JPH05172311A - Burner by spray combustion - Google Patents

Abstract

PURPOSE:To provide a burner spray combustion in which stable flame is formed and which exhibits excellent combustion characteristics when the fuel flow rate changes much from a large flow rate to a small flow rate. CONSTITUTION:A burner by spray combustion has rotating vane 9 as a flame holding device with a central hole 9a in the center and fuel injection valve 11 that sprays fuel into the combustion chamber 19 in a combustion cylinder 8 through the central hole 9a of the rotating vane 9. And, the burner has a first air chamber 21 that sends air into the combustion chamber 19 from the circumference of the fuel injection valve 11 through the central hole 9a of the rotating vane 9, second air chamber 22 that sends rotating air flow through the main body section of the rotating vane, and third air chamber 23 that sends air into the combustion chamber 19 from the hole provided on the inner circumferential face of the combustion cylinder 8, and the shape of the rotating vane 9 is a shape of cone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray combustor for spraying fuel from a fuel injection valve into a combustion chamber in a combustion cylinder for combustion.

[0002]

2. Description of the Related Art As a conventional spray combustor, there is, for example, a combustor shown in a sectional view of FIG. In this combustor, the rotary vanes of the flame stabilizer 31 are erected in the direction perpendicular to the axis X, and air is supplied while passing in parallel with the axis X. In addition, the secondary air is supplied to the combustion cylinder through the hole 33 of the combustion cylinder 32,
The fuel sprayed from the fuel injection valve 35 is filled with the fuel, and the central hole 31 of the flame stabilizer 31
It was supplied into the combustion cylinder 32 through a.

[0003]

However, in the conventional spray combustor shown in FIG. 3, the fuel spray angle is narrowed when the fuel spray amount is reduced and the supply air amount is also reduced, and the flame stabilizer.
31 Since the swirling air flow in the downstream becomes weak, the fuel spray is not sufficiently mixed with the air, which makes the flame unstable, which deteriorates combustibility and tends to cause blowout. Occurred, and the amount of fuel spray could not be narrowed down significantly.

Therefore, the present invention solves the above-mentioned drawbacks of the prior art, and provides a spray combustor capable of forming a stable flame even when the fuel flow rate is changed from a large flow rate to a small flow rate and exhibiting good combustion characteristics. With the goal.

[0005]

In order to achieve the above object, the spray combustor of the present invention has a swirl vane as a flame stabilizer having a central hole in the center, and a combustion cylinder through the central hole of the swirl vane. In a spray combustor having a fuel injection valve for spraying fuel into a combustion chamber therein, a first air chamber for sending air from around the fuel injection valve to the combustion chamber through a central hole of the swirl vane; A second air chamber for sending a swirling air flow into the combustion chamber through the main body of the swirl vane, and a third air chamber for sending air into the combustion chamber from a hole provided in the inner peripheral surface of the combustion cylinder.
The first feature is that the swirl vane has a cone shape. In addition to the first feature, the spray combustor of the present invention has a reduced diameter portion that communicates with the second air chamber on the base end side of the combustion cylinder, and the combustion chamber is provided on the inner peripheral surface of the reduced diameter portion. The second feature is that a hole for sending air in the radial direction is provided.

[0006]

According to the first feature described above, the primary air sent from the first air chamber through the center of the flame stabilizer into the combustion chamber provides a proper penetration force to the fuel sprayed from the fuel injection valve. Given, back flow of atomized fuel is prevented. The air that has passed from the second air chamber through the cone-shaped swirl vanes of the flame stabilizer causes a strong swirling air flow diagonally forward, in the center of the flame stabilizer,
The swirling airflow sufficiently disperses the sprayed fuel outwardly and promotes mixing. Therefore, the flame is broadly and stably maintained. Further, according to the second feature, in addition to the action of the first feature, the secondary air flowing from the second air chamber into the combustion cylinder through the hole on the inner peripheral surface of the combustion cylinder proximal end side reduced diameter portion Discharges from the outside of the fuel spray toward the center, promotes mixing with the spray fuel, improves combustibility, shortens flames, and prevents soot accumulation on the combustion cylinder.

