Aircraft turbine engine comprising heat pump

Abstract

An aircraft turbine engine comprising a heat pump (14) intended to cool oil, the heat pump (14) comprising a closed circuit (19) in which a heat transfer fluid circulates, the circuit (19) comprising:-a common part (20) comprising a first expansion valve (21), an evaporator (22) exchanging heat with oil, and a first compressor (23); -a first and a second branch (24, 25) mounted in parallel with each other, the first branch (24) comprising a first condenser (26) and the second branch (25) comprising a second condenser (28); the first compressor (23) is configured to adjust the pressure of the heat transfer fluid at the inlet of the first condenser (26) according to a first setpoint, and the second compressor (30) is configured to adjust the pressure of the heat transfer fluid at the inlet of the second condenser (28) according to a second setpoint.

Description

Technical Field

[0001] This invention relates to an aircraft turbine engine that includes a heat pump. Background Technology

[0002] A dual-flow turbine engine typically includes a fan driven by a power turbine and a gas generator, the gas produced by which the gas generator drives the power turbine. The gas generator includes at least one compressor, a combustion chamber, and at least one turbine. The fan generates an airflow that is split into a main flow and a secondary flow; the main flow is configured to supply the gas generator, while the secondary flow primarily contributes to the thrust provided by the turbine engine.

[0003] Turbine engines also include various oil circuits, the function of which is, for example, to lubricate the moving parts of the turbine engine (bearings, toothed wheels, etc.).

[0004] In order for the oil to perform its function to the fullest extent, it is crucial to use a cooling system to maintain the oil temperature within a given range.

[0005] Engine manufacturers are currently facing significant challenges. In fact, the new turbocharged engine architecture incorporates more oil circuits, primarily due to the inclusion of a gearbox (between the power turbine and the fan) and / or the increased use of a generator to enhance the hybrid characteristics of the turbocharged engine.

[0006] These additional oil circuits inevitably mean an increase in the heat power to be dissipated, thus necessitating a review of the existing cooling system.

[0007] To meet this need, heat pumps are known to be used to cool oil, as described in the applicant’s document FR2993610A1.

[0008] This type of heat pump includes a closed loop through which a heat transfer fluid flows, specifically including an evaporator, a condenser, a compressor, and an expansion valve.

[0009] More specifically, the evaporator evaporates the heat transfer fluid by absorbing heat from the oil (heat source). The condenser condenses the heat transfer fluid, dissipating the heat into a cold source (such as an airflow). The compressor compresses the heat transfer fluid (gaseous state) to increase its pressure (and thus its temperature) before it passes through the condenser. An expansion valve causes the heat transfer fluid (liquid state) to expand, reducing its pressure (and thus its temperature) before it passes through the evaporator.

[0010] To improve its performance, engine manufacturers have noted that integrating a second condenser into the heat pump circuit, whereby the second condenser would exchange heat with a second cold source (such as fuel), could be of interest.

[0011] However, engine manufacturers have encountered obstacles in integrating a second condenser.

[0012] This is because the two cold sources have different temperatures, which means that the temperature of the heat transfer fluid at the inlet of each condenser in the condenser must be different in order to achieve optimal heat exchange at each condenser in the condenser.

[0013] However, a circuit with a single compressor means that the temperature of the heat transfer fluid at the condenser inlet is the same, which implies that heat exchange at both the first condenser (heat transfer fluid / first cold source) and the second condenser (heat transfer fluid / second cold source) may not be optimal. It should be noted that the temperature of the heat transfer fluid at the condenser inlet is directly related to the pressure of the heat transfer fluid discharged through the compressor.

[0014] Suboptimal heat exchange at the condenser inevitably means installing an oversized condenser, which is undesirable from the perspective of the overall size and weight of the heat pump.

