Air inlet anti-icing system for airplane auxiliary power device and airplane auxiliary power device

Abstract

The utility model provides an air inlet anti-icing system for an airplane auxiliary power device, which is used for heating and deicing the airplane auxiliary power device so as to improve the running reliability and performance of the airplane auxiliary power device in a high and cold low-temperature environment without increasing the complexity of the airplane auxiliary power device basically. The airplane auxiliary power device comprises an air inlet channel, an air collecting cavity and an air entraining outlet, the air inlet anti-icing system comprises a heat exchange pipeline arranged around the air inlet channel and / or the air collecting cavity, the heat exchange pipeline is connected with the air entraining outlet, and air flowing out of the air entraining outlet can flow through the heat exchange pipeline. The utility model further provides an airplane auxiliary power device comprising the air inlet anti-icing system, and the air inlet anti-icing system can heat and deice the airplane auxiliary power device so as to improve the reliability and the performance of the airplane auxiliary power device in the high-cold and low-temperature environment.

Description

Technical Field

[0001] The utility model relates to the field of aviation aircraft, in particular to an aircraft auxiliary power unit, and more particularly to an air intake anti-icing system for the aircraft auxiliary power unit. Background Art

[0002] The APU is a critical, independent system on an aircraft. It's primarily used to start the main engines on the ground and provide bleed air and power to the aircraft's air conditioning system and electrical equipment, both on the ground and in flight. Because the APU doesn't generate thrust, it significantly reduces fuel consumption compared to the main engines, saving fuel and reducing noise.

[0003] Generally speaking, an aircraft's auxiliary power unit (APU) is primarily used on the ground and ceases operation after takeoff. However, if an aircraft encounters an engine failure during flight, such as when the main engine shuts down mid-flight, the APU can restart the aircraft, providing air or electricity to restart the engine.

[0004] Therefore, the aircraft auxiliary power unit is an important guarantee for the normal operation of the aircraft.

[0005] Civil transport aircraft require the APU to operate reliably in cold and low-temperature environments in many operational scenarios, such as operating at high-latitude, cold airports or starting the APU in mid-flight in the event of an engine failure at high altitude. In these cold and low-temperature environments, ice can accumulate in the APU's air inlet, contaminating the APU with dry / wet snow, mixed ice crystals, and supercooled water droplets. These conditions can prevent the APU from starting properly, leading to surge, flameout, or automatic shutdown. In severe cases, they can cause structural damage to critical APU structures such as the core compressor and inlet guide vanes. These factors can degrade the APU's operating performance and, in severe cases, lead to APU failure and loss of power and air supply. If the APU cannot be started in mid-flight due to air inlet icing, the aircraft's safety in emergency scenarios, such as a main engine shutdown in mid-flight, is significantly compromised.

[0006] Existing aircraft lack an air intake anti-icing system for their auxiliary power units (APUs). Prolonged exposure of the APU's dampers to light snow, moderate snow, or other cold and low-temperature conditions can restrict their operation. For example, when starting the APU at cold airports or at high altitudes, ice in the air intake can prevent the unit from starting or operating properly.

[0007] Therefore, it is necessary to invent an air intake anti-icing system for an aircraft auxiliary power unit to improve the reliability and performance of the aircraft auxiliary power unit in high and low temperature environments. Utility Model Content

[0008] To address the problems of the prior art, the present invention proposes an air intake anti-icing system for an aircraft auxiliary power unit (APU). The system heats and de-ices the APU, thereby improving the APU's reliability and performance in cold and low-temperature environments without substantially increasing the APU's complexity. The present invention also proposes an APU including an APU. The APU's air intake anti-icing system is capable of heating and de-icing the APU, thereby improving its reliability and performance in cold and low-temperature environments without substantially increasing its complexity.

[0009] Therefore, in a first aspect of the present invention, an air intake anti-icing system for an aircraft auxiliary power unit is proposed. The aircraft auxiliary power unit includes an air intake duct, an air collecting chamber and an air bleed outlet. The system is characterized in that the air intake anti-icing system includes a heat exchange pipeline arranged around the air intake duct and / or the air collecting chamber, and the heat exchange pipeline is connected to the air bleed outlet so that the gas flowing out of the air bleed outlet flows into the heat exchange pipeline.