[0007]

1 is a schematic sectional view of a spray combustor in one embodiment of the present invention, and FIG. 2 is a plan view of an air control plate and a damper.

The nozzle mounting flange 1 is provided with an annular plate-shaped main body portion 1a, a cylindrical portion 1b which is integrally projected from the inner circumference of the main body portion 1a, and is integrally projected from one surface of the main body portion 1a. And a nozzle guide 1c. On one surface of the nozzle mounting flange 1, a primary air cylinder 2 having a substantially cylindrical shape, a secondary air cylinder 3 having a substantially cylindrical shape that is fitted onto the primary air cylinder at a predetermined interval, and a secondary air cylinder. 3 is attached with a substantially cylindrical outer cylinder 4 which is externally fitted at a predetermined interval. The primary air cylinder 2 integrally has a cone portion 2a having a tapered shape on the tip side, and the base end portion is externally fitted to the annular flange portion 1d of the nozzle mounting flange 1. Two
The next air cylinder 3 has a tip end fitted on the combustion cylinder 8 and a base end fitted on the annular flange portion 1 e of the nozzle mounting flange 1. The outer cylinder 4 integrally has a ring-shaped plate-shaped annular plate portion 4 a at the tip portion, and the base end portion is in contact with the flange 1.

One end of the air inflow cylinder 5 is in contact with the air control plate 24, and a blower mounting flange 5a is formed. The air control plate 24 is provided with an air damper 25 which is operated by the drive device 7 on its upper surface (see FIG. 2),
It is connected to the outer cylinder 4 and the secondary air cylinder 3 via the air guide cylinder 6. The air control plate 24 is provided with a first air control hole 24a and a second air control hole 24b, and the first air control hole 24a
The air that has passed through is guided to the second air chamber 22 in the secondary air cylinder 3 by the guide cylinder 6. The air that has passed through the second air control hole 24b is guided to the third air chamber 23 in the outer cylinder 4.

The combustion cylinder 8 has a two-step diameter on the front end side and the base end side, and the base end side is reduced in diameter. The tip on the tip side having a large diameter is fixed to the inner circumference of the annular plate portion 4a of the outer cylinder 4. A plurality of holes 26 are formed in the inner peripheral surface of the base end side reduced diameter portion 8b of the combustion cylinder 8.
Is provided. A swirler cone portion 8a and a cone-shaped swirl vane 9 are integrally formed as a flame stabilizer on the base end side of the reduced diameter portion 8b. The swirler cone portion 8a and the cone-shaped swirl vane 9 are spread out toward the front, and a central hole 9a is formed in the center of the swirl vane 9, and the edge of the hole 9a is the secondary air cylinder. It is in contact with the outer circumference of the tip of the second cone portion 2a. A plurality of holes 27 are also provided in the inner peripheral surface 8c of the combustion cylinder 8 on the tip side. This hole 26, 27
Is a hole for sending air radially into the combustion chamber.

A substantially cylindrical nozzle adapter 10 is movable in the horizontal direction in FIG. 1 in the cylindrical portion 1c of the nozzle mounting flange 1, and a fuel injection valve 11 for spraying fuel to the tip of the nozzle adapter 10 is installed in the combustor. It is mounted on the central axis X, the other end is connected to a fuel supply fitting 15, and a nozzle driving device (not shown) is in contact therewith. At the tip of the nozzle guide 1c, a spray cutter 12 for cutting off a part of the fuel sprayed from the injection hole of the fuel injection valve 11 to adjust the combustion amount,
A spray cutter guide 13 which is installed around the spray cutter 12 at a predetermined interval is joined. 14 is an ignition electrode rod. Fuel supply pipe 15 of fuel injection valve 11 and nozzle adapter 10
Fuel is pressure-fed and sprayed from the fuel supply device (not shown) via the and, and the fuel blocked by the spray cutter 12 is recovered to the constant oil level device (not shown) via the nozzle guide 1c and the filler recovery pipe 16. ..

