Electric heating anti-icing system and aero-engine

Abstract

The electric heating anti-icing system is used for preventing the front edge of an air inlet channel of an engine from being frozen and comprises a plurality of heating electronic elements, a generator, a first switch, a temperature control switch and a controller, and the heating electronic elements are arranged on the front edge of the air inlet channel and used for generating heat; the generator is electrically connected with the heating electronic element; the first switch is arranged between the heating electronic element and the generator, the temperature control switch is arranged at the front edge of the air inlet channel, and a temperature sensor and a second switch are arranged in the temperature control switch; the controller is electrically connected with the temperature control switch and the first switch and used for judging the size relation between the temperature value transmitted by the temperature sensor and the low-temperature threshold value and the high-temperature threshold value so as to control on-off of the first switch and the temperature control switch. The electric heating anti-icing system has a simple and safe structure. The utility model further provides an aero-engine comprising the system.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of aero-engine, specifically relates to the field of deicing and anti-icing. BACKGROUND

[0002] The leading edge area of the inlet duct of an aero-engine is prone to ice accumulation. Ice formation can cause airflow separation and unstable engine operation, and in severe cases, the ice that falls off can be sucked into the engine, causing engine component damage and possibly leading to flight accidents.

[0003] Currently, most of the inlet duct deicing systems for civil aviation engines use hot air for deicing, and the hot air generally comes from the high-pressure compressor of the engine. With this bleed air design, the pipeline is relatively long, starting from the core cabin of the engine, passing through the fan cabin and the inlet duct cavity, and extending to the inlet duct. Since the pipeline or the connection position of the pipeline is prone to breakage, there is an urgent need for a safer anti-icing system. SUMMARY

[0004] An object of the utility model is to provide an electric heating anti-icing system with a simple and safe structure.

[0005] To achieve the above-mentioned purpose, the electric heating anti-icing system for preventing icing of the leading edge of the engine inlet duct comprises a plurality of heating electronic elements, a generator, a first switch, a temperature control switch, and a controller. The plurality of heating electronic elements are arranged at the leading edge of the inlet duct to generate heat. The generator is electrically connected to the heating electronic elements. The first switch is arranged between the heating electronic elements and the generator. The temperature control switch is arranged at the leading edge of the inlet duct and has a built-in temperature sensor and a second switch. The controller is electrically connected to the temperature control switch and the first switch, and is used to determine the size relationship between the temperature value transmitted by the temperature sensor and the low temperature threshold value and the high temperature threshold value, and then control the opening and closing of the first switch and the temperature control switch.

[0006] In one or more embodiments, the controller is used to determine the size relationship between the temperature value and the low temperature threshold value, and then control the opening and closing of the first switch, and to determine the size relationship between the temperature value and the high temperature threshold value, and then control the opening and closing of the second switch.

[0007] In one or more embodiments, the controller and the generator are arranged in the fan cabin.

[0008] In one or more embodiments, each of the heating electronic elements is uniformly arranged circumferentially along the inlet duct.

[0009] In one or more embodiments, the system includes a plurality of temperature control switches, each arranged adjacent to a respective heating electronic element.

[0010] In one or more embodiments, the first switch is disposed within a fan bay or an inlet duct bay.

[0011] In one or more embodiments, the first switch is an electromagnetic relay.

[0012] In one or more embodiments, the second switch is a temperature relay.

[0013] In one or more embodiments, the lip of the inlet duct leading edge includes a glass cloth layup stack region, and the electronic component is a resistance wire embedded in the glass cloth.

[0014] Another object of the present application is to provide an aero-engine comprising the above electric heating anti-icing system, and further comprising an electronic engine controller, wherein the controller of the electric heating anti-icing system is signal connected with the electronic engine controller.

