JPH05248637A - Combustion device of gas turbine - Google Patents

Abstract

PURPOSE:To prevent associated carbon from being deposited on a fuel injection valve in a combustion device of a gas turbine. CONSTITUTION:In a gas turbine combustion apparatus in which a swirler cylinder 3 is connected to the upstream side of a combustion cylinder 2, and a fuel jet valve 4 is disposed in the swirler cylinder 3, and further a plurality of vanes 6 for producing a spiral air stream which takes the fuel jet valve 4 as a center are fanned on the swirler cylinder 3, a plurality of auxiliary air supply holes 9 are opened through the swirler cylinder 3, located surrounding the vanes 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a gas turbine combustor.

[0002]

2. Description of the Related Art A combustor of a gas turbine is equipped with a swirler that produces a swirling flow in the combustion chamber in order to efficiently burn compressed air supplied to the combustion chamber and fuel injected from a fuel injection valve. (See JP-A-58-153021).

As a conventional swirler, there is a radial flow swirler in which a swirler cylinder is connected to an upstream side of a combustion cylinder, a fuel injection valve is arranged inside the swirler cylinder, and the swirler cylinder has a plurality of blades. A swirling air flow is generated from the cylinder to the combustion cylinder to promote the mixing of fuel and air and stabilize the flame.

[0004]

However, since the swirl flow generated by the radial swirler swirls around the fuel injection valve, the fuel injected around the fuel injection valve is trapped, and the swirl flow is generated in the vicinity of the fuel injection valve. There was a possibility that carbon was deposited on the fuel injection valve to create a fuel rich region.

The present invention focuses on the above problems and aims to prevent carbon from accumulating on the fuel injection valve.

[0006]

According to the present invention, a swirler cylinder having a diameter smaller than that of the combustion cylinder is connected to an upstream side of the combustion cylinder, a fuel injection valve is arranged inside the swirler cylinder, and the fuel injection valve is provided in the swirler cylinder. Is provided with a radial swirler for supplying a swirling air flow in the circumferential direction, and an auxiliary air supply means for supplying an air flow toward the fuel injection valve is provided at a position separated from the radial swirler in the axial direction of the swirler cylinder. Prepare

[0007]

The airflow flowing from the auxiliary air supply means into the swirler cylinder disturbs the swirl flow generated by the radial swirler, and supplies sufficient air near the fuel injection valve.
As a result, a fuel rich region is not formed in the vicinity of the fuel injection valve, and carbon can be prevented from depositing on the fuel injection valve.

[0008]

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

As shown in FIG. 1, a combustor 1 is provided with a swirler cylinder 3 upstream of a combustion cylinder 2, and a secondary air supply port 12 and a dilution air are provided downstream of the swirler cylinder 3 (to the left in the figure). The supply port 13 and a large number of louvers (not shown) are open.

Compressed air sent from a compressor (not shown) is heated by a heat exchanger, and then passes through a duct 10 and an outer liner 11 through a duct 10 and an outer liner 11 from a direction opposite to a direction in which a combustion gas is ejected and a combustion cylinder 2 and a swirler. It is guided along the outer circumference of the cylinder 3.

A fuel injection valve 4 is provided inside the swirler cylinder 3, and fuel injected from the fuel injection valve 4 burns with the air introduced into the combustion cylinder 2 to become a high temperature gas to drive a turbine (not shown). It has become. Incidentally, reference numeral 5 in the figure denotes an ignition plug.

As shown in FIG. 2, the radial flow swirler 7 provided in the swirler cylinder 3 is integrally formed with 16 blades 6 arranged in the circumferential direction, and a fuel injection valve is applied to the air flow flowing into the swirler cylinder 3. A swirling flow centering around 4 is generated.

In the radial swirler 7, as shown in FIG. 3, each substantially rectangular vane 6 and the tangent line of the swirler cylinder 3 are 45.
The swirler cylinder 3 is bent inward at an angle of degrees, and an opening 8 is formed in the swirler cylinder 3 at a portion where each blade 6 is removed.

In the swirler cylinder 3, as auxiliary air supply means for supplying auxiliary air to the fuel injection valve 4, eight auxiliary air supply holes 9 are located upstream (to the right in the drawing) of the radial swirler 7. It is formed.

The blades 6 and the openings 8 are arranged at equal intervals in the circumferential direction, and the auxiliary air supply holes 9 are located between the openings 8 and are also arranged at equal intervals in the circumferential direction.

The opening area of the auxiliary air supply holes 9 is set so that the air flow rate flowing from each auxiliary air supply hole 9 is smaller than the air flow rate flowing from the radial swirler 7 by a predetermined ratio.

Next, the operation will be described.

The air flow flowing in through the radial swirler 7 is from the swirler cylinder 3 to the combustion cylinder 2 as shown by the arrow in the figure.
A swirling flow centering on the fuel injection valve 4 flows into the combustion cylinder 2, and is mixed with the fuel spray injected from the fuel injection valve 4 and is entrained in the center direction of the combustion cylinder 2 to diffuse and burn the flame. Stabilize.

