An aircraft engine fuel thermal management system

Abstract

This application belongs to the technical field of fuel thermal management, and particularly relates to an aircraft engine fuel thermal management system. The system includes a low-pressure pump (1), a fuel filter (2), a high-pressure pump (3), a fuel dispenser (5), a fuel-oil cooler for aircraft electromechanical system (7), and a fuel-oil cooler for engine lubricating oil system (9); the front end of the low-pressure pump (1) is connected to the fuel pipeline from the aircraft, and the rear end of the low-pressure pump (1) is connected to the fuel inlet of the fuel-oil cooler for aircraft electromechanical system (7); the fuel outlet of the fuel-oil cooler for aircraft electromechanical system (7) is connected to the fuel filter (2) through a first check valve (11), the rear end of the fuel filter (2) is connected to the high-pressure pump (3), and the rear end of the high-pressure pump (3) is connected to the fuel inlet of the fuel-oil cooler for engine lubricating oil system (9). This application can make full use of the fuel heat sink while meeting the temperature resistance requirements of the media of fuel accessories.

Description

Technical Field

[0001] This application belongs to the technical field of fuel thermal management, and particularly relates to an aircraft engine fuel thermal management system. Background Art

[0002] With the improvement of aircraft performance, the heat dissipation of its electromechanical system has increased significantly. The cold source heat sinks on the aircraft include fuel and ram air. However, due to the requirements of aircraft stealth, the introduction of ram air from outside the aircraft is restricted, and the application of aircraft composite materials has reduced the ability of fuel to dissipate heat through the fuel tank structure. Therefore, the aircraft can only make more use of the heat sink of fuel, which makes the engine fuel inlet temperature continue to rise. At the same time, the aircraft transfers the heat dissipation of some electromechanical system components to the engine fuel system for heat dissipation. Due to the existence of fuel coking problems, the heat sink of fuel has certain limitations. At the same time, when the engine is matched with a high-performance aircraft, the heat dissipation of the engine's own lubricating oil system is already very difficult. Coupled with the heat from the aircraft, this brings new challenges to the comprehensive thermal management of engine fuel and lubricating oil. At the same time, under certain low-temperature conditions, fuel filter icing is not allowed, which brings certain contradictions to the entire aircraft thermal management system. Therefore, in view of the increase in engine fuel inlet temperature, the increase in heat dissipation of aircraft components, and a certain fuel heat sink, it is necessary to deeply explore the heat dissipation capacity of the cold source of the engine, and at the same time ensure that the fuel filter does not ice under low-temperature conditions. This requires the adoption of new technical means to design a thermal management architecture that meets the needs of the aircraft and the engine.

[0003] Figure 1 The schematic diagram of the existing engine fuel thermal management system is given, as Figure 1 shown. There are two lubricating oil radiators for fuel, one is the lubricating oil radiator for the engine, and the other is the lubricating oil radiator for the aircraft electromechanical system. Among them, the lubricating oil radiator for the engine is between the low-pressure pump and the fuel filter and belongs to the front end of the thermal management architecture, while the lubricating oil radiator for the aircraft electromechanical system is located between the high-pressure pump and the fuel distributor and belongs to the rear end of the thermal management architecture. The existing technical solutions for the engine fuel thermal management system have the following disadvantages:

[0004] 1. For the heat dissipation of the engine lubricating oil system, one lubricating oil radiator for fuel is used. Part of the fuel exchanges heat with the lubricating oil and is heated and then directly enters the combustion chamber, and part of the fuel is used for the actuation of the servo system (not shown in the figure). The fuel temperature at the outlet of the lubricating oil radiator for fuel needs to meet the temperature resistance of the medium of the fuel accessory (high-pressure pump). As a result, when the engine fuel inlet temperature increases, the cooling demand of the high-temperature lubricating oil of the engine lubricating oil system itself cannot be met.

[0005] 2. The lubricating oil radiator for the engine lubricating oil system must be placed at the front end of the thermal management architecture in order to heat the fuel to prevent fuel filter icing when the fuel temperature is low.

[0006] 3. In order to meet the heat dissipation requirements of the aircraft electromechanical system, the fuel-oil cooler has to be placed at the rear end of the thermal management architecture. However, when the fuel inlet temperature rises, it cannot meet the requirements for the lubricating oil temperature of the aircraft electromechanical system.

