JP2715697B2 - Spray 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 spray combustor for spraying fuel from a fuel injection valve into a combustion chamber in a combustion cylinder to perform combustion.

[0002]

2. Description of the Related Art As a conventional spray combustor, there is a combustor shown in a sectional view of FIG. This combustor sends the primary air into the combustion chamber 39 in the combustion tube 32 through the cut-and-raised portion 31a of the main body of the swirl vane, which is the flame stabilizer 31, and the center hole 31b, and the secondary air is supplied to the combustion tube 32. Combustion chamber 3 through hole 33
Send to 9. Further, the fuel sprayed from the fuel injection valve 35 is configured to be sent into the combustion chamber 39 through the center hole 31b of the flame stabilizer 31. However, in the conventional configuration, when the fuel spray amount is reduced, the primary air amount also needs to be reduced, so that the vortex downstream of the flame stabilizer 31 is weakened. Stability is deteriorated, blowout tends to occur, and the nozzle 35
A problem such as a flame entering the spray cutter 36 on the front surface occurred, and the spray amount of fuel could not be greatly reduced.
In addition, since most of the primary air is ejected from the center hole 31b without disturbance, there is a problem that mixing with the fuel is poor and soot and CO ₂ are generated.

Accordingly, the present applicant has filed a Japanese Patent Application No. 2-319239.
No. provided an instrument as shown in FIG. In this combustor,
The air sent through the center hole 41b of the flame stabilizer 41 and the air sent through the swirler vane 41a, which is the main body of the flame stabilizer 41, are completely independently separated, thereby being sent through the swirler vane 41a. The amount of air is increased so that it can be supplied to the combustion chamber 49 in the combustion cylinder 42, and another air is sent to the combustion chamber 49 as secondary air from the hole 43 on the inner peripheral surface of the combustion cylinder 42, and the fuel injection valve 44 Is supplied to the combustion chamber together with air through the center hole 41b of the flame stabilizer 41. Further, the combustion air is introduced into the chamber 48 from the supply pipe 47, and the rectified air holes 48a, 48
b and 48c so as to be supplied at a constant rate.

[0004]

However, even with the spray combustor having the structure shown in FIG. 5, when the fuel flow rate is greatly reduced, the supply of secondary air in the vicinity of the flame holding portion is small, so that CO and soot can be reduced. However, when the amount of discharged fuel is large, or when the fuel flow rate is large, there is a problem that the combustibility is not improved immediately, such as insufficient air near the base of the combustion cylinder 42 and soot.

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

[0006]

In order to achieve the above object, a spray combustor according to the present invention has a center hole 9a at the center.
That the swivel blade 9, in the spray combustor having a fuel injection valve 11 to spray the fuel into the combustion chamber 19 within combustion cylinder 8 through the central hole 9a of the orbiting scroll 9, the swirl vanes 9
A first air chamber 21 for sending air from the periphery of the fuel injection valve 11 to the combustion chamber 19 through the central hole 9a , and a swirling air flow through the main body of the swirling blade 9 to the combustion chamber 19 and the swirling. Toward the outer peripheral side of the blade 9 forward
The circumference of the swirler cone 8a that is configured to expand to the front
Through a large number of holes 8b in the wall combustion chamber air 19
2nd air chamber 2 which feeds diagonally forward toward the center of
2 and a hole 27 provided in the inner peripheral surface of the combustion cylinder 8 through a combustion chamber.
The third air chamber 23 for sending air into the air inlet 19 is provided separately .

[0007]

The first air chamber 21, the second air chamber 22, and the third
Since the air chambers 23 are separated and independent from each other, fuel
Air supply amount from first air chamber 21 due to increase / decrease of spray amount
The second sky, which is particularly important, regardless of changes in
The amount of air supplied from the air chamber 22 is adjusted to an appropriate amount independently.
Can be knotted. Therefore, the effects described below are
I can show it without regret. Turning from the first air chamber 21
The primary air sent into the combustion chamber 19 through the center hole 9a of the rotating blade 9 gives an appropriate penetration force to the fuel sprayed from the fuel injection valve 11 , thereby preventing the backflow of the sprayed fuel and preventing the sprayed fuel from flowing back. Air is supplied to the central part. Also the second
Through the main body of the swirl vanes 9 from the air chamber 22 of the combustion chamber
The primary air flowing into 19 becomes a sufficient swirling flow to form a good recirculation region and keep the flame stable. Similarly, the second air chamber 22 widens forward from the second air chamber 22 to the outer peripheral side of the swirling blade 9.
The secondary air flowing obliquely forward toward the center of the combustion chamber 19 through the hole 8b of the swirler cone 8a configured to rising, to promote mixing of the flame base, improvement in combustibility, shorter flames of And prevent soot accumulation in the combustion chamber 19 .

[0008]

FIG. 1 is a schematic sectional view of a spray combustor in one embodiment of the present invention, FIG. 2 is a plan view of an air control plate and a damper, and FIG. FIG. 5 is a diagram comparing the range of the flammable region in FIG.

