Isolation of turbine engine heat exchangers in the event of leakage from electro-hydraulic and mechanical hydraulic control valves

Abstract

The present invention relates to a component (60) for a fluid circuit (40) of a turbine engine (1). The component (60) includes a main branch (62), a fluid control valve (70) and a bypass branch (64), which is arranged parallel to the main branch (62). The fluid control valve (70) has: a main outlet (73), which is fluidically connected to the main branch (62); and a bypass outlet (75), which is fluidically connected to the bypass branch (64). The fluid control valve (70) includes: a gate (79), an elastic biasing device (78) for biasing the gate, and an electric actuator (72, 74) for electrically actuating the gate to a main open position or a bypass position. The elastic biasing device (78) for biasing the gate is configured to bias the gate (79) toward the bypass position when the fluid pressure value is lower than a first threshold.

Description

Technical Field

[0001] The present invention relates to the general technical field of aircraft turbine engines, such as turbojets and turboprops, and more particularly to the insulation of heat exchangers located in turbine engine stator blades in the event of leakage. Background Art

[0002] Turbine engines include air / oil heat exchangers for cooling the oil in contact with the ambient air. These exchangers operate only during certain engine states, to avoid excessive cooling of the oil during cold flight conditions or to prevent oil from stagnating in the engine lubrication enclosure during cruise conditions.

[0003] Some lubrication circuits include thermostatic valves with a solid wax at low temperatures to bypass the lubricant when the lubricant temperature falls below a threshold. However, these thermostatic valves do not allow the oil supply to the exchanger to be completely shut off. They also cannot withstand high levels of on / off flow.

[0004] The lubrication circuit includes a hydraulic valve that is configured to open when the lubricant pressure differential exceeds a second threshold, bypass the lubricant when the lubricant temperature drops below a first threshold, and circulate cool lubricant, resulting in a higher pressure drop in the hydraulic circuit. However, these hydraulic valves do not allow for complete shutoff of the oil supply to the exchanger. Furthermore, their operation is unstable, making them difficult to use in lubrication circuits.

[0005] Some of these air / oil heat exchangers are located in the stator blade sections and are arranged in parallel. The oil circulating in each exchanger is cooled by air that comes into contact with the stator blade sections of the turbine engine.

[0006] Such a turbine engine is known, for example, from patent application WO 2016 / 156743 of the company Snecma.

[0007] Nevertheless, the blades of the stator blade segment can be damaged, for example, in the event of a foreign object impacting the turbine engine, which can lead to relatively significant oil leaks from the exchangers housed in these blades. If these leaks continue, the amount of oil escaping from the lubrication circuit of the turbine engine can become so great that the remaining oil quantity is insufficient, leading to a turbine engine flameout in flight. Summary of the Invention

[0008] The present invention aims to at least partially solve the problems encountered in the solutions of the prior art.

[0009] In this respect, the invention relates to an assembly for a fluid circuit of a turbine engine. The assembly comprises a main branch including a heat exchanger.

[0010] According to the present invention, the assembly comprises a fluid control valve for controlling fluid to a heat exchanger, the fluid control valve comprising a fluid inlet, a main fluid outlet, a fluid bypass outlet, a gate, elastic means for biasing the gate and means for electrically controlling the gate.

[0011] The main fluid outlet is fluidically connected to the main branch. The fluid bypass outlet is fluidically connected to a bypass branch arranged parallel to the main branch. The gate is movable between a main open position, in which the gate closes the bypass outlet and allows fluid to flow through the main branch, and a bypass position, in which the gate closes the main outlet and allows fluid to flow through the bypass branch.

[0012] The resilient means for biasing the gate is configured to bias the gate to displace the gate so that the gate closes the main outlet when the fluid pressure value is below a first threshold. The means for electrically controlling the gate is configured to bias the gate to displace the gate to a main open position or a bypass position.

[0013] Thanks to the fluid control valve of the assembly according to the invention, the flow rate and cooling of the fluid can be controlled and adjusted according to the state of the turbine engine, while limiting the effects of leakages in the main branch and facilitating their detection in the main branch.

[0014] In particular, the shutter is automatically displaced to the bypass position by mechanical hydraulic control, which limits the intervention of the digital turbine engine regulation system to isolate the heat exchanger in the event of a heat exchanger leak.

[0015] In particular, the pressure of the fluid in the main branch upstream of the heat exchanger is compared with a first threshold value. For example, this is the pressure of the fluid at the inlet of the fluid control valve.

[0016] The present invention may optionally include one or more of the following features in combination or not.

[0017] In particular, the assembly comprises a bladed stator section in which the heat exchanger is located.

[0018] According to a particular embodiment, the device for electrically controlling the shutter comprises first means for electrically controlling the shutter, the first means being configured to bias the shutter into the main open position, in particular when the pressure value of the fluid is below a first threshold value.

[0019] In particular, the first electric control member enables the supply of fluid to the exchanger when starting the turbine engine.