[0015] Therefore, the object of this invention is to provide a simple, effective and economical solution to the problems mentioned above. Summary of the Invention

[0016] Therefore, the present invention proposes a turbine engine for use in an aircraft, the turbine engine including a heat pump configured to cool oil used in the turbine engine, the heat pump including a closed loop in which a heat transfer fluid flows, the loop including: - Common section, which includes a first expansion valve, an evaporator that exchanges heat with the oil to be cooled, and a first compressor; - A first branch and a second branch are installed in parallel with each other. The first branch includes a first condenser that exchanges heat with a first cold source, and the second branch includes a second condenser that exchanges heat with a second cold source. The first compressor is configured to adjust the pressure of the heat transfer fluid at the inlet of the first condenser according to a first set point, and the second branch includes a second compressor arranged upstream of the second condenser, the second compressor being configured to adjust the pressure of the heat transfer fluid at the inlet of the second condenser according to a second set point.

[0017] The first compressor is now dedicated to the first condenser to regulate the pressure (and thus the temperature) of the heat transfer fluid at the inlet of the first condenser, specifically according to the temperature of the first cold source, in order to achieve optimal heat exchange at the first condenser (heat transfer fluid / first cold source).

[0018] The second compressor is dedicated to the second condenser to specifically regulate the pressure (and thus the temperature) of the heat transfer fluid at the inlet of the second condenser according to the temperature of the second cold source, so as to achieve optimal heat exchange at the second condenser (heat transfer fluid / second cold source).

[0019] Optimizing heat exchange in this way means that the condenser can be precisely sized to meet practical requirements, minimizing the overall size and weight of the condenser, which in turn benefits the overall efficiency of the turbine engine.

[0020] If the cold source is airflow, then an optimally sized condenser can minimize the resistance in the airflow caused by the presence of the condenser, which also benefits the overall efficiency of the turbine engine.

[0021] The turbine engine according to the invention may include one or more of the following features and / or steps, which may be employed independently or in combination with each other: - The first cold source is the flow of fuel or air configured to supply the combustion chamber of the gas generator of the turbine engine; - The second cold source is a flow of fuel or air configured to supply the combustion chamber of the gas generator of a turbine engine, and the fluid of the second cold source is different from the fluid of the first cold source; - The branch inlet is connected to the outlet of the common section via a control valve with three passages; - The valve is configured to have at least a first position, in which the valve allows heat transfer fluid to enter into a first branch and a second branch; -The valve is also configured to have at least one of the following positions: --Second position, in the second position, the valve prevents the heat transfer fluid from passing through; --In the third position, the valve allows the heat transfer fluid to pass through only the first branch; -- Fourth position, in the fourth position, the valve allows the heat transfer fluid to pass through only the second branch; - The valve is controlled by the control system based on the temperature of the oil to be cooled; -The second branch includes a second expansion valve arranged downstream of the second condenser; - The first setpoint is determined based on the temperature of the first cold source, and the second setpoint is determined based on the temperature of the second cold source; - The oil to be cooled comes from an oil system, which includes a lubrication circuit configured to lubricate movable components of the turbine engine and / or a cooling circuit configured to cool at least one generator of the turbine engine. Attached Figure Description

[0022] The invention will be better understood through the following description, which is by way of non-limiting example and with reference to the accompanying drawings, and other details, features, and advantages of the invention will become clearer, as illustrated in the drawings: [ Figure 1 ] Figure 1 This is a schematic axial half-section view of a turbine engine including a heat pump according to the present invention; [ Figure 2 ] Figure 2 This is a detailed view of the heat pump in the first embodiment; [ Figure 3 ] Figure 3 This is a detailed view of the heat pump in the second embodiment. Detailed Implementation

[0023] Figure 1 The turbine engine 1 used for aircraft 2 is partially shown. For example, aircraft 2 is an airplane.

[0024] like Figure 1 As shown, turbine engine 1 is a dual-flow turbojet engine, which typically includes a ducted fan 3, a gas generator 4, and a power turbine 5.

[0025] More specifically, the fan 3 is capable of rotating about axis X relative to the fixed structure 6 of the turbine engine 1. The fan 3 is driven to rotate by the power turbine 5 via a reduction gear 7.

