An aero-engine fuel system icing test device and test method

Abstract

The present application relates to an aero-engine fuel system icing test device and test method. The aero-engine fuel system icing test device includes a supercooled water manufacturing unit to generate liquid water at a set temperature; a supercooled water and fuel collision unit for injecting liquid water at a set temperature into fuel to generate water-containing fuel or ice-containing fuel; a fuel storage unit for storing fuel; a circulation control and heat exchange unit for heating and cooling the fuel in the fuel storage unit; and an ejector pump connected to the circulation control and heat exchange unit and the supercooled water and fuel collision unit through fuel pipelines. The ejector pump is connected to the inlet pipeline of the engine, and is used to suck the water-containing fuel or ice-containing fuel in the fuel pipeline into the inlet pipeline of the engine. The present application provides an aero-engine fuel system icing test device and test method, which can achieve transient icing verification and steady-state icing verification.

Description

Technical Field

[0001] This invention relates to the field of engine fuel system testing, and more particularly to an apparatus and method for testing icing of an aircraft engine fuel system. Background Technology

[0002] Aircraft engine fuel systems are subject to water contamination during their intended operation under atmospheric conditions. The most severe water contamination is typically the freezing of water into ice. Ice can clog tiny pipes in the fuel supply system, such as fuel filters and valves, affecting fuel flow and, in severe cases, causing engine shutdown. Furthermore, airworthiness regulations CCAR 33.67(b)(4)(ii) specify fuel icing verification requirements. To demonstrate compliance with these airworthiness requirements, fuel system icing tests are generally conducted. Therefore, an aircraft engine fuel system icing test apparatus is needed to verify the normal operation of the engine fuel system under real icing environments (including steady-state and transient fuel icing environments).

[0003] For fuel system icing tests, existing solutions focus on steady-state icing verification test equipment, lacking dedicated testing equipment for transient icing verification. Furthermore, to achieve transient icing verification, current methods typically simulate transient icing conditions by running typical engine cycles. However, this approach requires setting up a complete original test pipeline between the aircraft and the engine, and necessitates prolonged engine operation to obtain the transient icing environment. Simulating these transient icing test conditions is difficult, requiring comprehensive consideration of the coupled effects of multiple factors such as fuel flow rate, fuel temperature, specific pipeline construction, external temperature changes, and vibration. This may result in simulated transient icing environments that do not meet regulatory requirements. Additionally, current testing methods struggle to simultaneously conduct steady-state and transient icing verification. Moreover, existing methods often employ offline water mixing or pre-mixing fuel and water before direct injection into the engine inlet pipeline, both of which fail to guarantee uniform water distribution within the fuel, leading to unreliable test results. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention proposes an icing test device and method for an aero-engine fuel system, which can achieve both transient and steady-state icing verification.

[0005] Specifically, the present invention proposes an icing test apparatus for an aircraft engine fuel system, comprising:

[0006] The subcooling water production unit is used to generate liquid water at a set temperature;

[0007] The supercooled water and fuel collision unit is used to inject liquid water at the set temperature into the fuel to generate water-containing fuel or ice-containing fuel.

[0008] A fuel storage unit for storing fuel, wherein the fuel storage unit and the supercooled water-fuel collision unit are connected via a fuel pipeline;

[0009] A circulation control and heat exchange unit is connected to the fuel storage unit via a fuel pipeline. The circulation control and heat exchange unit is used to heat up and cool down the fuel in the fuel storage unit.

[0010] An ejector pump is connected to the circulation control and heat exchange unit and the subcooled water and fuel collision unit via fuel lines. The ejector pump is connected to the engine inlet line and is used to draw water-containing fuel or ice-containing fuel from the fuel lines into the engine inlet line.

[0011] According to one embodiment of the present invention, the supercooled water manufacturing unit includes a temperature control system, a constant temperature chamber, and a water storage device. The temperature control system is used to control the temperature of the constant temperature chamber. The water storage device is disposed inside the constant temperature chamber, and the bottom of the water storage device is connected to the supercooled water and fuel collision unit through a first fuel pipeline.

[0012] According to one embodiment of the present invention, the subcooled water manufacturing unit further includes a first temperature sensor for measuring the temperature of the constant temperature chamber or water storage device, and the temperature control system controls the temperature of the constant temperature chamber based on the first temperature sensor.

[0013] The first fuel line is a downwardly expanding type, and a first valve is provided on the first fuel line.

