Engine bleed air system and engine

Abstract

The utility model relates to an air entraining system of an engine, which is used for cooling a fuel nozzle of the engine and comprises an air entraining fan, an air inlet pipe and an air outlet pipe, the air entraining pipeline is communicated with the fan cabin and a high-pressure stage of an air compressor of the engine and does not flow through a medium-pressure stage of the air compressor of the engine; and the control valve is arranged in the air entraining pipeline so as to open or close a flow passage from the fan cabin to the high-pressure stage of the air compressor, and the air entraining pipeline and the medium-pressure air passage of the engine and / or the high-pressure air passage of the engine are / is provided with an air passage which is at least partially shared. After the engine stops, the engine core engine is cooled through continuous operation of the engine bleed air system, it can be ensured that the temperature of the fuel nozzle is lower than the fuel coking temperature, coking of the fuel nozzle is relieved or avoided, and the aircraft operation cost and the engine maintenance cost are reduced. The utility model further relates to an engine.

Description

Technical Field

[0001] This utility model belongs to the field of aerospace structural design technology, and relates to an engine bleed air system, and more specifically, to an engine bleed air system capable of mitigating or eliminating coking of engine fuel nozzles. Additionally, this utility model also relates to an engine. Background Technology

[0002] In the field of civil aviation engines, the core components of an engine (such as a gas turbine engine) typically include key components such as the compressor, combustion chamber, and turbine. During normal engine operation, the high-temperature combustion gases in the combustion chamber drive the turbine to perform work. The turbine then transmits mechanical energy to the compressor via a drive shaft, thus maintaining the engine's continuous operation. In this process, the stability of the combustion chamber and the reliability of the fuel nozzles have a decisive impact on engine performance.

[0003] However, a long-standing and unresolved problem exists in existing technologies: fuel nozzle coking after engine shutdown. Specifically, when an aircraft completes its mission and the engine is shut down, the core components (especially the combustion chamber and fuel nozzle area) lose the forced cooling provided by high-speed airflow, resulting in significant temperature rebound due to thermal inertia (i.e., the "rebound effect"). Under this high-temperature environment, the trace amounts of fuel remaining inside the fuel nozzle undergo thermal decomposition, gradually forming coking deposits that are difficult to remove.

[0004] Although the amount of coking produced per flight is limited, the coking layer on the fuel nozzles can continue to grow and accumulate after multiple post-flight warm-up cycles. Coking can lead to uneven fuel atomization, localized hot spots in the combustion chamber, and even nozzle blockage, posing a potential threat to fleet operational safety. Therefore, to improve safety, fuel nozzles typically need to be replaced periodically, which presents significant challenges to fleet operation and engine costs, and substantially increases maintenance costs.

[0005] Currently, the industry mainly uses two methods to alleviate the problem of nozzle coking:

[0006] Active cooling systems rely on bleed air during engine operation for cooling, such as by introducing bypass airflow. However, when the engine is turned off, the bleed airflow is interrupted, causing the system to fail and thus still leading to the rapid formation of coking layers.

[0007] Redesigning the fuel injector: for example, using shape memory alloy materials to change the flow area of ​​the fuel injector's purge orifice. However, these measures cannot completely eliminate temperature rebound and increase structural weight or complexity.

[0008] Therefore, it is still necessary to optimize the structure of the engine bleed air system in the prior art in order to provide an improved engine bleed air system that can overcome one or more of the disadvantages of the prior art, in particular, to slow down or eliminate coking of engine fuel injectors. Utility Model Content

[0009] The purpose of this invention is to provide an engine bleed air system that can extend the cooling time of the core engine after the engine is shut down. Furthermore, this bleed air system is compatible with or can share existing engine architectures, avoiding a significant increase in weight or complexity.

[0010] According to one aspect of the present invention, an engine bleed air system is provided for cooling the fuel nozzles of an engine. The engine bleed air system may include: a bleed air fan disposed in the engine fan compartment; a bleed air line connecting the fan compartment and the high-pressure stage of the engine compressor, but not flowing through the intermediate-pressure stage of the engine compressor; and a control valve disposed in the bleed air line to open or close the flow passage from the fan compartment to the high-pressure stage of the compressor, wherein the bleed air line shares at least a portion of the air passage with the intermediate-pressure air passage and / or the high-pressure air passage of the engine.