[0007] 4. The fuel heat sink is not fully utilized. Due to the temperature resistance capacity limitations of the fuel accessory medium and the lubricating oil temperature limitations of the aircraft electrical system, the maximum temperature that the fuel can reach is far from the coking temperature. Summary of the Invention

[0008] To solve one of the above problems, the present application provides an aircraft engine fuel thermal management system. The fuel-oil cooler for the aircraft electromechanical system is placed at the front of the architecture to meet the lubricating oil temperature requirements of the electromechanical system. Multiple one-way valves are used to control the fuel flow path, which can ensure that the fuel filter does not freeze while meeting the temperature resistance capacity of the fuel accessory medium, and at the same time, the fuel heat sink is fully utilized.

[0009] The aircraft engine fuel thermal management system provided by the present application includes a low-pressure pump, a fuel filter, a high-pressure pump, a fuel distributor, a fuel-oil cooler for the aircraft electromechanical system, and a fuel-oil cooler for the engine lubricating oil system.

[0010] Among them, the front end of the low-pressure pump is connected to the aircraft incoming oil pipeline, and the rear end of the low-pressure pump is connected to the fuel inlet of the fuel-oil cooler for the aircraft electromechanical system.

[0011] The fuel outlet of the fuel-oil cooler for the aircraft electromechanical system is connected to the fuel filter through a first one-way valve. The rear end of the fuel filter is connected to the high-pressure pump, and the rear end of the high-pressure pump is connected to the fuel inlet of the fuel-oil cooler for the engine lubricating oil system. The fuel outlet of the fuel-oil cooler for the engine lubricating oil system is connected to the fuel distributor, and the fuel distributor is used to distribute a set amount of fuel to the combustion chamber.

[0012] The fuel-oil cooler for the aircraft electromechanical system has a first lubricating oil pipeline for connecting the lubricating oil pipeline of the aircraft electromechanical system. The fuel-oil cooler for the engine lubricating oil system has a second lubricating oil pipeline for connecting the lubricating oil pipeline of the engine lubricating oil system. The fuel-oil cooler for the engine lubricating oil system also has a secondary fuel flow path. The fuel outlet of the fuel-oil cooler for the aircraft electromechanical system is connected to the inlet end of the secondary fuel flow path through an oil inlet pipeline before the first one-way valve. The outlet end of the secondary fuel flow path is connected between the first one-way valve and the fuel filter through a return oil pipeline. A second one-way valve is provided on the oil inlet pipeline, and a third one-way valve is provided on the return oil pipeline.

[0013] Preferably, an air-oil cooler for the aircraft electromechanical system is connected in series at the front end of the first lubricating oil pipeline of the fuel-oil cooler for the aircraft electromechanical system.

[0014] Preferably, a direct pipeline is connected in parallel between the inlet and outlet of the air-oil radiator for the aircraft electro-mechanical system, and a fourth one-way valve is arranged on the direct pipeline.

[0015] Preferably, the cooling air used by the air-oil radiator for the aircraft electro-mechanical system includes bypass air, air in front of the fan or air at the booster stage.

[0016] Preferably, an air-oil radiator for the engine lubricating oil system is connected in series at the front end of the second lubricating oil pipeline of the fuel-oil radiator for the engine lubricating oil system.

[0017] Preferably, an air-oil radiator for the engine lubricating oil system is connected in parallel to the second lubricating oil pipeline of the fuel-oil radiator for the engine lubricating oil system, and a flow distribution device is used to distribute the lubricating oil flow between the fuel-oil radiator for the engine lubricating oil system and the air-oil radiator for the engine lubricating oil system.

[0018] In this application, the fuel-oil radiator for the aircraft electro-mechanical system is placed at the front end of the entire architecture. When the temperature of the engine fuel inlet increases, the lubricating oil cooling and temperature requirements of the aircraft electro-mechanical system can still be ensured. By adding control valves and controlling the fuel flow path, and using a three-inlet and three-outlet radiator, it is ensured that the fuel filter does not freeze when the fuel inlet temperature is low. While meeting the temperature resistance requirements of the fuel accessory medium, the fuel heat sink is fully utilized, and it has the advantages of simple and reliable control system. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of an existing engine fuel thermal management system.

[0020] Figure 2 It is a schematic structural diagram of a preferred embodiment of the aircraft engine fuel thermal management system of this application.

[0021] Figure 3 It is a schematic diagram of the second lubricating oil pipeline of the fuel-oil radiator for the engine lubricating oil system of this application.

[0022] Figure 4 It is a schematic diagram of the main fuel flow path of the fuel-oil radiator for the engine lubricating oil system of this application.

[0023] Figure 5 It is a schematic diagram of the auxiliary fuel flow path of the fuel-oil radiator for the engine lubricating oil system of this application.