[0010] According to the above technical solution, the air intake anti-icing system of the utility model can achieve the following beneficial effects: it can heat and de-ice the flight auxiliary power unit to improve the reliability and performance of the aircraft auxiliary power unit in high-cold and low-temperature environments, while basically not increasing the complexity of the aircraft auxiliary power unit.

[0011] In a preferred embodiment of the present invention, a one-way valve is provided on the heat exchange pipeline of the intake anti-icing system, and the one-way valve is located downstream of the intake duct and the air collecting cavity.

[0012] According to the above technical solution, the air intake anti-icing system of the present invention can achieve the following beneficial effects: it can prevent the backflow of gas flowing out of the heat exchange pipeline.

[0013] In a preferred embodiment of the present invention, the air intake anti-icing system includes a control module configured to adjust the flow of gas flowing through the heat exchange pipeline.

[0014] According to the above technical solution, the intake anti-icing system of the utility model can achieve the following beneficial effects: it can regulate the gas flow flowing through the heat exchange pipeline, improve the efficiency of the intake anti-icing system, and avoid overheating of the intake duct and / or the air collecting cavity.

[0015] In a preferred embodiment of the present invention, the control module of the intake anti-icing system includes a control unit, a control valve, and a temperature sensor located upstream of the control valve. The control unit is configured to adjust the control valve based on a temperature value measured by the temperature sensor.

[0016] According to the above technical solution, the intake anti-icing system of the utility model can achieve the following beneficial effects: it can regulate the gas flow flowing through the heat exchange pipeline, improve the efficiency of the intake anti-icing system, and avoid overheating of the intake duct and / or the air collecting cavity.

[0017] In a preferred embodiment of the present invention, the opening of the control valve is variable to adjust the gas flow through the heat exchange pipeline.

[0018] According to the above technical solution, the intake anti-icing system of the utility model can achieve the following beneficial effects: it can regulate the gas flow flowing through the heat exchange pipeline, improve the efficiency of the intake anti-icing system, and avoid overheating of the intake duct and / or the air collecting cavity.

[0019] In a preferred embodiment of the present invention, a heat insulation layer is arranged on the heat exchange pipeline.

[0020] According to the above technical solution, the air intake anti-icing system of the utility model can achieve the following beneficial effects: it can prevent the air intake duct and / or the air collecting chamber from overheating, avoid premature aging of the materials of the air intake duct and / or the air collecting chamber, and extend the service life of the air intake duct and / or the air collecting chamber.

[0021] In a preferred embodiment of the present invention, the material of the heat insulation layer includes ceramic fiber or rubber foam filler.

[0022] According to the above technical solution, the air intake anti-icing system of the utility model can achieve the following beneficial effects: it can prevent the air intake duct and / or the air collecting chamber from overheating, avoid premature aging of the materials of the air intake duct and / or the air collecting chamber, and extend the service life of the air intake duct and / or the air collecting chamber.

[0023] In a preferred embodiment of the present invention, the heat insulation layer is only arranged between the heat exchange pipeline and the air inlet and / or the air collecting cavity.

[0024] According to the above technical solution, the air intake anti-icing system of the present invention can achieve the following beneficial effects: only necessary insulation layers are arranged, which can save costs and reduce the weight of the air intake anti-icing system.

[0025] In a preferred embodiment of the present invention, the air intake anti-icing system further comprises an ejector pump circuit configured to guide the gas flowing out of the heat exchange pipeline into the main flow of bleed air of the aircraft auxiliary power unit.

[0026] According to the above technical solution, the air intake anti-icing system of the present invention can achieve the following beneficial effects: the gas with reduced temperature flowing out of the heat exchange pipeline is guided to the main bleed air stream, which can improve the bleed air utilization efficiency of the aircraft auxiliary power unit.

[0027] In a second aspect of the present invention, an aircraft auxiliary power unit is provided, comprising the air intake anti-icing system according to the first aspect.

[0028] According to the above technical solution, the aircraft auxiliary power unit of the utility model can achieve the following beneficial effects: the air intake anti-icing system can heat and de-ice the aircraft auxiliary power unit to improve the reliability and performance of the aircraft auxiliary power unit in high-cold and low-temperature environments.