[0011] Because the engine fan compartment is large and relatively cool, placing the bleed air fan in the engine fan compartment can maximize the use of the cooler airflow to achieve a good cooling effect. This arrangement allows the cool air blown out by the bleed air fan to enter directly from the high-pressure stage of the compressor, without passing through the intermediate-pressure stage, thus reducing flow and flow resistance losses and improving cooling efficiency.

[0012] After the engine stops, the continuous operation of the engine bleed air system cools the engine core, ensuring that the fuel nozzle temperature remains below the fuel coking temperature, thus mitigating or preventing fuel nozzle coking. This significantly increases the fuel nozzle replacement interval, reducing aircraft operating costs and engine maintenance costs.

[0013] According to the above aspects of the present invention, preferably, the bleed air pipeline may include a first bleed air section, a second bleed air section, a third bleed air section and a fourth bleed air section arranged in series, wherein the first bleed air section connects the fan compartment and the medium-pressure air path, the second bleed air section is a first common air path shared with the medium-pressure air path, the third bleed air section connects the medium-pressure air path and the high-pressure air path, and the fourth bleed air section is a second common air path shared with the high-pressure air path.

[0014] This shared gas path saves space and weight associated with new system piping and improves system reliability.

[0015] According to the above aspects of the present invention, preferably, in order to better share the intermediate pressure air passage of the engine while still ensuring the anti-icing / de-icing function of the engine nacelle during normal engine operation, an intermediate pressure air passage control valve may be included in the intermediate pressure air passage for at least partially opening or closing the intermediate pressure air passage.

[0016] According to the above aspects of the present invention, preferably, the medium-pressure gas path control valve includes a first medium-pressure gas path control valve and a second medium-pressure gas path control valve arranged in series along the medium-pressure gas path, wherein the second priming section is disposed between the first medium-pressure gas path control valve and the second medium-pressure gas path control valve.

[0017] Thus, the bleed air pipeline according to this invention can reliably utilize the intermediate pressure air path between the first and second intermediate pressure air path control valves, while ensuring the proper operation of the intermediate pressure air path during normal engine operation.

[0018] According to the above aspects of this utility model, preferably, in order to better share the high-pressure air circuit of the engine while still ensuring the use of the engine's high-temperature bleed air to ensure functions such as air conditioning, a high-pressure air circuit control valve may be included in the high-pressure air circuit for at least partially opening or closing the high-pressure air circuit.

[0019] According to the above aspects of this utility model, preferably, the third bleed section is connected to the fourth bleed section at a position between the high-pressure gas circuit control valve and the high-pressure stage of the compressor.

[0020] Thus, the bleed air pipeline according to this utility model can reliably utilize the high-pressure air path between the high-pressure air path control valve and the high-pressure stage of the compressor, while ensuring the good operation of the high-pressure air path during normal engine operation.

[0021] According to the above aspects of this utility model, preferably, the control valve may include a fan control valve, which is disposed in the first bleed section. This prevents air from the medium-pressure air path from entering the first bleed section and thus the fan compartment.

[0022] According to the above aspects of this utility model, preferably, the control valve may include a medium-pressure bypass control valve, which may be located in the third bleed section. This prevents air from the high-pressure gas path from entering the third bleed section and subsequently entering the compressor intermediate compressor or the nacelle anti-icing pipe.

[0023] According to the above aspects of this invention, preferably, the bleed air fan can be an electric fan and provides a gas flow rate of 0.1-0.2 kg / s, such as air flow. In this way, after the engine is turned off, the temperature rise of the core components can be continuously suppressed without relying on the power provided by the engine operation to supply cooling airflow.

[0024] According to another aspect of the present invention, an engine is provided that may include an engine bleed air system according to the above aspects.

[0025] The beneficial technical effects of the engine bleed air system according to this utility model may include, but are not limited to, the following aspects:

[0026] 1) Through the continuous operation of this system, the core of the engine can be cooled when the engine is stopped, ensuring that the fuel injector temperature is lower than the fuel coking temperature, thus slowing down or preventing fuel injector coking.