The nozzle mounting flange 1 has an annular plate-shaped main body 1a, a cylindrical section 1b integrally protruded from the inner periphery of the main body 1a, and a single body protruded from one surface of the main body 1a. Nozzle guide 1c. On one surface of the nozzle mounting flange 1, a cylindrical primary air cylinder 2, a cylindrical secondary air cylinder 3 externally fitted to the primary air cylinder at a predetermined interval, and a secondary air cylinder 3 are provided. A substantially cylindrical outer cylinder 4 fitted outside at a predetermined interval is attached. The primary air cylinder 2 has a cone portion 2 that is tapered toward the tip end.
a, and the base end is fitted to the annular flange 1 d of the nozzle mounting flange 1. The secondary air cylinder 3 has a distal end externally fitted to the combustion cylinder 8, and a proximal end externally fitted to the annular flange 1 e of the nozzle mounting flange 1.

The air inflow cylinder 5 has a combustion air introduction chamber 20, and an air control plate 24 is provided in front of the air introduction chamber 20. The air control plate is provided with an air damper 25 operated by the driving device 7 (see FIG. 2). The air control plate 24 is provided with a first air control hole 24a and a second air control hole 24b, and the air passing through the first air control hole 24a is supplied by the guide cylinder 6 to the second air control hole in the secondary air cylinder 3. Air chamber 2
It is led to 2. 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.

A swirler cone 8a as a flame stabilizer is formed at the base end of the combustion tube 8. Swara cone 8a
Is extended forward and has a plurality of holes 8b.
Are formed. Also, a large number of holes 27 are formed on the inner peripheral surface of the combustion cylinder 8. A swirling blade 9 is provided on the base end side of the swirler cone 8a. A center hole 9a is formed in the center of the swirling blade 9, and the edge of the hole 9a is
It is in contact with the outer periphery of the tip of the cone portion 2a of the next air cylinder 2.

The nozzle adapter 10 is movable in the left-right direction in FIG. 1. A fuel injection valve 11 for spraying fuel is attached to the tip of the nozzle adapter 10, and a fuel supply fitting 15 is connected to the other end. . At the tip of the nozzle guide 1c, there is provided a spray cutter 12 for shutting off a part of the fuel sprayed from the injection hole of the fuel injection valve 11 and adjusting the amount of combustion. 14 is an ignition electrode rod. The fuel spray-cut by the spray cutter 12 is collected by a constant oil leveler (not shown) through the fuel collection pipe 16.

As described above, the air chamber is surrounded by the combustion air introduction chamber 20 surrounded by the air inflow cylinder 5 and the air control plate 24, and surrounded by the primary air cylinder 2 and the nozzle mounting flange 1. A first air chamber 2 configured to send primary air into the combustion chamber 19 through a center hole 9a of the swirling blade 9;
1, a secondary air cylinder 3, a nozzle mounting flange 1, and a primary air cylinder 2. The primary air is sent into the combustion chamber 19 through the main body of the swirling blade 9, and a plurality of swirler cones 8 a are provided. A second air chamber 22 for feeding the secondary air obliquely forward toward the center of the combustion chamber 19 through the hole 8b, the outer cylinder 4, the main body 1a of the nozzle mounting flange 1, and the secondary air cylinder 3. A third air chamber 23 further surrounded by the combustion tube 8 is formed.

Next, the operation will be described. Fuel is fuel injector 1
The fuel is sprayed from the first injection port and flows into the combustion cylinder 8 through the center hole 9 a of the swirling blade 9. On the other hand, combustion air is supplied to the combustion air introduction chamber 20 by a blower (not shown), and is adjusted to an air amount corresponding to the amount of combustion by an air damper 25 installed on the upper surface of the air control plate 24. The air control plate 24 is provided with a first air control hole 24a reaching the second air chamber 22 and a second air control hole 24b reaching the third air chamber 23. Air control holes 24
b is closed, and a part of the first air control hole 24a is opened to supply combustion air. The opening degree is increased as the combustion amount increases, and the first air control hole 24a and the second air control hole 24b are fully opened at the maximum combustion amount.

First, a certain percentage of the air supplied to the second air chamber 22 is supplied to the first air chamber 21 through a plurality of holes 2a provided on the side surface of the primary air cylinder 2, and the fuel is injected. The primary air flows into the combustion chamber 19 through the center hole 9a of the swirl blade 9 as primary air while being mixed with the fuel sprayed from the valve 11. Most of the air that has entered the second air chamber 22 becomes a swirling flow by passing through the swirl vanes 9 and the air that passes through a plurality of holes 8b provided in the swirler cone 8a. 19. Since the air ejected from the second air chamber 22 is separated from the primary air cylinder 2, it does not escape directly to the center hole 9 a of the swirling blade 9 having a small resistance, and is sufficiently discharged from the swirling blade 9. A swirling airflow having a strong swirling force and a high-speed airflow from the hole 8b of the swirler cone 8a are formed in the combustion chamber 19. As a result, even when the combustion amount is small, a recirculation region is formed in the downstream of the swirling blade 9, and strong flame holding is performed. In addition,
By supplying air having a penetrating force from the plurality of holes 8b of the cone 8a, mixing with fuel is performed quickly, and excellent combustion characteristics can be obtained.

