An anti-icing system for a turboshaft engine

Abstract

The application relates to an anti-icing system of a turboshaft engine, which comprises an air bleed port, an anti-icing valve, a heat exchange device and an engine air intake casing which are sequentially communicated through pipelines; the air bleed port is communicated with an exhaust port of the turboshaft engine to introduce hot air flow discharged by the turboshaft engine into the pipeline, the turboshaft engine comprises a fuel system, and the fuel system comprises the heat exchange device; the engine air intake casing comprises an air inlet channel, the hot air flow heats and warms the engine air intake casing through the air inlet channel, the air inlet channel comprises an air inlet and an air outlet, the air inlet is communicated with the heat exchange device through a pipeline, and the air outlet is communicated with an external environment. The application has the effects of preventing the engine air intake casing from icing and not affecting the performance of the engine.

Description

Technical Field

[0001] This application relates to the technical field of turboshaft engines, and in particular to an anti-icing system for turboshaft engines. Background Technology

[0002] When turboshaft engines operate in icy weather conditions, ice easily forms on the surfaces of components such as the engine lip, cowling, and support plates, which has a severe impact on their performance, operating range, and safety reliability. Therefore, an anti-icing system needs to be installed in the turboshaft engine. Existing anti-icing systems generally draw pressurized hot air from the compressor outlet. After the bleed air valve is opened, the hot air flows through the corresponding pipeline to the components that need anti-icing to heat them, thereby achieving the purpose of anti-icing. However, the anti-icing system needs to provide enough heat to completely evaporate the impact water that accumulates on the surfaces of components such as the lip, fairing, and support plates, achieving evaporative anti-icing and ensuring that no ice forms on the component surfaces. Drawing air from the compressor outlet will inevitably reduce the airflow in the main duct, greatly affecting the working performance of the turboshaft engine and its power output. Alternatively, the heat provided by the anti-icing system may only be used to ensure that the surface temperature of components such as the lip, fairing, and support plates is above the freezing point for wet-flow anti-icing, but the overflow water that is not completely evaporated will continue to flow along the surface and out of the anti-icing area, eventually forming ice lumps behind it, which will also affect other components located behind it.

[0003] Regarding the aforementioned technologies, the inventors believe that there are defects that affect engine performance. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this application provides an anti-icing system for a turboshaft engine that prevents ice formation on the surface of the engine intake casing without affecting the performance of the turboshaft engine.

[0005] The turboshaft engine provided in this application adopts the following technical solution:

[0006] A turboshaft engine includes an air intake port, an anti-icing valve, a heat exchange device, and an engine intake casing, which are sequentially connected by pipelines. The air intake port is connected to the exhaust port of the turboshaft engine to introduce the hot gas flow discharged from the turboshaft engine into the pipeline. The turboshaft engine includes a fuel system, and the fuel system includes the heat exchange device. The engine intake casing includes an intake passage through which the hot gas flow heats the engine intake casing. The intake passage includes an intake port and an exhaust port. The intake port is connected to the heat exchange device via a pipeline, and the exhaust port is connected to the external environment.

[0007] By adopting the above technical solutions, the air intake of the anti-icing system is connected to the exhaust port of the turboshaft engine. The exhaust gas from the turboshaft engine can be used as a hot airflow to heat the engine intake casing, solving the problem of air intake from the compressor affecting engine performance. The existing heat exchange equipment in the fuel system is used to cool the hot airflow, which lowers the temperature of the hot airflow while increasing the temperature of the fuel, thus improving the combustion efficiency of the combustion chamber. By setting an intake channel inside the engine intake casing to introduce hot airflow for heating, surface icing is prevented. This method is more efficient and energy-saving than directly heating the surface with hot airflow.

[0008] Preferably, a condensing device is also included, which is located between the heat exchange device and the engine intake casing and is interconnected by pipelines, and the hot airflow is cooled down by the condensing device.