[0014] According to one embodiment of the present invention, the supercooled water and fuel collision unit includes a fuel tank and an agitator disposed on the fuel tank, the agitator being used to fully mix the fuel and liquid water.

[0015] According to one embodiment of the present invention, the supercooled water and fuel collision unit further includes a first filler port and an observation window. The first filler port is disposed on the top of the fuel tank, and the observation window is disposed on the fuel tank. The bottom of the fuel tank is connected to the ejector pump through a second fuel pipeline. A second valve and a third valve are provided on the second fuel pipeline. The second valve is used to control the injection of water-containing fuel or ice-containing fuel from the fuel tank into the second fuel pipeline, and the third valve is used to control the injection of water-containing fuel or ice-containing fuel from the second fuel pipeline into the ejector pump.

[0016] According to one embodiment of the present invention, an ice collection unit is further provided in the second fuel line, the ice collection unit being disposed between the third valve and the ejector pump.

[0017] According to one embodiment of the present invention, the fuel storage unit includes a fuel storage tank, and a sampling port, a second temperature sensor and a second filler port are provided on the fuel storage tank. The second temperature sensor is used to measure the temperature inside the fuel storage tank, and the sampling port and the second filler port are respectively located at the bottom and top of the fuel storage tank.

[0018] According to one embodiment of the present invention, the fuel storage tank is provided with an inlet, the fuel storage tank is connected to the second fuel line through a third fuel line, one end of the third fuel line is connected to the inlet, the other end is connected to the second fuel line and is located between the second valve and the third valve, and a fourth valve is provided on the third fuel line.

[0019] According to one embodiment of the present invention, the fuel storage tank is further provided with a delivery port and a return port, and the circulation control and heat exchange unit is connected to the delivery port and the return port through a fourth fuel pipeline to form a circulating fuel passage, and a heat exchanger is provided on the fourth fuel pipeline;

[0020] A fifth valve and a power pump are provided on the fuel line between the heat exchanger and the return port. The fifth valve is located between the return port and the power pump. A sixth valve is provided on the fuel line between the heat exchanger and the delivery port.

[0021] According to one embodiment of the present invention, the cycle control and heat exchange unit further includes a fuel bypass, one end of which is connected to the fuel line between the heat exchanger and the power pump, and the other end is connected to the fuel line between the sixth valve and the return port. A seventh valve is provided on the fuel bypass.

[0022] According to one embodiment of the present invention, the circulation control and heat exchange unit is connected to the ejector pump through a fifth fuel line. One end of the fifth fuel line is connected to the fourth fuel passage and is located between the fifth valve and the power pump, and the other end is connected to the ejector pump. An eighth valve is provided on the fifth fuel line.

[0023] According to one embodiment of the present invention, a ninth valve and a flow meter are provided on the inlet pipe of the engine.

[0024] This invention also provides a method for testing icing in an aircraft engine fuel system, applicable to the aforementioned aircraft engine fuel system icing test apparatus, including a transient icing test, comprising the following steps:

[0025] S1, the fuel stored in the fuel storage unit is conditioned to reach the first set temperature through the circulation control and heat exchange unit;

[0026] S2, the subcooled water manufacturing unit generates subcooled water at a set temperature, and injects the set amount of subcooled water into the subcooled water and fuel collision unit that stores fuel.

[0027] S3, fuel from the fuel storage unit is delivered to the ejector pump through the circulation control and heat exchange unit, and fuel containing subcooled water is delivered to the ejector pump through the subcooled water and fuel collision unit. The subcooled water forms ice and enters the engine inlet pipe along with the fuel through the ejector pump.

[0028] S4, the engine operates under the most severe transient icing condition, and relevant operating parameters of the engine are monitored.

[0029] According to an embodiment of the present invention, the icing test method for the aero-engine fuel system further includes a steady-state icing test, comprising the steps of:

[0030] T1 adjusts the temperature of the fuel stored in the fuel storage unit to reach the second set temperature through the circulation control and heat exchange unit.

[0031] T2, the supercooled water manufacturing unit generates liquid water at a set temperature and injects it into the supercooled water and fuel collision unit. The supercooled water and fuel collision unit fully mixes the liquid water and fuel into an oil-water emulsion. The supercooled water and fuel collision unit then transports the oil-water emulsion with a set water content to the fuel storage unit through the fuel pipeline.

[0032] T3 uses a circulation control and heat exchange unit to circulate and cool the fuel containing oil and water emulsion stored in the fuel storage unit to reach the third set temperature.