As described above, the air chamber is a combustion air introduction chamber surrounded by the air inflow cylinder 5 and the air control plate 24.
A first air chamber that is surrounded by 20, a primary air cylinder 2 and a nozzle mounting flange 1 and sends primary air to a combustion chamber 19 in the combustion cylinder 8 through a center hole 9a of a swirl vane 9. 21, secondary air cylinder 3 and nozzle mounting flanges 1 and 1
The combustion chamber 19 in the combustion cylinder 8 is configured to be surrounded by the next air cylinder 2 and through the plurality of holes 26 in the main body portion of the swirl vane 9 and the inner peripheral surface of the reduced diameter portion 8b of the combustion cylinder 8. Second communication with
Of the air chamber 22, the outer cylinder 4, the main body 1a of the nozzle mounting flange 1, the secondary air cylinder 3, and the inner peripheral surface 8c of the combustion cylinder 8 on the tip side.
A third air chamber 23 surrounded by and is formed.

Next, the operation will be described. The fuel supplied to the fuel injection valve 11 via the fuel supply fitting 15 and the nozzle adapter 10 is sprayed from the injection port of the fuel injection valve 11, and the swirl vane 9
Through the center hole 9a of the above. At this time,
When the nozzle adapter 10 is retracted to the right of the illustrated position by the nozzle drive device, the fuel injection valve 11 retracts integrally with the nozzle adapter 10, and a part of the fuel sprayed from the injection port of the fuel injection valve 11 is sprayed. Blocked by cutter 12 and combustion cylinder 8
The amount of fuel sprayed in is reduced. The amount of this reduction depends on the position of the fuel injection valve 11. On the other hand, the combustion air is supplied to the combustion air introduction chamber 20 by a blower (not shown), and the air damper 25 installed on the upper surface of the air control plate 24 adjusts the air amount according to the combustion amount. The air control plate 24 has a first air control hole 24a reaching the second air chamber 22 and a third air chamber 23.
Is provided with a second air control hole 24b. When the amount of combustion is small, the second air control hole 24b is closed and a part of the first air control hole 24a is opened to supply combustion air. ..
The opening increases as the amount of combustion increases, and the maximum amount of combustion is the first
The air control hole 24a and the second air control hole 24b are fully opened.

First, part of the air supplied to the second air chamber 22 is a plurality of holes 2 provided on the side surface of the primary air cylinder 2.
It is supplied to the first air chamber 21 through b and mixed with the fuel sprayed from the fuel injection valve 11 to flow as primary air into the combustion chamber 19 through the central hole 9a of the swirl vane 9. Also, most of the air that has entered the second air chamber 22 is a cone-type swirl vane 9.
That becomes a swirl flow by passing through the combustion cylinder 8
Those that pass through the plurality of holes 26 on the inner peripheral surface of the base end side reduced diameter portion 8b respectively flow into the combustion chamber 19. This second air chamber 22
Since the air ejected from the primary air cylinder 2 is separated from the primary air cylinder 2, it does not escape directly to the central hole 9a of the swirl vane 9 having a small resistance, and is obliquely forward from the cone swirl vane 9 and the flame stabilizer. A strong swirling air flow is generated in the center of the combustion chamber 19, and a high-speed air flow is radially supplied from the holes 26 into the combustion chamber 19. As a result, the swirling flow emitted from the cone-shaped swirl vane 9 reaches the center of the spray even when the amount of combustion is small,
Since it is possible to sufficiently disperse the spray, strong flame holding is performed, and the air having a penetrating force is supplied from the plurality of holes 26 so that the fuel is rapidly mixed,
It is possible to obtain excellent combustion characteristics.

