JP2998352B2 - Ram 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 ram combustor.

[0002]

2. Description of the Related Art In recent years, high-performance turbofan engines used from stationary on the ground to low Mach numbers as engines used for airframes flying at Mach numbers of 2.5 to 5, ram combustors used at Mach numbers of 3 or more. It has been considered to use a combined cycle engine combining the above.

FIG. 3 shows an example of a combined cycle engine.
Turbo fan engine space 11 penetrating in the front-back direction
And an outer shell 1 having a ram combustor space 12 penetrating in the front-rear direction alongside the turbofan engine space 11
3, a compressor 14, a combustor 15, a turbine 16, and the like, a turbofan engine 17 disposed in the turbofan engine space 11, and a ram combustion disposed in the ram combustor space 12. And a cover 19 for an engine space capable of closing a front end of the turbofan engine space 11. In an aircraft having the above-described combined cycle engine, a speed from a stationary state on the ground to a speed of about 3 Mach number is provided. When flying at a speed exceeding the Mach number 3, the front end of the turbofan engine space 11 is closed by the engine space cover 19 and the turbofan engine 1
The flight is performed by the ram combustor 18 in place of 7.

As a ram combustor used in the above-described combined cycle engine, air flows into a cylindrical liner like a main combustor of a gas turbine engine, and fuel is injected into the air flow to mix air and fuel. A fluid burner (a main combustor type ram combustor) and a V burner such as an afterburner additionally provided in the gas turbine engine.
It is considered that a fuel is injected into a flame holder having a blunt form such as a gutter to burn the fuel (flame holder type ram combustor).

[0005]

In the ram combustor used in the above-described combined cycle engine, in order to achieve a flight speed of Mach number 3 or more, an inlet temperature of 6 is required.
Under a wide operating condition of 00 to 1350 ° K, inlet pressure of 1 to 5 atm and inlet Mach number of 0.1 to 0.3, combustion efficiency of 99% or more and pressure loss coefficient of 10 or less (total pressure difference before and after the ram combustor) Divided by the dynamic pressure at the inlet of the ram combustor).

However, the main combustor type ram combustor has:
The larger the pressure loss coefficient is, the faster the flow velocity of the air flowing into the liner is, and the mixing of air and fuel in the liner is promoted and the combustion efficiency is increased. Advantageously, the pressure loss coefficient is large (the pressure loss coefficient of the main combustor of the gas turbine engine capable of achieving a combustion efficiency of 99% or more is 20 or more), and the performance required at a flight speed of Mach number 3 or more is achieved. It is difficult.

On the other hand, in the flame stabilizer type ram combustor, the pressure loss coefficient can be reduced, but the combustion efficiency depends on the length of the circulating flow region formed downstream of the flame stabilizer type ram combustor and the spread of the flame. Even if the shape of the flame stabilizer type ram combustor is devised, it is considered difficult to achieve both a significant improvement in combustion efficiency and a decrease in pressure loss coefficient near Mach number 3 where the inlet temperature and pressure are low.

Further, since it is not expected that the combustion efficiency of the flame-holding type ram combustor is improved, flying the airframe with the flame-holding type ram combustor means that the remaining unburned fuel is removed from the atmosphere and the ozone layer. And cause environmental destruction.

The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a ram combustor capable of achieving required performance at a flight speed of Mach number 3 or more.

[0010]

Means for Solving the Problems To achieve the above object,
Therefore, in the ram combustor of the present invention, a plurality of air
A slit-shaped empty space is formed at the front end of a cylindrical liner
Combustion with a substantially warhead swirler with multiple holes
Flow from the front of the swirler to the liner through the air hole.
Each air hole is designed to provide a swirl force to the incoming airflow.
Girder swirl vanes and a liner incorporated in said swirler
A fuel injection valve capable of injecting fuel into the interior and after the liner
A plurality of V's are provided on the outer periphery of the rear end of the flame stabilizer base provided coaxially
With a flame stabilizer with gutters attached at approximately equal intervals in the circumferential direction
ing.

[0011]

In the ram combustor of the present invention, a plurality of air holes are provided.
From the front of the ram combustor by the swirler
Only part of the airflow flowing backwards is inside the liner.
And most of the airflow flows outside the combustor body .

Also, an air inlet hole is provided from outside the combustor body.
Another air flow into the liner via
The air flow inside the liner to which the turning force is applied is agitated,
Due to the oxygen contained in these air streams, fuel injection valves
The fuel injected from the liner is stable and rich in the liner.
Combustion efficiently.

Further, a circulation area formed behind the V-gutter.
Included in the airflow flowing outside the combustor body
The combustion gas that blows backward from the liner due to the oxygen
The unburned fuel contained in the gas stream is lean and stable.
Combustion efficiently.

As a result, the generation of nitrogen oxides increases.
Avoids combustion near the stoichiometric mixture ratio and suppresses the generation of unburned fuel
Control.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of a ram combustor according to the present invention, in which 1 is a cylindrical liner having a plurality of air inlet holes 2 in the circumferential direction, and 3 is a front A side of the liner 1. The outer shape having a plurality of air holes 4 attached to the end is a swirler of a substantially warhead type, and the liner 1 and the swirler 3 constitute a combustor main body 5. Is provided with a fuel injection valve 6 that can inject fuel F toward the inside of the liner 1.

Each of the air holes 4 is provided with a swirling blade 7 for imparting a swirling force to the air flow flowing into the swirler 3 through the air holes 4.