[0033] T4, through the circulation control and heat exchange unit, delivers the water-containing fuel from the fuel storage unit to the ejector pump, and then enters the inlet pipe of the engine through the ejector pump;

[0034] T5, the engine operates under the most severe steady-state icing condition, and relevant operating parameters of the engine are monitored.

[0035] According to one embodiment of the present invention, in step T2, the liquid water and fuel oil are stirred and thoroughly mixed to form an oil-water emulsion.

[0036] The present invention provides an icing test device for an aero-engine fuel system, which is designed with a supercooled water manufacturing unit and a supercooled water-fuel collision unit to provide a transient ice generation environment, thereby realizing transient icing verification and steady-state icing verification.

[0037] It should be understood that the above general description and the following detailed description of the present invention are exemplary and illustrative, and are intended to provide further explanation of the present invention. Attached Figure Description

[0038] The accompanying drawings are included to provide a further understanding of the invention. They are incorporated in and constitute a part of this application. The drawings illustrate embodiments of the invention and, together with this specification, serve to explain the principles of the invention.

[0039] In the attached image:

[0040] Figure 1 A schematic diagram of an aircraft engine fuel system icing test apparatus according to an embodiment of the present invention is shown.

[0041] Figure 2 A flowchart illustrating a transient icing test of an aero-engine fuel system icing test apparatus according to an embodiment of the present invention is shown.

[0042] Figure 3 A flowchart illustrating a steady-state icing test of an aero-engine fuel system icing test apparatus according to an embodiment of the present invention is shown.

[0043] The above figures include the following reference numerals:

[0044] Subcooled water production unit 100

[0045] Supercooled water and fuel collision unit 200

[0046] Fuel storage unit 300

[0047] Circulation control and heat exchange unit 400

[0048] Ejector pump 500

[0049] Engine 600

[0050] Temperature control system 101

[0051] Incubator 102

[0052] Water storage device 103

[0053] First fuel line 104

[0054] First temperature sensor 105

[0055] First valve 106

[0056] Oil tank 201

[0057] Mixer 202

[0058] First refueling port 203 Observation window 204 Second fuel line 205

[0059] Second valve 206

[0060] Third valve 207 Ice collection unit 208 Fuel storage tank 301 Sampling port 302 Second temperature sensor 303

[0061] Second refueling port 304 Oil inlet 305 Third fuel line 306

[0062] Fourth valve 307 Conveyor Port 308 Return port 309 Fourth fuel line 401 Heat exchanger 402

[0063] Fifth valve 403 404 Power Pump

[0064] Sixth valve 405 Fuel Bypass 406

[0065] Seventh Valve 407 Fifth fuel line 408

[0066] Eighth valve 409 Inlet Pipeline 601

[0067] Ninth Valve 602 Flowmeter 603 Detailed Implementation

[0068] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0069] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0070] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0071] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0072] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0073] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, rotated 90 degrees, or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0074] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0075] Figure 1 A schematic diagram of an aircraft engine fuel system icing test apparatus according to an embodiment of the present invention is shown. As shown in the figure, an aircraft engine fuel system icing test apparatus mainly includes a supercooled water production unit 100, a supercooled water and fuel collision unit 200, a fuel storage unit 300, a circulation control and heat exchange unit 400, and an ejector pump 500.

[0076] The subcooled water production unit 100 is used to generate liquid water at a set temperature. The liquid water includes subcooled water, which is water that remains liquid even below zero degrees Celsius.

[0077] The supercooled water and fuel collision unit 200 is used to inject the liquid water generated by the supercooled water production unit 100 into the fuel to generate fuel containing liquid water.

[0078] The fuel storage unit 300 is used to store fuel. The fuel storage unit 300 and the supercooled water and fuel collision unit 200 are connected through a fuel pipeline.

[0079] The circulation control and heat exchange unit 400 is connected to the fuel storage unit 300 via a fuel line. The circulation control and heat exchange unit 400 is used to heat up and down the fuel in the fuel storage unit 300 so that the fuel reaches the set temperature that meets the test conditions.

[0080] The ejector pump 500 is connected to the circulation control and heat exchange unit 400 and the subcooled water and fuel collision unit 200 via fuel lines. The ejector pump 500 is connected to the inlet line 601 of the engine 600. The ejector pump 500 is used to draw water-containing fuel or ice-containing fuel from the fuel lines into the inlet line 601 of the engine 600, ensuring that fuel can effectively enter the inlet line of the engine 600 without causing backflow. It should be noted that the engine 600 is a test piece.