[0024] Among them, 1 - low-pressure pump, 2 - fuel filter, 3 - high-pressure pump, 4 - control system regulator, 5 - fuel distributor, 6 - air-oil radiator for aircraft electromechanical system, 7 - fuel-oil radiator for aircraft electromechanical system, 8 - air-oil radiator for engine lubricating oil system, 9 - fuel-oil radiator for engine lubricating oil system, 10 - fourth check valve, 11 - first check valve, 12 - second check valve, 13 - third check valve. Detailed implementation mode

[0025] To make the purpose, technical solution and advantages of the implementation of this application clearer, the technical solution in the implementation mode of this application will be described in more detail below in conjunction with the accompanying drawings in the implementation mode of this application. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described implementation mode is part of the implementation modes of this application, not all of them. The implementation mode described below by referring to the accompanying drawings is exemplary and is intended to explain this application, and should not be construed as a limitation to this application. Based on the implementation modes in this application, all other implementation modes obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application. The implementation mode of this application will be described in detail below in conjunction with the accompanying drawings.

[0026] The technical problems to be solved by this application are as follows:

[0027] 1. Solve the problem of meeting the heat dissipation requirements of high-temperature lubricating oil in the engine lubricating oil system under the condition that the fuel temperature at the engine inlet increases;

[0028] 2. Solve the problem that the fuel-oil radiator for the engine lubricating oil system has to be placed at the front end of the architecture;

[0029] 3. Solve the problem that the lubricating oil temperature of the aircraft electromechanical system does not meet the requirements under the condition that the fuel temperature at the engine inlet increases;

[0030] 4. Solve the problem of insufficient utilization of fuel heat sink.

[0031] For this reason, this application provides an aviation engine fuel heat management system, as Figure 2 shown, mainly including a low-pressure pump 1, a fuel filter 2, a high-pressure pump 3, a fuel distributor 5, a fuel-oil radiator 7 for the aircraft electromechanical system, and a fuel-oil radiator 9 for the engine lubricating oil system;

[0032] Among them, the front end of the low-pressure pump 1 is connected to the fuel pipeline from the aircraft, and the rear end of the low-pressure pump 1 is connected to the fuel inlet of the fuel-oil radiator 7 for the aircraft electromechanical system;

[0033] The fuel outlet of the fuel-oil radiator 7 for the aircraft electromechanical system is connected to the fuel filter 2 through a first one-way valve 11. The rear end of the fuel filter 2 is connected to a high-pressure pump 3. The rear end of the high-pressure pump 3 is connected to the fuel inlet of the fuel-oil radiator 9 for the engine lubricating oil system. The fuel outlet of the fuel-oil radiator 9 for the engine lubricating oil system is connected to a fuel distributor 4, and the fuel distributor 4 is used to distribute a set amount of fuel to the combustion chamber.

[0034] The fuel-oil radiator 7 for the aircraft electromechanical system has a first lubricating oil pipeline for connecting the lubricating oil pipeline of the aircraft electromechanical system. The fuel-oil radiator 9 for the engine lubricating oil system has a second lubricating oil pipeline for connecting the lubricating oil pipeline of the engine lubricating oil system. The fuel-oil radiator 9 for the engine lubricating oil system also has a secondary fuel flow path. The fuel outlet of the fuel-oil radiator 7 for the aircraft electromechanical system is connected to the inlet end of the secondary fuel flow path through an oil inlet pipeline before the first one-way valve 11. The outlet end of the secondary fuel flow path is connected between the first one-way valve 11 and the fuel filter 2 through a return oil pipeline. A second one-way valve 12 is provided on the oil inlet pipeline, and a third one-way valve 13 is provided on the return oil pipeline.

[0035] The fuel-oil radiator 9 for the engine lubricating oil system of the present application is a three-in-three-out radiator. One path is for engine lubricating oil, and the other two paths are for engine fuel. The two paths of fuel are not related to each other. Figures 3 to 5 The specific layout of these three flow paths is given.

[0036] The aviation engine fuel thermal management system provided by the present application has two working modes.