Reference numeral 8 denotes a flame stabilizer attached to the rear B side end of the liner 1 substantially coaxially with the liner 1. The flame stabilizer 8 is provided on the outer peripheral surface of the rear B side end of the liner 1. It comprises a substantially cylindrical flame stabilizer base 9 externally fitted and fixed, and V-gutters 10 attached to the outer peripheral surface of the flame stabilizer base 9 at substantially equal intervals in the circumferential direction.

The liner 1 is provided with an ignition plug (not shown).

Hereinafter, the operation of the ram combustor according to the present invention will be described.

[0021] ram combustor airflow S ₁ of a given flow rate to the rear from the front of flows, some of air stream S ₁ flows in from the air holes 4 of the swirler 3 to ram combustor, this time, the air stream S ₂ which has flowed into the ram combustor than air holes 4 swirling force is imparted by swirl vanes 7.

On the other hand, most of the airflow S ₁ that has not flowed into the ram combustor flows from the front A side to the rear B
And a circulating flow region is formed on the rear B side of the V-gutter 10 of the flame stabilizer 8, and a part of the air flow S ₁ flows into the liner 1 from the air inlet 2 of the liner 1. Then, the air flow S ₂ is stirred by the air flow S ₃ flowing into the liner 1.

Next, when an excessive amount of fuel F is injected into the liner 1 by the fuel injection valve 6 with respect to the oxygen contained in the air flows S ₂ and S ₃ , the fuel F becomes the air flows S ₂ and S 3. _When the ignition plug provided in the liner 1 is actuated, most of the fuel F is generated in the liner 1 by the oxygen contained in the air flows S ₂ and S ₃ , and the swirl flow from the swirler 7 and the air Stirring with the jet from the inflow hole 2 stably and efficiently burns, and the combustion gas flow S containing the fuel F partially unburned
₄ gushes toward the rear B side end of the liner 1.

Further, in the circulation area of the air flow S ₁ formed on the rear B side of the V-gutter 10, the unburned fuel F in the combustion gas flow S ₄ is stabilized by the oxygen contained in the air flow S ₁ . The ram combustor is continuously burned in a state, and high combustion efficiency can be achieved as a whole ram combustor.

As described above, in the ram combustor of this embodiment,
Since only a part of the air flow S ₁ circulates inside the combustor main body 5 having a large pressure loss coefficient and most of the air flow S ₁ circulates outside the combustor main body 5, the pressure loss coefficient of the ram combustor is reduced. The required performance can be achieved at a flight speed of Mach number 3 or more.

Further, in the above-described ram combustor, since the combustion efficiency is increased, the discharge of unburned fuel F into the atmosphere is suppressed, and no environmental destruction occurs.

As described above, the fuel F burns in the liner 1 in an excessively rich state and the fuel F burns in a lean state behind the flame stabilizer 8, so that unburned fuel is burned from the viewpoint of environmental protection. At the same time, it is possible to avoid combustion in the vicinity of a stoichiometric mixture ratio where a large amount of nitrogen oxides, which are problematic, are generated, thereby suppressing the generation of nitrogen oxides.

It should be noted that the ram combustor of the present invention is not limited to the above-described embodiment, but may be configured to provide an air inlet without a swirler at the front end of the liner. It goes without saying that various changes can be made without departing from the spirit of the invention.

[0029]

According to the above-described ram combustor of the present invention,
The following various excellent effects can be obtained.

(1) A swirler having a plurality of air holes
Accordingly, only a portion of the airflow flowing toward the rear side from the front side of the ram combustor flows into the inner liner, the majority of
Since the air flow circulates outside the combustor body, the pressure loss coefficient of the ram combustor can be reduced, and a flight speed of Mach number 3 or more can be achieved.

(2) An air inlet from outside the combustor body
Another air flow into the liner via
The air flow inside the liner to which the turning force is applied is agitated,
Due to the oxygen contained in these air streams, fuel injection valves
The fuel injected from the liner in an over-concentrated state inside the liner stably and
And efficiently burned can Rukoto.

(3) Circulation area formed behind V-gutter
Included in the airflow flowing outside the combustor body
The combustion gas that blows backward from the liner due to the oxygen
Unburned fuel contained in the gas stream stably and leanly.
Can be efficiently burned, and thus nitrogen oxides
Combustion around the stoichiometric mixture ratio where the generation of
In addition , the combustion efficiency is high and the generation of unburned fuel is suppressed .
Therefore, no environmental destruction occurs.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of a ram combustor according to the present invention.

FIG. 2 is a sectional view of the ram combustor shown in FIG.

FIG. 3 is a conceptual diagram illustrating an example of a combined cycle engine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liner 2 Air inlet 3 Swirler 4 Air hole 5 Combustor main body 6 Fuel injection valve 7 Swirl vane 8 Flame stabilizer 9 Flame stabilizer base 10 V gutter

Continuing on the front page (72) Inventor Takeo Mitsuoka 229 Torogaya, Mizuho-cho, Nishitama-gun, Tokyo Inside the Mizuho Plant, Harima Heavy Industries, Ltd. Harima Heavy Industries Co., Ltd. Mizuho Plant (56) References Jiraku Sho 62-156260 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02K 7/10

Claims (1)

(57) [Claims] 1. A plurality of air inlets are formed in a circumferential direction.
Multiple slit-shaped air holes are drilled at the front end of the cylindrical liner
The combustor body with the substantially warhead swirler
Air flowing into the liner from the front through the air holes.
Swirling vanes provided in each air hole to provide swirling force
And the fuel incorporated into the swirler and into the liner.
A fuel injection valve that can be injected, and a coaxial
Multiple V gutters around the rear end of the flame stabilizer base
A flame burner comprising: a flame stabilizer attached at substantially equal intervals in the direction .