[0027] 2) It increases the time required to replace fuel nozzles, thereby reducing the operating costs of aircraft (e.g., airplanes) and the maintenance costs of engines.

[0028] Therefore, the engine bleed air system of this utility model can meet the usage requirements, overcome the shortcomings of the prior art, and achieve the intended purpose. Attached Figure Description

[0029] To further describe the engine bleed air system according to the present invention clearly, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. In the accompanying drawings:

[0030] Figure 1 A schematic diagram of an engine and an engine bleed air system according to a non-limiting embodiment of the present invention is shown.

[0031] The above figures are for illustrative purposes only and are not drawn to scale.

[0032] The reference numerals in the figures are listed in the figures and embodiments:

[0033] 1000 - Engine, including:

[0034] 100 - Engine bleed air system, including:

[0035] 10 - Exhaust fan;

[0036] 20 - Bleed air tubing, including:

[0037] 21 – First priming stage;

[0038] 22 – Second intake section;

[0039] 23 – Third intake section;

[0040] 24 – Fourth intake section;

[0041] 30 – Control valve, including:

[0042] 31 – Fan control valve;

[0043] 32 – Medium-pressure bypass control valve;

[0044] 40 - Medium-pressure gas path, including:

[0045] 40A – Nacelle anti-icing valve;

[0046] 50 - High-pressure gas path, including:

[0047] 50A - Transient bleed valve for engine;

[0048] 60 - Medium-pressure air circuit control valve, including:

[0049] 61 – First intermediate pressure air circuit control valve;

[0050] 62 – Second intermediate pressure air circuit control valve;

[0051] 70 - High-pressure gas circuit control valve;

[0052] 200 - Fan compartment;

[0053] 300 - High-pressure stage of the compressor;

[0054] 400 - Compressor intermediate pressure stage. Detailed Implementation

[0055] It should be understood that, unless explicitly stated otherwise, the present invention may employ various alternative orientations and sequences of steps. It should also be understood that the specific devices shown in the drawings and described in the specification are merely exemplary embodiments of the inventive concept disclosed and defined herein. Therefore, unless expressly stated otherwise, the specific orientations, directions, or other physical features involved in the various disclosed embodiments should not be considered as limiting.

[0056] Figure 1 A schematic diagram of an engine 1000 and an engine bleed air system 100 according to a non-limiting embodiment of the present invention is shown.

[0057] As shown in the figure and as a non-limiting example, the engine 1000 can be a gas turbine engine, such as a turbofan engine. A fan can be installed at the front end of the engine 1000. When the fan rotates, part of the air enters the core engine (inner duct), and the other part of the air is discharged to the rear from the passage outside the core engine (outer bypass duct). The air in the outer bypass duct and the gas in the inner duct work together to generate thrust.

[0058] As an example, engine 1000 may mainly include an air intake, fan, compressor, combustion chamber, and turbine. The fan may be located in fan nacelle 200. The compressor may include multiple stages of moving blades and stationary blades, with the air pressure gradually increasing as it passes through each stage of moving blades and stationary blades. Figure 1As shown, the compressor may include a high-pressure stage 300 and an intermediate-pressure stage 400. The high-pressure stage 300 may be located downstream of the intermediate-pressure stage 400.

[0059] The combustion chamber can be located downstream of the high-pressure stage 300 of the compressor, and a fuel nozzle can be installed in the combustion chamber. The fuel nozzle is not shown in detail in the accompanying drawings; however, as an example, the fuel nozzle can be configured as an annular shape at the front of the combustion chamber. Here, the high-pressure air is thoroughly mixed with the injected fuel and ignited, resulting in a violent combustion reaction that releases a large amount of heat energy, causing the gas temperature to rise sharply.

[0060] The turbine can be located downstream of the combustion chamber to convert the thermal and kinetic energy of the high-temperature, high-pressure gas into mechanical energy, driving the rotation of fans and compressors.

