Staged ignition system for afterburner

Abstract

The invention discloses a staged ignition system for an afterburner, which is used for solving the problems of unreliable afterburner ignition caused by small radial size, low oil supply pressure and the like of small and medium-sized turbine engines in the prior art, easiness in flameout of the afterburner in a mode conversion process, easiness in influence of afterburner on pneumatic stability of front parts and the like. The device comprises a first nozzle, a second nozzle, a thrust augmentation fuel oil main pipe, an ignition fuel oil pipe and an annular flame stabilizer assembly, wherein the annular flame stabilizer assembly is composed of an air inlet nozzle, an evaporation pipe and a flame stabilizer. According to the invention, ignition starting of the afterburner is realized by innovatively adopting a staged ignition mode. The grading ignition system basically does not occupy an inner runner of an engine, the requirement for the radial size of the afterburner is small, the ignition envelope of the afterburner can be greatly widened, reliable ignition is achieved, and due to the fact that an electric ignition device and a complex fuel metering device are not arranged, the development cost and the development period of the ignition system are greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of turbine combination power, in particular to a staged ignition system for an afterburner. Background Art

[0002] Compared with the existing aircraft engine turbine power unit, the turbine-based combined power has a wider working envelope and higher unit thrust, and countries are competing to carry out key technology research on this power. The turbine-based combined power is a combined power based on the existing turbine engine and ramjet engine. The turbine engine and the ramjet engine have the same afterburner. This feature causes the back pressure to rise suddenly after the afterburner is working, affecting the aerodynamic stability of the inlet duct, and the engine cannot work normally; the ramjet duct has low intake temperature, low pressure, and low fuel evaporation, but the turbine-based combined power requires that the afterburner does not shut down when the turbine mode is switched to the ramjet mode, and the afterburner thrust is continuous, which requires the afterburner to have a duty flame, and at the same time requires a small increase in ignition fuel to control the amplitude of the pressure increase in the afterburner, thereby reducing the impact of the sudden increase in afterburner pressure on the aerodynamic stability of the inlet duct. Furthermore, when the size of the turbine-based combined power is "miniaturized", the engine diameter is greatly reduced and the internal flow space of the engine is limited. If too many components are arranged in the afterburner, the flow loss of the afterburner will be greatly increased, affecting the afterburner performance. Summary of the invention

[0003] The purpose of the present invention is to provide a staged ignition system for a small turbine-based combined power afterburner in order to solve the above problems, so as to solve the problems of limited flow space in the afterburner, unreliable afterburner ignition performance under conditions of poor fuel atomization, easy flameout of the afterburner during mode conversion, and sudden pressure increase after afterburner that easily affects the aerodynamic stability of the front components.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0005] The present invention provides a staged ignition system for an afterburner, comprising a nozzle 1 (12), a nozzle 2 (31), an afterburner fuel main pipe (32), an ignition fuel pipe (41), and an annular flame stabilizer assembly (42), wherein the annular flame stabilizer assembly (42) comprises an air inlet nozzle (421), an evaporation pipe (422), and an annular flame stabilizer (423). The nozzle 1 (12) is installed on the casing of the main combustion chamber (1), the nozzle 2 (31) is installed at the inlet of the afterburner diffuser assembly (3), the afterburner fuel main pipe (32) is located in the middle of the afterburner diffuser assembly (3), the ignition fuel pipe (41) is located at the inlet of the combustion section of the afterburner (4), and the annular flame stabilizer assembly (42) is located behind the ignition fuel pipe (41).

[0006] As a preferred embodiment of the present invention, the annular flame stabilizer assembly (42) includes an air inlet nozzle (421), an evaporator tube (422), and an annular flame stabilizer (423). The evaporator tube (422) is provided with a third oil injection hole (4221). The atomized fuel (b) is mixed with the fuel gas (a) entering the air inlet nozzle (421) and flows into the evaporator tube (422), and is injected into the interior of the annular flame stabilizer (423) through the third oil injection hole (4221) on the evaporator tube (422).