[0009] By adopting the above technical solution, the hot airflow exchanges heat with the heat exchange equipment and then is further cooled by the condensation equipment. The combination of dual cooling can ensure that the hot airflow drops to a suitable temperature. The first cooling aims to increase the temperature of the fuel and improve combustion efficiency by utilizing the thermal energy of the hot airflow while cooling. The second cooling aims to ensure that the temperature of the hot airflow is suitable, so that it will not affect the engine intake casing due to excessive temperature, nor will it fail to achieve the effect of preventing icing due to excessive temperature.

[0010] Preferably, the engine intake casing includes an outer casing, an intake support plate, and a fairing. The intake support plate includes a first support plate and a second support plate arranged opposite to each other. The two ends of the first support plate and the second support plate are respectively connected to the outer casing and the fairing, and are distributed at intervals along the circumference of the fairing. The first support plate and the second support plate are respectively provided with a first cavity and a second cavity. The first cavity and / or the second cavity are used for laying cables. The air inlet communicates with the first cavity, and the air outlet communicates with the second cavity.

[0011] By adopting the above technical solution, the air inlet and outlet of the air intake channel are set at the cable inlet and outlet, so that the first and second cavities, which are originally used as cable trays, can also be used as air intake channels at the same time. This allows for the flow of hot air to heat the first and second support plates, eliminating the need to set up a separate air intake channel in the engine intake casing, reducing costs and not affecting the original structural strength.

[0012] Preferably, the fairing includes a plurality of wire-passing holes arranged in a ring around the axis of the fairing, and the plurality of wire-passing holes communicate with a first cavity and a second cavity.

[0013] By adopting the above technical solution, using the first and second cavities as air intake channels, the hot airflow can also heat the fairing through the multiple cable holes originally used for cable routing. This eliminates the need for a separate cooling channel for the fairing, reducing costs and preserving the original structural strength. Furthermore, utilizing the first and second cavities and multiple cable holes for hot airflow also facilitates the upgrading of older turboshaft engines by adding an anti-icing system.

[0014] Preferred, the air intake support plate includes two opposing third support plates, the air intake channel includes a first cavity, a second cavity, two third cavities disposed within the two third support plates, and an annular cavity surrounding the outer casing. The annular cavity communicates with the air intake and the second cavity, and the two third cavities communicate with the annular cavity. The fairing is provided with a first hot air port, a second hot air port, and two third hot air ports. The first hot air port and the second hot air port communicate with the first cavity and the second cavity, respectively, and the two third hot air ports communicate with the two third cavities.

[0015] By adopting the above technical solution, a hollow annular cavity is set inside the outer casing. This annular cavity, connected to the air intake, allows hot airflow to circulate around the outer casing. A third cavity is set inside each of the two third support plates. This third cavity, connected to the annular cavity, allows hot airflow to be introduced to heat the third support plate. Combined with the first cavity, second cavity, and multiple through-holes forming the entire air intake channel, heating and raising the temperature of the entire engine intake casing is achieved, comprehensively preventing surface icing. Simultaneously, by setting the first, second, and third hot air inlets in the fairing, and with the annular cavity connected to the second cavity, hot airflow can flow and exit within each cavity, preventing hot airflow from accumulating inside the cavities and causing overheating and water accumulation.

[0016] Preferably, the air intake channel includes an air distribution ring, which is located at the connection between the air intake and the annular cavity. The air distribution ring includes a first air hole and two second air holes, the first air hole being connected to the first cavity and the two second air holes being connected to the annular cavity.

[0017] By adopting the above technical solution, the hot air flow is distributed by using the air distribution ring located at the connection between the air inlet and the annular cavity. The flow rate of the hot air flow can be distributed according to the difference in icing risk of each component. Combined with the setting of various cavities, it can ensure that the icing effect can be achieved for each component of the engine intake casing.

[0018] Preferably, the cross-sectional area of ​​the first vent is greater than the sum of the cross-sectional areas of the two second vents, and the sum of the areas of the two second vents is greater than the sum of the areas of the two second hot vents.

