JP6615641B2 - Centrifugal spray combustor and flying body equipped with the same - Google Patents

Description

  The present invention relates to a centrifugal spray combustor and a flying body provided with the same.

  A centrifugal spray combustor is used as a flying body engine (Patent Document 1). This centrifugal spray combustor used a fuel that had been widely distilled from gasoline to kerosene (for example, JP-4, which is a hydrocarbon fuel having a carbon content of about C8.5). On the other hand, in recent years, there is a tendency to use kerosene-based fuel (for example, hydrocarbon fuel JetA-1 having a carbon content of about C11), which is a low-cost and low-quality fuel from the viewpoint of cost reduction.

JP-A-8-32370

However, kerosene-based fuel has a larger viscosity coefficient and surface tension than gasoline-based fuel, so that fuel atomization is insufficient and combustion efficiency is lowered.
Therefore, it is necessary to develop a centrifugal spray combustor that can atomize the fuel more.

  The present invention has been made in view of such circumstances, and can improve the combustion efficiency even for a low-quality fuel such as kerosene fuel JetA-1 compared to gasoline fuel JP-4. An object of the present invention is to provide a centrifugal spray combustor and a flying body equipped with the same.

In order to solve the above problems, the centrifugal spray combustor of the present invention and the flying body equipped with the same employ the following means.
That is, a centrifugal spray combustor according to the present invention rotates around a central axis, and sprays fuel supplied to the inside from a spray hole of a fuel nozzle formed on the outer periphery toward the outer periphery, A combustion chamber that is provided on the outer peripheral side of the rotating body and burns fuel sprayed from the spray holes, and the diameter of the spray holes is 0.044 times to 0. 0 with respect to the rotation radius of the fuel nozzle. It is characterized by being 116 times.

The fuel supplied to the rotating body is guided to the fuel nozzle and sprayed from the spray hole toward the outer peripheral side by centrifugal force. The fuel sprayed on the outer peripheral side of the fuel nozzle is guided to the combustion chamber and mixed with an oxidant (for example, air) to be burned. The combustion gas formed in the combustion chamber is guided to, for example, a turbine and rotationally drives the turbine.
The hole diameter of the spray hole was set to 0.044 to 0.116 times the rotation radius of the fuel nozzle. In this way, by setting the hole diameter of the spray hole large and increasing the area of the inner peripheral surface of the spray hole, the film thickness of the fuel flowing along the inner peripheral surface of the spray hole is reduced, and the fuel fine particles Can be promoted.
For example, when the rotation radius of the fuel nozzle is 43 mm, the diameter of the spray hole is preferably 1.9 mm to 5 mm. The upper limit of the hole diameter of the spray hole depends on the size of the upstream space facing the spray hole. When the width of the space in the central axis direction is 8.5 mm, the upper limit of the hole diameter is 5 mm.
The rotation radius of the fuel nozzle means the distance from the rotation center at the outer peripheral end of the fuel nozzle.

  Furthermore, in the centrifugal spray combustor according to the present invention, the rotation radius of the fuel nozzle is 43 mm to 113 mm.

  Centrifugal force can be increased by setting the rotation radius of the fuel nozzle to 43 mm to 113 mm. Thereby, the film thickness of the fuel can be reduced and atomization of the fuel can be promoted.

  Furthermore, in the centrifugal spray combustor of the present invention, the spray hole has a hole length of 0.070 to 0.086 times the rotation radius of the fuel nozzle.

The hole length of the spray hole was set to be 0.070 to 0.086 times the rotation radius of the fuel nozzle, and the hole length was set short. Thereby, the Weber number of the fuel flowing through the spray holes can be reduced, and the atomization of the fuel can be promoted.
For example, when the rotation radius of the fuel nozzle is 43 mm, the hole length is desirably 3 mm to 3.7 mm. The lower limit of the hole length, 3 mm, is set as a dimension that can be processed thinly. In this case, the width of the upstream space facing the spray hole in the direction of the central axis is, for example, 8.5 mm.

  Furthermore, in the centrifugal spray combustor according to the present invention, the spray hole is inclined toward an oxidant supply unit provided in the combustion chamber.

By inclining the spray holes toward the oxidant supply section provided in the combustion chamber, the fuel sprayed from the spray holes can collide with the flow of the oxidant. Thereby, the fuel flow is easily torn off and the atomization of the fuel can be promoted.
The inclination angle of the spray hole is, for example, 0 ° (not including 0 °) to 75 ° when the radial direction orthogonal to the rotation axis is 0 °.

