JPH07279759A - Ram combustion device - Google Patents

Abstract

PURPOSE:To improve combustion efficiency in a wide flying Mach number range by adopting a main combustor type flame holder, arranging first fuel nozzle in the central position and second fuel nozzle on the side, respectively, and also arranging a swirler on the front end outer wall of the main combustor type flame holder. CONSTITUTION:A ram combustion device 20 has a plurality of main combustor type flame holder 10 on the inner wall of a combustor duct 2 in a condition of being supported by a supporting beam 9, for example, leaving a space in the circumferential direction of the combustor duct 2, and a plurality of gutter type flame holder 11 in the position nearby a downstream opening leaving a space in the circumferential direction. A fuel feeding first fuel nozzle 21 feeding fuel to the central position is arranged in the front end of the flame holder 10 and second fuel nozzle 22 on the side of the flame holder 10. In this case, the interior of the flame holder is prevented from becoming thick in fuel flowing condition by providing a swirler 23, which takes in a part of air flow into the interior of the flame holder 10 as swirling it, in the front end of the flame holder 10 on the outer wall around first fuel nozzle 21 in a piercing condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ram combustion device,
In particular, the present invention relates to a technique for operating a ramjet engine with high combustion efficiency in a wide flight Mach number range.

[0002]

2. Description of the Related Art Although a ramjet engine does not have an air compressor like a gas turbine engine, it is designed to compress the air flowing into a combustor duct at high speed by using ram pressure. It is thought that combustion efficiency can be improved as the structure is simple and the navigation speed of the airframe becomes higher. For example, it is applicable to supersonic aircraft and space vehicles with navigation speeds of Mach number 2.5 to 5. Being researched.

FIG. 3 shows a schematic structure of a ramjet engine. Reference numeral 1 is a diffuser, 2 is a combustor duct, 3 is a combustion chamber, 4 is a jet nozzle, and 5 is a combustion device (ram combustion device). . Then, as the combustion device 5, those shown in FIGS. 4 and 5 have been proposed.

The combustion apparatus 5 of FIG. 4 has a plurality of fuel nozzles 6 arranged inside a cylindrical combustor duct 2.
An annular frame holder (flame stabilizer) 7 is arranged at a position downstream of each fuel nozzle 6, and a spark plug 8 is provided in the vicinity of the frame holder 7.
Fuel nozzle 6 and frame holder 7
Are supported on the inner surface of the combustor duct 2 by a plurality of cantilever-shaped support beams 9 arranged at intervals in the circumferential direction. Then, the fuel is injected from the plurality of ejection holes 6a of the fuel nozzle 6 into the air flow G indicated by the arrow to form a mixed flow, and the spark plug 8
In addition to igniting the mixed flow, the V-shaped cross section of the frame holder 7 generates a low flow velocity region in which there is much turbulence in the subsequent flow, and flame holding for maintaining a combustion state is performed.

In the combustion apparatus 5 shown in FIG. 4, when the air is compressed by an appropriate ram pressure as in the case of high Mach, the mixed flow of air and fuel becomes a low speed region behind the frame holder 7. Based on this, in addition to maintaining the combustion state, the mixing and stirring of air and fuel is promoted, and high combustion efficiency can be obtained.

On the other hand, in the combustion apparatus 5 of the example of FIG. 5, a hollow hemispherical main combustor type flame stabilizer 10 is arranged in the combustion chamber 3 of the cylindrical combustor duct 2 and the main combustor type flame stabilizer is provided. The main combustor type flame stabilizer is configured so that the gutta type flame stabilizers 11 are circumferentially spaced on the downstream side outer periphery of the chamber 10 and the fuel nozzle 12 is connected to the main combustor type flame stabilizer 10. The portions of 10 and the gutta-type flame stabilizer 11 are supported by a plurality of cantilever-shaped support beams 9. Then, when the fuel supply system 13 is operated, fuel is injected from the fuel nozzle 12 to be ignited by the spark plug 8 and, while performing flame holding based on the shape of the main combustor type flame stabilizer 10, while maintaining the gutta type flame holding flame. The V-shaped cross section of the vessel 11 is used to generate a low flow velocity region with a large amount of turbulence to achieve complete combustion by mixing the combustion flame and air.