[0020] According to another particular embodiment, the device for electrically controlling the shutter comprises second means for electrically controlling the shutter, the second means being configured to bias the shutter towards the bypass position, in particular when the temperature of the fluid is below a second threshold value.

[0021] The second means for electrically controlling the shutter is configured, for example, to stop supplying fluid to the exchanger when the temperature of the fluid is abnormally low and the pressure of the fluid is greater than a first threshold, which may occur in a cruising state of the turbine engine.

[0022] According to certain embodiments, a fluid control valve includes a first chamber and a second chamber separated from each other by a gate. The fluid control valve includes a pressurized inlet for introducing fluid into the first chamber. The resilient biasing device includes a return spring configured to bias the gate to a bypass position against fluid pressure in the first chamber.

[0023] The return spring may be a tension spring located in the first chamber or a compression spring located in the second chamber.

[0024] According to another particular embodiment, the main branch comprises a non-return device configured to limit / prevent the flow of fluid towards the heat exchanger when the gate is in the bypass position.

[0025] Preferably, the non-return device comprises a non-return valve.

[0026] According to a particular embodiment, the bypass branch comprises a hydraulic resistance element designed such that the value of the hydraulic resistance in the bypass branch is substantially equal to the value of the hydraulic resistance in the main branch.

[0027] Preferably, the hydraulic resistance element comprises a diaphragm.

[0028] According to another specific embodiment, the gate of the fluid control valve is in the main open position when the temperature of the fluid is greater than a second threshold, when the rotation value of the turbine engine shaft is greater than a third threshold, and when no fluid leakage is detected in the main branch.

[0029] The value of the turbine engine shaft's rotation determines the component's fluid pressure and can be measured independently of the component.

[0030] According to another particular embodiment, the gate of the fluid control valve is in the bypass position when the temperature of the fluid is strictly below a second threshold, or when the rotation value of the turbine engine shaft is strictly below a third threshold, or when a fluid leakage is detected in the main branch.

[0031] According to a specific embodiment, in the transient state of the fluid control valve, the position of the gate of the fluid control valve is controlled by electrical control.

[0032] According to certain embodiments, in a stable state of the fluid control valve, the position of the gate of the fluid control valve is controlled by mechanical hydraulic control.

[0033] In particular, the electrical control of the position of the gate makes it possible to limit the positional instability of the gate during transient conditions of the position of the gate of the fluid control valve. Furthermore, the digital regulating system can be biased only during normal operation of the turbine engine to control the displacement of the gate and only for a short period of time.

[0034] The mechanical hydraulic gate position control is passive, that is, it works automatically without intervention of an electronic control unit or a digital regulating system.

[0035] According to another specific embodiment, the fluid control valve includes a safety position in which the gate is in a bypass position and is blocked in the safety position when the gate is displaced from the main open position to the bypass position by mechanical hydraulic control of the gate.

[0036] According to a specific embodiment, the assembly includes a leak detector configured to detect a leak in the main branch when the gate of the fluid control valve is displaced from the main open position to the bypass position without electrically controlling the gate to displace the gate to the bypass position.

[0037] According to another particular embodiment, the assembly comprises a bladed stator segment in which the heat exchanger is located.

[0038] Preferably, the bladed stator segment comprises blades for straightening the secondary flow of the turbine engine.

[0039] Preferably, the blade section comprises a radially inner platform, a radially outer platform and at least one vane extending between the radially inner platform and the radially outer platform.

[0040] The control valve then makes it possible to limit leakage when a body external to the turbine engine strikes the blade and when the heat exchanger inside the blade is damaged.

[0041] The invention also relates to a fluid circuit for a turbine engine. The fluid circuit comprises a first assembly for a turbine engine as defined above and a second assembly as defined above, the second assembly being arranged fluidically parallel to the first assembly.

[0042] According to a particular embodiment, the fluid is a lubricant. The fluid circuit includes a lubricant supply pump and a lubrication enclosure of the turbine engine, and each heat transfer assembly is fluidly located between the lubricant supply pump and the lubrication enclosure.

[0043] The invention also relates to a turbine engine comprising an assembly as defined above or a fluid circuit as defined above. In particular, the turbine engine is an aircraft turbine engine. Preferably, the turbine engine is a bypass turbojet engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be better understood by reading the description of exemplary embodiments, which are given for purposes of illustration only and are not intended to be limiting in any way, with reference to the accompanying drawings, in which:

[0045] - Figure 1 is a partial schematic diagram of a longitudinal section of a turbine engine for an aircraft according to a first preferred embodiment;

[0046] - Figure 2 is a partial schematic diagram of a lubrication circuit for a turbine engine when starting the turbine engine according to a first embodiment;

[0047] - Figure 3 is a partial schematic diagram of a lubrication circuit for a turbine engine according to a first embodiment, in a state where the lubricant of the turbine engine is cooled;

[0048] - Figure 4a is a partial schematic diagram of a heat exchange assembly of a lubrication circuit in a first transient state when starting a turbine engine;

[0049] - Figure 4b is a partial schematic diagram of a heat exchange assembly of a lubrication circuit after starting a turbine engine;