[0019] By adopting the above technical solution, it can be ensured that the air intake support plate with a higher risk of icing can circulate more hot airflow than the fairing with a lower risk of icing.

[0020] Preferably, the turboshaft engine includes a nozzle located between the compressor and the combustion chamber, with a first end of the nozzle communicating with the combustion chamber, and an air intake located on the nozzle and close to a second end of the nozzle, the axis of the air intake having an angle with the axis of the nozzle, the angle being greater than or equal to 30° and less than or equal to 60°.

[0021] By adopting the above technical solution, bleed air can be drawn from the hot gas discharged from the turboshaft engine. The nozzle is located between the compressor gas and the combustion chamber, which can reduce the bleed air pipeline and reduce the risk of insufficient exhaust pressure. The angle between the axis of the bleed air port and the axis of the nozzle can avoid the hot gas from impacting the bleed air port and losing gas, and ensure that the pressure at the exhaust port is sufficient to deliver the airflow to the intake casing.

[0022] Preferably, it also includes a gas collecting ring, which is connected to the nozzle and located above the nozzle. The air intake includes a first air intake and a plurality of second air intakes, which are arranged in a ring array along the nozzle. The gas collecting ring is hollow inside and communicates with the plurality of second air intakes. The first air intake is communicated with the inside of the gas collecting ring and is connected to the heat exchange gas through a pipeline.

[0023] By adopting the above technical solution, multiple second air intake ports are set in the nozzle annular array to achieve uniform air intake and avoid single-point air intake from affecting the exhaust balance. The hot air flow drawn from multiple second air intake ports is collected by the air collecting ring and then concentrated through the first air intake port to flow to the engine intake casing, ensuring that the hot air flow has sufficient flow pressure.

[0024] Preferably, the anti-icing valve includes a first flow valve and a second flow valve, the first flow valve being located between the air inlet and the second flow valve, and the flow regulation accuracy of the first flow valve being greater than that of the second flow valve.

[0025] By adopting the above technical solution, the valve combination can achieve coarse and fine adjustment of the bleed air volume, avoiding the impact of excessive bleed air on the shaft power generated by the turboshaft engine.

[0026] The anti-icing system for a turboshaft engine provided by this application embodiment heats up the engine intake casing to prevent ice formation on its surface. Since there is no need to bleed air from the compressor, it does not affect the performance of the turboshaft engine. Moreover, by bleeding air from the exhaust port, heat energy is recovered and utilized, achieving energy-saving and high-efficiency effects. Attached Figure Description

[0027] Figure 1This is a schematic diagram of an anti-icing system for a turboshaft engine provided in this embodiment.

[0028] Figure 2 This is a three-dimensional schematic diagram of the engine intake casing provided in the embodiments of this application.

[0029] Figure 3 This is a rear view schematic diagram of the engine intake casing provided in the embodiments of this application.

[0030] Figure 4 This is a three-dimensional cross-sectional view of the engine intake casing provided in an embodiment of this application.

[0031] Figure 5 This is another three-dimensional cross-sectional view of the engine intake casing provided in the embodiments of this application.

[0032] Figure 6 This is a cross-sectional schematic diagram of the engine intake casing provided in an embodiment of this application.

[0033] Figure 7 This is a cross-sectional schematic diagram of the nozzle provided in an embodiment of this application.

[0034] Figure 8 This is an internal top view schematic diagram of a turboshaft engine provided in an embodiment of this application.