[0037] Mode 1: When all the electromechanical systems of the aircraft are turned on and the heat dissipation of the electromechanical systems is the largest, it can meet the condition that the fuel filter does not freeze under the condition of low-temperature incoming oil. At this time, the control system closes the second one-way valve 12 and the third one-way valve 13, and opens the first one-way valve 11. The lubricating oil of the aircraft electromechanical system flows through the fuel-oil radiator 7 for the aircraft electromechanical system to ensure the full heat dissipation of the lubricating oil of the aircraft electromechanical system and at the same time ensure that the medium temperature of the high-pressure pump is within the allowable temperature range. After the incoming oil of the aircraft is pressurized by the low-pressure pump 1, the fuel flows through the fuel-oil radiator 7 for the aircraft electromechanical system, then through the first one-way valve 11, and then through the fuel filter 2, and then flows into the high-pressure pump 3. The fuel pressure increases significantly after passing through the high-pressure pump 3, and then passes through the fuel-oil radiator 9 for the engine lubricating oil system. At this time, the fuel is heated by the lubricating oil and flows into the combustion chamber through the fuel distributor 5 for combustion. Part of the fuel is controlled by the control system regulator 4 to actuate the servo mechanism and circulates in the system.

[0038] Mode 2: Only some of the aircraft's electromechanical systems are turned on. The heat dissipation of the electromechanical systems is relatively small, and the fuel filter will freeze under the condition of low-temperature incoming fuel. At this time, the control system opens the second check valve 12 and the third check valve 13 and closes the first check valve 11. After the incoming fuel of the aircraft is pressurized by the low-pressure pump 1, the fuel passes through the fuel-oil cooler 7 for the aircraft's electromechanical system to cool the lubricating oil of the aircraft's electromechanical system, and the temperature rises to a certain extent. However, at this time, it is still not enough to prevent the fuel filter from freezing. The fuel passes through the second check valve 12 and flows through the fuel-oil cooler 9 for the engine lubricating oil system, and is further heated by the engine lubricating oil. The fuel passes through the third check valve 13 and flows to the front of the fuel filter. At this time, the fuel temperature has made the fuel filter not freeze. Then it flows into the high-pressure pump. The fuel pressure of the fuel passing through the high-pressure pump 3 increases significantly, and then it passes through the fuel-oil cooler 9 for the engine lubricating oil system again. At this time, the fuel is heated by the lubricating oil again, so that the fuel heat sink is fully utilized. The fuel flows into the combustion chamber through the fuel distributor 5 for combustion. Part of the fuel is controlled by the control system regulator (4) to actuate the servo mechanism and circulates in the system.

[0039] In some alternative embodiments, an air-oil cooler 6 for the aircraft's electromechanical system is connected in series at the front end of the first oil pipeline of the fuel-oil cooler 7 for the aircraft's electromechanical system.

[0040] In some alternative embodiments, a direct pipeline is connected in parallel between the inlet and outlet of the air-oil cooler 6 for the aircraft's electromechanical system, and a fourth check valve 10 is provided on the direct pipeline.

[0041] This embodiment increases the further heat dissipation of the lubricating oil by the air-oil cooler 6 for the aircraft's electromechanical system. In Mode 1, the fourth check valve 10 is closed, and the lubricating oil of the aircraft's electromechanical system first flows through the air-oil cooler 6 for the aircraft's electromechanical system and then through the fuel-oil cooler 7 for the aircraft's electromechanical system to ensure the full heat dissipation of the lubricating oil of the aircraft's electromechanical system and at the same time ensure that the medium temperature of the high-pressure pump is within the allowable temperature. On the contrary, in Mode 2, the fourth check valve 10 is opened, and the lubricating oil does not pass through the air-oil cooler 6 for the aircraft's electromechanical system.

[0042] In some alternative embodiments, the cooling air used by the air-oil cooler 6 for the aircraft's electromechanical system includes bypass air, air in front of the fan, or air at the booster stage.

[0043] In some alternative embodiments, an air-oil cooler 8 for the engine lubricating oil system is connected in series at the front end of the second oil pipeline of the fuel-oil cooler 9 for the engine lubricating oil system.

[0044] In some alternative embodiments, an air-oil radiator 8 for the engine lubricating oil system is connected in parallel to the second lubricating oil pipeline of the fuel-oil radiator 9 for the engine lubricating oil system, and a flow distribution device is used to distribute the lubricating oil flow between the fuel-oil radiator 9 for the engine lubricating oil system and the air-oil radiator 8 for the engine lubricating oil system.

