 24a, 24b, 24c de réchauffage du fluide hydraulique sont pilotés par des moyens de commande communs 26 par l'intermédiaire de liaisons respectives 27a, 27b, 27c. Pour la clarté de la figure, les moyens de commande 26 et les liaisons 27a, 27b, 27c ne sont pas représentés : ils sont similaires aux. moyens de commande 26 et à la liaison 27 représentés sur la figure 3 et décrits précédemment. En mode de fonctionnement normal, les moyens de commande 26 commandent respectivement chacun des dispositifs de réchauffage 24a, 24b, 24c de la façon décrite précédemment en référence à la figure 3. De plus, en cas de panne d'un desdits dispositifs de réchauffage, ces moyens de commande 26 permettent de commander les autres dispositifs de réchauffage (qui ne sont pas en panne) selon des modes de fonctionnement spécifiques. Dans le premier mode de réalisation desdits dispositifs de réchauffage selon lequel un dispositif de réchauffage comporte un restricteur de débit calibré auquel est associée une électrovanne montée en série avec ce restricteur de débit calibré, les modes de panne peuvent en particulier correspondre à un blocage de ladite électrovanne, soit en position ouverte, soit en position fermée.In the case where the high pressure line 16 comprises several branches, the heating system according to the invention may comprise several heating devices associated with at least some of said branches respectively. The different heating devices may correspond to separate heating systems, controlled by separate control means. However, in a preferred embodiment, these different heating devices are part of the same heating system and are controlled by common control means. FIG. 4 represents an aircraft, in particular a civil or military transport aircraft, comprising a hydraulic circuit whose high-pressure line 16 comprises at least two branches 16a and 16b respectively corresponding to the two half-wings of the aircraft, and possibly a third branch 16c corresponding to the rear part of the aircraft. In practice, for reasons of redundancy related to operational safety, the aircraft has at least one other hydraulic circuit not shown in the figure. Each of the first two branches 16a and 16b makes it possible to supply the hydraulic energy necessary for the operation of actuators (flaps, flaps, etc.) 18a, 18b of the half-wing in question. The third branch 16c makes it possible to supply the hydraulic energy necessary for operating actuators 18c of the rear part of the aircraft (drift, adjustable horizontal plane ...). The high pressure line is fed by at least one high pressure pump 12 which can be a pump driven by an aircraft engine or an electric pump. This high pressure pump 12 draws hydraulic fluid contained in the tank 10, through the suction pipe 14. For clarity of the figure, the low pressure return lines of the hydraulic fluid to the tank 10 are not shown. The first one. branch 16a of the high pressure line comprises a first device 24a for heating the hydraulic fluid, substantially at its end opposite the end of the high pressure line connected to the high pressure pump 12. The second branch 16b of the high pressure line comprises a second device 24b for heating the hydraulic fluid, substantially at its end opposite the end of the high pressure line connected to the high pressure pump 12. The third branch 16c of the high pressure line comprises a third device 24c for heating the fluid hydraulic, substantially at its end opposite the end of the high pressure pipe connected to the high pressure pump 12. The various devices 24a, 24b, 24c for heating the hydraulic fluid are controlled by common control means 26 via respective links 27a, 27b, 27c. For clarity of the figure, the control means 26 and the links 27a, 27b, 27c are not shown: they are similar to. control means 26 and the link 27 shown in Figure 3 and previously described. In normal operating mode, the control means 26 respectively control each of the reheating devices 24a, 24b, 24c as described above with reference to FIG. 3. In addition, in the event of failure of one of said reheating devices, these control means 26 make it possible to control the other heating devices (which are not out of order) according to specific operating modes. In the first embodiment of said reheating devices in which a reheat device comprises a calibrated flow restrictor which is associated a solenoid valve connected in series with this calibrated flow restrictor, failure modes can in particular correspond to a blockage of said solenoid valve, either in the open position or in the closed position.