[0015] The above electric heating anti-icing system realizes the anti-icing function by heating the engine leading edge skin using the heating electronic component located at the inlet duct leading edge; a temperature sensor is arranged in the icing area of the engine leading edge skin to detect the temperature signal and feed back to the anti-icing system controller for high or low temperature adjustment, thereby avoiding the cold and hot alternating transformation of the structure subjected to hot air heating in the flight cycle of the aircraft, and significantly improving the safety of the system. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other features, properties, and advantages of the present application will become more apparent by describing in detail the following embodiments with reference to the attached drawings, in which:

[0017] Figure 1 is a schematic diagram of the electric heating anti-icing system;

[0018] Figure 2 is a circuit schematic diagram of the electric heating anti-icing system;

[0019] Figure 3 is a schematic diagram of the glass cloth layup stack region;

[0020] Figure 4 is a schematic diagram of the inlet duct leading edge lip. DETAILED DESCRIPTION

[0021] The present application will be further described below with reference to the specific embodiments and the accompanying drawings, and more details are set forth in the following description in order to fully understand the present application, but it is obvious that the present application can be implemented in many other ways different from the description, and those skilled in the art can make similar generalizations and deductions according to the actual application without departing from the connotation of the present application, therefore the protection scope of the present application should not be limited by the content of the specific embodiments.

[0022] It should be noted that these and other subsequent drawings are only as examples, which are not drawn in proportion, and should not be used as a limitation on the actual protection required by the utility model.

[0023] The leading edge area of the air intake of the aero-engine is prone to ice accumulation, mainly due to the icing of supercooled water droplets in the cloud and precipitation on the surface of the air intake lip, or the direct sublimation of water vapor in the air on the surface of the lip. When flying under continuous maximum icing conditions and intermittent maximum icing conditions, the leading edge of the engine nacelle is prone to icing due to the collection of water in the atmosphere.

[0024] Icing can cause airflow separation and unstable engine operation, and in severe cases, the ice blocks that fall off can cause damage to engine components, which can cause flight accidents. When the leading edge of the air intake is iced, the air intake area is reduced, the air intake flow is reduced, and the engine thrust is reduced. In order to maintain engine thrust, the fuel supply needs to be increased, thereby increasing the turbine inlet temperature and shortening the service life of the engine. In addition, the ice that falls off from the air intake lip can be sucked into the engine and hit the fan blades, causing serious consequences. Therefore, the ice protection device of the air intake becomes indispensable, and it needs to protect the air intake lip from icing during the flight of the aircraft.

[0025] The currently active engines all use the method of heating the icing area structure to prevent icing. There are two forms of heating methods: hot gas anti-icing and electric heating anti-icing. Hot gas anti-icing is to introduce high-temperature and high-pressure gas from the engine high-pressure compressor to the icing area. For example, the high-temperature and high-pressure gas passes through the flow regulator and the valve, enters the D-shaped cavity of the air intake, and the D-shaped cavity is designed with a flute-shaped pipe, and a plurality of small holes are arranged on the flute-shaped pipe. The high-temperature gas is sprayed to the inner surface of the leading edge of the air intake, and the leading edge skin is heated. In order to introduce gas from the engine high-pressure compressor, a relatively long pipeline needs to be designed, which extends from the engine core compartment, passes through the fan compartment and the air intake cavity, and extends to the D-shaped cavity of the air intake. Due to the need for flow regulators, valves and pipelines to pass through the partition frame of the nacelle components, connection joints are designed on the pipeline, and there is a risk of pipeline rupture near the joint during engine operation, and the introduction of hot gas from the engine high-pressure compressor also causes a loss of engine thrust performance.

[0026] In addition, the flute-shaped pipe of the traditional gas anti-icing scheme is a whole annular pipe. In order to allow the pipeline to freely expand and reduce structural thermal stress, a bellows and a connecting rod with a ball hinge are usually designed on the pipeline to fix the flute-shaped pipe, and in the use process, there are problems of high structural vibration stress level and low service life.

[0027] Based on this problem, the present disclosure proposes a safer electric heating anti-icing system, which refers to Figure 1 and Figure 2It is understood that the heating electronic element 26, the temperature control switch 25, the generator 22, the first switch 24 and the controller 23 are included.

[0028] The heating electronic element 26 is arranged at the leading edge of the air inlet duct for generating heat, such as a resistance wire heating element, a carbon fiber heating element, etc.

[0029] In the electric heating anti-icing scheme, the leading edge lip 201 of the air inlet duct includes a glass cloth layer stack area, which is stacked with glass cloth 2011 layers, as shown in Figure 3 The electronic element 26 can be a resistance wire embedded in the glass cloth layer stack. The electronic element of the electric heating anti-icing system can be arranged in parallel, series or mixed series-parallel at the lip.