The second air control hole 24b of the air control plate 24
The combustion air supplied to the third air chamber 23 flows into the combustion chamber 19 through the plurality of holes 27 in the inner peripheral surface 8c of the tip end side of the combustion cylinder 8. Since the amount of this air increases as the amount of combustion increases, the air is shortened and the combustion characteristics are improved by achieving good mixing with the fuel. Thus, when the fuel sprayed from the injection port of the combustion injection valve 11 is ignited by the electrode rod 14, a stable flame is formed in the combustion chamber 19.

In this way, the first air chamber 21 and the second air chamber 22 are separately provided, the amount of air from the center of the swirl vane 9 is suppressed, and the pressure of the second air chamber 22 is increased. , The shape of the swirl vane 9 is made cone-shaped to strengthen the swirl flow in the center of the combustion chamber 19, and a plurality of holes 26 are provided in the inner peripheral surface of the base end side reduced diameter portion 8b of the combustion cylinder 8 By increasing the air flow velocity of the above, it becomes possible to obtain stable flame and combustion characteristics even when the combustion amount is greatly reduced. Although the spray cutting method by the spray cutter 12 is adopted in the above-described embodiment, the fuel injection amount to the combustion chamber 19 is changed by adopting an air injection nozzle, an ultrasonic nozzle, a fuel return method nozzle, or the like as the fuel injection valve. You may adjust. Further, not only the proportional control injection valve but also a single input injection valve may be used. Regarding the supply of air, when the combustion amount is reduced, it is necessary to prevent dew condensation water from the heat exchanger, but a method of supplying air to the combustion chamber as the fourth air and lowering the relative humidity is is there. The one to which the fourth air is added is also the first embodiment.
Is one.

[0017]

According to the spray combustor according to the first aspect of the present invention, the air is sent from the periphery of the fuel injection valve to the combustion chamber through the central hole of the swirl vane. A first air chamber, a second air chamber for sending a swirling air flow into the combustion chamber through the main body of the swirl vane, and a third air chamber for sending air into the combustion chamber from a hole provided in the inner peripheral surface of the combustion cylinder. Since the swirl vane has an air chamber and the swirl vane has a cone shape, the swirl airflow can reach the central portion of the spray, so that even if the fuel spray angle becomes narrow when the input is narrowed. , Sprayed fuel is widely dispersed by swirling flow,
The mixture can be mixed, and thus the flame can be sufficiently stabilized and held. According to the spray combustor according to claim 2, in addition to the effect of the configuration according to claim 1, the base end side of the combustion cylinder is a reduced diameter portion that communicates with the second air chamber, Since a hole for sending air in the radial direction into the combustion chamber is provided on the inner peripheral surface of the reduced diameter portion, when the input is small, the second
The penetrating air from the air chamber can be supplied up to the center of the spray in the combustion chamber, and stable combustion can be performed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a spray combustor in an apparatus according to one embodiment of the present invention.

FIG. 2 is a plan view of an air control plate and a damper.

FIG. 3 is a sectional view of a conventional spray combustor.

[Explanation of symbols]

 8 Combustion Cylinder 8b Reduced Diameter 9 Swirling Blade 9a Center Hole 11 Fuel Injection Valve 19 Combustion Chamber 21 First Air Chamber 22 Second Air Chamber 23 Third Air Chamber 26 Hole

Claims (2)

[Claims] 1. A spray combustor having a swirl vane as a flame stabilizer having a central hole in the center, and a fuel injection valve for spraying fuel into a combustion chamber in a combustion cylinder through the central hole of the swirl vane. A first air chamber for sending air from around the fuel injection valve to the combustion chamber through a central hole of the swirl vane, and a second air chamber for sending swirl airflow to the combustion chamber through the main body of the swirl vane. And a third air chamber for sending air into a combustion chamber from a hole provided in the inner peripheral surface of the combustion cylinder, and the swirl vane has a cone shape. 2. A reduced diameter portion that communicates with the second air chamber is provided on the base end side of the combustion cylinder, and a hole is provided on the inner peripheral surface of the reduced diameter portion to send air into the combustion chamber in the radial direction. 1. The spray combustor according to 1.