[0029] It should be understood that the above summary is provided to introduce a selection of concepts further described in the detailed description in a simplified form. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined solely by the appended claims. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further features and exemplary embodiments and advantages of the present invention are explained in more detail below with reference to the accompanying drawings. It will be understood that this embodiment is not exhaustive of the full scope of the present invention. It will be further understood that some or all of the features described below may also be combined in other ways, including:

[0031] Figure 1 A schematic diagram of the framework of an air intake anti-icing system for an aircraft auxiliary power unit according to the present invention is shown;

[0032] Figure 2 A three-dimensional schematic diagram of an air intake anti-icing system for an aircraft auxiliary power unit according to the present invention is shown.

[0033] Reference Signs List

[0034] 100 Air intake anti-icing system;

[0035] 101 heat exchange pipeline;

[0036] 101a Insulation layer;

[0037] 102 bleed air outlet;

[0038] 103 air intake;

[0039] 104 gas collection chamber;

[0040] 105 control valve;

[0041] 106 temperature sensor;

[0042] 107 control unit;

[0043] 108 one-way valve;

[0044] 109 ejector pump;

[0045] 110 air conditioning system;

[0046] 111 upstream pipeline;

[0047] 112 downstream pipeline;

[0048] 115 control module. DETAILED DESCRIPTION

[0049] The present invention is described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the present invention are described. Obviously, all features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes, that is, unless otherwise described, each feature is only an example of a series of equivalent or similar features. The technical solution of the present invention is described in many aspects below in conjunction with the figures and embodiments.

[0050] In this document, serial numbers such as "first" and "second" do not represent order (for example, do not imply a precedence relationship unless explicitly stated) or priority or importance. The above serial numbers are only used to indicate that they are different and independent devices, elements or steps.

[0051] In this document, the terms "inside", "outside", "inward", "outward", "proximal", "distal", etc. are only used to describe the relative positions of various elements.

[0052] Figure 1 FIG. 1 shows a schematic diagram of a frame of an air intake anti-icing system 100 for an aircraft auxiliary power unit according to the present invention, wherein arrows show the direction of gas flow in the air intake anti-icing system 100. Figure 2 FIG2 shows a perspective schematic diagram of an air inlet anti-icing system 100. The air inlet anti-icing system 100 is particularly used for an aircraft auxiliary power unit and can heat and de-ice the aircraft auxiliary power unit, and more specifically, can heat and de-ice the air inlet duct 103 and / or the plenum 104 of the aircraft auxiliary power unit.

[0053] The aircraft auxiliary power unit includes an air intake duct 103 and an air collecting chamber 104. The air intake duct 103 of the aircraft auxiliary power unit can be used to introduce external air into the interior of the aircraft auxiliary power unit, thereby burning fuel in the combustion chamber to generate power. In high-altitude and low-temperature environments, the external air entering the air intake duct 103 may carry low-temperature water vapor and / or ice particles. The air collecting chamber 104 of the aircraft auxiliary power unit can be used to collect the external air entering through the air intake duct 103, rectify the external air entering the aircraft auxiliary power unit, reduce the turbulence and eddy currents of the airflow, provide the aircraft auxiliary power unit with sufficient air flow for combustion and power generation, and improve the efficiency of the aircraft auxiliary power unit. In addition, the air collecting chamber 104 can also help reduce the noise generated by the aircraft auxiliary power unit during operation and improve the acoustic environment inside the aircraft. A filter can be set in the air collecting chamber 104 to filter foreign matter from the external air entering the aircraft auxiliary power unit, helping to protect the aircraft auxiliary power unit from direct impacts of the external environment. In a cold and low-temperature environment, the external air entering the air inlet 103 and the air collecting cavity 104 may carry low-temperature water vapor and / or ice particles, which may cause ice to form in the air inlet 130 and / or the air collecting cavity 104, affecting the normal operation of the aircraft auxiliary power unit.

[0054] The aircraft auxiliary power unit further includes a load compressor and a bleed air outlet 102 for the load compressor. The load compressor can be used to compress air entering the aircraft auxiliary power unit and discharge the compressed gas through the bleed air outlet 102 to drive the air conditioning system 110.

