JP2580510B2 - High speed aero engine combustor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustor for a high speed aircraft engine, and more particularly to a main combustor for an afterburner of a turbojet engine and a ram engine of a supersonic aircraft.

[0002]

2. Description of the Related Art In a conventional aviation engine main combustor, a flame stabilizer and a liner forming a combustion area are cooled by flowing air. In addition, in reheat combustion flame stabilizers such as afterburners, conventionally, the speed of an aircraft is at most Mach 2-3.
The airflow temperature was so low that no special cooling other than air cooling was required.

In a conventional engine afterburner flame stabilizer,
During combustion, the fuel is heated by combustion heat. On the other hand, as shown in FIG. 4, liquid fuel is injected from the fuel injector 1 at the front surface of the flame holder 3, and the vaporized heat and sensible heat of the atomized fuel 2 are emitted. This cools the flame stabilizer 3. 4 is a flame formed.

[0004]

Recently, supersonic aircraft of Mach 5 to 6 have been planned. However, in the case of a high-speed engine used in such an aircraft, the air taken in is high speed, The total air temperature in the combustor becomes extremely high, exceeding the heat-resistant temperature of 800 ° C. to 1000 ° C. of the constituent materials of the fuel injector and the flame stabilizer, and the durability of the fuel injector and the flame stabilizer is poor. Become. In addition, when fuel is supplied, there is a high risk that the fuel will ignite spontaneously and burn the flame stabilizer. Further, when the fuel is supplied upstream of the flame stabilizer as in the conventional system, there is a risk that the fuel is ignited and the flame stabilizer is burned during the fuel supply. In particular, there is a problem that the heat transfer coefficient becomes maximum near the stagnation point of the flame stabilizer and the temperature rises. The present invention seeks to increase the durability of the fuel injector and the flame stabilizer by effectively cooling or insulating the portions exposed to high temperatures as described above.

[0005]

In order to achieve the above object,
In the combustor according to the present invention, the fuel chamber is disposed immediately before the stagnation point of the flame stabilizer to prevent the tip of the flame stabilizer from being directly exposed to the high-temperature air flowing in, and to move the fuel along the flame stabilizer surface. The fuel flow cools the flame holder.
On the other hand, the fuel chamber is cooled by the fuel flowing therein. The above-mentioned fuel chamber is desirably formed integrally with the tip of the flame stabilizer.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A combustor according to the present invention will be described below in detail with reference to embodiments. FIG. 1 is a partial sectional view of a first embodiment of the combustor of the present invention, and the same parts as those in FIG. 4 are denoted by the same reference numerals. The fuel injector is disposed immediately before the tip of the flame stabilizer 3 and is configured as a ring-shaped fuel pipe 5 which also serves as a passage for a gas or liquid fuel such as natural gas or hydrogen, and is provided on the flame stabilizer side. Opening 6 such as a small hole or slit provided
The fuel injected from the tank flows along the surface of the flame holder 3,
The fuel film 7 is formed. In this embodiment, the fuel pipe 5
Is cooled by the fuel flowing through it, while the flame holder is prevented from being directly exposed to the incoming hot air blocked at its tip by the fuel tube 5. Further, the fuel film 7 on the surface of the flame stabilizer main body formed by the injected fuel,
The flame stabilizer body 3 is shut off from the hot air. Furthermore, the flame holder 3 is heated by the formed flame 4 and the recirculating flow 8, but is cooled by the flow of the fuel film 7. In this embodiment, since the fuel tube 5 and the flame stabilizer main body 3 can be made of different materials, the difference in thermal expansion due to the difference in the ultimate temperature during operation is determined by appropriately selecting the expansion coefficient of each material. Can be suppressed.

FIG. 2 shows a second embodiment, in which a fuel pipe 5 is formed integrally with the tip of a flame stabilizer main body 3. In this embodiment, the fuel flows out of the opening 6 provided in the fuel pipe 5 directly along the surface of the flame stabilizer main body 3 to cool the flame stabilizer 3. Since the cooled fuel is vaporized or atomized, good combustion can be performed in the combustion region.

FIG. 3 shows a third embodiment. In this embodiment, the combustor is formed as a full-pressure damming plate covering a flame stabilizer main body 3 integrally provided with a fuel pipe 5 and its tip. It is composed of a cover 9 arranged. In this embodiment, the fuel is ejected from the opening 6 to the inner surface of the cover 9 to cool the cover 9. The fuel that has cooled the cover 9 flows out along the outer surface of the flame stabilizer main body 3 to cool the flame stabilizer.
In the combustor of this embodiment, the high-temperature air flow collides, the heat transfer is the largest, and the front surface of the fuel tube, which is the tip of the flame stabilizer whose temperature rises, can be cooled by the fuel. Further, the flow of the fuel ejected in opposition to the mainstream is stabilized, and the flame stabilizer hardly causes vibration combustion or the like.

[0009]

As described above, in the combustor of the present invention, the total temperature of the air flowing into the high-speed flight engine is extremely high, but the end of the flame stabilizer is cooled by the fuel, so that the durability is greatly improved. I can do it. In addition, the flame stabilizer main body has a remarkable effect such as being able to suppress an increase in wall surface temperature due to heat of vaporization even for a high-temperature air flow due to film cooling by fuel.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a first embodiment of a combustor according to the present invention.

FIG. 2 is a partial sectional view of a second embodiment of the combustor according to the present invention.

FIG. 3 is a partial sectional view of a third embodiment of the combustor according to the present invention.

FIG. 4 is a partial sectional view of a conventional combustor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Fuel injector 2 Atomized fuel 3 Flame stabilizer
4 Flame 5 Fuel pipe 6 Opening 7 Fuel film
8 Recirculation flow 9 Cover

Claims (4)

(57) [Claims] 1. A high speed aviation engine characterized by disposing a fuel chamber immediately before a stagnation point of a flame stabilizer, discharging fuel along a surface of the flame stabilizer, and cooling the flame stabilizer by the fuel flow. For combustor 2. A combustor for a high-speed aero engine according to claim 1, wherein a fuel pipe is integrally provided at an upstream end of the flame stabilizer. 3. The combustor according to claim 1, wherein fuel is injected into an inner surface of a cover formed as a full pressure dam plate provided upstream of the flame stabilizer. 4. The combustor for a high speed aero engine according to claim 3, wherein the fuel cooled in the cover upstream of the flame stabilizer performs film cooling of the flame stabilizer main body.