Dans le cas où l'électrόvânne d'un dispositif de réchauffage 24a, 24b ou 24c correspondant respectivement à la branche 16a, 16b ou 16c de la canalisation haute pression est bloquée en position fermée, Ie fluide hydraulique ne peut pas circuler dans le restricteur de débit correspondant à ce dispositif de réchauffage et par conséquent ce dernier ne réchauffe pas le fluide hydraulique. Toutefois, ce mode de panne n'est pas pénalisant pour le fonctionnement des consommateurs d'énergie hydraulique puisqu'il n^entraîne aucune consommation de fluide hydraulique par le dispositif de réchauffage. Afin de maintenir néanmoins un réchauffage du fluide hydraulique du circuit hydraulique considéré, les moyens de commande 26 communs aux différents dispositifs de réchauffage 24a, 24b, 24c commandent le ou les autre(s) dispositifs de réchauffage dont l'électrovanne n'est pas en panne de façon à réguler la température du fluide hydraulique contenu dans le réservoir 10, sur la base des informations de température fournies par lés moyens de mesure de température 32.In the case where the electrόvânne of a heating device 24a, 24b or 24c respectively corresponding to the branch 16a, 16b or 16c of the high pressure line is locked in the closed position, the hydraulic fluid can not flow in the restrictor of flow corresponding to this heating device and therefore the latter does not heat the hydraulic fluid. However, this mode of failure is not detrimental to the operation of hydraulic energy consumers since it causes no consumption of hydraulic fluid by the heating device. In order nevertheless to maintain a heating of the hydraulic fluid of the hydraulic circuit in question, the control means 26 common to the different heating devices 24a, 24b, 24c control the other heating device (s) whose solenoid valve is not in contact. failure to regulate the temperature of the hydraulic fluid contained in the tank 10, based on the temperature information provided by the temperature measuring means 32.
Dans le cas où l'électrovanne d'un dispositif de réchauffage 24a, 24b ou 24c correspondant respectivement à la branche 16a, 16b ou 16c de la canalisation haute pression est bloquée en position ouverte, le fluide hydraulique circule en permanence dans le restricteur de débit correspondant à ce dispositif de réchauffage et par conséquent ce dernier réchauffe en permanence le fluide hydraulique. Afin que ce mode de panne ne soit pas pénalisant pour le fonctionnement des consommateurs d'énergie hydraulique en entraînant une baisse de la pression dans la branche de canalisation haute pression considérée, les moyens de commande 26 communs aux différents dispositifs de réchauffage 24a, 24b, 24c commandent alors l'arrêt du ou des autre(s) dispositifs de réchauffage dont l'électrovanne n'est pas en panne. Cela permet de limiter le plus possible la consommation de fluide hydraulique de la canalisation haute pression par le système de réchauffage et par conséquent de limiter le plus possible l'effet dudit. système de réchauffage sur la pression du fluide hydraulique dans la canalisation haute pression. In the case where the solenoid valve of a heating device 24a, 24b or 24c respectively corresponding to the branch 16a, 16b or 16c of the high pressure line is blocked in the open position, the hydraulic fluid circulates continuously in the flow restrictor corresponding to this heating device and therefore the latter continuously heats the hydraulic fluid. So that this failure mode is not detrimental to the operation of the hydraulic energy consumers by causing a drop in pressure in the branch of high pressure pipe considered, the control means 26 common to the various heating devices 24a, 24b, 24c then order the shutdown of the other (s) reheating devices whose solenoid valve is not out of order. This makes it possible to limit as much as possible the consumption of hydraulic fluid of the high-pressure pipe by the heating system and consequently to limit as much as possible the effect of said pipe. heating system on the pressure of the hydraulic fluid in the high pressure pipeline.