[0035] Explanation of reference numerals in the attached drawings: 1. Air intake port; 11. First air intake port; 12. Second air intake port; 13. Air collection ring; 2. Anti-icing valve; 3. Heat exchange equipment; 4. Condensation equipment; 5. Engine intake casing; 51. Intake passage; 511. Air intake port; 512. Air outlet; 513. First cavity; 514. Second cavity; 515. Annular cavity; 516. Third cavity; 52. Outer casing; 53. Intake support plate; 531. First support plate; 532. Second support plate; 533. Third support plate; 54. Fairing; 541. First hot air port; 542. Second hot air port; 543. Wiring hole; 544. Third hot air port; 6. Nozzle; 61. Exhaust port; 62. Filter box; 63. Filter element; 64. Filter outlet;

[0036] 40. Compressor unit; 50. Gearbox unit; 60. Turbine unit; 70. Combustion chamber unit. Detailed Implementation

[0037] To better understand the purpose, technical solutions, and advantages of this application, it has been described and illustrated below with reference to the accompanying drawings and embodiments. However, those skilled in the art should understand that this application can be implemented without these details. In some cases, to avoid obscuring various aspects of this application due to unnecessary description, well-known methods, processes, systems, components, and / or circuits already described at a higher level will not be elaborated upon. It will be apparent to those skilled in the art that various modifications can be made to the embodiments disclosed in this application, and the general principles defined in this application can be applied to other embodiments and application scenarios without departing from the principles and scope of this application. Therefore, this application is not limited to the illustrated embodiments, but conforms to the broadest scope consistent with the scope of protection claimed in this application.

[0038] It should be noted that the descriptions of these embodiments are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0040] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples.

[0041] This application discloses an anti-icing system for a turboshaft engine.

[0042] like Figure 1As shown, the anti-icing system of the turboshaft engine includes an air intake 1, an anti-icing valve 2, a heat exchange device 3, and an engine intake casing 5, which are connected in sequence through pipelines. The air intake 1 is connected to the exhaust port 61 of the turboshaft engine to introduce the hot airflow discharged from the turboshaft engine into the pipeline. The anti-icing valve 2 can be a switch controlled by an electrical signal. When an electrical signal is received, the anti-icing valve 2 opens to allow the hot airflow to pass through. When the electrical signal is lost, the anti-icing valve 2 closes. The electrical signal can be sent by a control unit. The control unit can detect the ambient temperature or the surface temperature of the engine intake casing 5 through a temperature sensor. When the temperature is lower than a set threshold, it sends an electrical signal to the anti-icing valve 2 to deliver hot airflow to the engine intake casing 5 to prevent ice formation on the surface of the engine intake casing 5. Because the exhaust gas from the turboshaft engine is very hot, it needs to be cooled to a suitable temperature. Therefore, this application uses a heat exchange device 3 to exchange heat with the hot gas to reduce its temperature. The heat exchange device 3 is a configuration of the turboshaft engine's own fuel system. While reducing the temperature of the hot gas, it also increases the temperature of the fuel, improving the efficiency of fuel combustion in the combustion chamber and enhancing the performance of the combustion chamber. Furthermore, by utilizing the turboshaft engine's existing configuration to build an anti-icing system, costs can be reduced. The engine intake casing 5 is hollow and has an intake passage 51. The intake passage 51 includes an intake port 511 and an outlet 512. The intake port 511 is connected to the heat exchange device 3 through a pipe. The cooled hot gas flows through the pipe to the intake passage 51 and exchanges heat with the intake support plate 53 to raise its temperature and prevent icing on the surface of the intake support plate 53. The outlet 512 can be connected to the external environment, and the hot gas that has exchanged heat with the intake support plate 53 can be discharged through the outlet 512.

[0043] This application solves the problem of compressor-induced air bleed affecting turboshaft engine performance by drawing hot air from the exhaust port 61 of the turboshaft engine to heat the engine intake casing 5. It also controls the opening and closing of the anti-icing valve 2 via electrical signals to activate the anti-icing system as needed, preventing indiscriminate air bleed from affecting the shaft power generated by the turboshaft engine. Furthermore, it utilizes the heat exchange equipment 3 configured in the turboshaft engine's fuel system to cool the hot air, reducing it to a suitable temperature and increasing the fuel temperature, thus improving combustion efficiency. Finally, by setting an intake channel 51 inside the intake support plate 53, the intake support plate 53 is heated to evaporate moisture on its surface, preventing surface icing. Therefore, the entire anti-icing system prevents icing without affecting the turboshaft engine's performance.