[0007]

However, when the combustion device 5 has the structure shown in FIG. 4, the combustor utilizing ram pressure is used in a low supersonic navigation state or a subsonic navigation state in which the Mach number is small. The airflow inside the duct 2 cannot be compressed sufficiently and the air temperature rises insufficiently, so that the combustion efficiency is lowered and the ignitability of fuel is adversely affected. . Further, in the case where the combustion device 5 has the structure of the example of FIG. 5, in the supersonic navigation state in which the Mach number is large, when the fuel supply amount from the fuel nozzle 12 is increased, the main combustor flame stabilizer 10 is provided with The increase in the amount of air introduced from the air introduction hole 10a cannot be followed, and the main combustor type flame stabilizer 1
It is conceivable that the inside of 0 will be in a fuel rich state and the phenomenon of flame blowout will occur and combustion efficiency will decrease.

The present invention has been made in view of these problems, and has the following objects in addition to improving the combustion efficiency in a wide flight Mach number range. To prevent the inside of the main combustor type flame stabilizer from becoming fuel rich and improve the combustion efficiency in a wide flight Mach number range. Prevent the occurrence of the flame blowout phenomenon inside the main combustor type flame stabilizer. To achieve high engine output by increasing the amount of combustion.

[0009]

As a ram combustion device, a main combustor type flame stabilizer arranged in the air flow of a combustor duct for burning the supplied fuel, and a front end of the main combustor type flame stabilizer. A first fuel nozzle that is disposed in the center and supplies fuel to a central position;
A second fuel nozzle, which is arranged on the side of the main combustor flame stabilizer and supplies fuel to a position near the inner circumference, and a part of the air flow which is arranged in a penetrating state on the outer wall of the front end of the main combustor flame stabilizer. Is adopted in the main combustor type flame stabilizer while being swirled. An airflow isolation wall is arranged between the first fuel nozzle and the swirler so as to surround the tip end of the first fuel nozzle. The fuel supply position of the second fuel nozzle is set to a position downstream of the swirler, and the second fuel nozzle is provided with fuel ejection holes for ejecting fuel at a plurality of locations inside the main combustor type flame stabilizer. It

[0010]

From the first fuel nozzle, fuel is supplied to the inner center of the main combustor type flame stabilizer and ignited. When the fuel is supplied from the second fuel nozzle to a position near the inner circumference of the main combustor type flame stabilizer, the fuel is ignited by the flame near the inner center of the main combustor type flame stabilizer and the combustion range is expanded. . As the air velocity in the combustor duct increases, a part of the air flow is taken in via the swirler, which creates a swirling flow of gas inside the main combustor type flame stabilizer and mixes the fuel and air. Facilitate. The fuel ejected from the first fuel nozzle and the air passing through the swirler are guided in a state of being isolated up to the periphery of the tip of the first fuel nozzle by the airflow isolation wall. Therefore, the flame holding property in the range surrounded by the airflow isolation wall near the tip of the first fuel nozzle is improved. When the fuel supply position by the second fuel nozzle is a position downstream of the swirler,
Fuel is dispersed inside the main combustor flame stabilizer by using the swirling airflow by the swirler, and the fuel is ejected from multiple fuel ejection holes, so that the entire area inside the main combustor flame stabilizer is released. , The fuel and air are mixed to achieve complete combustion, and the main combustor type flame stabilizer is maintained while the mixing ratio of the fuel and air inside the main combustor type flame stabilizer is maintained within the set range. The combustion amount of the vessel increases.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a ram combustion device according to the present invention will be described below with reference to FIGS. 1 and 2, reference numeral 20 is a ram combustion device, 21 is a first fuel nozzle, 22 is a second fuel nozzle, 23 is a swirler, 24 is an airflow separating wall, 25 is fuel control means, and 26 is fuel control. Reference numeral 27 is a fuel supply means for ignition, and 28 is a fuel supply means for main combustion.

In the ram combustor 20, a plurality of main combustor types are arranged, for example, in a state of being supported by the support beams 9 on the inner wall of the combustor duct 2 and spaced apart in the circumferential direction of the combustor duct 2. A flame stabilizer 10, a plurality of gutter type flame stabilizers 11 arranged circumferentially at a position near the downstream opening of the main combustor type flame stabilizer 10, and a main combustor type flame stabilizer 10 The first fuel nozzle 21 which is arranged at the front end (upstream wall) of the main fuel and which supplies fuel to the central position, and the fuel which is arranged on the side of the main combustor type flame stabilizer 10 and near the downstream of the swirler 23. The second fuel nozzle 22 and the front end of the main combustor type flame stabilizer 10 and the outer wall around the first fuel nozzle 21 are arranged in a penetrating state so that a part of the air flow is transferred to the main combustor type flame stabilizer 10. The swirler 23, which is swirled in while being swirled, and the first fuel nozzle 21
And fuel control means 2 connected to the second fuel nozzle 22
5 and.