Claims

REVENDICATIONS
1- Système de réchauffage du fluide hydraulique d'un aéronef (2), ledit aéronef comportant au moins un circuit hydraulique comprenant :1- A system for heating the hydraulic fluid of an aircraft (2), said aircraft comprising at least one hydraulic circuit comprising:
- au moins une pompe haute pression (12, 12a, 12b) raccordée à une bâche (10) contenant du fluide hydraulique par une canalisation d'aspiration (14) et alimentant en fluide hydraulique une canalisation haute pression (16) dudit circuit hydraulique ; et - un ensemble de consommateurs (18, 18a, 18b, 18c) d'énergie hydraulique raccordés à ladite canalisation haute pression, caractérisé en ce qu'il comporte :- At least one high pressure pump (12, 12a, 12b) connected to a cover (10) containing hydraulic fluid by a suction pipe (14) and supplying hydraulic fluid to a high pressure line (16) of said hydraulic circuit; and a set of consumers (18, 18a, 18b, 18c) of hydraulic energy connected to said high pressure pipe, characterized in that it comprises:
- un dispositif de réchauffage commandé (24, 24a, 24b, 24c), apte à être raccordé à cette canalisation haute pression, ledit dispositif de réchauffage comprenant un restricteur de débit ; et- A controlled heating device (24, 24a, 24b, 24c), adapted to be connected to this high pressure pipe, said heating device comprising a flow restrictor; and
- des moyens de commande (26) dudit dispositif de réchauffage, aptes à commander le fonctionnement dudit dispositif de réchauffage de façon à garantir un niveau de pression dans ladite canalisation haute pression permettant le fonctionnement desdits consommateurs d'énergie hydraulique' pendant toute la durée de fonctionnement de l'aéronef.- control means (26) of said heating device, adapted to control the operation of said heating device so as to ensure a pressure level in said high pressure piping permitting the operation of said hydraulic energy consumers' for the duration of operation of the aircraft.
2- Système de réchauffage selon la revendication 1, caractérisé en ce que les moyens de commande (26) du dispositif de réchauffage sont aptes à réguler la température du fluide hydraulique dans une plage de température prédéterminée.2- heating system according to claim 1, characterized in that the control means (26) of the heating device are adapted to regulate the temperature of the hydraulic fluid in a predetermined temperature range.
"3- Système de réchauffage selon l'une quelconque des revendications3- heating system according to any one of the claims
1 ou 2, caractérisé en ce que le restricteur de débit est installé à une, seconde extrémité (B) de la canalisation haute pression, opposée à une première extrémité (A) de ladite canalisation haute pression raccordée à ladite au moins une pompe haute pression (12, 12a, 12b).1 or 2, characterized in that the flow restrictor is installed at a second end (B) of the high pressure pipe opposite a first end (A) of said high pressure pipe connected to said at least one high pressure pump (12, 12a, 12b).
4- Système de réchauffage selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il comporte des moyens de mesure de la température (30, 32) et/ou de la pression (28) du fluide hydraulique, raccordés aux dits moyens de commande (26), ces moyens de commande étant aptes à élaborer des signaux de commande du dispositif de réchauffage en fonction d'informations de température et/ou de pression reçues desdits moyens de mesure.4- heating system according to any one of the preceding claims, characterized in that it comprises means for measuring the temperature (30, 32) and / or the pressure (28) of the hydraulic fluid, connected to said control means (26), these control means being adapted to develop control signals of the heating device according to temperature and / or pressure information received from said measuring means.
5- Système de réchauffage selon l'une quelconque des revendications, précédentes, caractérisé en ce que le restricteur de débit (24, 24a, 24b, 24c) est choisi dans le groupe composé de :5- heating system according to any one of the preceding claims, characterized in that the flow restrictor (24, 24a, 24b, 24c) is chosen from the group consisting of:
- un restricteur de débit calibré dont le passage du fluide hydraulique est contrôlé par une électrovanne commandée par lesdits moyens de commande ; ou- A calibrated flow restrictor whose passage of the hydraulic fluid is controlled by a solenoid valve controlled by said control means; or
- un restricteur de débit variable dont la valeur du débit est commandée par lesdits moyens de commande.a variable flow restrictor whose flow value is controlled by said control means.
6- Aéronef (2) comportant au moins un circuit hydraulique comprenant une canalisation haute pression (16) qui comporte une pluralité de branchesAircraft (2) comprising at least one hydraulic circuit comprising a high pressure line (16) which comprises a plurality of branches
(16a, 16b, 16c) correspondant respectivement :(16a, 16b, 16c) respectively corresponding:
- à des consommateurs (18a) d'énergie hydraulique situés dans une première demi-voilure de l'aéronef ; et/ou - à des consommateurs (18b) d'énergie hydraulique situés dans une deuxième demi-voilure de l'aéronef ; et/ouhydraulic consumers (18a) located in a first half-wing of the aircraft; and / or - consumers (18b) of hydraulic energy located in a second half-wing of the aircraft; and or
- à des consommateurs (18c) d'énergie hydraulique situés dans la partie arrière du fuselage de l'aéronef, caractérisé en ce que au moins une desdites branches de la canalisation haute pression comporte un système de réchauffage (24a, 24b, 24c) selon l'une quelconque des revendications 1 à 5.to consumers (18c) of hydraulic energy located in the rear part of the fuselage of the aircraft, characterized in that at least one of said branches of the high pressure line comprises a heating system (24a, 24b, 24c) according to any of claims 1 to 5.
7- Procédé de réchauffage du fluide hydraulique d'un aéronef (2), ledit aéronef comportant au moins un circuit hydraulique comprenant : - au moins une pompe haute pression (12, 12a, 12b) raccordée à une bâche (10) contenant du fluide hydraulique par une canalisation d'aspiration (14) et alimentant en fluide hydraulique une canalisation haute pression (16) dudit circuit hydraulique ; et - un ensemble de consommateurs (18, 18a, 18b, 18c) d'énergie hydraulique raccordés à ladite canalisation haute pression, caractérisé en ce que l'on commande un dispositif de réchauffage (24, 24a, 24b, 24c) comprenant un restricteur de débit raccordé à une seconde extrémité (B) de la canalisation haute pression, opposée à une première extrémité (A) de ladite canalisation haute pression raccordée à ladite au moins une pompe haute pression, de façon à garantir un niveau de pression dans ladite canalisation haute pression permettant le fonctionnement desdits consommateurs d'énergie hydraulique pendant toute la durée de fonctionnement de l'aéronef.7- A method of heating the hydraulic fluid of an aircraft (2), said aircraft comprising at least one hydraulic circuit comprising: - at least one high pressure pump (12, 12a, 12b) connected to a tarpaulin (10) containing fluid hydraulically by a suction pipe (14) and supplying hydraulic fluid a high pressure line (16) of said hydraulic circuit; and a set of consumers (18, 18a, 18b, 18c) of hydraulic energy connected to said high pressure pipe, characterized in that a heating device (24, 24a, 24b, 24c) is controlled comprising a flow restrictor connected to a second end (B) of the high-pressure pipe, opposite a first end (A) of said high pressure pipe connected to said at least one high pressure pump, so as to ensure a pressure level in said high pressure pipe for the operation of said hydraulic energy consumers during the entire operating life of the aircraft.
8- Procédé selon la revendication 7 caractérisé en ce que l'on commande également le dispositif de réchauffage. (24, 24a, 24b,, 24c) de façon à réguler la température du fluide hydraulique dans une plage de température prédéterminée.8- Process according to claim 7 characterized in that one also controls the heating device. (24, 24a, 24b, 24c) so as to regulate the temperature of the hydraulic fluid within a predetermined temperature range.
9- Procédé selon l'une quelconque des revendications 7 ou 8 caractérisé en ce que lorsqu'on mesure un niveau de pression, dans ladite canalisation haute pression, inférieur à un seuil prédéterminé, on commande l'arrêt dudit dispositif de réchauffage.9- Method according to any one of claims 7 or 8 characterized in that when measuring a pressure level in said high pressure pipe, less than a predetermined threshold, it controls the shutdown of said heating device.
10- Procédé selon la revendication 9 caractérisé en ce que l'arrêt du dispositif de réchauffage est commandé pendant une durée prédéterminée après le retour de ladite pression à une valeur supérieure à ce seuil prédéterminé. 10- The method of claim 9 characterized in that the shutdown of the heating device is controlled for a predetermined time after the return of said pressure to a value greater than this predetermined threshold.
PCT/FR2009/000306 2008-03-25 2009-03-23 System and method for heating the hydraulic fluid of an aircraft WO2009125090A1 (en)

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FR0801602A FR2929240B1 (en) 2008-03-25 2008-03-25 SYSTEM AND METHOD FOR HEATING THE HYDRAULIC FLUID OF AN AIRCRAFT
FR08/01602 2008-03-25

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EP3499049A1 (en) * 2017-12-15 2019-06-19 Airbus Operations Limited Hydraulic system with a reservoir having heating means

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CN106382361A (en) * 2016-11-16 2017-02-08 常州耐强传动机械有限公司 Oil pipe of speed reducer

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EP3499049A1 (en) * 2017-12-15 2019-06-19 Airbus Operations Limited Hydraulic system with a reservoir having heating means
GB2569783A (en) * 2017-12-15 2019-07-03 Airbus Operations Ltd Hydraulic system characteristics

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FR2929240B1 (en) 2010-06-18

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