[0007] As a preferred embodiment of the present invention, the afterburner fuel main pipe (32) is a component welded by an afterburner ring pipe (321) and an afterburner injection rod (322), located in the middle of the afterburner diffuser (3), one end of which is fixed on the inner cone (33) and the other end of which is fixed on the diffuser (3) casing; each afterburner injection rod (322) is provided with a specific injection hole (3221). The afterburner fuel main pipe (32) injects the afterburner fuel (b) into the internal flow channel of the afterburner combustor diffuser (3), and the afterburner fuel (b) is atomized under the aerodynamic force of the gas (a) and mixed with the gas (a) inside the diffuser (3) and flows downward, and is ignited by the high-temperature gas (a3) ​​in the combustion zone inside the annular flame stabilizer (423) at the end.

[0008] As a preferred embodiment of the present invention, the ignition fuel pipe (41) is a component welded together by an annular tube (411) and a fuel injection rod (412), is located at the inlet of the combustion section of the afterburner (4), is fixed to the annular flame stabilizer (423) by a connecting piece (43), is detachable, and has two fuel injection holes (4121) on the end face of the fuel injection rod (412); the number of fuel injection rods (412) of the ignition fuel pipe (41) is between 10 and 16, and the fuel injection rod (412) forms an angle of 40° to 60° with the air inlet nozzle (421). The fuel (b) of the ignition fuel pipe (41) is sprayed into the air intake nozzle (421) at a certain angle to form initial fuel atomization; then, it is further atomized under the action of the gas force of the gas (a) entering the air intake nozzle (421); the atomized fuel (b) is mixed with the gas (a) entering the air intake nozzle (421) and flows into the evaporation tube (422); it is injected into the interior of the annular flame stabilizer (423) through the second fuel injection hole (4221) on the evaporation tube (422); and after mixing with the gas passing through the air intake groove (4231) of the annular flame stabilizer (423), it flows downstream and forms a stable recirculation zone (c) inside the annular flame stabilizer (423); the oil-gas mixture (a) in the recirculation zone (c) is ignited by the second hot jet (a2), and a stable combustion zone (a3) ​​is formed in the middle and rear of the flame stabilizer (423). The reflux high-temperature combustion gas (a3) ​​can ignite the fresh oil-gas mixture (ab) sprayed out from the fuel injection hole three (4221), thereby establishing an automatic ignition source (d).

[0009] As a preferred embodiment of the present invention, the number of the fuel injection rods (412) of the ignition fuel pipe (41) is between 10 and 16, and the fuel injection rods (412) form an angle of 40° to 60° with the air intake nozzle (421).

[0010] As a preferred embodiment of the present invention, the number of the three oil injection holes (4221) on the evaporating tube (422) is between 20 and 32, and the hole diameter is between φ4 mm and φ6 mm.

[0011] As a preferred embodiment of the present invention, the air inlet grooves (4231) on the front end of the annular flame stabilizer (423) are rectangular, and the number of the air inlet grooves (4231) is the same as the number of the three oil injection holes (4221) on the evaporator tube (422).

[0012] As a preferred embodiment of the present invention, the fuel injection holes on the nozzle 1 (12), the nozzle 2 (31), the afterburner fuel main pipe (32), and the ignition fuel main pipe (41) are all circular hole type nozzles, and the fuel flow rates are all independently controlled.

[0013] The beneficial effects of the present invention are:

[0014] (1) The booster staged ignition system of the present invention forms a large high temperature zone of the heat jet (or combustion zone), a short ignition time, and more reliable ignition.

[0015] (2) The afterburner staged ignition system of the present invention can establish a stable duty flame zone. The afterburner chamber is not easy to extinguish during the mode conversion process, and the fuel flow rate can be adjusted independently, thereby reducing the impact of the pressure surge after the afterburner ignition is successful on the aerodynamic stability of the front components.

[0016] (3) The ignition system of the present invention has a small demand for the flow channel space inside the afterburner and a small requirement for the fuel supply pressure, which can achieve the high performance working requirements of the afterburner and has a low development cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the staged ignition system of the present invention;

[0018] Figure 2 It is a working principle diagram of the staged ignition system of the present invention;

[0019] Figure 3 It is a partial enlarged view of the staged ignition system of the present invention;

[0020] Figure 4 It is a structural schematic diagram of the booster fuel main pipe of the staged ignition system of the present invention.