[0050] - Figure 4c is a partial schematic diagram of a heat exchange assembly of a lubrication circuit during a second transient state of the heat exchange assembly;

[0051] - Figure 4d is a partial schematic diagram of a heat exchange assembly of a lubrication circuit of a turbine engine in a cruising state;

[0052] - Figure 4e is a partial schematic diagram of a heat exchange assembly of a lubrication circuit during a third transient state of the heat exchange assembly;

[0053] - Figure 4f is a partial schematic diagram of a heat exchange assembly of a lubrication circuit in a heat exchange assembly under an abnormal pressure drop condition;

[0054] - Figure 5 is a partial schematic diagram of a lubrication circuit for a turbine engine according to a first embodiment, wherein one of the heat exchange components of the lubrication circuit is in an abnormal pressure drop state;

[0055] - Figure 6A method for controlling the position of a gate of a fluid control valve of a lubrication circuit according to parameters of a turbine engine is shown;

[0056] - Figure 7 A method for controlling the position of a gate of a fluid control valve of a lubrication circuit based on the gate position and gate position control is presented. DETAILED DESCRIPTION

[0057] Identical, similar or equivalent parts in different drawings are provided with the same reference numerals to facilitate transition from one drawing to another.

[0058] Figure 1 A bypass and a twin-shaft turbine engine are shown.The turbine engine 1 is a turbojet engine having a shape that rotates about a longitudinal axis AX.

[0059] The turbine engine 1 comprises, on the path of a main flow path 16 of the main flow, an air inlet liner 2 , a fan 3 , a low-pressure compressor 4 , a high-pressure compressor 6 , a combustion chamber 7 , a high-pressure turbine 8 and a low-pressure turbine 10 .

[0060] The radial direction is a direction which is orthogonal to the longitudinal axis AX and intersects this axis.The circumferential direction is defined as a direction which is locally orthogonal to the radial direction and the direction of the longitudinal axis AX.

[0061] In general, the term “air” refers to any gas that may be used as an oxidant in the turbine engine 1 .

[0062] The low-pressure compressor 4 , the high-pressure compressor 6 , the high-pressure turbine 8 , and the low-pressure turbine 10 define a secondary flow 17 for the flow of the secondary flow bypassing them.

[0063] The high-pressure compressor 6 and the high-pressure turbine 8 are mechanically connected by a shaft for driving the high-pressure compressor 6, thereby forming the high-pressure body of the turbine engine 1. Similarly, the low-pressure compressor 4 and the low-pressure turbine 10 are mechanically connected by the turbine engine shaft 1, thereby forming the low-pressure body of the turbine engine 1.

[0064] The low-pressure compressor 4 , the high-pressure compressor 6 , the combustion chamber 7 , the high-pressure turbine 8 and the low-pressure turbine 10 are surrounded by an inner fairing 9 which extends from the inlet liner 2 to the low-pressure turbine 10 .

[0065] This inner fairing 9 is surrounded by an outer casing 11 which delimits the turbine engine radially outwards relative to the longitudinal axis AX. The outer casing 11 delimits a secondary flow path 17 radially outwards, in particular at the fan 3.

[0066] The turbine engine 1 comprises at least one first blade segment 12 and one second blade segment 12, each blade segment extending between an inner fairing 9 and an outer casing 11. The blade segments 12 are blade stator segments.

[0067] Each blade segment 12 includes a radially inner platform 13 , a radially outer platform 15 and at least one blade 14 located between the radially inner platform 13 and the radially outer platform 15 .

[0068] The radially inner platform 13 of each blade segment 12 is rigidly fixed to the inner fairing 9 . The radially inner platform is delimited radially outwardly by a first aerodynamic surface which is in contact with the air of the secondary flow path 17 .

[0069] The radially outer platform 15 of each blade segment 12 is rigidly fixed to the outer casing 11 . The radially outer platform is delimited radially inwardly by a second aerodynamic surface which is in contact with the air of the secondary flow path 17 .

[0070] The blades 14 of each blade segment 12 extend radially from a radially inner platform 13 to a radially outer platform 15. The blades 14 are spaced apart from one another in the circumferential direction of the blade segment 12. In the embodiment shown, each blade 14 is a blade for straightening the secondary flow of the turbine engine.

[0071] The first blade 14 of the first blade section 12 houses the first heat exchanger 20a. In the embodiment shown, the first blade 14 also houses the first hydraulic control valve 70a and the first non-return device 30a.

[0072] The second blade 14 of the second blade section 12 houses the second heat exchanger 20b. In the embodiment shown, the second blade 14 also houses the second hydraulic control valve 70b and the second non-return device 30b.

[0073] The third blade 14 of one of the blade sections 12 houses the third heat exchanger 20c. In the embodiment shown, the third blade 14 also houses the third hydraulic control valve 70c and the third non-return device 30c.

[0074] Reference Figure 2 and Figure 3 The turbine engine 1 comprises a fluid circuit 40. In the embodiment shown, the fluid is a lubricant, typically oil. The fluid circuit 40 is then a lubrication circuit.