[0081] This invention provides an icing test apparatus for an aero-engine fuel system capable of both transient and steady-state icing verification. During transient icing verification, the supercooled water-fuel collision unit 200 injects supercooled water generated by the supercooled water production unit 100 into the fuel to generate fuel containing supercooled water. The fuel stored in the fuel storage unit 300 is then temperature-controlled to a set temperature via a circulation control and heat exchange unit 400. The fuel containing supercooled water in the supercooled water-fuel collision unit 200 and the fuel in the fuel storage unit 300 are transported through fuel pipelines to an ejector pump 500, and then flow into the inlet pipe 601 of the engine 600, thereby simulating a transient fuel icing environment. During steady-state icing verification, the supercooled water-fuel collision unit 200 injects liquid water generated by the liquid water production unit into the fuel to generate water-containing fuel. The water-containing fuel is then injected into the fuel storage unit 300 through fuel pipelines. Next, the water-containing fuel stored in the fuel storage unit 300 is conditioned to reach the set temperature through the circulation control and heat exchange unit 400. Finally, the water-containing fuel in the fuel storage unit 300 is transported to the ejector pump 500 through the circulation control and heat exchange unit 400, and then flows into the inlet pipe 601 of the engine 600 through the ejector pump 500.

[0082] Preferably, the supercooled water production unit 100 includes a temperature control system 101, a constant temperature chamber 102, and a water storage device 103. The temperature control system 101 controls the temperature of the liquid water within the constant temperature chamber 102. The supercooled water production unit 100 can utilize cooling equipment such as liquid nitrogen to lower the water temperature, maintaining it at a supercooled water temperature or other set temperature. The water storage device 103 is disposed within the constant temperature chamber 102 and is enclosed by it. Distilled water or water of higher purity can be cooled and cooled in the constant temperature chamber 102 to become supercooled water. The water storage device 103 provides the required amount of water for the experiment. The water temperature within the water storage device 103 is the same as the temperature of the constant temperature chamber 102. The bottom of the water storage device 103 is connected to the supercooled water and fuel collision unit 200 via a first fuel line 104.

[0083] Preferably, the subcooled water manufacturing unit 100 further includes a first temperature sensor 105 for measuring the temperature of the thermostat 102 or the water storage device 103. The temperature control system 101 controls the temperature of the thermostat 102 based on the first temperature sensor 105. A first valve 106 is provided on the first fuel line 104. The first valve 106 is located near the bottom of the water storage device 103. The first valve 106 is used to control the entry of liquid water in the water storage device 103 into the first fuel line 104. The first fuel line 104 is a downwardly expanding type. This ensures that once the first valve 106 is opened, the liquid water will directly reach the subcooled water and fuel collision unit 200 without contacting the pipe wall of the first fuel line 104, effectively preventing the subcooled water from accumulating into ice in the first fuel line 104.

[0084] Preferably, the supercooled water and fuel collision unit 200 includes a fuel reservoir 201 and an agitator 202 disposed on the fuel reservoir 201. The agitator 202 is used to thoroughly mix the fuel and liquid water. By way of example and not limitation, the agitator 202 can be an ultrasonic generator. More preferably, the fuel reservoir 201 is used to store fuel, and the fuel reservoir 201 has a converging shape from top to bottom, such as an inverted cone shape. The converging shape of the fuel reservoir 201 ensures that the water-containing fuel or ice-containing fuel can be completely delivered to the bottom of the fuel reservoir 201 during downward conveying.

[0085] Preferably, the supercooled water and fuel collision unit 200 further includes a first filler neck 203 and an observation window 204. The first filler neck 203 is located on the top of the fuel tank 201 and is used to fill the fuel tank 201 with ordinary engine fuel. The observation window 204 is located on the fuel tank 201 to facilitate observation of the fuel icing inside the fuel tank 201. In this embodiment, the observation window 204 is located on the top of the fuel tank 201 for easy observation. The bottom of the fuel tank 201 is connected to the ejector pump 500 via a second fuel line 205. A second valve 206 and a third valve 207 are provided on the second fuel line 205. The second valve 206 is used to control the injection of water-containing fuel or ice-containing fuel from the fuel tank 201 into the second fuel line 205, and the third valve 207 is used to control the injection of water-containing fuel or ice-containing fuel from the second fuel line 205 into the ejector pump 500.