The second fuel nozzle 22 has a fuel supply pipe 22a for supplying the fuel from the main combustion fuel supply means 28 to the inside of the main combustor type flame stabilizer 10, and the fuel supply pipe 22a. A plurality of fuel headers 22b connected to each other and arranged on the side wall of the main combustor type flame stabilizer 10 and a plurality of communicating the fuel header 22b and the inside of the main combustor type flame stabilizer 10 at a position near the downstream of the swirler 23. It has a fuel ejection hole 22c.

The airflow separating wall 24 is formed in a cylindrical shape, and the first fuel nozzle 21 is surrounded by the first fuel nozzle 21 and the swirler 23 so as to surround the tip end of the first fuel nozzle 21. It is arranged so as to project further downstream than the tip of 21 and the swirler 23. Inside the airflow isolation wall 24, as shown in FIG. 1, the spark plug 8 is arranged.

In the fuel control means 25, the fuel supply amount required for ignition or maintaining the flight Mach number is calculated, and the fuel to the first fuel nozzle 21 and the second fuel nozzle 22 is fueled. Fuel control unit 26 for setting the distribution ratio according to the Mach number in the ignition mode and the flight mode
And the first fuel nozzle 21 and the second fuel nozzle 22 are interposed, and the ignition fuel supply means 27 and the main fuel supply means 27 for supplying fuel according to the fuel distribution ratio are instructed by the fuel controller 26. And a fuel supply means 28 for combustion.

The ram combustion device 2 configured as described above
At 0, when the ignition mode is selected, the fuel is supplied only to the first fuel nozzle 21 and burned. That is, the fuel control unit 26 calculates the fuel supply amount required for ignition, and the ignition fuel supply unit 2
The fuel is injected from the first fuel nozzle 21 by the operation of No. 7, and the fuel concentration is increased inside the main combustor type flame stabilizer 10, especially in the atmosphere surrounded by the airflow separating wall 24, and the spark plug 8 By activating, the fuel supplied to the inner center of the main combustor type flame stabilizer 10 is ignited, and the combustion state is continued.

When the flight mode is selected, combustion is performed with the fuel supply to the first fuel nozzle 21 and the fuel supply to the second fuel nozzle 22 added. From the second fuel nozzle 22, the main combustor type flame stabilizer 1
When the fuel is supplied to the position near the inner periphery of 0, the flame is ignited by the flame downstream of the airflow isolation wall 24 formed near the inner center of the main combustor type flame stabilizer 10, and the combustion range is expanded. Then, the combustion flame F spreads throughout the combustion chamber 3.

At this time, the fuel control unit 26 sets conditions such as the amount of air inserted into the combustor duct 2 corresponding to the flight Mach number, and the amount of air taken into the main combustor type flame stabilizer 10 by the swirler 23. The fuel supply amount to the first fuel nozzle 21 and the second fuel nozzle 22 is calculated, and the combustion flame F is calculated.
To induce a complete combustion state.

Since the air velocity in the combustor duct 2 increases as the flight Mach number increases, the amount of air taken into the main combustor type flame stabilizer 10 via the swirler 23 is substantially proportional. growing. Therefore, it becomes possible to adjust the relationship between the fuel supply amount and the air supply amount inside the main combustor type flame stabilizer 10 and the air-fuel ratio to the optimum state, and the inside of the main combustor type flame stabilizer 10 can be adjusted. Suppress the occurrence of fuel rich condition.

The air taken into the main combustor type flame stabilizer 10 is made by taking in a part of the air flow G through the swirler 23 as shown in FIG. A swirl vortex A is generated downstream of the swirler 23 as shown by a chain line arrow, and the fuel from the first fuel nozzle 21 and the fuel from the second fuel nozzle 22 is entrained to promote mixing of the fuel and air. Let

The fuel supplied to the main combustor type flame stabilizer 10 is the first fuel nozzle 21 and the second fuel nozzle 2.
2 is performed via the first fuel nozzle 21, the fuel is supplied to the central portion of the main combustor flame stabilizer 10 by the first fuel nozzle 21, and Fuel supply to the periphery is added. Therefore, the fuel injected from the second fuel nozzle 22 is sent to the central portion of the main combustor type flame stabilizer 10 by the vortex B shown by the broken line at the center of the swirling vortex A to promote mixing. in this way,
In the main combustor type flame stabilizer 10, mixing is promoted by sending fuel into the swirling vortex A from inside and outside, and combustion efficiency is improved.