[0044] like Figure 1As shown, the anti-icing system also includes a condensing device 4, located between the heat exchange device 3 and the engine intake casing. The hot airflow, after heat exchange with the heat exchange device 3, undergoes secondary cooling through the condensing device 4 to ensure it reaches a suitable temperature. The condensing device 4 includes copper pipes, a compression pump, and Freon. The compression pump compresses the gaseous Freon into a high-temperature, high-pressure gas, which is then liquefied through the copper pipes, carrying away a significant amount of heat from the hot airflow and further reducing its temperature. The liquefied Freon is then recycled back through a circulation pump. The condensing device 4 is powered by the turboshaft engine itself, eliminating the need for additional power and reducing the overall cost of the anti-icing system.

[0045] Please refer to Figure 2 and Figure 3 The engine intake casing 5 also includes an annular outer casing 52, an intake support plate 53, and a conical fairing 54. The fairing 54 is located at the center of the outer casing 52 and is coaxial with the outer casing 52. The intake support plate 53 includes a first support plate 531 and a second support plate 532 arranged opposite to each other. The two ends of the first support plate 531 and the second support plate 532 are respectively connected to the outer casing 52 and the fairing 54, and are distributed circumferentially along the fairing 54. Turboshaft engines are generally equipped with cable trays for laying cables, such as... Figure 4 As shown, the first support plate 531 and the second support plate 532 are hollow inside and are respectively provided with a first cavity 513 and a second cavity 514. The first cavity 513 and / or the second cavity 514 are used to lay cables connected to the motor or other components. Both ends of the first cavity 513 and the second cavity 514 pass through the outer shell 52 and the rectifier 54 to allow the cables to enter and exit. Thus, the first cavity 513 and the second cavity 514 are connected through the rectifier 54. The air inlet 511 passes through the outer shell 52 and is connected to the first cavity 513. The air outlet 512 passes through the outer shell 52 and is connected to the second cavity 514. Thus, the first cavity 513 and the second cavity 514 form an air intake channel 51. Hot air enters the first cavity 513 and the second cavity 514 through the air inlet 511 and is discharged through the air outlet 512, thereby heating the first support plate 531 and the second support plate 532 and preventing ice from forming on the surface of the first support plate 531 and the second support plate 532. In this embodiment, the second cavity 514 is larger than the first cavity 513, serving as the main cable tray. The first cavity 513 can have a small amount of cable laid or no cable laid, allowing sufficient flow space for hot airflow in both cavities. This application utilizes the original cable tray design of the engine intake casing 5 as the intake channel 51, eliminating the need for additional installations, thus achieving both anti-icing effects and reducing the cost of installing an anti-icing system.

[0046] like Figure 3 and Figure 4As shown, the fairing 54 includes multiple cable passage holes 543 arranged in a ring array around the axis of the fairing 54. The walls of the multiple cable passage holes 543 are close to the inner wall of the fairing 54, and are used to allow cables connected to the motor to pass through. This application provides multiple cable passage holes 543 that communicate with the air intake channel 51. When hot air flows through the air intake channel 51 to the cable passage holes 543, it exchanges heat with the fairing 54, thereby heating the fairing 54 and preventing its surface from freezing. The ring array arrangement of the multiple cable passage holes 543 ensures that the fairing 54 is heated evenly. By connecting the original cable passage holes 543 of the fairing 54 to the air intake channel 51, and using the original cable passage holes 543 to guide the flow of hot air, the hot air comes into contact with the fairing 54 and heats it, preventing freezing. This eliminates the need to process additional hot air flow channels on the fairing 54, thus not affecting the original structural strength and reducing costs. The fairing 54 is provided with a first hot air port 541 and a second hot air port 542. The first hot air port 541 and the second hot air port 542 are located opposite each other between the small diameter end of the fairing 54 and the wire passage hole 543. The first cavity 513 and the second cavity 514 are respectively connected to the first hot air port 541 and the second hot air port 542, thereby realizing the connection between the air intake channel 51 and the multiple wire passage holes 543 of the fairing 54. That is, after the hot air enters the first cavity 513 from the air intake port 511, it flows through the first hot air port 541 to the second hot air port 542 and the multiple wire passage holes 543 respectively. The hot air flowing to the second hot air port 542 enters the second cavity 514. By setting the first hot air port 541 and the second hot air port 542 on the side near the small diameter end, the hot air flow can first gather between the small diameter end and the wire passage hole 543 after flowing out from the first hot air port 541, heating up the part of the cover body located in this area and improving the heating effect. Then, it diffuses to the large diameter end through multiple wire passage holes 543, heating up the other parts of the cover body of the fairing 54, thereby achieving heating up the entire fairing 54.