[0086] Preferably, an ice collection unit 208 is also provided in the second fuel line 205. This ice collection unit 208 is located between the third valve 207 and the ejector pump 500, and is used to collect ice from the fuel. The ice collection unit 208 can be a removable filter, and its removal does not affect the fuel flow rate from the second fuel line 205 to the ejector pump 500.

[0087] Preferably, the fuel storage unit 300 includes a fuel storage tank 301, on which a sampling port 302, a second temperature sensor 303, and a second filler neck 304 are provided. The second temperature sensor 303 is used to measure the temperature inside the fuel storage tank 301. The sampling port 302 and the second filler neck 304 are respectively located at the bottom and top of the fuel storage tank 301. Workers can extract fuel samples through the sampling port 302 to analyze the water content in the fuel. The second filler neck 304 is used to add ordinary engine fuel to the fuel storage tank 301.

[0088] Preferably, the fuel storage tank 301 is provided with a fuel inlet 305. The fuel storage tank 301 is connected to the second fuel line 205 via a third fuel line 306. One end of the third fuel line 306 is connected to the fuel inlet 305, and the other end is connected to the second fuel line 205 and located between the second valve 206 and the third valve 207. A fourth valve 307 is provided on the third fuel line 306. By opening the second valve 206 and the fourth valve 307, and closing the third valve 207, water-containing fuel in the supercooled water and fuel collision unit 200 can be injected into the fuel storage tank 301.

[0089] Preferably, the fuel storage tank 301 is further provided with a delivery port 308 and a return port 309. The circulation control and heat exchange unit 400 connects the delivery port 308 and the return port 309 through the fourth fuel line 401, forming a circulating fuel passage. In this example, the delivery port 308 is located on the side wall of the fuel storage tank 301 near the bottom, and the return port 309 is located at the top of the fuel storage tank 301. A heat exchanger 402 is provided on the fourth fuel line 401. The heat exchanger 402 regulates the temperature of the fuel in the fuel storage tank 301 through the circulating fuel passage, and heats or cools the fuel based on the temperature measured by the second temperature sensor 303. By way of example and not limitation, the heat exchanger 402 can heat the fuel by exchanging heat with hot lubricating oil, and cool it by using a compressor / liquid nitrogen. Furthermore, a fifth valve 403 and a power pump 404 are provided on the fuel line between the heat exchanger 402 and the return port 309. The fifth valve 403 is located between the return port 309 and the power pump 404. The power pump 404 provides power for fuel delivery and can be a gear pump. Activating the fifth valve 403 and the power pump 404 allows the fuel in the fuel line to return to the fuel storage tank 301 via the fifth valve 403 and the return port 309. A sixth valve 405 is provided on the fuel line between the heat exchanger 402 and the delivery port 308. Opening the sixth valve 405, the fifth valve 403, and the power pump 404 allows the fuel output from the delivery port 308 of the fuel storage tank 301 to pass through the heat exchanger 402 and return to the fuel storage tank 301 via the return port 309.

[0090] Preferably, the circulation control and heat exchange unit 400 also includes a fuel bypass 406 connected in parallel to the fourth fuel line 401. One end of the fuel bypass 406 is connected to the fuel line between the heat exchanger 402 and the power pump 404, and the other end is connected to the fuel line between the sixth valve 405 and the return port 309. A seventh valve 407 is provided on the fuel bypass 406. The purpose of the fuel bypass 406 is that when the fuel in the fuel storage tank 301 reaches the set temperature, the fuel no longer needs to pass through the heat exchanger 402; the fuel can flow through the fuel bypass 406 for fuel circulation or be delivered to the ejector pump 500 via the fuel bypass 406.

[0091] Preferably, the circulation control and heat exchange unit 400 is connected to the ejector pump 500 via a fifth fuel line 408. One end of the fifth fuel line 408 is connected to the fourth fuel passage 401 and located between the fifth valve 403 and the power pump 404, while the other end is connected to the ejector pump 500. An eighth valve 409 is provided on the fifth fuel line 408. It is easy to understand that opening the fifth valve 403, the sixth valve 405, and the power pump 404, and closing the seventh valve 407 and the eighth valve 409, allows fuel to circulate through the heat exchanger 402. Opening the fifth valve 403, the seventh valve 407, and the power pump 404, and closing the sixth valve 405 and the eighth valve 409, allows fuel to circulate through the fuel bypass 406. Opening the seventh valve 407, the eighth valve 409, and the power pump 404, and closing the fifth valve 403 and the sixth valve 405, allows fuel to be delivered to the ejector pump 500 through the fuel bypass 406 and the fourth fuel passage 401.