[0055] The air intake anti-icing system 100 includes a heat exchange line 101 arranged around the air intake duct 103 and / or the plenum 104. Preferably, the heat exchange line 101 is arranged around the air intake duct 103 and the plenum 104. More preferably, the heat exchange line 101 contacts the air intake duct 103 and the plenum 104, thereby exchanging heat with the air intake duct 103 and the plenum 104 to transfer heat from the fluid within the heat exchange line 101 to the air intake duct 103 and the plenum 104. In such a manner, in a high-altitude, low-temperature environment, the heat transferred from the heat exchange line 101 to the air intake duct 103 and the plenum 104 can remove low-temperature water vapor or ice particles from the external air entering the air intake duct 103 and the plenum 104, or regulate the external air temperature.

[0056] The heat exchange line 101 of the air intake anti-icing system 100 is connected to the bleed air outlet 102 of the aircraft's auxiliary power unit. This allows the compressed gas flowing out of the bleed air outlet 102 to flow through the heat exchange line 101, acting as a heat exchange fluid between the air intake duct 103 and the plenum chamber 104. In cold and low-temperature environments, the compressed gas flowing out of the bleed air outlet 102 is relatively hot. When this hot compressed gas flows through the heat exchange line 101, its heat is transferred to the air intake duct 103 and the plenum chamber 104, removing cold water vapor or ice particles from the air outside the air intake duct 103 and the plenum chamber 104, or regulating the outside air temperature.

[0057] In particular, the compressed gas temperature at the bleed air outlet 102 under different working conditions is shown in Table 1 below:

[0058]

[0059] Table 1 causes the temperature at the outlet 102 under different working conditions

[0060] As shown in Table 1, the temperature of the compressed gas at the bleed air outlet 102 is generally above 150°C.

[0061] The air inlet duct 103 and the plenum chamber 104 can be made of metal or a composite material containing a composite material and a honeycomb core. In particular, for air inlet ducts 103 and plenum chamber 104 made of composite materials, since the maximum long-term operating temperature of the honeycomb core is 150°C, overheating protection of the air inlet duct 103 and / or plenum chamber 104 surrounded by the heat exchange pipe 101 is necessary to prevent premature aging of the materials of the air inlet duct 103 and / or plenum chamber 104 and extend their service life.

[0062] In a preferred embodiment, a thermal insulation layer 101a is disposed on the heat exchange piping 101 of the air inlet anti-icing system 100 to protect the air inlet duct 103 and / or the plenum chamber 104 from overheating and extend their service life. More preferably, the thermal insulation layer 101a is disposed only between the heat exchange piping 101 and the air inlet duct 103 and / or the plenum chamber 104 to save costs. The thermal insulation layer is preferably ceramic fiber or rubber foam filler, but other commonly used aircraft insulation materials may also be used.

[0063] In a preferred embodiment, the intake anti-icing system 100 includes a control module 115 located on the heat exchange line 101. For example, the control module 115 may be located upstream of the intake duct 103 and the plenum 104. The control module 115 is capable of regulating the flow of compressed gas through the heat exchange line 101, improving the efficiency of the intake anti-icing system 100 and preventing overheating of the intake duct 103 and / or the plenum 104. Specifically, the control module 115 includes a control unit 107, a control valve 105, and a temperature sensor 106 located upstream of the control valve 105. The opening of the control valve 105 is variable or adjustable, thereby adjusting the flow of gas into the heat exchange line 101. The temperature sensor 106 can be used to monitor the gas temperature upstream of the control valve 105 and send the gas temperature value to the control unit 107. Control unit 107 is configured to adjust control valve 105 based on the temperature value measured by temperature sensor 106 to adjust the gas flow in heat exchange line 101, thereby improving the efficiency of intake anti-icing system 100 and preventing overheating of intake duct 103 and / or plenum 104.

[0064] The air intake anti-icing system 100 also includes a one-way valve 108 arranged on the heat exchange pipeline 101. In the exemplary structure shown in the figure, the one-way valve 108 is located downstream of the air intake duct 103 and the gas collecting chamber 104, for example. It can prevent the gas in the heat exchange pipeline 101 from flowing back and affecting the efficiency of the air intake anti-icing system 100.