[0026] For example, reducer 7 is a planetary reducer, which has the advantages of being compact and having a high reduction ratio. Reducer 7 is housed in a housing commonly referred to as an "oil seal" and is lubricated with oil. The oil is specifically configured to lubricate the moving parts of reducer 7, particularly the bearings and toothed gears.

[0027] The gas generator 4 includes a low-pressure compressor 8, a high-pressure compressor 9, a combustion chamber 10, and a high-pressure turbine 11 (or an expansion turbine). The high-pressure compressor 9 is driven to rotate by the high-pressure turbine 11. The low-pressure compressor 8 is driven by a fan 3.

[0028] like Figure 1 As shown, the airflow F generated by the fan 3 is divided into a main flow f1 and a secondary flow f2 by the fixed structure 6 of the turbine engine 1. The main flow enters the main duct 12 to supply the gas generator 4, and the secondary flow flows in the secondary duct 13 surrounding the gas generator 4 to provide most of the thrust.

[0029] Figure 1The examples shown are by no means limiting. Turbine engine 1 can be, for example, a turbojet engine, a turboprop engine, a turboshaft engine, or even a turbo engine including one or more ductless fans (e.g., unducted fan (UDF) type or unducted single fan (USF) type).

[0030] like Figure 1 As shown, the turbine engine 1 also includes a heat pump 14 configured to cool the oil in the oil system 15 of the turbine engine 1.

[0031] The heat pump 14 is located in a compartment 16 defined between the housing 17 (generally referred to as the "fan housing") surrounding the fan 3 and the cowling of the nacelle 18 of the turbine engine 1. Alternatively, the heat pump 14 may be located, for example, in a channel compartment, such as in the turbine engine 1, between the flow path 12 for the main flow f1 and the flow path 13 for the secondary flow f2.

[0032] like Figure 2 and Figure 3 As shown, the heat pump 14 includes a closed loop 19 in which the heat transfer fluid flows. Loop 19 includes: - Common part 20, which includes a first expansion valve 21, an evaporator 22 that exchanges heat with the oil to be cooled, and a first compressor 23; - A first branch 24 and a second branch 25 are installed in parallel with each other. The first branch 24 includes a first condenser 26 that exchanges heat with a first cold source 27, and the second branch 25 includes a second condenser 28 that exchanges heat with a second cold source 29.

[0033] According to the invention, the first compressor 23 is configured to adjust the pressure of the heat transfer fluid at the inlet of the first condenser 26 according to a first setpoint. The second branch 25 includes a second compressor 30 located upstream of the second condenser 28. The second compressor 30 is configured to adjust the pressure of the heat transfer fluid at the inlet of the second condenser 28 according to a second setpoint.

[0034] The first compressor 23 is now dedicated to the first condenser 26 to regulate the pressure (and thus the temperature) of the heat transfer fluid at the inlet of the first condenser 26, specifically according to the temperature of the first cold source 27, in order to achieve optimal heat exchange at the first condenser 26 (heat transfer fluid / first cold source).

[0035] The second compressor 30 is dedicated to the second condenser 28 to regulate the pressure (and thus the temperature) of the heat transfer fluid at the inlet of the second condenser 28, specifically according to the temperature of the second cold source 29, so as to achieve optimal heat exchange at the second condenser 28 (heat transfer fluid / second cold source).

[0036] Optimizing heat exchange in this way means that the condensers 26 and 28 can be precisely sized according to actual requirements to minimize the overall size and weight of the condensers 26 and 28, thereby benefiting the overall efficiency of the turbine engine.

[0037] If the cold sources 27 and 29 are airflow, then the optimized condensers 26 and 28 minimize the resistance generated in the airflow due to their presence, which also benefits the overall efficiency of the turbine engine.

[0038] As is customary in this application, the terms “upstream” and “downstream” or “inlet” and “outlet” are defined relative to the flow direction of the heat transfer fluid in the closed loop 19 of the heat pump 14.

[0039] As mentioned above, the oil cooled by the heat pump 14 comes from the oil system 15.

[0040] The oil system 15 may include one or more lubrication circuits through which oil flows and which one or more lubrication circuits are configured to lubricate movable elements of the turbine engine 1.