[0075] The lubrication circuit 40 includes a reservoir 41, a lubricant supply circuit 50, at least one lubrication enclosure 43, and a lubricant return circuit 80. The lubrication circuit 40 is configured to circulate lubricant in a closed loop between the supply circuit 50 and the return circuit 80.

[0076] The lubrication enclosure 43 is an enclosure inside which lubricant is used to lubricate and / or cool components (not shown) of the turbine engine 1 , such as a shaft and / or bearings. The lubrication enclosure 43 is typically a bearing lubrication enclosure of the turbine engine 1 .

[0077] The lubricant return circuit 80 is configured to circulate lubricant from each lubrication enclosure 43 to the reservoir 41. The lubricant return circuit includes a return pump 82 and a return conduit 81.

[0078] The return pump 82 is, for example, a positive displacement pump or a centrifugal pump, configured to deliver lubricant originating from the lubrication enclosure 43 to the reservoir 41 through the return conduit 81 .

[0079] The lubricant supply circuit 50 includes, from upstream to downstream, an upstream pipe 51 , a supply pump 52 , a cooling circuit 54 , and a distribution pipe 57 .

[0080] Generally, upstream and downstream directions are used herein with reference to the overall direction of overall fluid flow in the fluid circuit 40 .

[0081] The supply pump 52 is, for example, a positive displacement pump or a centrifugal pump, configured to deliver lubricant from the reservoir 41 to the lubrication enclosure 43 through the upstream conduit 51 .

[0082] The upstream conduit 51 includes one or more conduits and fluidly connects the reservoir 41 to the cooling circuit 54 .

[0083] The distribution conduit 57 comprises one or more conduits. The distribution conduit fluidically connects the cooling circuit 54 to the lubrication enclosure 43.

[0084] The cooling circuit 54 includes a first thermal assembly 60a, a second thermal assembly 60b, and at least one third thermal assembly 60c, which are arranged in parallel in pairs.

[0085] The first thermal component 60a is fluidly connected to the upstream pipe 51 through a first inlet node A and is fluidly connected to the distribution pipe 57 through a first outlet node B. The second thermal component 60b is fluidly connected to the upstream pipe 51 through a second node input C and is fluidly connected to the distribution pipe 57 through a second outlet node D. The third thermal component 60c is fluidly connected to the upstream pipe 51 through a third inlet node F and is fluidly connected to the distribution pipe 57 through a third outlet node G.

[0086] In the embodiment shown, the inlet nodes A, C, and F generally coincide, and the outlet nodes B, D, and G generally coincide.

[0087] In the present disclosure, each heat exchange assembly 60 has the same structure. The constituent elements of the heat exchange assembly have the same reference numerals, with the additional letter a specifically referring to the first heat exchange assembly 60a, the additional letter b specifically referring to the second heat exchange assembly 60b, and the additional letter c specifically referring to the third heat exchange assembly 60c.

[0088] Each thermal assembly 60 includes an inlet conduit 65 , a main branch 62 , a bypass branch 64 , a hydraulic control valve 70 , and an outlet conduit 67 .

[0089] The inlet pipe 65 of each thermal component 60 is connected to the upstream pipe 51 through its inlet node. The outlet pipe 67 of each thermal component 60 is connected to the distribution pipe 57 through its outlet node. Each of the main branch 62 and the bypass branch 64 is arranged in parallel with each other by being connected to the inlet pipe 65 and to the outlet pipe 67.

[0090] The main branch 62 of each thermal assembly 60 comprises, from upstream to downstream, one of the heat exchangers 20 and the non-return device 30 , which are fluidically connected via a main conduit 61 .

[0091] Each heat exchanger 20 is configured to cool the lubricant of the primary branch 62 in contact with the air circulating around the blades 14 of the stator in the secondary flow path 17 .

[0092] In the illustrated embodiment, each check device 30 comprises a check valve configured to restrict / prevent fluid flow through the heat exchanger 20 when the gate 79 of the hydraulic control valve 70 is in the bypass position to direct lubricant to the bypass branch 64 .

[0093] The bypass branch 64 of each thermal assembly 60 includes a hydraulic resistance element 66 and a bypass conduit 63 .

[0094] Typically, the hydraulic resistance element 66 is designed so that the hydraulic resistance value in the bypass branch 64 is substantially equal to the hydraulic resistance value in the main branch 62 .

[0095] In the present disclosure, by analogy to an electric field, the hydraulic resistance of an element of the lubrication circuit 40 is defined as the magnitude of the ratio of the pressure drop across the element to the flow rate of the lubricant through the element. By metonymy and always by analogy to the electric field, the hydraulic resistance or hydraulic resistance element corresponds to an element of the lubrication circuit 40 characterized by the value of its hydraulic resistance.

[0096] In the illustrated embodiment, the hydraulic resistance element 66 comprises a diaphragm. The lubrication circuit 40 comprises a first diaphragm 66a, a second diaphragm 66b, and a third diaphragm 66c.