The second air control hole 2 of the air control plate 24
4b, the combustion air supplied to the third air chamber 23 flows into the combustion chamber 19 from the plurality of holes 27 on the inner peripheral surface of the combustion cylinder 8. Since the amount of this air increases as the amount of combustion increases, good mixing with fuel improves the flame shortening and the combustion characteristics.
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.

As described above, the first air chamber 21 and the second air chamber 22 are separately provided, the amount of air from the center of the swirling vanes is suppressed, and the pressure of the second air chamber 22 is increased. In addition to strengthening the swirling flow from the swirling blades 9, in particular, the oblique air flow from the plurality of holes 8b of the swirler cone 8a can be increased, and stable flame and combustion characteristics can be obtained even when the amount of combustion is greatly reduced. Becomes possible. In the above-described embodiment, the spray cutting method using the spray cutter 12 is adopted. However, by adopting an air injection nozzle, an ultrasonic nozzle, a fuel return type nozzle, or the like as a fuel injection valve,
The fuel injection amount to the combustion chamber 19 may be adjusted. As for the supply of air, there is a method in which air is supplied to the combustion chamber as fourth air to lower the relative humidity. The embodiment to which the fourth air is added is also one of the embodiments.

[0018]

According to the first aspect of the present invention, there is provided a spray combustor according to the first aspect of the present invention, wherein the combustion chamber 1 extends from the periphery of the fuel injection valve 11 through the center hole 9a of the swirl vane 9.
9 , a first air chamber 21 for feeding air to the rotating blade 9,
The swirling air flow is sent into the combustion chamber 19 through the main body portion of the swirling blade 9 and a divergent shape is formed forward on the outer peripheral side of the swirling blade 9.
On the peripheral wall of the swirler cone 8a
A second air chamber 22 to feed obliquely forward through a number of holes 8b which kicked toward the air towards the center of the combustion chamber 19,
Since the third air chamber 23 for feeding air into the combustion chamber 19 is provided separately from the hole 27 provided on the inner peripheral surface of the combustion cylinder 8 , the combustion amount is small , that is, the fuel spray amount is small and
Injected into the combustion chamber 19 together with fuel from the first air chamber 21
Separated from the first air chamber 21 even when the amount of air
From the ventilated second air chamber 22 through the swirl vanes 9
Swirling air flow and swirl cone 8 introduced into firing chamber 19
a into the combustion chamber 19 through the hole 8b
Due to the introduced air flow, the combustion chamber 1
Recirculation zone is formed in 9 and sufficient mixing is achieved
It can prevent blowout and incomplete combustion. On the other hand , when the combustion amount is large , that is, when the fuel spray amount is large and the first air chamber
The air blown into the combustion chamber 19 together with the fuel from the
Is not affected by the airflow in the first air chamber 21
Through the swirl vanes 9 from the second air chamber 22
And the swirl cone 8a
The air flow introduced obliquely forward centrally through the hole 8b
By promoting the mixing of air and fuel in the flame base
Can prevent incomplete combustion, flammability
Improvement, prevention of soot accumulation, and shortening of flame can be ensured . That is, according to the present invention, stable combustion can be performed in a wide combustion adjustment range.

[Brief description of the drawings]

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

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

3 is a diagram comparing the range of the flammable region in the device according to the present invention and the conventional device shown in FIG. 5;

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

FIG. 5 is a sectional view of a conventional spray combustor.

[Explanation of symbols]

 2 Primary Air Cylinder 3 Secondary Air Cylinder 5 Air Inlet Cylinder 8 Combustion Cylinder 8a Swirler Cone 9 Swirl Blade 11 Fuel Injection Valve 19 Combustion Chamber 20 Combustion Air Inlet Chamber 21 First Air Chamber 22 Second Air Chamber 23 Third air chamber

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tatsuhiko Yoshida 32nd Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Pref. (56) References JP-A-3-110310 (JP, A) JP-A-63-70019 (JP, A) JP-A-4-190006 (JP, A) JP-A-1-101023 (JP, U) 2-28924 Kai (JP, U) JP-A 1-170821 (JP, U)

Claims (1)

(57) [Claims] 1. A swivel blade 9 that it has a central hole 9a in the center
When the combustion cylinder 8 through the central hole 9a of the swirl vane 9
In spray combustor to the combustion chamber 19 of the inner and a fuel injection valve 11 to spray the fuel, the central hole 9a of the orbiting scroll 9
The outer periphery of the swirl vane 9 with fed into the combustion chamber 19 and the first air chamber 21 for feeding air into the combustion chamber 19 from the ambient, a swirling air flow through the body portion of the swirl vanes 9 of the fuel injection valve 11 via the To the front
Provided on the peripheral wall of the swirl cone 8a
And a second air chamber 22 to feed obliquely forward towards the air through a number of holes 8b in the center of the combustion chamber 19, the combustion chamber 19 from the hole 27 provided on the inner peripheral surface of the combustion cylinder 8 A spray combustor characterized in that a third air chamber ( 23) for feeding air is provided separately .