When the airflow separating wall 24 is disposed between the first fuel nozzle 21 and the swirler 23, the combustion flame of the fuel injected from the first fuel nozzle 21 is at least in the airflow separating wall 24. Even if the amount of air changes due to an increase or decrease in the flight Mach number without being affected by the swirling vortex A inside, stable combustion is performed and flame holding performance is improved.

Further, downstream of the main combustor type flame stabilizer 10, further mixing with the air flow G of the combustor duct 2 is performed based on the shapes of the main combustor type flame stabilizer 10 and the gutta type flame stabilizer 11. As a result, the combustion flame F in the complete combustion state is obtained.

[0024]

The ram combustion apparatus according to the present invention has the following excellent effects. (1) A main combustor type flame stabilizer is adopted, a first fuel nozzle for supplying fuel is arranged at a central position, a second fuel nozzle is arranged on a side portion, and a main combustor type flame stabilizer is arranged. By adopting a configuration in which a swirler is arranged on the outer wall of the front end of the, the intake of air and the combustion of fuel according to the flight Mach number are performed inside the main combustor type flame stabilizer to increase the combustion amount of fuel. Moreover, it is possible to prevent the inside of the main combustor type flame stabilizer from being in a fuel rich state, and improve the combustion efficiency in a wide flight Mach number range. (2) By arranging an airflow isolation wall between the first fuel nozzle and the swirler to isolate it from the airflow taken into the main combustor type flame stabilizer, It is possible to prevent the phenomenon of blowing out the flame. (3) The fuel supply position of the second fuel nozzle is set to a position downstream of the swirler, so that the fuel joins the swirling air flow of the swirler to improve the mixing property and further improve the fuel efficiency. be able to. (4) The second fuel nozzle is provided with fuel injection holes for injecting fuel to a plurality of locations inside the main combustor type flame stabilizer, so that the swirling air flow by the swirler and the fuel supply from a plurality of locations in the circumferential direction are provided. Is performed to bring the fuel and air into a uniform mixed state, and the combustion amount by the main combustor type flame stabilizer is increased, so that a high output of the engine can be achieved.

[Brief description of drawings]

FIG. 1 is a front sectional view including a block diagram showing a first embodiment of a ram combustion device according to the present invention.

FIG. 2 is a cross-sectional view near the swirler in FIG.

FIG. 3 is a front sectional view showing a schematic structure of a ramjet engine.

FIG. 4 is a front sectional view showing a conventional structure example of a ram combustion device.

FIG. 5 is a front sectional view showing another example of the conventional structure of the ram combustion device.

[Explanation of symbols]

 G Airflow 2 Combustor duct 3 Combustion chamber 8 Spark plug 9 Support beam 10 Main combustor type flame stabilizer 11 Gutta type flame stabilizer 20 Ram combustion device 21 First fuel nozzle 22 Second fuel nozzle 22a Fuel supply pipe 22b Fuel header 22c Fuel injection hole 23 Swirler 24 Airflow isolation wall 25 Fuel control means 26 Fuel control section 27 Fuel supply means for ignition 28 Fuel supply means for main combustion F Combustion flame A Swirling vortex B Vortex

Claims (4)

[Claims] 1. A ram combustion device mounted inside a combustor duct of a ramjet engine, wherein the main combustor type protector is arranged in the air flow of the combustor duct (2) and burns the supplied fuel. A flamer (10), a first fuel nozzle (21) arranged at a front end of the main combustor type flame stabilizer to supply fuel to a central position, and arranged on a side portion of the main combustor type flame stabilizer. A second fuel nozzle (22) for supplying fuel to a position near the inner circumference;
A ram combustion characterized by comprising a swirler (23) which is arranged in a penetrating state on the outer wall of the front end of the main combustor type flame stabilizer and takes in a part of the airflow while swirling it inside the main combustor type flame stabilizer. apparatus. 2. An airflow isolation wall (24) is disposed between the first fuel nozzle (21) and the swirler (23) so as to surround the tip of the first fuel nozzle. The ram combustion device according to claim 1. 3. The ram combustion device according to claim 1, wherein the fuel supply position of the second fuel nozzle (22) is set at a position downstream of the swirler (23). 4. The second fuel nozzle (22) is provided with fuel ejection holes (22c) for ejecting fuel at a plurality of locations inside the main combustor type flame stabilizer (10). The ram combustion device according to claim 1, 2 or 3.