[0097] In this disclosure, each hydraulic control valve 70 is also referred to as a fluid control valve 70 . Each hydraulic control valve includes a main lubricant inlet 71 , a boost inlet 77 , a gate 79 , a device for controlling the gate, a main outlet 73 , and a bypass outlet 75 .

[0098] In the illustrated embodiment, the lubricant control valve 70 includes a first chamber and a second chamber, which are separated from each other by a gate 79, which is a sliding valve. Specifically, the control device includes a return spring, which may be a tension spring located in the first chamber and / or a compression spring located in the second chamber, to bias the gate 79 against displacement against the lubricant pressure in the first chamber.

[0099] The gate 79 can be moved between a main open position and a bypass position. In the embodiment shown, each hydraulic control valve 70 is bi-stable. The main open position is a first stable open position of the gate 79, and the bypass position is a second stable open position of the gate 79.

[0100] In the main open position, the gate 79 closes the bypass outlet 75 and allows fluid to flow through the main outlet 73 into the main branch 62. In the bypass position, the gate 79 closes the main outlet 73 and allows fluid to flow through the bypass outlet 75 into the bypass branch 64.

[0101] The lubricant control valve 70 includes a safety position in which the gate 79 is blocked when the gate 79 is moved from the main open position to the bypass position by mechanical hydraulic control of the gate 79. The safety position of the gate 79 is the bypass position.

[0102] The main inlet 71 of each hydraulic control valve is fluidly connected to the inlet conduit 65 of the corresponding heat exchange assembly 60 .

[0103] Reference Figures 2 to 5 Boost inlet 77 is fluidly connected to inlet conduit 65 of heat exchange assembly 60 via boost conduit 69. Boost inlet 77 is designed to introduce fluid into the first chamber of hydraulic control valve 70. Boost conduit 69 is designed to apply pressure to the lubricant. Specifically, the pressure of the lubricant at boost inlet 77 is substantially the same as the pressure at main inlet 71.

[0104] The main fluid outlet 73 is fluidly connected to the main branch 62 upstream of the heat exchanger 20 and the check device 30 .

[0105] The fluid bypass outlet 75 is fluidly connected to the bypass branch 64 upstream of the hydraulic resistance element 66 .

[0106] Reference Figures 2 to 5The means for controlling each gate 79 comprises means 72, 74 for electrically controlling the gate, resilient means 78 for biasing the gate, and means 76 for hydraulically controlling the gate.

[0107] The elastic means 78 for biasing the gate plate and the means 76 for hydraulically controlling the gate plate control the displacement of the gate plate 79 in a stable state of the hydraulic control valve 70 .

[0108] The resilient means 78 for biasing the shutter plate includes a return spring configured to bias the shutter plate 79 to the bypass position against the pressure of the lubricant in the first chamber. The return spring is configured to bias the shutter plate 79 to the bypass position when the pressure of the lubricant at the main inlet 71 is below a first threshold. In particular, the lubricant pressure is the pressure value of the fluid in the main branch 62 upstream of the heat exchanger 20.

[0109] The means 76 for hydraulic control of the gate comprises a pressure boost inlet 77 and a pressure boost conduit 69. When the lubricant pressure at the main input 71 is greater than a first threshold, the return spring is configured to bias the displacement of the gate 79 to the main open position.

[0110] In particular, the elastic means 78 for biasing the shutter and the hydraulic control means 76 are intended to automatically control the displacement of the shutter to the bypass position by mechanical hydraulic control in the event of an abnormal pressure drop in the main branch 62 during flight of the turbine engine 1 .

[0111] The means 72 , 74 for electrically controlling the gate are configured to control the displacement of the gate 79 to the main open position or the bypass position. The means 72 , 74 for electrically controlling the gate are configured to control the displacement of the gate 79 in a transient state of the hydraulic control valve 70 .

[0112] The term "transient state of the hydraulic control valve 70" refers to a transient operating phase of the hydraulic control valve 70. In other words, the transient operating phase is an operating phase during which the position of the gate 79 of the hydraulic control valve 70 is not the position it would have in the steady state of the turbine engine. The term "stable state of the hydraulic control valve 70" refers to a substantially constant operating phase of the hydraulic control valve 70. In other words, it is the operation of the hydraulic control valve 70 during which the position of the gate 79 of the hydraulic control valve 70 corresponds to the position it would have in the steady state of the turbine engine.

[0113] The device 72 , 74 for electrically controlling the shutter comprises a first member 72 for electrically controlling the shutter and a second member 74 for electrically controlling the shutter.

[0114] The first means 72 for electrically controlling the shutter is configured to control the displacement of the shutter 79 to the main open position against control of the shutter 79 by the elastic means 78 for biasing the shutter, in particular when the pressure of the lubricant is below a first threshold.

[0115] In particular, the first means for electrically controlling the shutter 72 is configured to shift the shutter 79 to the main open position when the temperature of the lubricant is greater than the second threshold and the pressure of the lubricant is likely to be lower than the first threshold.

[0116] The first means 72 for electrically controlling the shutter are used, for example, to shift the shutter 79 to the main open position in a first transient state 201 for starting the turbine engine 1 or in a third transient state for delivering lubricant to the corresponding heat exchanger 20 .