[0021] Figure numerals: a-air (or gas) inside the engine, a1-first hot jet, a2-second hot jet, a3-high-temperature gas, b-fuel, ab-fuel-gas mixture, c-recirculation zone, d-automatic ignition source, 1-main combustion chamber, 11-flame tube, 12-nozzle one, 2-turbine component, 21-turbine stator, 22-turbine rotor, 3-afterburner diffuser assembly, 31-nozzle two, 32-afterburner fuel main pipe, 3 21-afterburner ring pipe, 322-afterburner injection rod 3221-injection hole one, 33-inner cone, 4-afterburner combustion chamber, 41-ignition fuel pipe, 411-ring pipe, 412-injection rod, 4121-injection hole two, 42-annular flame stabilizer assembly, 421-intake nozzle, 422-evaporation tube, 4221-injection hole three, 423-annular flame stabilizer, 4231-intake groove, 43-connecting plate, 44-pull rod. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer, the implementation method of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0024] As attached Figure 1-4 As shown, an embodiment of the present invention provides a staged ignition system for an afterburner, such as Figure 1 and Figure 3-4As shown, the staged ignition system for the afterburner combustion chamber includes nozzle 12, nozzle 2 31, afterburner fuel main pipe 32, ignition fuel pipe 41, and annular flame stabilizer assembly 42, wherein the annular flame stabilizer assembly 42 includes an air inlet nozzle 421, an evaporation pipe 422, and annular flame stabilizer 423. Nozzle 12 is installed on the casing of the main combustion chamber 1, and its oil injection hole is deep into the flame tube 11. Nozzle 2 31 is located at the inlet of the afterburner diffuser assembly 3 and fixed on the diffuser casing 3, and its oil injection hole is located in the flow channel of the afterburner diffuser 3. The afterburner fuel main pipe 32 is an assembly welded by the afterburner ring pipe 321 and the afterburner injection rod 322, located in the middle of the afterburner diffuser 3, one end of which is fixed on the inner cone 33, and the other end is fixed on the diffuser 3 casing; each afterburner injection rod 322 is arranged with a specific injection hole 1 3221. The ignition fuel pipe 41 is a component welded by the annular pipe 411 and the injection rod 412, located at the inlet of the combustion section of the afterburner 4, fixed to the annular flame stabilizer 423 by the connecting piece 43, and is detachable; the end face of the injection rod 412 has a second injection hole 4121. The annular flame stabilizer component 42 is located behind the injection rod 412, and is formed by the air inlet nozzle 421, the evaporator tube 422, and the annular flame stabilizer 423 by welding, and is fixed to the casing of the afterburner diffuser 41 by the tie rod 44. The air inlet slot 4231 on the front end of the annular flame stabilizer 423 is rectangular, and the number is the same as the number of the third injection hole 4221 on the evaporator tube 422.

[0025] like Figure 1-2As shown, the nozzle 1 12 sprays the first fuel oil b into the high temperature combustion zone inside the main combustion chamber 1, and the fuel oil b is ignited by the high temperature combustion gas a in the high temperature combustion zone to form the first hot jet a1, and the first hot jet a1 passes through the turbine stator 21 and the turbine rotor 22 of the turbine component 2 and enters the afterburner diffuser 3. Simultaneously, the nozzle 2 31 sprays the second fuel oil b into the combustion gas a channel inside the afterburner diffuser 3, and the fuel oil b is ignited by the first hot jet a1 to form the second hot jet a2. At the same time, the ignition fuel pipe 41 sprays fuel b into the air intake nozzle 421 at a certain angle to form initial fuel atomization; then it is further atomized under the action of the gas force of the gas a entering the air intake nozzle 421, and the atomized fuel b is mixed with the gas a entering the air intake nozzle and flows into the evaporator tube 422, and is injected into the interior of the annular flame stabilizer 423 through the injection hole three 4221 on the evaporator tube 422, and is mixed with the gas a passing through the air intake groove 4231 of the annular flame stabilizer 423 and flows downstream, and a stable reflow zone c is constructed inside the annular flame stabilizer 423, and the oil-gas mixture ab in the reflow zone c is ignited by the second hot jet a2, forming a stable combustion zone in the middle and rear of the annular flame stabilizer 423; the reflux high-temperature gas a3 can ignite the fresh oil-gas mixture ab sprayed out from the injection hole three 4221, establish an automatic ignition source d, and stop supplying oil to the nozzle one 12 and the nozzle two 31. Next, the afterburner fuel main pipe 32 sprays the afterburner fuel b into the internal flow channel of the afterburner diffuser 3. The afterburner fuel b is atomized under the aerodynamic force of the fuel gas a and mixed with the three fuel gases a in the diffuser, then flows downward and is ignited by the high-temperature fuel gas a inside the duty flame at the end of the annular flame stabilizer 423.