  Furthermore, in the centrifugal spray combustor of the present invention, a plurality of the spray holes are formed at an angular pitch of 45 ° or less around the outer periphery of the fuel nozzle.

  Many spray holes are formed by forming a plurality of spray holes at an angular pitch of 45 ° or less around the outer periphery of the fuel nozzle. Thereby, it can be set as the spray concentration uniform in the circumferential direction, and combustion efficiency can be improved.

  Furthermore, in the centrifugal spray combustor of the present invention, a plurality of the spray holes are formed, and outlets of the spray holes are formed so as to be shifted in the central axis direction.

Since the outlet of each spray hole is formed so as to be shifted in the central axis direction, the spray concentration can be uniform in the central axis direction, and the combustion efficiency can be improved.
For example, each spray hole can have a staggered arrangement in which adjacent spray holes are alternately shifted in the central axis direction.

  Moreover, the flying body of the present invention includes the centrifugal spray combustor described in any of the above, and a turbine driven by combustion gas generated by the centrifugal spray combustor.

  Since any one of the above centrifugal spray combustors is provided, a flying object including a propulsion device with good combustion efficiency can be provided.

  Since the atomization performance can be improved, combustion efficiency can be improved even for a low-quality fuel such as kerosene fuel JetA-1 as compared with gasoline fuel JP-4.

It is the longitudinal section showing the centrifugal spray combustor concerning a 1st embodiment of the present invention. It is the elements on larger scale which expanded and showed the principal part of the centrifugal spray combustor of FIG. It is the elements on larger scale which expanded and showed the principal part of the centrifugal spray combustor of FIG. FIG. 2 is a perspective view showing a plurality of spray holes formed in the fuel nozzle of FIG. 1. It is the longitudinal cross-sectional view which showed the centrifugal spray combustor which concerns on 2nd Embodiment of this invention. The principal part of the centrifugal spray combustor which concerns on 3rd Embodiment of this invention is shown, (a) is the perspective view in which the several spray hole formed in the fuel nozzle was shown, (b) showed the surroundings of the fuel nozzle It is a longitudinal cross-sectional view.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
The first embodiment of the present invention will be described below.
The principal part of the centrifugal spray combustor 1 which concerns on this embodiment is shown by FIG. The centrifugal spray combustor 1 is used as a combustor of a flying body engine (propulsion device).

  The centrifugal spray combustor 1 includes a rotating body 3 that rotates around a central axis (rotating axis) A1 and a combustion chamber 5 that is positioned on the outer peripheral side of the rotating body 3.

  The rotating body 3 includes a cylindrical portion 3a and a disc portion 3b connected to one end of the cylindrical portion 3a. The cylindrical portion 3a and the disc portion 3b are integrally formed, and a communicating space 3c is formed inside these portions. A fuel F such as a low-quality kerosene-based fuel JetA-1 having a viscosity coefficient and a surface tension larger than those of JP-4 is supplied to the space 3c from the direction of arrow B1 from a fuel supply unit (not shown).

The cylindrical portion 3a has a hollow pipe shape and serves as an introduction portion that supplies the fuel F to the disk portion 3b side.
The disc part 3b is connected to the downstream end part of the cylindrical part 3a, and has an outer diameter larger than that of the cylindrical part 3a. A fuel nozzle 3d for spraying fuel F is provided on the outer periphery of the disc portion 3b. The radius of the disk portion 3b is the rotation radius R of the fuel nozzle 3d, and this rotation radius R is the distance from the central axis A1 to the outer peripheral end of the fuel nozzle 3d.

  A plurality of spray holes 3e are formed in the fuel nozzle 3d. Each spray hole 3e is formed perpendicular to the central axis A1 and radially. As shown in FIG. 2, the inner diameter of the spray hole 3e is d, and the hole length is L. As shown in FIG. 3, the hole diameter d of the spray hole 3e is smaller than the axial distance D at the outer peripheral end 3c1 of the space 3c facing the upstream end of the spray hole 3e.

  The combustion chamber 5 is fixed to the main body side of the flying body, and is provided so as to cover the outer peripheral side of the fuel nozzle 3d of the rotating body 3. The combustion chamber 5 has a connection portion 5a at a position facing the fuel nozzle 3d, and an ignition combustion portion 5b on the outer peripheral side of the connection portion 5a. A dilution section 5c is provided on the downstream side (right side in FIG. 1) in the direction of the central axis A1 of the ignition combustion section 5b. A turbine (not shown) is provided on the downstream side of the dilution section 5c.