[0065] Inlet air anti-icing system 100 also includes an ejector pump circuit 109, which is configured to direct the gas exiting heat exchange line 101 back into the main bleed air stream of the aircraft's auxiliary power unit, thereby driving air conditioning system 110. The gas exiting heat exchange line 101 releases heat, reducing its temperature. Therefore, its return to the main bleed air stream of the aircraft's auxiliary power unit improves the inlet airflow parameters of air conditioning system 110, enhancing its performance and, to a certain extent, reducing the likelihood of ground overheating of air conditioning system 110.

[0066] In summary, the air intake anti-icing system 100 according to the present invention has the following beneficial effects:

[0067] 1. Using the bleed air of the aircraft auxiliary power unit as a heat source to provide de-icing heating function for the intake air of the aircraft auxiliary power unit can add the de-icing function without basically increasing the complexity of the system, which can greatly improve the reliability of the aircraft auxiliary power unit in high-altitude and low-temperature environments.

[0068] 2. The variable opening control valve 105 and the heat insulation layer 101a are used to protect the heat exchange object, and the material properties of the air inlet duct 103 and the air collecting cavity 104 are fully considered to make the operation of the aircraft auxiliary power unit more reliable.

[0069] 3. Use the one-way valve 108 and the ejector pump circuit 109 to collect and reuse the gas after heat exchange, reducing the impact on the bleed air performance of the aircraft auxiliary power unit. In addition, the ejector pump circuit 109 avoids the need to set up an additional power source and does not require additional energy consumption.

[0070] 4. It can also actively adjust the temperature of the external air entering the aircraft's auxiliary power unit (APU) to match its operating characteristics, thereby improving its operating efficiency. The temperature of the air flowing through heat exchange pipe 101 decreases, and thus, upon returning to the APU's main bleed air stream, it improves inlet airflow parameters, enhancing the performance of air conditioning system 110 and, to a certain extent, reducing the likelihood of ground-level overheating of APU 110.

[0071] As used herein, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, structure, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, structure, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises..." does not preclude the presence of additional identical elements in the process, method, structure, or apparatus that includes the element.

[0072] The description of the utility model is provided for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the disclosed form. Many modifications and variations will be apparent to those skilled in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the utility model and to enable those skilled in the art to understand the utility model and design various embodiments with various modifications suitable for specific applications.

Claims

1. An air intake anti-icing system for an aircraft auxiliary power unit, the aircraft auxiliary power unit comprising an air intake duct, an air collecting cavity and an air bleed outlet, characterized in that: The air intake anti-icing system includes a heat exchange pipeline arranged around the air intake duct and / or the air collecting cavity, and the heat exchange pipeline is connected to the bleed air outlet so that the gas flowing out of the bleed air outlet flows into the heat exchange pipeline.

2. The air intake anti-icing system according to claim 1, characterized in that: A one-way valve is provided on the heat exchange pipeline of the intake anti-icing system, and the one-way valve is located downstream of the intake duct and the air collecting cavity.

3. The air intake anti-icing system according to claim 1, characterized in that: The air intake anti-icing system includes a control module configured to adjust a gas flow rate flowing through the heat exchange line.

4. The air intake anti-icing system according to claim 3, characterized in that: The control module of the intake air anti-icing system includes a control unit, a control valve, and a temperature sensor located upstream of the control valve. The control unit is configured to adjust the control valve based on a temperature value measured by the temperature sensor.

5. The air intake anti-icing system according to claim 4, characterized in that: The opening of the control valve is variable to adjust the gas flow through the heat exchange pipeline.

6. The air intake anti-icing system according to claim 1, characterized in that: A heat insulation layer is arranged on the heat exchange pipeline.

7. The air intake anti-icing system according to claim 6, characterized in that: The material of the heat insulation layer includes ceramic fiber or rubber foam filler.

8. The air intake anti-icing system according to claim 6, characterized in that: The heat insulation layer is only arranged between the heat exchange pipeline and the air inlet duct and / or the air collecting cavity.

9. The air intake anti-icing system according to claim 1, characterized in that: The air inlet anti-icing system further includes an ejector pump circuit configured to guide the gas flowing out of the heat exchange line into the main bleed air flow of the aircraft auxiliary power unit.

10. An aircraft auxiliary power unit comprising the air inlet anti-icing system according to any one of claims 1 to 9.

Images