[0061] In addition, the engine 1000 can usually be equipped with corresponding gas lines, such as medium-pressure gas line 40 and high-pressure gas line 50, to draw out gas at appropriate pressure and temperature for use in anti-icing / de-icing and air conditioning systems, etc.

[0062] In the embodiment shown in the attached drawings, the intermediate-pressure gas path 40 can be used to guide gas to the fan compartment and feed it to the engine nacelle anti-icing pipe for anti-icing / de-icing. A nacelle anti-icing valve 40A can be installed in the anti-icing pipe section. For example, Figure 1 The two nacelle anti-icing valves 40A are shown.

[0063] The high-pressure gas path 50 can be used to guide gas to air conditioning systems, etc. The schematic flow path arrangement of the medium-pressure gas path 40 and the high-pressure gas path 50 is shown in the figure. Figure 1 The solid line in the diagram indicates the direction of gas flow, and the arrow points in the direction of the flow. An engine transient vent valve 50A can be installed on the high-pressure gas line 50.

[0064] It should be understood that these gas path arrangements are merely illustrative, and those skilled in the art can use various alternative arrangements.

[0065] According to an embodiment of the present invention, the engine 1000 is further provided with an engine bleed air system 100 for cooling the engine fuel nozzles, thereby slowing down or eliminating coking of the engine fuel nozzles.

[0066] In a preferred embodiment, the engine bleed air system 100 may mainly include: bleed air fan 10, bleed air pipeline 20, and control valve 30, etc.

[0067] The bleed air fan 10 can be installed in the fan compartment 200 of the engine 1000. Since the fan compartment 200 of the engine has a large space and a relatively low temperature, it is advantageous to install the bleed air fan 10 in the fan compartment 200 of the engine 1000.

[0068] It should be understood that the bleed air fan 10 is not a fan commonly found in gas turbine engines, such as a turbine-driven fan, but a separately configured fan. The bleed air fan 10 may be an electric fan powered by onboard power (such as an APU) or airport power, and typically operates only when the engine is stopped.

[0069] Preferably, the bleed air fan 10 is capable of providing a gas flow rate of approximately 0.1-0.2 kg / s, such as an air flow rate, thereby providing a desired flow rate of cool air for cooling the fuel nozzle.

[0070] The bleed air line 20 can connect the fan compartment 200 and the high-pressure stage 300 of the engine compressor, without flowing through the intermediate-pressure stage 400 of the engine compressor. In this way, the cold air blown out by the bleed air fan 10 enters directly from the high-pressure stage 300 of the compressor without passing through the intermediate-pressure stage 400 of the compressor, thereby reducing flow and flow resistance losses and improving cooling efficiency.

[0071] As an example, the bleed air line 20 from the fan compartment 200 to the compressor high-pressure stage 300 may sequentially include multiple bleed air sections arranged in series, such as the first bleed air section 21, the second bleed air section 22, the third bleed air section 23 and the fourth bleed air section 24 shown in the attached figures.

[0072] As shown in the figure, the first bleed section 21 can connect the fan compartment 200 and the medium-pressure air passage 40, the second bleed section 22 is a first common air passage shared with the medium-pressure air passage 40, the third bleed section 23 connects the medium-pressure air passage 40 and the high-pressure air passage 50, and the fourth bleed section 24 is a second common air passage shared with the high-pressure air passage 50.

[0073] Thus, a continuous and sealed bleed air duct 20 is formed between the fan nacelle 200 and the high-pressure stage 300 of the engine compressor, and this bleed air duct 20 is, in a broad sense, a reverse bleed air system. The airflow path driven by the bleed air fan 10 is as follows: Figure 1 The dashed line with arrows indicates the direction of gas flow.

[0074] It should be understood that, according to this utility model, the bleed air pipe 20 can only add pipelines and arrangements for the first bleed air section 21 and the third bleed air section 23, while the second bleed air section 22 and the fourth bleed air section 24 utilize the existing pipelines and arrangements on the engine. As described above, the bleed air pipe 20 can share at least a portion of the air passage with the engine's intermediate pressure air passage 40 and / or the engine's high pressure air passage 50, thereby saving space and weight occupied by the new system piping, reducing production and installation costs, and allowing for retrofitting on existing engines.