[0045] In this application, the fuel-oil radiator for the aircraft electromechanical system is placed at the front end of the entire architecture to ensure the lubricating oil heat dissipation and temperature requirements of the aircraft electromechanical system. If the fuel inlet temperature is relatively high or the heat dissipation is relatively large in some cases of the aircraft electromechanical system, an air-oil radiator is connected in series in front of its fuel-oil radiator and the fourth one-way valve 10 is closed. When the fuel inlet temperature is relatively high and the heat dissipation of the engine lubricating oil system itself is relatively large, an air-oil radiator is connected in series / parallel in front of the engine fuel-oil radiator. Figure 2 The series connection scheme is shown in the figure. When the fuel inlet temperature is relatively low, the control system controls the opening and closing of the one-way valve so that the fuel flows through the fuel-oil radiator of the aircraft electromechanical system, then through the engine fuel-oil radiator and then into the fuel filter, solving the problem of ice formation on the fuel filter at low temperatures. At the same time, the heat sink of the fuel is fully utilized, solving the system contradiction. Since all one-way valves are used, the control system is simple and reliable. This application uses a fuel-oil radiator with three inlets and three outlets, solving the problem of ice formation on the fuel filter in some states with relatively low fuel inlet temperatures. At the same time, it solves the problem of heat dissipation of the engine lubricating oil system when the fuel inlet temperature is relatively high and the temperature resistance of the medium of the fuel accessories (high-pressure pump) is relatively low, thus ensuring the full utilization of the fuel heat sink.

[0046] Although the present application has been described in detail above with general descriptions and specific embodiments, based on the present application, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present application all fall within the scope of protection required by the present application.

Claims

1. An aviation engine fuel thermal management system, characterized in that, it includes a low-pressure pump (1), a fuel filter (2), a high-pressure pump (3), a fuel dispenser (5), a fuel-oil radiator (7) for the aircraft electromechanical system, and a fuel-oil radiator (9) for the engine lubricating oil system; wherein, the front end of the low-pressure pump (1) is connected to the incoming fuel pipeline of the aircraft, and the rear end of the low-pressure pump (1) is connected to the fuel inlet of the fuel-oil radiator (7) for the aircraft electromechanical system; the fuel outlet of the fuel-oil radiator (7) for the aircraft electromechanical system is connected to the fuel filter (2) through a first one-way valve (11), the rear end of the fuel filter (2) is connected to the high-pressure pump (3), the rear end of the high-pressure pump (3) is connected to the fuel inlet of the fuel-oil radiator (9) for the engine lubricating oil system, and the fuel outlet of the fuel-oil radiator (9) for the engine lubricating oil system is connected to the fuel dispenser (4), and the fuel dispenser (4) is used to distribute a set amount of fuel to the combustion chamber; the fuel-oil radiator (7) for the aircraft electromechanical system has a first lubricating oil pipeline for connecting the lubricating oil pipeline of the aircraft electromechanical system, the fuel-oil radiator (9) for the engine lubricating oil system has a second lubricating oil pipeline for connecting the lubricating oil pipeline of the engine lubricating oil system, the fuel-oil radiator (9) for the engine lubricating oil system also has a secondary fuel flow path, the fuel outlet of the fuel-oil radiator (7) for the aircraft electromechanical system is connected to the inlet end of the secondary fuel flow path through an oil inlet pipeline before the first one-way valve (11), the outlet end of the secondary fuel flow path is connected between the first one-way valve (11) and the fuel filter (2) through a return oil pipeline, a second one-way valve (12) is arranged on the oil inlet pipeline, and a third one-way valve (13) is arranged on the return oil pipeline.

2. The aviation engine fuel thermal management system according to claim 1, characterized in that, a fuel-air radiator (6) for the aircraft electromechanical system is connected in series at the front end of the first lubricating oil pipeline of the fuel-oil radiator (7) for the aircraft electromechanical system.

3. The aviation engine fuel thermal management system according to claim 2, characterized in that, a direct pipeline is connected in parallel between the inlet and outlet of the fuel-air radiator (6) for the aircraft electromechanical system, and a fourth one-way valve (10) is arranged on the direct pipeline.

4. The aviation engine fuel thermal management system according to claim 2, characterized in that, the cooling air used by the fuel-air radiator (6) for the aircraft electromechanical system includes bypass air, air in front of the fan, or air at the booster stage.

5. The aviation engine fuel thermal management system according to claim 1, characterized in that, a fuel-air radiator (8) for the engine lubricating oil system is connected in series at the front end of the second lubricating oil pipeline of the fuel-oil radiator (9) for the engine lubricating oil system.

6. The aviation engine fuel thermal management system according to claim 1, characterized in that, a fuel-air radiator (8) for the engine lubricating oil system is connected in parallel to the second lubricating oil pipeline of the fuel-oil radiator (9) for the engine lubricating oil system, and a flow distribution device is used to distribute the lubricating oil flow rate between the fuel-oil radiator (9) for the engine lubricating oil system and the fuel-air radiator (8) for the engine lubricating oil system.

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