Collaborative cooling system for lubricating oil and fuel oil of aero-engine

Abstract

The invention belongs to the technical field of aero-engine cooling, and particularly relates to an aero-engine lubricating oil and fuel oil collaborative cooling system which is characterized in that lubricating oil in an engine lubricating oil tank circularly flows through a lubricating oil system pipeline; the lubricating oil circulation path is sequentially connected in series with a lubricating oil pump, a fuel and lubricating oil radiator, an internal flow channel of an engine air inlet structure, an internal flow channel of a fan stator blade, a bearing cavity, a casing and a transmission accessory to form a closed loop; the fuel oil system comprises a fuel oil tank, a fuel oil pump and a fuel oil and lubricating oil radiator. Fuel oil is conveyed to the fuel oil and lubricating oil radiator through a fuel oil pipeline to be injected into an engine combustion chamber after exchanging heat with lubricating oil. The system is provided with a temperature closed-loop control module, the temperature of lubricating oil is monitored in real time through a temperature sensor arranged in a lubricating oil tank, a temperature signal is transmitted to an engine control unit through an engine cable, and a lubricating oil pump is driven to execute variable-frequency speed regulation to achieve dynamic regulation of the flow of the lubricating oil.

Description

Technical Field

[0001] The present application belongs to the field of aircraft engine cooling technology, and in particular relates to an aircraft engine lubricating oil and fuel coordinated heat dissipation system. Background Art

[0002] As the core power unit of an aircraft, the aircraft engine provides the power required for take-off, landing, cruising and maneuvering, and is one of the most critical systems of an aircraft. When the engine is working, its lubricating oil system outputs the lubricating oil stored in the lubricating oil tank through the lubricating oil pump, and after completing the heat exchange with the fuel, it is transported to each support point for lubrication and cooling, and finally returns to the lubricating oil tank after oil and gas separation to complete the cycle.

[0003] Generally, the lubrication performance of lubricating oil is greatly affected by temperature, and its lubrication performance directly affects the life of bearing-related components. When the lubricating oil temperature is too high, its lubrication performance will be significantly reduced, so aircraft engines must provide heat dissipation and cooling measures for the lubricating oil system. At present, the more common way to dissipate heat from lubricating oil is mainly through a fuel-lubricating oil heat exchanger, in which fuel and lubricating oil are introduced separately, and each exchanges heat through its internal layer plate or tube flow channels. Part of the heated fuel enters the combustion chamber for combustion, and the other part returns to the fuel system to continue to participate in the circulation; the cooled lubricating oil is transported to the engine's bearing cavities, casings, transmission accessories and other parts that require lubrication and cooling, and finally returns to the lubricating oil tank. The shortcomings of the existing technical solutions and the existing technology include:

[0004] 1. The lubricating oil of an aircraft engine generally needs to exchange heat with the engine fuel through a dedicated fuel and lubricating oil heat exchange device to reduce the lubricating oil temperature and keep it in good working condition. The structure of a separate fuel and lubricating oil heat exchange device is complex;

[0005] 2. The heat dissipation of aircraft engine lubricating oil is completely dependent on the fuel system. The heat exchange causes the fuel temperature in the system to rise, which deteriorates the working environment of the related fuel system and accessories.

[0006] When the engine fuel temperature is too high, hot oil needs to be returned to the aircraft fuel tank to lower the temperature of the fuel system. This increases the mechanical connection interface between the aircraft and the engine and increases the difficulty of aircraft thermal management. Summary of the invention

[0007] In order to solve the above problems, the present application provides an aircraft engine lubricating oil and fuel coordinated heat dissipation system, comprising: the lubricating oil in the engine lubricating oil tank circulates through the lubricating oil system pipeline, and the lubricating oil circulation path is connected in series with the lubricating oil pump, the fuel lubricating oil radiator, the internal flow channel of the engine intake structure, the internal flow channel of the fan stator blade, the bearing cavity, the casing and the transmission accessories in sequence to form a closed loop;

[0008] The fuel system includes a fuel tank, a fuel pump and a fuel and lubricating oil radiator. The fuel is transported to the fuel and lubricating oil radiator through the fuel pipeline, and then injected into the engine combustion chamber after heat exchange with the lubricating oil.