[0092] Preferably, a ninth valve 602 and a flow meter 603 are provided on the inlet pipe 601 of the engine 600. When the ninth valve 602 is opened, water-containing fuel or ice-containing fuel enters the engine 600 through the ejector pump 500. The flow meter 603 is used to monitor the fuel flow rate into the engine 600.

[0093] Figure 2 A flowchart illustrating a transient icing test of an aero-engine fuel system icing test apparatus according to an embodiment of the present invention is shown. As shown, the present invention also provides an aero-engine fuel system icing test method, applicable to the aforementioned aero-engine fuel system icing test apparatus. This test method includes a transient icing test and comprises the following steps:

[0094] S1, the fuel stored in the fuel storage unit 300 is conditioned to reach a first set temperature through the circulation control and heat exchange unit 400. Specifically, the required fuel is injected into the fuel storage tank 301 through the second filler port 304. The fifth valve 403, the sixth valve 405, and the power pump 404 are opened, while the seventh valve 407 and the eighth valve 409 are closed. This allows the fuel to circulate from the fuel storage tank 301 through the delivery port 308, the sixth valve 405, the heat exchanger 402, the power pump 404, the fifth valve 403, and the return port 309 back into the fuel storage tank 301 until the fuel is conditioned to the first set temperature. This first set temperature is set to -11℃.

[0095] S2, the subcooled water manufacturing unit 100 generates subcooled water at a set temperature and adjusts the set amount of subcooled water into the water storage device 103. The first valve 106 is opened to inject the subcooled water into the fuel tank 201 of the fuel collision unit 200 to mix.

[0096] S3: Open valves 407 (seventh), 409 (eighth), and 404 (power pump); close valves 403 (fifth) and 405 (sixth). Fuel from fuel storage unit 300 is delivered to ejector pump 500 via fuel bypass 406 and fourth fuel passage in circulation control and heat exchange unit 400. Simultaneously, valves 206 (second), 207 (third), and 602 (ninth) are opened, and valve 307 (fourth) is closed. Fuel containing supercooled water is delivered to ejector pump 500 via fuel tank 201 in supercooled water and fuel collision unit 200. The supercooled water forms ice and travels with the fuel through ejector pump 500 into inlet pipe 601 of engine 600 to simulate transient fuel icing environment. Transient fuel icing environment refers to an environment in which the fuel delivered to the engine contains a high concentration of ice due to the accumulation and subsequent shedding of ice in the aircraft fuel system within a short period of time.

[0097] S4 is the most severe operating condition for engine 600 under transient icing. The relevant operating parameters of engine 600 are monitored to determine whether engine 600 is working properly.

[0098] Figure 3 A flowchart illustrating a steady-state icing test of an aero-engine fuel system icing test apparatus according to an embodiment of the present invention is shown. As shown, preferably, the aero-engine fuel system icing test method further includes a steady-state icing test, comprising the following steps:

[0099] T1, through the circulation control and heat exchange unit 400, adjusts the temperature of the fuel stored in the fuel storage unit 300 to reach a first set temperature. Specifically, the required fuel is injected into the fuel storage tank 301 through the second filler port 304. The fifth valve 403, the sixth valve 405, and the power pump 404 are opened, while the seventh valve 407 and the eighth valve 409 are closed. This allows the fuel to circulate from the fuel storage tank 301 through the delivery port 308, the sixth valve 405, the heat exchanger 402, the power pump 404, the fifth valve 403, and the return port 309 back into the fuel storage tank 301 until the fuel is heated to the second set temperature. This second set temperature is set to 27°C.

[0100] T2, the supercooled water production unit 100 generates liquid water at a set temperature and stores a set amount of liquid water in the water storage device 103. The first valve 106 is opened, injecting the liquid water into the supercooled water and fuel collision unit 200, which stores fuel. The supercooled water and fuel collision unit 200 thoroughly mixes the liquid water and fuel in the fuel tank 201 to form an oil-water emulsion. The second valve 206 and the fourth valve 307 are opened, and the third valve 207 is closed. The supercooled water and fuel collision unit 200 then delivers the oil-water emulsion with a set water content to the fuel storage unit 300 through the third fuel pipeline 306.