[0117] In particular, when the temperature of the lubricant is lower than the second threshold value, the second member 74 for electrically controlling the gate is configured to control the gate 79 to shift toward the bypass position against the control of the hydraulic control device 76 .

[0118] The second means 74 for electrically controlling the shutter is configured to stop the lubricant supply to the main branch 62 when the lubricant pressure is greater than a first threshold and the lubricant temperature is less than a second threshold. This situation may occur in the cruise state of the turbine engine 1.

[0119] Figure 6 A method 300 is shown for controlling the position of the gate 79 of each hydraulic control valve 70 based on operating parameters of the turbine engine.

[0120] In this embodiment, when the rotation value XN of the turbine engine shaft is greater than the third threshold value, the pressure of the lubricant at the main inlet 71 of each hydraulic control valve 70 is greater than the first threshold value.

[0121] Considering that each hydraulic control valve 70 is controlled by a corresponding control device, the input parameters 301 include the temperature T of the lubricant, the rotation value XN of the shaft of the high-pressure body of the turbine engine 1 and the position of the gate 79 of the hydraulic control valve from its main open position to its bypass position.

[0122] Method 300 for controlling the position of shutter 79 takes into account that no leak is detected 317 or that a leak is detected 319 in the main branch 62 of heat exchange assembly 60 .

[0123] When the temperature T of the lubricant is greater than the second threshold value in step 307 and the rotation value XN of the turbine engine shaft is greater than the third threshold value in step 309, and when no leakage is detected 317 in the main branch 62, the device for controlling each gate 79 controls the position of the gate 79 so that the gate is in the main open position in step 302.

[0124] In step 313, when the temperature T of the lubricant is strictly lower than the second threshold value, or when the rotation value of the turbine engine shaft is strictly lower than the third threshold value 315, or when a lubricant leakage is detected in the main branch 62 in the leakage detection step 319, the device for controlling each gate 79 controls the position of each gate 79 so that the gate is in the bypass position in step 304.

[0125] Now refer to Figures 4a to 4f A method for controlling each gate plate 79 of the hydraulic control valve 70 according to the state of the turbine engine 1 will be described.

[0126] When the turbine engine is started, each hydraulic control valve 70 is in a first, transient start-up state 201, wherein the lubricant pressure at the main inlet 71 is below a first threshold and the lubricant temperature is above a second threshold. The lubricant pressure in the supply circuit 50 increases as the rotational speed of the high-pressure main shaft increases. The first electrical control member 72 controls the gate 79 to shift from the bypass position to the main open position against the spring means 78 for biasing the gate. As indicated by arrow 91, the first electrical control member 72 maintains electrical control of the gate 79 in the main open position as long as the lubricant pressure remains unstably above the first threshold.

[0127] In a first flight condition with the turbine engine cooled, each hydraulic control valve 70 is in a first stable cooling state 203, wherein the lubricant pressure at the main inlet 71 is greater than a first threshold value, and the lubricant temperature is greater than a second threshold value. According to arrow 93, the position of the gate 79 is mechanically and hydraulically controlled by the hydraulic control device 76 and the spring device 78 for biasing the gate. The gate 79 is in the main open position, allowing the lubricant to circulate in the main branch 62 while being cooled in the heat exchanger 20.

[0128] When turbine engine 1 is at a high altitude and the lubricant temperature becomes too low to cool the lubricant in heat exchanger 20, each hydraulic control valve 70 is placed in a second transient bypass state 205, wherein the lubricant temperature falls below a second threshold. Second electrical control member 74 controls the gate 79 from its main open position to its bypass position, acting against device 76 for hydraulic control of the gate 79. As per arrow 94, second electrical control member 74 maintains electrical control of the gate 79 in its bypass position as long as the lubricant pressure remains unstably below the first threshold.

[0129] In a first flight condition with the turbine engine cooled, each hydraulic control valve 70 is in a second, stable lubricant diversion state 207, wherein the lubricant pressure at the main inlet 71 is below a first threshold and the lubricant temperature is below a second threshold. According to arrow 95, the position of gate 79 is controlled by the mechanical hydraulic control, hydraulic control device 76, and spring device 78 for biasing the gate. Gate 79 is in the bypass position, and lubricant flows through bypass branch 64 without being cooled in heat exchanger 20.

[0130] When the altitude of turbine engine 1 decreases and the lubricant needs to be cooled in heat exchanger 20, each hydraulic control valve 70 enters a third transient state 209 for conveying lubricant in main branch 62, where the lubricant temperature becomes greater than a second threshold. First electrical control member 72 controls the gate 79 to shift from the bypass position to the main open position against spring means 78 for biasing the gate. As indicated by arrow 97, the first electrical control member 72 maintains electrical control of the gate 79 in the main open position as long as the lubricant pressure remains unstably greater than the first threshold.