[0009] The system is equipped with a temperature closed-loop control module, in which the temperature sensor built into the lubricating oil tank monitors the lubricating oil temperature in real time, transmits the temperature signal to the engine control unit through the engine cable, and drives the lubricating oil pump to perform variable frequency speed regulation to achieve dynamic regulation of the lubricating oil flow.

[0010] Preferably, the engine air intake structure includes an air intake casing, a support plate and a cap cover; the cap cover is connected to the center of the air intake casing through a plurality of circumferentially arranged support plates, and the air intake casing, the support plate and the cap cover all have internal flow passages for the circulation of lubricating oil, and the lubricating oil is cooled by flowing through the internal flow passages of the engine air intake structure.

[0011] Preferably, the fan stator blades are connected between the air intake casing and the cap cover, and the fan stator blades have an internal flow channel connecting the air intake casing and the internal flow channel of the cap cover. The lubricating oil passes through the internal flow channel of the fan stator blades, and the lubricating oil is cooled by flowing through the internal flow channel of the fan stator blades.

[0012] Preferably, the lubricating oil inlet is arranged at one end of the air intake casing, and the lubricating oil outlet is arranged at the other end of the air intake casing.

[0013] Preferably, the lubricating oil inlet is arranged on the cap cover, and the lubricating oil outlet is arranged on the air intake casing.

[0014] Preferably, the fuel and lubricating oil radiator adopts a counter-current heat exchange structure, and the lubricating oil and fuel oil flow in a cross-countercurrent manner in the fuel and lubricating oil radiator. A spiral guide vane is provided on the lubricating oil side, and a honeycomb diverter is configured on the fuel oil side.

[0015] Preferably, the engine control unit has a built-in fuzzy PID algorithm to calculate the oil pump speed increment according to the oil temperature deviation value and the rate of change of the oil temperature deviation value.

[0016] Preferably, a double-stage filtering device is provided at the connection between the fuel system pipeline and the fuel and lubricating oil radiator, which has a pressure difference self-cleaning function.

[0017] The advantages of this application include: the invention comprehensively utilizes the characteristics of high heat of lubricating oil return that needs to be dissipated and low temperature of engine air intake structure and fan stator blades and uninterrupted mainstream gas heat dissipation, which can completely or partially replace the function of traditional fuel and lubricating oil radiator and reasonably utilize the necessary structure of existing engines. At the same time, since the demand for cooling capacity of the fuel and lubricating system is reduced, the temperature of the fuel system is indirectly reduced, and the working environment of related fuel systems and accessories is improved. In addition, the heat dissipation of lubricating oil provided by the main flow channel can avoid the return of hot oil to the aircraft tank, reduce the mechanical connection interface of the aircraft and the engine, and reduce the difficulty of aircraft thermal management. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a coordinated heat dissipation system for lubricating oil and fuel of an aircraft engine according to a preferred embodiment of the present application.

[0019] Figure 2 It is a schematic diagram of the engine intake structure of a preferred embodiment of the present application.

[0020] Figure 3 It is a schematic diagram of a fan stator blade according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0022] like Figure 1-Figure 3 As shown, the present application provides an aircraft engine lubricating oil and fuel coordinated heat dissipation system, including: the lubricating oil 2 in the engine lubricating oil tank 1 circulates through the lubricating oil system pipeline 3, and the lubricating oil circulation path is connected in series in sequence to the lubricating oil pump 4, the fuel lubricating oil radiator 5, the internal flow channel of the engine intake structure 9, the internal flow channel of the fan stator blade 10, the bearing cavity 6, the casing 7 and the transmission accessories 8 to form a closed loop;

[0023] It can be understood that the lubricating oil 2 in the lubricating oil tank 1 is driven by the lubricating oil pump 4 to form a closed loop in the lubricating oil system pipeline 3. The circulation path is connected in series with the fuel oil radiator 5, the internal flow channel of the engine intake structure 9, the internal flow channel of the fan stator blade 10, the bearing cavity 6, the casing 7 and the transmission accessories 8, and finally returns to the lubricating oil tank. This design realizes the lubrication and cooling of the core components of the engine by the lubricating oil through multi-stage flow channels.