[0030] The generator 22 is electrically connected to the heating electronic element 26, and the first switch 24 is arranged between the heating electronic element 26 and the generator 22, as shown in Figure 2 The first switch 24 can be arranged both outside the air inlet duct rear bulkhead 42 (in the fan compartment P3) and inside the air inlet duct compartment P2. The first switch 24 can be an electromagnetic relay. By arranging the generator, the heating anti-icing system does not need to draw air from the engine, so there is no need to arrange anti-icing equipment in the core engine compartment P4, and there is no need to design pipeline and control valve elements in the structure, avoiding high-temperature and high-pressure gas leakage and pipeline burst during engine operation, reducing the thermal insulation requirements of the structure, such as not designing fan compartment, anti-icing pipeline and air inlet duct wall panels, etc., thereby simplifying the structure and improving the safety and reliability of the structure.

[0031] In addition, the electric anti-icing system has high heat energy utilization rate. The efficiency of the generator for the heating function of the electronic element can reach more than 95%, and the loss is only the loss of the wire resistance heating. The efficiency of the heated electronic element converting heat energy to supply the engine air inlet duct leading edge skin is related to the flight state, and the heat energy efficiency can usually reach 80%, so the thermal efficiency of the electric anti-icing system is about 76%. To achieve the same anti-icing effect, the hot gas anti-icing system needs about 1.5 times the energy of the anti-icing system.

[0032] The heating area A of the anti-icing cavity P1 is arranged with a temperature control switch 25 as needed. The temperature control switch 25 includes a temperature sensor 251 and a second switch 252, which can sense temperature and trigger switch action when the set threshold is reached, so the temperature control switch 25 has the functions of monitoring temperature, feeding back overheating alarm and triggering switch action. The second switch 252 includes but is not limited to a temperature relay. The working principle of the temperature relay is usually based on a temperature-sensitive element to sense temperature changes, drive the switch action of the relay to cut off or connect the circuit, and then control the working or off state of each heating electronic element 26.

[0033] In some embodiments, the plurality of heating electronic elements 26 are arranged evenly along the circumference of the air intake duct, and the engine front edge is heated in sections. The temperature control switch 25 is arranged adjacent to each heating electronic element 26. Each electronic element is controlled by an independent temperature control switch 25, and the temperature control switch 25 is controlled by the controller 23. The temperature control switch 25 detects each section of the air intake duct, and generates an alarm signal when the local area overheats.

[0034] The system further comprises a controller 23, which is electrically connected to the temperature control switch 25 and the first switch 24. The controller 23 determines the size relationship between the temperature value transmitted by the temperature sensor and the low temperature threshold and the high temperature threshold, and controls the opening and closing of the temperature relay and the electromagnetic relay.

[0035] Specifically, the controller 23 determines the size relationship between the temperature value and the low temperature threshold T min , and controls the opening and closing of the first switch 24. At this time, the controller plays a role in preventing icing. When the engine front edge is in icing conditions, the controller 23 sends a signal, and the first switch 24 in the open state is closed. The circuit of the wire 31 from the generator 22 to the heating electronic element 26 is connected. The heating electronic element 26 continuously heats the icing area A of the engine front edge. When there is no icing condition, the first switch 24 is open, the circuit of the wire 31 from the generator 22 to the heating electronic element 26 is disconnected, and the heating electronic element 26 stops working.

[0036] The controller 23 also determines the size relationship between the temperature value and the high temperature threshold T max , and controls the opening and closing of the second switch 252. The second switch can be a temperature relay. When the temperature sensor 251 detects that the temperature of a local area heated by icing is too high, the relay switch embedded in the temperature control switch 25 automatically opens, the heating circuit from the generator to the heating electronic element 26 of the area is disconnected, and the area stops heating. When the temperature of the area drops to the icing condition and needs to be heated again for deicing, the branch circuit temperature control switch 25 automatically closes, and is connected to the generator 22 to supply power to the electronic element to heat and achieve deicing. In this way, when a certain area has icing conditions and is not overheated, only the electronic element in the specific area is conductive, and the precise position control of the icing area heating is achieved.

[0037] In some embodiments, the controller 23 is also connected to the signal of the electronic engine controller 21 (Engine Electronic Control, EEC) of the aero-engine.

[0038] The components are connected by wires 31. The wires include three parts of wires 31a, 31b, and 31c. The wire 31c is fixed on the front bulkhead 41 of the air intake duct 40 by high-temperature-resistant glue or welding.