[0131] More specifically, refer to Figure 4f and Figure 5 When a leak occurs in the main branch 62 of one of the defective heat exchange assemblies 60 during steady-state operation of the turbine engine, and with the gate 79 in the main open position, the hydraulic control valve 70 of the defective heat exchange assembly 60 switches to an emergency diversion state 211. As indicated by arrow 99, the lubricant pressure rapidly drops below a first threshold, causing the spring member 78, which biases the gate, to resist the hydraulic control member 76, causing the gate 79 to shift from the main open position to the bypass position. The gate 79 of the hydraulic control valve 70 is then blocked in the bypass position, which serves as a safe position for the gate 79, until the end of the flight of the turbine engine 1. The lubricant in the heat exchange assembly 60 is fully circulated in the bypass branch 64 of the heat exchange assembly 60.

[0132] Due to the membrane 66 of the bypass branch 64 , the pressure and flow rate of the lubricant remain constant in the heat exchange assembly that is arranged in parallel with the defective heat exchange assembly 60 .

[0133] Now combine the reference Figure 2 and Figure 7 A leakage detection method 400 for each gate plate 79 of the hydraulic control valve 70 will be described.

[0134] The turbine engine 1 comprises a system for monitoring the position of each shutter and for detecting leaks. The position monitoring system of each shutter 79 comprises a sensor 92 and a digital regulation system 90 of the turbine engine.

[0135] Sensors 92a, 92b, 92c are configured to perform measurements that enable the digital regulating system 90 to determine the position of each gate 79 of the hydraulic control valve. Each sensor 92a, 92b, 92c comprises, for example, a linear position sensor of each gate, known as an "LVDT" sensor.

[0136] The turbine engine digital regulation system 90 is also referred to as a "FADEC." The turbine engine digital regulation system includes a redundant dual-channel, full-authority digital computer. The turbine engine digital regulation system is configured to determine the position of each damper 79 based on measurements performed by sensors 92 and to implement a leak detection method 400.

[0137] The leak detection method 400 comprises determining, in step 401 , the position of each shutter 79 , in particular by means of the digital regulating system 90 from measurements performed by sensors 92 a , 92 b , 92 c .

[0138] The leakage detection method 400 includes a step 403 of verifying whether the second means 74 for electrically controlling the shutters electrically controls each shutter 79 to be displaced to its bypass position.

[0139] The leak detection method 400 includes verifying at step 405 whether each gate 79 is displaced from its main open position to its bypass position.

[0140] At step 402 , after the gate 79 is electrically controlled to shift to its bypass position, the leak detection method 400 detects that there is no leak in the main branch 62 of the corresponding heat exchange assembly 60 when the gate 79 has shifted from its main open position to its bypass position.

[0141] At step 404 , the leak detection method 400 detects a leak in the main branch 62 of the corresponding heat exchange assembly 60 when the gate 79 has moved from its main open position to its bypass position without the gate 79 being electrically controlled to shift to its bypass position.

[0142] Thanks to the hydraulic control valve 70 of each thermal assembly 60 according to the invention, the flow rate and cooling of the lubricant can be controlled and adjusted according to the speed of the turbine engine 1 , while limiting the effects of leakage in the main branch 62 and facilitating the detection of leakage in the main branch 62 .

[0143] In particular, the gate 79 of each hydraulic control valve 70 is automatically displaced to the bypass position by mechanical hydraulic control, which limits the intervention of the digital regulation system 90 of the turbine engine to isolate the heat exchanger 20 in the event of leakage from the heat exchanger 20 .

[0144] Of course, those skilled in the art may make various modifications to the invention that has just been described without departing from the scope of the invention disclosed.

[0145] Alternatively, the turbine engine 1 is a turboshaft engine or a turboprop engine.

[0146] Alternatively, the fluid is a fuel. The fluid circuit 40 is then a fuel circuit for the turbine engine 1 .

[0147] Each main branch 62 and each bypass branch 64 is of variable structure. In particular, the arrangement, number and nature of the hydraulic resistance elements in the lubrication circuit 40 can be changed.

[0148] The structure of each hydraulic resistance element 66 of the lubrication system can be varied. For example, each of these hydraulic resistance elements 66 can include a heat exchanger, a filter, a shutoff valve and / or a flow meter.

[0149] The number of heat exchangers 20 per main branch 62 may vary. Each main branch 62 may include at least one filter or another type of hydraulic resistance element.

[0150] Each bypass branch 64 may include at least one heat exchanger.

[0151] Alternatively, the supply circuit 50 may include at least two heat exchange assemblies 60 arranged in series.

[0152] The structure of each hydraulic control valve 70 can be modified, in particular, as long as each hydraulic control valve 70 allows the lubricant to circulate in the main branch 62 at least for certain operating conditions of the turbine engine 1, and directs the lubricant to the bypass branch 64 in other operating conditions of the turbine engine 1 and in the event of leakage.

[0153] Alternatively, at least in steady state of the turbine engine, at least one of the hydraulic control valves 70 is pneumatically controlled.

[0154] Alternatively, at least one of the hydraulic control valves 70 comprises at least one stable open position between a main open position and a bypass position, wherein the gate 79 of the hydraulic control valve partially supplies the corresponding main branch 62 and partially supplies the corresponding bypass branch 64 .