[0075] To connect new pipelines with existing pipelines, appropriate pipeline joints can be installed, such as threaded joints, flange joints, compression fittings, and / or welded joints.

[0076] A control valve 30 can be installed in the bleed air line 20 to open or close the flow passage from the fan compartment 200 to the compressor high-pressure stage 300.

[0077] As an example and as shown in the figure, control valve 30 may include a fan control valve 31 and a medium-pressure bypass control valve 32. The fan control valve 31 may be located in the first bleed section 21, while the medium-pressure bypass control valve 32 may be located in the third bleed section 23.

[0078] The fan control valve 31 and the medium-pressure bypass control valve 32 can be shut-off valves, gate valves, or shut-off valves, and may include solenoid valves to better control their opening or closing.

[0079] In order to achieve the desired airflow control, such as ensuring the normal operation of the intermediate pressure air passage and the bleed air passage 20 when the engine is running normally and stopped, the engine bleed air system 100 according to the present invention may further include an intermediate pressure air passage control valve 60 disposed in the intermediate pressure air passage 40 for at least partially opening or closing the intermediate pressure air passage 40.

[0080] As shown in the figure, the medium-pressure gas path control valve 60 may include a first medium-pressure gas path control valve 61 and a second medium-pressure gas path control valve 62 arranged in series along the medium-pressure gas path 40. In this case, the second bleed section 22 may be located between the first medium-pressure gas path control valve 61 and the second medium-pressure gas path control valve 62. It should be understood that the effective path through which the actual bleed air flows may only be a portion of the gas path between the first medium-pressure gas path control valve 61 and the second medium-pressure gas path control valve 62.

[0081] In order to achieve the desired airflow control, such as ensuring the normal operation of the high-pressure air passage 50 and the bleed air passage 20 when the engine is running normally and stopped, the engine bleed air system 100 according to the present invention may further include a high-pressure air passage control valve 70 disposed in the high-pressure air passage 50 for at least partially opening or closing the high-pressure air passage 50.

[0082] As shown in the figure, the third bleed air section 23 can be connected to the fourth bleed air section 24 at a position between the high-pressure air circuit control valve 70 and the compressor high-pressure stage 300. As an example, the third bleed air section 23 can be connected to the fourth bleed air section 24 at a position between the high-pressure air circuit control valve 70 and the engine transient bleed valve 50A.

[0083] The engine bleed air system 100 of this utility model is a reverse bleed air system in a broad sense. Its airflow direction is opposite to the airflow direction in the pipeline when the normal bleed air system is in use. For example, it is opposite to the normal airflow direction of a part of the medium-pressure air line 40 and the high-pressure air line 50.

[0084] During engine 1000 operation, the first intermediate-pressure air path control valve 61 and the second intermediate-pressure air path control valve 62 can be opened to ensure unobstructed airflow in the intermediate-pressure air path 40. At this time, the intermediate-pressure bypass control valve 32 located in the third bleed air section 23 (intermediate-pressure bypass line) can be closed to ensure that bleed air from the compressor high-pressure stage 300 does not enter the compressor intermediate-pressure stage 400. Additionally, the fan control valve 31 can be closed, thereby ensuring that the first bleed air section 21 of the bleed air line 20 is closed and preventing bleed air from the nacelle anti-icing line from entering the fan compartment. These valves / valve mechanisms ensure the normal operation of the bleed air system during engine 1000 operation.

[0085] After the engine 1000 stops, the bleed air fan 10 located in the fan compartment 200 can be powered on and operated to continuously generate cooling airflow. At this time, the fan control valve 31 can be opened to ensure that airflow is input to the first bleed air section 21 of the bleed air line 20. At the same time, the first intermediate pressure air line control valve 61 and the second intermediate pressure air line control valve 62 can be closed to ensure that cold air does not enter the compressor intermediate pressure stage 400 and the fan compartment 200 of the engine. In addition, the intermediate pressure bypass control valve 32 can be opened and the high pressure air line control valve 70 can be closed to ensure that the cold air from the third bleed air section 23 (intermediate pressure bypass line) flows in the reverse direction (i.e., opposite to the flow direction during normal engine operation as described above) into the engine core to cool the engine's fuel injectors.