[0041] according to Figure 1 In the example shown, the oil system 15 includes at least one lubrication circuit configured to lubricate the reducer 7, and more specifically, to lubricate the bearings and toothed wheels of the reducer 7.

[0042] The oil system 15 may include one or more cooling circuits through which oil flows and which cooling circuits are configured to cool the motor of the turbine engine 1.

[0043] like Figures 1 to 3 As shown, the oil system 15 includes at least one cooling circuit configured to cool the generator 31 of the turbine engine 1. The generator 31 can be specifically used to enable the turbine engine 1 to have hybrid power capabilities.

[0044] Advantageously, the first cold source 27 is separated from the second cold source 29.

[0045] The first cold source 27 may be a flow of fuel or air configured to supply the combustion chamber 10 of the gas generator 4 of the turbine engine 1.

[0046] In the same manner, the second cold source 29 may be a stream of fuel or air configured to supply the combustion chamber 10 of the gas generator 4 of the turbine engine 1.

[0047] The airflow that forms the cold sources 27 and 29 can be obtained from one of the pipes 12 and 13 of the turbine engine 1, or from the outside of the turbine engine 1.

[0048] Advantageously, one of the cold sources 27 and 29 is an airflow, while the other cold source 27 and 29 is fuel.

[0049] Heat pump 14 can be configured to operate according to one or more of the following cycles: - First cycle, wherein the heat transfer fluid flows in the first branch 24 and the second branch 25 (heat is discharged to the first cold source 27 and the second cold source 29). - Second cycle, in which the heat transfer fluid flows only in the first branch 24 (heat is only discharged to the first cold source 27). - The third cycle, in which the heat transfer fluid flows only in the second branch 25 (the heat is discharged only to the second cold source 29).

[0050] The inlets of branches 24 and 25 can be connected to the outlet of the common component 20 via a three-passage control valve 32. If this is the case, valve 32 includes one inlet pass and two outlet passes. The inlet pass connects to the outlet of the common component 20, and each of the outlet passes connects to the inlet of one of the branches 24 or 25.

[0051] Advantageously, the three-way valve 32 is configured to have at least a first position in which the valve 32 allows the heat transfer fluid to pass through the first branch 24 and the second branch 25.

[0052] The three-way valve 32 can also be configured to have one or more of the following positions: - Second position: In the second position, valve 32 prevents the heat transfer fluid from passing through; - Third position, in the third position, valve 32 allows the heat transfer fluid to pass only through the first branch 24; - Fourth position, in the fourth position, valve 32 allows the heat transfer fluid to pass only through the second branch 25.

[0053] Therefore, the three-way valve 32 can be configured to have, for example, only two of the positions described above (first position and second position) or all of the positions, as needed.

[0054] Advantageously, the three-way valve 32 is controlled by the control system 33 based on the temperature of the oil to be cooled. Of course, the control system 33 can also consider other parameters to control the three-way valve 32.

[0055] Alternatively, the inlets of branches 24 and 25 may be connected to the outlet of the common section 20 via branches or connectors. If this is the case, the first branch 24 and / or the second branch 25 may include a valve having two passages and configured to have two positions, namely a first position and a second position, in which the valve allows heat transfer fluid to pass through the corresponding branch 24 or 25, and in the second position, the valve prevents heat transfer fluid from passing through the corresponding branch 24 or 25.

[0056] Similar to three-way valves, one or more two-way valves can be controlled by the control system based on the temperature of the oil to be cooled. Of course, the control system can also consider other parameters to control one or more two-way valves.

[0057] Advantageously, compressors 23 and 30 are driven by electric motors controlled by the controlled equipment.

[0058] Advantageously, the first setpoint is determined based on the temperature of the first cold source 27. Of course, other parameters can be considered to determine the first setpoint.

[0059] Advantageously, and in the same manner as the first setpoint, the second setpoint is determined based on the temperature of the second cold source 29. Of course, other parameters can be considered to determine the second setpoint.