[0155] At least one of the hydraulic control valves 70 may include a plurality of stable open positions between the main open position and the bypass position, such as a continuous stable open position or a series of discrete stable open positions.

[0156] More generally, each hydraulic control valve 70 may be another type of control valve other than a three-way, two-position hydraulic control valve.

[0157] Alternatively, the gate 79 of each hydraulic control valve may include a valve other than a sliding valve.

[0158] The structures of the hydraulic control valves 70 may be different from each other.

[0159] According to a variant, the means for monitoring the position of each shutter are configured to determine the lubricant pressure in the main branch 62, for example by means of a first pressure sensor 92, and the lubricant pressure in the bypass branch 64, for example by means of a second pressure sensor 92. The monitoring means can monitor the position of the shutter 79 by comparing the lubricant pressure value in the main branch 62 with the lubricant pressure value in the bypass branch 64.

Claims

1. An assembly (60) for a fluid circuit (40) of a turbine engine (1), the assembly comprising: a main branch (62), said main branch including a heat exchanger (20), Characterized in that the assembly (60) comprises a fluid control valve (70) for controlling the fluid to the heat exchanger (20), the fluid control valve (70) comprising: fluid inlet (71); a main fluid outlet (73), said main fluid outlet being fluidly connected to said main branch (62); a fluid bypass outlet (75), the fluid bypass outlet being fluidically connected to a bypass branch (64), the bypass branch being arranged parallel to the main branch (62); a gate (79) movable between a main open position, wherein the gate closes the fluid bypass outlet (75) and enables fluid to flow through the main branch (62), and a bypass position, wherein the gate closes the main fluid outlet (73) and enables fluid to flow through the bypass branch (64); an elastic device (78) for biasing the gate, the elastic device being configured to bias the gate (79) to displace the gate so that the gate closes the main fluid outlet (73) when the fluid pressure value is below a first threshold, and the elastic device (78) comprising a return spring, and A control device (72, 74) for electrically controlling a gate, the control device being configured to bias the gate (79) to shift the gate to the main open position or the bypass position.

2. The assembly (60) according to claim 1, wherein The control device (72, 74) for electrically controlling a shutter comprises a first member (72) for electrically controlling the shutter, the first member being configured to bias the shutter (79) into the main open position.

3. The assembly (60) of claim 1, wherein: The control device (72, 74) for electrically controlling the shutter comprises a second member (74) for electrically controlling the shutter, the second member being configured to bias the shutter (79) towards the bypass position.

4. The assembly (60) of claim 1, wherein: The fluid control valve (70) includes a first chamber and a second chamber, wherein the first chamber and the second chamber are separated from each other by the gate (79). The fluid control valve (70) includes a pressurization inlet (77), which is used to introduce the fluid into the first chamber. The return spring is configured to bias the gate (79) to the bypass position against the fluid pressure in the first chamber.

5. The assembly (60) of claim 1, wherein: The main branch (62) includes a check device (30) configured to restrict or prevent the fluid from flowing toward the heat exchanger (20) when the gate (79) is in the bypass position.

6. The assembly (60) of claim 1, wherein: The bypass branch (64) includes a hydraulic resistance element (66) designed so that the hydraulic resistance value in the bypass branch (64) is substantially equal to the hydraulic resistance value in the main branch (62).

7. The assembly (60) of claim 1, wherein: When the temperature of the fluid is greater than a second threshold, when the rotation value of the turbine engine shaft is greater than a third threshold, and when no fluid leakage is detected in the main branch (62), the gate (79) of the fluid control valve is in the main open position, and / or Wherein, when the temperature of the fluid is strictly lower than the second threshold, or when the rotation value of the turbine engine shaft is strictly lower than the third threshold, or when a fluid leakage is detected in the main branch (62), the gate (79) of the fluid control valve is in the bypass position.

8. The assembly (60) of claim 1, wherein: In the instantaneous state of the fluid control valve (70), the position of the gate (79) of the fluid control valve is controlled by electrical control.

9. The assembly (60) of claim 1, wherein: The fluid control valve (70) includes a safety position in which the gate (79) is in the bypass position, wherein the gate (79) is blocked in the safety position when the gate (79) is shifted from the main open position to the bypass position by mechanical hydraulic control of the gate (79).

10. An assembly (60) according to claim 1, comprising a leak detector (90), which is configured to detect a leak in the main branch (62) when the gate (79) of the fluid control valve has moved from the main open position to the bypass position without electrically controlling the gate (79) to shift the gate to the bypass position.

11. The assembly (60) of claim 1, comprising a vaned stator segment (12), the heat exchanger (20) being located in the vaned stator segment (12).

12. A fluid circuit (40) for a turbine engine (1), the fluid circuit comprising a first component (60a) and a second component (60b), wherein: Each of the first assembly and the second assembly is an assembly (60) according to claim 1, and the second assembly (60b) is arranged in fluid parallel with the first assembly (60a).

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