[0047] This application utilizes the heat exchange equipment 3 of its own fuel system to cool down, and uses the original wiring holes 543 of the fairing 54 and the original cavity of the intake support plate 53 as a wiring channel to form an intake channel 51. This method is also conducive to upgrading and modifying old turboshaft engines that are not equipped with anti-icing systems, and has great promotional value.

[0048] Please refer to Figure 5 and Figure 6The intake support plate 53 also includes two opposing third support plates 533. The intake channel 51 also includes an annular cavity 515 disposed inside the outer casing 52 and surrounding the outer casing 52, and a third cavity 516 disposed inside the two third support plates 533. One end of the two third cavities 516 is connected to the annular cavity 515, and the other end is connected to two third hot air ports 544 disposed on the fairing 54. The annular cavity 515 is connected to the air inlet 511 and the second cavity 514. After the hot air enters from the air inlet 511, in addition to The hot airflow flows into the first cavity 513 and the second cavity 514, and can also flow into the annular cavity 515, so that the hot airflow can surround the outer casing 52 and heat up the outer casing 52. At the same time, the hot airflow will also enter the two third cavities 516 through the annular cavity 515 to heat up the two third support plates 533. Finally, it flows out from the third hot air port 544 designed on the fairing 54. Combined with the heating up of the two first support plates 531, the surface of the entire engine intake casing 5 is fully heated.

[0049] Specifically, the annular cavity 515 has two opposing inlets. The air inlet 511 is connected to both inlets of the annular cavity 515. A distribution ring (not shown in the figure) is provided at the connection between the air inlet 511 and the annular cavity 515. The distribution ring includes a first air hole and two second air holes. The first air hole is connected to the first cavity 513, and the two second air holes are connected to the two inlets of the annular cavity 515. Because the icing risk varies in different parts of the engine intake casing 5, for example, the intake support plate 53, being a hollow, thin structure, requires cable laying. If its heat capacity is small, heat loss after impact with supercooled water droplets is rapid, and it cannot quickly balance its temperature through its own heat conduction, making it prone to icing. The icing risk of this intake support plate 53 is higher than that of other components. The thick-walled annular structure of the fairing 54 has a large heat capacity and often conducts heat with other engine components, which can slowly release heat to inhibit ice formation, and the icing risk is relatively low. In this application, the diameter of the first air hole is larger than that of the second air hole. For example, the cross-sectional area of ​​the first air hole is at least 1.15 times the sum of the cross-sectional areas of the two second air holes, so as to ensure that the airflow entering the first cavity 513 is maximized, so that the intake support plate 53 has sufficient hot airflow for heating. The sum of the cross-sectional areas of the two third hot air ports 544 is less than the sum of the cross-sectional areas of the two second air holes, so that the hot airflow flowing to the fairing 54 is minimized.