  A primary air supply part 7a for supplying air as an oxidant is provided on the wall part (right side wall part in FIG. 1) 5a1 of the connection part 5a located on the opposite side to the cylindrical part 3a. The ignition / combustion unit 5b is provided with an ignition / combustion air supply unit 7b for supplying ignition / combustion air and an ignition plug 9 for ignition. A dilution air supply unit 7c for dilution is provided between the ignition combustion unit 5b and the dilution unit 5c.

The centrifugal spray combustor 1 configured as described above operates as follows.
Fuel F is supplied from a fuel supply unit (not shown) to the space 3c in the cylindrical portion 3a of the rotor 3. The fuel F flows radially outward in the disk portion 3b by centrifugal force rotating around the central axis A1 while passing through the cylindrical portion 3a. The fuel F reaches the spray hole 3e of the fuel nozzle 3d, passes through the spray hole 3e, and is guided into the combustion chamber 5.
When the fuel F is detached from the spray hole 3e of the fuel nozzle 3d, the fuel F is atomized and guided into the connection portion 5a of the combustion chamber 5. The fuel F guided to the connection part 5a is guided to the ignition combustion part 5b while being mixed with the air supplied from the primary air supply part 7a. In the ignition combustion part 5b, it is made to ignite and burn with the air supplied from the ignition combustion air supply part 7b. At the time of ignition, a spark plug 9 is used.

The combustion gas ignited and combusted in the ignition / combustion unit 5b is introduced into the dilution unit 5c after being diluted with the air supplied from the dilution air supply unit 7c.
The combustion gas guided to the dilution unit 5 c is guided to a turbine (not shown) located outside the combustion chamber 5. The turbine is rotationally driven around the central axis A1 by the combustion gas, and generates a propelling force of the flying body. A part of the rotational power of the turbine is used as the rotational power of the rotating body 3.

The diameter d of the spray hole 3e of the fuel nozzle 3d of the present embodiment is 0.044 times to 0.116 times the rotation radius R of the fuel nozzle 3d. Thus, the atomization of the fuel F can be promoted by setting the hole diameter of the spray hole 3e large. Specifically, as shown in FIG. 2, since the fuel F flowing in the spray hole 3e flows along the inner peripheral surface of the spray hole 3e, the diameter of the spray hole 3e is increased to increase the area of the inner peripheral surface. By increasing the thickness, the film thickness t of the fuel F is reduced. Thereby, atomization of the fuel F is promoted. Therefore, the combustion efficiency can be improved even for a low-quality fuel such as kerosene-based fuel JetA-1.
For example, when the rotation radius R of the fuel nozzle 3d is 43 mm, the hole diameter d of the spray hole 3e is preferably 1.9 mm to 5 mm. The upper limit of the hole diameter d of the spray hole 3e depends on the size of the upstream space 3c facing the spray hole 3e, and the axial distance D (see FIG. 3) which is the width in the central axis direction of this space is 8. In the case of 5 mm, the upper limit of the hole diameter is 5 mm.

  Furthermore, the rotation radius R of the fuel nozzle 3d is preferably 43 mm to 113 mm. As described above, the centrifugal radius can be increased by increasing the rotation radius R. Thereby, the film thickness t of the fuel F can be made smaller and atomization of the fuel F can be promoted.

Furthermore, it is preferable that the hole length L of the spray hole 3e is 0.070 to 0.086 times the rotation radius R of the fuel nozzle 3d. Thus, by setting the hole length L short, the number of Webers of the fuel F flowing through the spray holes 3e can be reduced, and the atomization of the fuel can be further promoted.
For example, when the rotation radius R of the fuel nozzle 3d is 43 mm, the hole length L is desirably 3 mm to 3.7 mm. The lower limit of 3 mm for the hole length L is set as a dimension that can be processed thinly. In this case, the axial distance D, which is the width in the central axial direction of the upstream space 3c facing the spray hole 3e, is, for example, 8.5 mm.

Furthermore, as shown in FIG. 4, it is preferable to set a large number of the plurality of spray holes 3e formed on the outer peripheral surface of the fuel nozzle 3d. Specifically, the spray holes 3e are formed at an angular pitch of 45 ° or less around the outer periphery of the fuel nozzle 3d. For example, the number of spray holes 3e is preferably 32 or less.
Thus, by forming many spray holes 3e, it is possible to obtain a uniform spray concentration in the circumferential direction, and to improve the combustion efficiency.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that the direction of the spray hole 3e is different, and the others are the same. Therefore, the same reference numerals are assigned to configurations common to the first embodiment, and the description thereof is omitted.