[0039] Further, the electronic engine control system 21 and the controller 23 are installed in the fan cabin P2, and the generator 22 is installed in the area of the fan case P5. The generator 22 generates heat during operation, and therefore the generator 22 is arranged away from the EEC and the controller, so as to avoid the heat generated after the operation of the generator from affecting the normal operation of the engine electronic controller and the controller 23.

[0040] The system has the following advantages:

[0041] (1) The electronic heating component is used for deicing, and the electric anti-icing system does not need to arrange equipment in the core engine cabin area, and the working environment is in the cold end area of the engine, which can significantly improve the safety;

[0042] (2) The icing area is divided into several areas by the electronic heating components and temperature sensors and temperature relays arranged in the leading edge of the air inlet, so that the entire engine leading edge can be heated for anti-icing, and part of the icing area can be heated for deicing, so that the system has great flexibility;

[0043] (3) The controller is used to control the heating time and heating frequency of each subarea, so that the energy can be more reasonably distributed, the energy waste can be reduced, and the thermal efficiency of the system can be improved;

[0044] (4) Through the cooperation of the temperature sensor, the temperature relay, the electromagnetic relay and the controller, the system has high-temperature and low-temperature detection and alarm functions, so that the system can be heated for deicing when there is icing condition in a certain area, and the heating can be stopped when the temperature of a certain area is too high, so as to avoid the problem of structural damage caused by the cold and hot alternating transformation of the structure subjected to hot air heating in the flight cycle of the aircraft, and further improve the energy utilization rate.

[0045] In combination with the introduction of the above-mentioned electric heating anti-icing system, an aero-engine including the system can also be connected.

[0046] It should be noted that the terms "first", "second", etc. used to limit parts are only used to facilitate the differentiation of the corresponding parts, and the above terms have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the protection scope of the present application.

[0047] Meanwhile, specific terms are used in the present application to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" means a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "one alternative embodiment" mentioned in different positions in the specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be properly combined.

[0048] The utility model discloses although the above-mentioned preferable embodiment is disclosed, but it is not used to limit the utility model, and any person skilled in the art can make possible change and modification without departing from the spirit and scope of the utility model. Therefore, all the contents without departing from the technical scheme of the utility model, according to the technical essence of the utility model, any modification, equivalent change and modification of the above embodiment, all fall into the protection scope defined in the utility model claim.

Claims

1. An electrically heated anti-icing system for preventing icing of the leading edge of an engine inlet duct, characterised in that, The system comprises: a plurality of heating electronic elements arranged at the leading edge of the air inlet duct for generating heat; a generator electrically connected to the heating electronic elements; a first switch arranged between the heating electronic elements and the generator; a temperature control switch arranged at the leading edge of the air inlet duct, which is internally provided with a temperature sensor and a second switch; and a controller electrically connected to the temperature control switch and the first switch, which is used to determine the size relationship between the temperature value transmitted by the temperature sensor and the low temperature threshold value and the high temperature threshold value, and then control the opening and closing of the first switch and the temperature control switch.

2. The electrically heated ice protection system of Claim 1, wherein, The controller is used to determine the size relationship between the temperature value and the low temperature threshold value, and then control the opening and closing of the first switch, and determine the size relationship between the temperature value and the high temperature threshold value, and then control the opening and closing of the second switch.

3. The electrically heated ice protection system of Claim 1, wherein, The controller and the generator are arranged in the fan cabin.

4. The electrically heated ice protection system of Claim 1, wherein, Each of the heating electronic elements is uniformly arranged circumferentially along the air inlet duct.

5. The electrically heated ice protection system of Claim 1, wherein, The system comprises a plurality of temperature control switches, each of which is arranged adjacent to each of the heating electronic elements.

6. The electrically heated ice protection system of Claim 1, wherein, The first switch is arranged in the fan cabin or the air inlet duct cabin.

7. The electrically heated ice protection system of Claim 1, wherein, The first switch is an electromagnetic relay.

8. The electrically heated ice protection system of Claim 1, wherein, The second switch is a temperature relay.

9. The electrically heated ice protection system of Claim 1, wherein, The lip of the leading edge of the air inlet duct comprises a glass cloth layer stacking area, and the electronic component is a resistance wire embedded in the glass cloth.

10. An aeroengine characterised in that, The system comprises the electric heating anti-icing system according to any one of claims 1-9, and further comprises an electronic engine controller, and the controller of the electric heating anti-icing system is signal connected to the electronic engine controller.

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