[0101] In step T3, referring to step T1, the fuel containing the oil-water emulsion stored in the fuel storage unit 300 is circulated and cooled through the circulation control and heat exchange unit 400 to reach a third set temperature. This third set temperature is the lowest fuel temperature and critical icing temperature that the aircraft can experience. Fuel circulation further ensures that water is evenly distributed in the fuel.

[0102] T4, once the third set temperature is reached, opens the seventh valve 407, the eighth valve 409, and the power pump 404, and closes the fifth valve 403 and the sixth valve 405. The water-containing fuel in the fuel storage unit 300 is transported to the ejector pump 500 through the fuel bypass 406 and the fourth fuel passage of the circulation control and heat exchange unit 400, and then enters the inlet pipe 601 of the engine 600 through the ejector pump 500.

[0103] T5 represents the most severe steady-state icing condition for engine 600, monitoring relevant operating parameters of engine 600 to determine whether engine 600 is operating normally.

[0104] Preferably, after completing step T2 and before performing step T3, a fuel sample is taken from sampling port 302 for moisture determination to determine the water content required by airworthiness clause 33.67(b)(4)(ii). It should be noted that the moisture content can be determined using a caliper moisture determination method.

[0105] Preferably, in step T2, the liquid water and fuel can be thoroughly stirred by the agitator 202 installed on the oil tank 201 to make them fully mixed into an oil-water emulsion.

[0106] The present invention provides an apparatus and method for testing icing of an aircraft engine fuel system, which has the following advantages:

[0107] 1. By designing devices such as a supercooled water manufacturing unit and a supercooled water-fuel collision unit, the effect of transient water injection and ice formation is achieved, and ice-containing fuel can be effectively injected into the inlet pipeline of the aircraft engine, which can effectively solve the problem that it is difficult to simulate the actual transient ice environment.

[0108] 2. This experimental method can effectively control the amount of ice generated.

[0109] 3. This test device can carry out steady-state icing tests and transient icing tests of fuel systems, and effectively coordinates test resources.

[0110] 4. This test device can improve the uniformity of water distribution in fuel oil.

[0111] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments described above without departing from the spirit and scope of the invention. Therefore, it is intended that this invention cover modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. An icing test apparatus for an aircraft engine fuel system, comprising: The subcooling water production unit is used to generate liquid water at a set temperature; The supercooled water and fuel collision unit is used to inject liquid water at the set temperature into the fuel to generate water-containing fuel or ice-containing fuel. A fuel storage unit for storing fuel, wherein the fuel storage unit and the supercooled water-fuel collision unit are connected via a fuel pipeline; A circulation control and heat exchange unit is connected to the fuel storage unit via a fuel pipeline. The circulation control and heat exchange unit is used to heat up and cool down the fuel in the fuel storage unit. An ejector pump is connected to the circulation control and heat exchange unit and the subcooled water and fuel collision unit via fuel lines. The ejector pump is connected to the engine inlet line and is used to draw water-containing fuel or ice-containing fuel from the fuel lines into the engine inlet line.

2. The aircraft engine fuel system icing test apparatus as described in claim 1, characterized in that, The supercooled water production unit includes a temperature control system, a constant temperature chamber, and a water storage device. The temperature control system is used to control the temperature of the constant temperature chamber. The water storage device is installed inside the constant temperature chamber, and the bottom of the water storage device is connected to the supercooled water and fuel collision unit through a first fuel pipeline.

3. The aircraft engine fuel system icing test apparatus as described in claim 2, characterized in that, The subcooled water manufacturing unit also includes a first temperature sensor for measuring the temperature of the constant temperature chamber or water storage device, and the temperature control system controls the temperature of the constant temperature chamber based on the first temperature sensor. The first fuel line is a downwardly expanding type, and a first valve is provided on the first fuel line.

4. The aircraft engine fuel system icing test apparatus as described in claim 1, characterized in that, The supercooled water and fuel collision unit includes a fuel tank and an agitator mounted on the fuel tank, the agitator being used to thoroughly mix the fuel and liquid water.

5. The aircraft engine fuel system icing test apparatus as described in claim 4, characterized in that, The supercooled water and fuel collision unit also includes a first filler neck and an observation window. The first filler neck is located on the top of the fuel tank, and the observation window is located on the fuel tank. The bottom of the fuel tank is connected to the ejector pump through a second fuel line. A second valve and a third valve are provided on the second fuel line. The second valve is used to control the injection of water-containing fuel or ice-containing fuel from the fuel tank into the second fuel line, and the third valve is used to control the injection of water-containing fuel or ice-containing fuel from the second fuel line into the ejector pump.