The spray hole 3e of this embodiment is inclined toward the primary air supply part 7a side (the opposite side to the cylindrical part 3a) provided in the connection part 5a of the combustion chamber 5. That is, the inclination angle α of the spray hole 3e is set to 0 ° (not including 0 °) to 75 ° when the radial direction orthogonal to the central axis A1 is set to 0 °.
For example, when the rotation radius R of the fuel nozzle 3d is 43 mm, the spray hole 3e from the orthogonal plane P1 with respect to the central axis A1 passing through the corner portion 3c2 on the cylindrical portion 3a side of the outer peripheral end 3c1 of the space 3c of the disc portion 3b. The distance x in the direction of the central axis A1 to the center of the outlet portion is set to 0 (not including 0) to 13.1 mm. The maximum value of the distance x of 13.1 mm is the hole center position when the spray hole 3e outlet is positioned most downstream in the axial direction (right side in FIG. 5) when the minimum hole diameter d is 1.9 mm. . Further, 75 ° which is the maximum value of the inclination angle α of the spray hole 3e is a value at this position. At this time, the hole length L of the spray hole 3e is 3 mm, and the inlet (upstream) position of the spray hole 3e is a position closest to the corner 3c2 on the cylindrical part 3a side.

  Thus, in this embodiment, the fuel F sprayed from the spray hole 3e is 1 by inclining the spray hole 3e toward the primary air supply part 7a provided in the connection part 5a of the combustion chamber 5. It can collide with the next air flow. Thereby, the flow of the fuel F becomes easy to be torn off, and atomization of the fuel F can be promoted.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that the positions of the spray holes 3e are different, and the others are the same. Therefore, the same reference numerals are assigned to configurations common to the first embodiment, and the description thereof is omitted.

  As shown in FIG. 6A, the outlets of the spray holes 3e are formed so as to be shifted in the direction of the central axis A1. Specifically, each spray hole 3e has a staggered arrangement in which adjacent spray holes 3e are alternately shifted in the direction of the central axis A1.

As shown in FIG. 6B, the position of the outlet center of the spray hole 3e is that of the central axis A1 passing through the corner 3c2 on the cylindrical portion 3a side of the outer peripheral end 3c1 of the space 3c of the disc portion 3b. From the orthogonal plane P1 to the central axis A1 direction (see distance x in the figure), the rotation radius R of the fuel nozzle 3d is set in the range of 0 (not including 0) to 0.018.
For example, when the rotation radius R of the fuel nozzle 3d is 43 mm, the distance x is 0 (excluding 0) to 7.6 mm.

  Thus, in this embodiment, since the exit of each spray hole 3e is shifted and formed in the direction of the central axis A1, the spray concentration can be uniform in the direction of the central axis A1, and the combustion efficiency can be improved. Can do. The maximum value of 7.6 mm of the distance x is the hole center position when the spray hole 3e outlet is positioned most downstream in the axial direction (right side in FIG. 6) when the minimum hole diameter d is 1.9 mm. .

DESCRIPTION OF SYMBOLS 1 Centrifugal spray combustor 3 Rotating body 3a Cylindrical part 3b Disk part 3c Space 3d Fuel nozzle 5 Combustion chamber 7a Primary air supply part 7b Ignition combustion air supply part 7c Diluted air supply part 9 Spark plug A1 Center axis (rotation axis)
R turning radius

Claims (6)

A rotating body that rotates around a central axis and sprays fuel supplied to the inside from a spray hole of a fuel nozzle formed on the outer periphery toward the outer periphery;
A combustion chamber that is provided on the outer peripheral side of the rotating body and burns fuel sprayed from the spray holes;
With
The diameter of the spray hole is 0.044 times to 0.116 times the rotation radius of the fuel nozzle ,
The centrifugal spray combustor characterized in that the hole length of the spray hole is 0.070 to 0.086 times the rotation radius of the fuel nozzle .   The centrifugal spray combustor according to claim 1, wherein a rotation radius of the fuel nozzle is 43 mm to 113 mm. The centrifugal spray combustor according to claim 1 or 2 , wherein the spray hole is inclined toward an oxidant supply unit provided in the combustion chamber. The centrifugal spray combustor according to any one of claims 1 to 3 , wherein a plurality of the spray holes are formed at an angular pitch of 45 ° or less around the outer periphery of the fuel nozzle. A plurality of the spray holes are formed,
The centrifugal spray combustor according to any one of claims 1 to 4 , wherein an outlet of each spray hole is formed so as to be shifted in the central axis direction. A centrifugal spray combustor according to any of claims 1 to 5 ;
A turbine driven by combustion gas generated by the centrifugal spray combustor;
A flying object characterized by comprising:

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