[0060] Advantageously, the setpoint is determined in real time by the control equipment specifically based on the inlet parameters (and specifically the temperatures of the cold sources 27 and 29).

[0061] Advantageously, the second branch 25 includes a second expansion valve 34 located downstream of the second condenser 28.

[0062] exist Figure 2 and Figure 3 In the illustrated embodiment, the inlets of branches 24 and 25 are connected to the outlet of common component 20 via a three-way control valve 32. The three-way valve 32 is controlled by a control system 33. The control system 33 is a calculator, which can be a Full Authority Digital Engine Control (FADEC) calculator or a standalone calculator.

[0063] according to Figure 2 In the first embodiment shown, the first cold source 27 is fuel configured to supply the combustion chamber 10 of the gas generator 4, and the second cold source 29 is an airflow from the secondary duct 13.

[0064] exist Figure 3 In the second embodiment shown, the first cold source 27 is an airflow from the secondary pipe 13, and the second cold source 29 is fuel configured to supply the combustion chamber 10 of the gas generator 4.

Claims

1. A turbine engine (1) for an aircraft (2), the turbine engine including a heat pump (14) configured to cool oil used in the turbine engine (1), the heat pump (14) including a closed loop (19) in which a heat transfer fluid flows, the loop (19) including: - Common section (20), the common section includes a first expansion valve (21), an evaporator (22) that exchanges heat with the oil to be cooled, and a first compressor (23). - First branch and second branch (24, 25), the first branch and the second branch are installed in parallel with each other, the first branch (24) includes a first condenser (26) that exchanges heat with a first cold source (27), and the second branch (25) includes a second condenser (28) that exchanges heat with a second cold source (29). The first compressor (23) is configured to adjust the pressure of the heat transfer fluid at the inlet of the first condenser (26) according to a first set point, and the second branch (25) includes a second compressor (30) arranged upstream of the second condenser (28), the second compressor (30) being configured to adjust the pressure of the heat transfer fluid at the inlet of the second condenser (28) according to a second set point.

2. The turbine engine (1) according to claim 1, characterized in that, The first cold source (27) is a flow of fuel or air configured to supply the combustion chamber (10) of the gas generator (4) of the turbine engine (1).

3. The turbine engine (1) according to any one of the preceding claims, characterized in that, The second cold source (29) is a flow of fuel or air configured to supply the combustion chamber (10) of the gas generator (4) of the turbine engine (1), and the fluid of the second cold source (29) is different from the fluid of the first cold source (27).

4. The turbine engine (1) according to any one of the preceding claims, characterized in that, The inlets of the branches (24, 25) are connected to the outlet of the common section (20) via a control valve (32) having three passages.

5. The turbine engine (1) according to the preceding claim, characterized in that, The valve (32) is configured to have at least a first position in which the valve (32) allows the heat transfer fluid to enter the first branch and the second branch (24, 25).

6. The turbine engine (1) according to the preceding claim, characterized in that, The valve (32) is also configured to have at least one of the following positions: - Second position, in which the valve (32) prevents the heat transfer fluid from passing through; - In the third position, the valve (32) allows the heat transfer fluid to pass only through the first branch (24). - Fourth position, in which the valve (32) allows the heat transfer fluid to pass only through the second branch (25).

7. The turbine engine (1) according to any one of claims 4 to 6, characterized in that, The valve (32) is controlled by the control system (33) according to the temperature of the oil to be cooled.

8. The turbine engine (1) according to any one of the preceding claims, characterized in that, The second branch (25) includes a second expansion valve (34) disposed downstream of the second condenser (28).

9. The turbine engine (1) according to any one of the preceding claims, characterized in that, The first set point is determined based on the temperature of the first cold source (27), and the second set point is determined based on the temperature of the second cold source (29).

10. The turbine engine (1) according to any one of the preceding claims, characterized in that, The oil to be cooled comes from an oil system (15) which includes a lubrication circuit configured to lubricate the movable components of the turbine engine (1) and / or a cooling circuit configured to cool at least one generator (31) of the turbine engine (1).

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