6. The aircraft engine fuel system icing test apparatus as described in claim 5, characterized in that, An ice collection unit is also provided in the second fuel line, and the ice collection unit is located between the third valve and the ejector pump.

7. The aircraft engine fuel system icing test apparatus as described in claim 5, characterized in that, The fuel storage unit includes a fuel storage tank, on which a sampling port, a second temperature sensor, and a second filler port are provided. The second temperature sensor is used to measure the temperature inside the fuel storage tank. The sampling port and the second filler port are respectively located at the bottom and top of the fuel storage tank.

8. The aircraft engine fuel system icing test apparatus as described in claim 7, characterized in that, The fuel storage tank is provided with an inlet. The fuel storage tank is connected to the second fuel line through a third fuel line. One end of the third fuel line is connected to the inlet, and the other end is connected to the second fuel line and located between the second valve and the third valve. A fourth valve is provided on the third fuel line.

9. The aircraft engine fuel system icing test apparatus as described in claim 8, characterized in that, The fuel storage tank is also provided with a delivery port and a return port. The circulation control and heat exchange unit is connected to the delivery port and the return port through a fourth fuel pipeline to form a circulating fuel passage. A heat exchanger is provided on the fourth fuel pipeline. A fifth valve and a power pump are provided on the fuel line between the heat exchanger and the return port. The fifth valve is located between the return port and the power pump. A sixth valve is provided on the fuel line between the heat exchanger and the delivery port.

10. The aircraft engine fuel system icing test apparatus as described in claim 9, characterized in that, The cycle control and heat exchange unit also includes a fuel bypass, one end of which is connected to the fuel line between the heat exchanger and the power pump, and the other end is connected to the fuel line between the sixth valve and the return port. A seventh valve is provided on the fuel bypass.

11. The aircraft engine fuel system icing test apparatus as described in claim 10, characterized in that, The circulation control and heat exchange unit is connected to the ejector pump through a fifth fuel line. One end of the fifth fuel line is connected to the fourth fuel line and is located between the fifth valve and the power pump, while the other end is connected to the ejector pump. An eighth valve is provided on the fifth fuel line.

12. The aircraft engine fuel system icing test apparatus as described in claim 1, characterized in that, A ninth valve and a flow meter are installed on the inlet pipe of the engine.

13. A method for testing icing in an aircraft engine fuel system, applicable to the aircraft engine fuel system icing test apparatus as described in claim 1, characterized in that, Including transient icing tests, including the following steps: S1, the fuel stored in the fuel storage unit is conditioned to reach the first set temperature through the circulation control and heat exchange unit; S2, the subcooled water manufacturing unit generates subcooled water at a set temperature, and injects the set amount of subcooled water into the subcooled water and fuel collision unit that stores fuel. S3, fuel from the fuel storage unit is delivered to the ejector pump through the circulation control and heat exchange unit, and fuel containing subcooled water is delivered to the ejector pump through the subcooled water and fuel collision unit. The subcooled water forms ice and enters the engine inlet pipe along with the fuel through the ejector pump. S4, the engine operates under the most severe transient icing condition, and relevant operating parameters of the engine are monitored.

14. The method for testing icing of an aircraft engine fuel system as described in claim 13, characterized in that, It also includes a steady-state icing test, which includes the following steps: T1 adjusts the temperature of the fuel stored in the fuel storage unit to reach the second set temperature through the circulation control and heat exchange unit. T2, the supercooled water manufacturing unit generates liquid water at a set temperature and injects it into the supercooled water and fuel collision unit. The supercooled water and fuel collision unit fully mixes the liquid water and fuel into an oil-water emulsion. The supercooled water and fuel collision unit then transports the oil-water emulsion with a set water content to the fuel storage unit through the fuel pipeline. T3 uses a circulation control and heat exchange unit to circulate and cool the fuel containing oil and water emulsion stored in the fuel storage unit to reach the third set temperature. T4, through the circulation control and heat exchange unit, delivers the water-containing fuel from the fuel storage unit to the ejector pump, and then enters the inlet pipe of the engine through the ejector pump; T5, the engine operates under the most severe steady-state icing condition, and relevant operating parameters of the engine are monitored.

15. The method for testing icing of an aircraft engine fuel system as described in claim 14, characterized in that, In step T2, the liquid water and fuel oil are stirred and thoroughly mixed to form an oil-water emulsion.

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