[0024] The fuel system includes a fuel tank 11, a fuel pump 13 and a fuel radiator 5. The fuel is transported to the fuel radiator 5 through a fuel pipeline 12 and then injected into the engine combustion chamber 14 after heat exchange with the lubricating oil. It can be understood that the fuel in the fuel tank 11 is pressurized by the fuel pump 13 and then transported to the fuel radiator 5 through the fuel pipeline 12 to perform countercurrent heat exchange with the lubricating oil. The cooled fuel is divided into two parts: one part enters the engine combustion chamber 14 for combustion, and the other part returns to the fuel tank after being cooled by ram air. The lubricating oil tank 1 has a built-in temperature sensor 15 to monitor the lubricating oil temperature in real time, and the signal is transmitted to the control unit 17 through the engine cable 16. The control unit has a built-in fuzzy PID algorithm, which calculates the speed increment of the lubricating oil pump according to the temperature deviation value and the rate of change to achieve dynamic flow regulation.

[0025] The system is equipped with a temperature closed-loop control module, and the temperature sensor 15 built into the oil tank 1 monitors the oil temperature in real time, transmits the temperature signal to the engine control unit 17 through the engine cable 16, and drives the oil pump 4 to perform variable frequency speed regulation to achieve dynamic regulation of the oil flow.

[0026] Preferably, the engine air intake structure 9 includes an air intake casing 20, a support plate 21 and a cap 22; the cap 22 is connected to the center of the air intake casing 20 through a plurality of support plates 21 arranged circumferentially, and the air intake casing 20, the support plate 21 and the cap 22 all have internal flow passages for lubricating oil to flow through, and the lubricating oil is cooled by flowing through the internal flow passages of the engine air intake structure 9. When the lubricating oil flows through, the space of the air intake structure can be fully utilized to achieve efficient cooling.

[0027] Preferably, the fan stator blades 10 are connected between the air intake casing 20 and the cap 22, and the fan stator blades 10 have an internal flow channel connecting the air intake casing 20 and the internal flow channel of the cap 22. The lubricating oil passes through the internal flow channel of the fan stator blades 10, and the lubricating oil is cooled by flowing through the internal flow channel of the fan stator blades 10. In other words, the fan stator blades are internally designed with a flow channel connecting the air intake casing and the cap, and when the lubricating oil flows through this flow channel, the airflow generated by the rotation of the fan is used to further dissipate heat, thereby improving the heat exchange efficiency. The air intake structure and the internal flow channel of the fan stator blades are used to reduce the weight of additional heat dissipation components, so as to meet the lightweight requirements of modern aircraft engines.

[0028] Preferably, the lubricating oil inlet 19 is arranged at one end of the air intake casing 20 , and the lubricating oil outlet 23 is arranged at the other end of the air intake casing 20 .

[0029] Preferably, the lubricating oil inlet 19 is arranged on the cap cover 22 , and the lubricating oil outlet 23 is arranged on the air intake casing 20 .

[0030] Preferably, the fuel and lubricating oil radiator 5 adopts a counter-current heat exchange structure, and the lubricating oil and the fuel oil flow in a cross-countercurrent manner in the fuel and lubricating oil radiator 5. A spiral guide vane is provided on the lubricating oil side, and a honeycomb diverter is configured on the fuel oil side.

[0031] Preferably, the engine control unit 17 has a built-in fuzzy PID algorithm to calculate the oil pump speed increment according to the oil temperature deviation value and the rate of change of the oil temperature deviation value. The oil flow rate is dynamically adjusted by the fuzzy PID algorithm to balance the heat dissipation demand and fuel economy. For example, ram air cooling is used preferentially during low-speed flight, and the fuel heat dissipation mode is switched to during high-speed flight to reduce fuel consumption. The oil and fuel achieve efficient heat transfer through countercurrent heat exchange, reducing the oil temperature to below 200°C and avoiding degradation of lubrication performance.