[0050] like Figure 7As shown, the turboshaft engine includes a nozzle 6, which has a first end and a second end. The first end is connected to the combustion chamber. An air intake 1 is located on the nozzle 6 and near the second end of the nozzle 6. The axis of the air intake 1 forms an angle with the axis of the nozzle 6, which is greater than or equal to 30° and less than or equal to 60°. In this embodiment, a gas collecting ring 13 is also provided above the nozzle 6. The gas collecting ring 13 is arranged around the outside of the nozzle 6 and near the second end of the nozzle 6. The air intake 1 includes a first air intake 11 and a plurality of second air intakes 12. The plurality of second air intakes 12 penetrate the pipe wall of the nozzle 6 and are arranged in a ring array along the periphery of the nozzle 6. The gas collecting ring 13 is hollow inside and communicates with the plurality of second air intakes 12. The first air intake 11 is connected to the inside of the gas collecting ring 13 and is connected to the heat exchange gas through a pipeline. The hot gas flow discharged from the turboshaft engine flows into the inside of the gas collecting ring 13 through the plurality of second air intakes 12, and then flows to the engine intake casing 5 through the first air intake 11. By setting multiple annular arrays of second air intakes 12, air can be drawn in evenly, avoiding single-point air intake from affecting the gas emission balance of the turboshaft engine. In this embodiment, the angle between the axis of the second air intake 12 and the axis of the nozzle 6 is set to 30°, or the axis of the second air intake 12 is parallel to the wall of the nozzle 6, so that the discharged hot gas can naturally enter the air intake 1 along the flow direction, reducing impact and heat loss.

[0051] In this embodiment, the anti-icing system also includes a filter box 62, which contains a filter element 63 made of high-temperature ceramic, capable of trapping fine particles and incompletely burned hydrocarbons in the hot airflow. For example... Figure 7 As shown, the filter box 62 is connected to the air collecting ring 13 and communicates with the first air inlet 11. After the hot air enters the filter box 62, it is connected to the anti-icing valve 2 through the filter outlet 64. The filter box 62 and the air collecting ring 13 are detachably connected, which facilitates the replacement of the internal filter element 63.

[0052] Please refer to Figure 8The diagram illustrates a turboshaft engine, comprising a compressor unit 50, a gearbox unit 40, a turbine unit 60, and a combustion chamber unit 70. Two nozzles 6 are located within the turbine unit 60, which includes a gas turbine and a power turbine. The gas turbine is connected to the combustion chamber unit 70. The two nozzles 6 are connected to the power turbine and, through internal channels, to the combustion chamber, exhausting upwards. In other words, the nozzles 6 are located between the compressor and the combustion chamber. If the turboshaft engine's intake casing were positioned at the very front and the nozzles at the very rear, drawing air from the nozzles to the intake casing, a long pipeline would be required, increasing pipeline costs. Furthermore, an excessively long pipeline would result in insufficient exhaust pressure at the nozzles to transport the hot air to the intake casing. This application shortens the distance between the nozzle and the intake casing by placing the nozzle between the compressor and the combustion chamber. Gas flowing from the compressor first detours to the combustion chamber at the rear end, and then flows back towards the turbine unit before being discharged from the nozzle. This reduces the amount of bleed air piping, lowers costs, and solves the problem of insufficient exhaust pressure at the nozzle. Furthermore, the dual-nozzle design splits the hot airflow into two paths, dispersing the impact force and heat load of a single airflow on the nozzle. The angle between the axes of the two nozzles can be set according to the suitable aircraft. The turbine unit has a relatively large operating flow requirement. In this embodiment, the diameter of nozzle 6 gradually decreases from the second end to the first end, causing the cross-sectional area of ​​the nozzle to gradually increase from the connection point with the power turbine towards the exhaust port 61. This facilitates flow through the turbine channel, ensuring sufficient flow to the turbine during actual operation of the turboshaft engine.

[0053] In this embodiment, the anti-icing valve 2 includes a first flow valve and a second flow valve. The first flow valve can be a pneumatic diaphragm valve, and the second flow valve can be an electric butterfly valve. The pneumatic diaphragm valve is located between the bleed air port 1 and the electric butterfly valve. The flow regulation accuracy of the pneumatic diaphragm valve is greater than that of the electric butterfly valve. Coarse and fine adjustments to the bleed air flow can be achieved through the valve combination. For example, the maximum bleed air flow can be set to control 3%-5% of the total exhaust flow to avoid excessive bleed air affecting the shaft power generated by the turboshaft engine.