[0026] The specific oil supply sequence of the 4 oil circuits in this solution can be adaptively adjusted according to specific circumstances.

[0027] Such afterburner staged ignition system has good ignition performance and stable combustion performance, and is suitable for use in small turbine-based combined power in a wider airspace and speed range.

[0028] Working principle: When the aircraft issues an afterburner-on command, the engine control system will supply fuel to the oil circuit in a specific sequence, and the fuel supply sequence is nozzle 1 and nozzle 2 → ignition fuel pipe → afterburner fuel main pipe. Among them, when the on-duty flame stabilizer builds a stable combustion zone inside, the fuel supply to nozzle 1 and nozzle 2 can be stopped.

[0029] This solution can also be based on the working requirements of the engine. The fuel sprayed from the ignition fuel pipe and the afterburner fuel main pipe is mixed with the combustion gas inside the engine diffuser, and the high-temperature hot jet formed by the second nozzle is ignited. When the afterburner fuel is ignited, a stable combustion zone is also constructed inside the duty flame stabilizer. The order of fuel supply can be determined according to the specific situation.

[0030] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, the above embodiments are only preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and embodiments, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A staged ignition system for an afterburner, characterized in that: The ignition system comprises a nozzle 1 (12), a nozzle 2 (31), an afterburner fuel main pipe (32), an ignition fuel pipe (41), and an annular flame stabilizer assembly (42). The nozzle 1 (12) is installed on the casing of the main combustion chamber (1), the nozzle 2 (31) is installed at the inlet of the afterburner diffuser assembly (3), the afterburner fuel main pipe (32) is located in the middle of the diffuser assembly (3), the ignition fuel pipe (41) is located at the inlet of the combustion section of the afterburner combustion chamber (4), and the annular flame stabilizer assembly (42) is located at the rear of the ignition fuel pipe (41).

2. A staged ignition system for an afterburner according to claim 1, characterized in that: The annular flame stabilizer assembly (42) comprises an air inlet nozzle (421), an evaporator tube (422), and an annular flame stabilizer (423). The evaporator tube (422) is provided with a third oil injection hole (4221). Atomized fuel (b) is mixed with the fuel gas (a) entering the air inlet nozzle (421) and flows into the evaporator tube (422), and is injected into the interior of the annular flame stabilizer (423) through the third oil injection hole (4221) on the evaporator tube (422).

3. A staged ignition system for an afterburner according to claim 1 or 2, characterized in that: The afterburner fuel main pipe (32) is a component welded by an afterburner ring pipe (321) and an afterburner fuel injection rod (322), located in the middle of the afterburner diffuser (3), with one end fixed on the inner cone (33) and the other end fixed on the diffuser (3) casing; each afterburner fuel injection rod (322) is arranged with a specific fuel injection hole (3221).

4. A staged ignition system for an afterburner according to claim 3, characterized in that: The ignition fuel pipe (41) is a component welded together by an annular pipe (411) and a fuel injection rod (412), located at the inlet of the combustion section of the afterburner (4), fixed to the annular flame stabilizer (423) through a connecting piece (43), and is detachable. The end surface of the fuel injection rod (412) is provided with two fuel injection holes (4121); the number of the fuel injection rods (412) of the ignition fuel pipe (41) is between 10 and 16, and the fuel injection rods (412) and the air intake nozzle (421) form an angle of 40° to 60°.

5. A staged ignition system for an afterburner according to claim 4, characterized in that: The number of the three oil injection holes (4221) on the evaporating tube (422) is between 20 and 32, and the hole diameter is between φ4 mm and φ6 mm.

6. A staged ignition system for an afterburner according to claim 5, characterized in that: The air inlet grooves (4231) on the front end of the annular flame stabilizer (423) are rectangular, and the number of the air inlet grooves (4231) is the same as the number of the oil injection holes (4221) on the evaporator tube (422).

7. A staged ignition system for an afterburner according to claim 6, characterized in that: The fuel injection holes on the nozzle 1 (12), the nozzle 2 (31), the afterburner fuel main pipe (32), and the ignition fuel main pipe (41) are all circular hole type nozzles, and the flow of fuel (b) in each oil circuit is independently controlled.

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