[0032] Preferably, a double-stage filtering device is provided at the connection between the fuel system pipeline 12 and the fuel and lubricating oil radiator 5, which has a pressure difference self-cleaning function.

[0033] The advantages of this application include: the invention comprehensively utilizes the characteristics of high heat of lubricating oil return that needs to be dissipated and low temperature of engine air intake structure and fan stator blades and uninterrupted mainstream gas heat dissipation, which can completely or partially replace the function of traditional fuel and lubricating oil radiator and reasonably utilize the necessary structure of existing engines. At the same time, since the demand for cooling capacity of the fuel and lubricating system is reduced, the temperature of the fuel system is indirectly reduced, and the working environment of related fuel systems and accessories is improved. In addition, the heat dissipation of lubricating oil provided by the main flow channel can avoid the return of hot oil to the aircraft tank, reduce the mechanical connection interface of the aircraft and the engine, and reduce the difficulty of aircraft thermal management.

[0034] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An aircraft engine lubricating oil and fuel coordinated cooling system, characterized in that: include: The lubricating oil (2) in the engine lubricating oil tank (1) circulates through the lubricating oil system pipeline (3), and the lubricating oil circulation path is connected in series with the lubricating oil pump (4), the fuel and lubricating oil radiator (5), the internal flow channel of the engine intake structure (9), the internal flow channel of the fan stator blade (10), the bearing cavity (6), the casing (7) and the transmission accessories (8) to form a closed loop; The fuel system comprises a fuel tank (11), a fuel pump (13) and a fuel and lubricating oil radiator (5); the fuel is transported to the fuel and lubricating oil radiator (5) through a fuel pipeline (12) to undergo heat exchange with the lubricating oil and then injected into the engine combustion chamber (14); The system is equipped with a temperature closed-loop control module, wherein a temperature sensor (15) built into the lubricating oil tank (1) monitors the lubricating oil temperature in real time, transmits the temperature signal to the engine control unit (17) via the engine cable (16), and drives the lubricating oil pump (4) to perform variable frequency speed regulation to achieve dynamic regulation of the lubricating oil flow.

2. The aircraft engine lubricating oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: The engine air intake structure (9) comprises an air intake casing (20), a support plate (21) and a cap cover (22); the cap cover (22) is connected to the center of the air intake casing (20) through a plurality of support plates (21) arranged circumferentially; the air intake casing (20), the support plate (21) and the cap cover (22) all have internal flow passages for lubricating oil to flow through, and the lubricating oil is cooled by flowing through the internal flow passages of the engine air intake structure (9).

3. The aircraft engine oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: The fan stator blade (10) is connected between the air intake casing (20) and the cap cover (22). The fan stator blade (10) has an internal flow channel connecting the air intake casing (20) and the internal flow channel of the cap cover (22). The lubricating oil passes through the internal flow channel of the fan stator blade (10), and the lubricating oil is cooled by flowing through the internal flow channel of the fan stator blade (10).

4. The aircraft engine oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: The lubricating oil inlet (19) is arranged at one end of the air intake casing (20), and the lubricating oil outlet (23) is arranged at the other end of the air intake casing (20).

5. The aircraft engine oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: The lubricating oil inlet (19) is arranged on the cap cover (22), and the lubricating oil outlet (23) is arranged on the air intake casing (20).

6. The aircraft engine oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: The fuel and lubricating oil radiator (5) adopts a counter-current heat exchange structure, and the lubricating oil and the fuel oil flow in a cross-countercurrent manner in the fuel and lubricating oil radiator (5). A spiral guide vane is arranged on the lubricating oil side, and a honeycomb flow divider is arranged on the fuel oil side.

7. The aircraft engine lubricating oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: The engine control unit (17) has a built-in fuzzy PID algorithm, which calculates the lubricating oil pump speed increment according to the lubricating oil temperature deviation value and the lubricating oil temperature deviation value change rate.

8. The aircraft engine lubricating oil and fuel cooperative heat dissipation system according to claim 1, characterized in that: A double-stage filtering device is arranged at the connection between the fuel system pipeline (12) and the fuel and lubricating oil radiator (5), and has a pressure difference self-cleaning function.

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