[0054] In other embodiments, the low-temperature hot air after heat exchange with the engine intake casing 5 may not be directly discharged. Instead, it is led to the mixing chamber before the compressor inlet via a return air line, where it mixes with the outside intake air and re-enters the engine cycle, reducing energy waste. The return air line may be equipped with a one-way valve to prevent reverse airflow.

[0055] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An anti-icing system for a turboshaft engine, characterized in that: This includes the air intake, anti-icing valve, heat exchange equipment, and engine intake casing, which are connected in sequence by pipelines. The air intake is connected to the exhaust port of the turboshaft engine to introduce the hot airflow discharged by the turboshaft engine into the pipeline. The turboshaft engine includes a fuel system, and the fuel system includes the heat exchange device. The engine intake casing includes an intake passage, through which the hot airflow heats the engine intake casing. The intake passage includes an intake port and an outlet. The intake port is connected to the heat exchange device via a pipeline, and the outlet is connected to the external environment. The engine intake casing includes an outer shell, an intake support plate, and a fairing. The intake support plate includes a first support plate and a second support plate arranged opposite each other, as well as two third support plates arranged opposite each other. The two ends of the first support plate and the second support plate are respectively connected to the outer shell and the fairing, and are distributed at intervals along the circumference of the fairing. The first support plate and the second support plate are respectively provided with a first cavity and a second cavity. The first cavity and / or the second cavity are used for laying cables. The air outlet communicates with the second cavity. The air intake channel includes a first cavity, a second cavity, a third cavity disposed inside the two third support plates, and an annular cavity surrounding the outer casing. The two third cavities are connected to the annular cavity. The air intake channel includes an air distribution ring, which is located at the connection between the air intake and the annular cavity. The air distribution ring includes a first air hole and two second air holes. The first air hole is connected to the first cavity, and the two second air holes are connected to the annular cavity. The cross-sectional area of ​​the first pore is greater than the sum of the cross-sectional areas of the two second pores.

2. The anti-icing system for a turboshaft engine according to claim 1, characterized in that: It also includes a condensing device, which is located between the heat exchange device and the engine intake casing and is interconnected by pipelines. The hot airflow is cooled down by the condensing device.

3. The anti-icing system for a turboshaft engine according to claim 1, characterized in that: The fairing includes a plurality of wire-passing holes arranged in a ring around the axis of the fairing, and the plurality of wire-passing holes communicate with a first cavity.

4. The anti-icing system for a turboshaft engine according to claim 3, characterized in that: The fairing is provided with a first hot air inlet, a second hot air inlet and two third hot air inlets. The first hot air inlet and the second hot air inlet are respectively connected to the first cavity and the second cavity, and the two third hot air inlets are connected to the two third cavities.

5. The anti-icing system for a turboshaft engine according to claim 4, characterized in that: The sum of the cross-sectional areas of the two second air vents is greater than the sum of the cross-sectional areas of the two third hot air vents.

6. The anti-icing system for a turboshaft engine according to claim 1, characterized in that: The turboshaft engine includes a nozzle located between the compressor and the combustion chamber. The first end of the nozzle is connected to the combustion chamber. The air intake is located on the nozzle and close to the second end of the nozzle. The axis of the air intake is at an angle to the axis of the nozzle, which is greater than or equal to 30° and less than or equal to 60°.

7. The anti-icing system for a turboshaft engine according to claim 6, characterized in that: It also includes a gas collecting ring, which is connected to the nozzle and located above the nozzle. The air intake includes a first air intake and a plurality of second air intakes, which are arranged in a ring array along the nozzle. The gas collecting ring is hollow inside and communicates with the plurality of second air intakes. The first air intake is communicated with the inside of the gas collecting ring and is connected to the heat exchange device through a pipeline.

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