[0086] The terms "upstream" and "downstream" used herein to indicate orientation or direction, and "first" and "second" used to indicate sequence, are merely to enable those skilled in the art to better understand the concept of the present invention as shown in the preferred embodiments, and are not intended to limit the present invention. Unless otherwise stated, all sequences, orientations, or directions are used only to distinguish one element / component / structure from another, and unless otherwise stated, do not indicate any particular order, sequence of operations, direction, or orientation. For example, in an alternative embodiment, a "first intermediate-pressure air circuit control valve" could be a "second intermediate-pressure air circuit control valve."

[0087] In summary, the engine bleed air system 100 according to the embodiments of this utility model overcomes the shortcomings of the prior art and achieves the intended purpose of the utility model.

[0088] Although the engine bleed air system of this utility model has been described above with reference to preferred embodiments, those skilled in the art should recognize that the above examples are merely illustrative and should not be construed as limiting the utility model. Therefore, various modifications and variations can be made to this utility model within the spirit and scope of the claims, and all such modifications and variations will fall within the scope claimed by the claims of this utility model.

Claims

1. An engine air induction system (100) for cooling a fuel nozzle of an engine, characterized by, The engine bleed air system (100) comprises: a bleed air fan (10) arranged in a fan bay (200) of the engine; a bleed air line (20) communicating the fan bay (200) and a high pressure stage (300) of a compressor of the engine without flowing through an intermediate pressure stage (400) of the compressor of the engine; and a control valve (30) arranged in the bleed air line (20) to open or close a flow path from the fan bay (200) to the high pressure stage (300) of the compressor, wherein the bleed air line (20) has at least one part of a common air path with an intermediate pressure air path (40) of the engine and / or a high pressure air path (50) of the engine.

2. The engine bleed air system (100) of claim 1, characterized in that, The bleed air line (20) comprises a first bleed air section (21), a second bleed air section (22), a third bleed air section (23) and a fourth bleed air section (24) arranged in series, wherein the first bleed air section (21) couples the fan bay (200) and the intermediate pressure air path (40), the second bleed air section (22) is a first common air path with the intermediate pressure air path (40), the third bleed air section (23) couples the intermediate pressure air path (40) and the high pressure air path (50), and the fourth bleed air section (24) is a second common air path with the high pressure air path (50).

3. The engine bleed air system (100) of claim 2, characterized in that, Further comprising an intermediate pressure air path control valve (60) arranged in the intermediate pressure air path (40) for at least partially opening or closing the intermediate pressure air path (40).

4. The engine bleed air system (100) of claim 3, characterized in that, The intermediate pressure air path control valve (60) comprises a first intermediate pressure air path control valve (61) and a second intermediate pressure air path control valve (62) arranged in series along the intermediate pressure air path (40), wherein the second bleed air section (22) is arranged between the first intermediate pressure air path control valve (61) and the second intermediate pressure air path control valve (62).

5. The engine bleed air system (100) of claim 2, wherein, Further comprising a high pressure air path control valve (70) arranged in the high pressure air path (50) for at least partially opening or closing the high pressure air path (50).

6. The engine bleed air system (100) of claim 5, characterized by The third bleed air section (23) is coupled to the fourth bleed air section (24) at a position between the high pressure air path control valve (70) and the high pressure stage (300) of the compressor.

7. The engine bleed air system (100) according to any one of claims 2-6, characterized in that, The control valve (30) comprises a fan control valve (31) arranged in the first bleed air section (21).

8. The engine bleed air system (100) according to any one of claims 2-6, characterized in that, The control valve (30) comprises an intermediate pressure bypass control valve (32) arranged in the third bleed air section (23).

9. The engine bleed air system (100) of any one of claims 1-6, wherein, The bleed air fan (10) is an electric fan and provides a gas flow of 0.1-0.2 Kg / s.

10. An engine (1000) characterized by, The engine comprises the engine bleed air system (100) according to any one of claims 1-9.

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