However, as described above, the swirl flow generated by the radial swirler 7 entrains the fuel injected around the fuel injection valve 4 and creates a fuel rich region in the vicinity of the fuel injection valve 4. There was a possibility that carbon was deposited on the fuel injection valve 4.

As a countermeasure against this, the present invention provides a plurality of auxiliary air supply holes 9 upstream of the radial swirler 7 of the swirler cylinder 3.
As a result, the air flow that flows into the swirler cylinder 3 from each auxiliary air supply hole 9 flows along the cylindrical body 3A of the fuel injection valve 4 as indicated by the arrow in the figure, and the radial flow swirler Sufficient air is supplied to the vicinity of the fuel injection valve 4 by entering the swirl flow generated by 7. As a result, a fuel rich region is not formed in the vicinity of the fuel injection valve 4, and carbon can be prevented from depositing on the fuel injection valve 4.

Next, in another embodiment shown in FIG. 4, as auxiliary air supply means, eight auxiliary air supply holes 21 are formed downstream of the radial flow swirler 7 of the swirler cylinder 3 (to the left in the drawing). To do.

The 16 blades 6 are arranged at equal intervals in the circumferential direction, and the auxiliary air supply holes 21 are arranged axially side by side with the respective openings 8 and are also arranged at equal intervals in the circumferential direction.

In this case, the airflow flowing into the swirler cylinder 3 from each auxiliary air supply hole 21 penetrates the swirl flow generated by the radial swirler 7 as shown by the arrow in the figure, and the swirl flow of the fuel injection valve 4 flows. Reach near. As a result, a fuel rich region is not created near the fuel injection valve 4,
It is possible to prevent carbon from depositing on the fuel injection valve 4.

Next, in another embodiment shown in FIG. 6, as auxiliary air supply means, eight auxiliary air supply holes are located upstream of the radial swirler 7 of the swirler cylinder 3 (to the right in the figure). 9 is formed, and 8 is formed downstream (to the left in the figure)
The two auxiliary air supply holes 21 are formed.

The 16 blades 6 are arranged at equal intervals in the circumferential direction, and the auxiliary air supply holes 9 and 21 are arranged in a zigzag pattern with each opening 8 in between. Reference numeral 14 in the figure denotes a large number of louvers for cooling air in the combustion cylinder 2.

In this case, the air flow flowing from each auxiliary air supply hole 9 into the swirler cylinder 3 flows along the fuel injection valve, and the air flow flowing from each auxiliary air supply hole 21 into the swirler cylinder 3 has a radius. It reaches the vicinity of the fuel injection valve 4 through the swirl flow generated by the flow swirler 7. As a result, a fuel rich region is not formed in the vicinity of the fuel injection valve, and it is possible to prevent carbon from depositing on the fuel injection valve 4.

As shown in FIG. 7, the auxiliary air supply holes 9 and 21 may be arranged side by side in the axial direction with the openings 8 of the radial swirler 7 interposed therebetween.

FIG. 8 is a schematic diagram of each of the embodiments and the conventional example shown in FIG.
The experimental results of measuring the amount of carbon deposited on the fuel injection valve 4 and the stability of the combustion flame by the rated operation for 0 minutes are shown.
The amount of carbon to be deposited was 1.0 to 1.5 g in the conventional example having no auxiliary air supply hole, whereas the second embodiment in which the auxiliary air supply hole 21 was formed on the downstream side of the radial swirler 7 was used. In the example, the amount is 0.005 g, and in the third embodiment in which the auxiliary air supply holes 9 and 21 are formed on the upstream side and the downstream side of the radial swirler 7, the amount is 0.002 g, and the auxiliary air is supplied only to the upstream side of the radial swirler 7. It was found that no carbon was deposited in the first example in which the holes 9 were formed. The stability of the combustion flame tends to deteriorate as the amount of auxiliary air increases, but no deterioration is observed when the amount of auxiliary air is about 1/2 of the amount of swirling air, and the amount of auxiliary air is equal to the amount of swirling air. In the third embodiment, which has been increased up to, there was a sign of deterioration.

[0029]

As described above, according to the present invention, the swirler cylinder having a diameter smaller than that of the combustion cylinder is connected to the upstream side of the combustion cylinder, the fuel injection valve is arranged inside the swirler cylinder, and the fuel injection is performed in the swirler cylinder. Auxiliary air supply means that includes a radial swirler that supplies a swirling air flow in the circumferential direction centered on the valve, and that supplies an air flow toward the fuel injection valve to a position that is separated from the radial flow swirler in the axial direction of the swirler cylinder Since the fuel injection valve is provided, it is possible to prevent carbon from accumulating on the fuel injection valve and maintain combustion stability.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustor showing an embodiment of the present invention.

FIG. 2 is a sectional view of the swirler cylinder.

FIG. 3 is a transverse sectional view of the swirler cylinder, which is also taken along the line AA of FIG.

FIG. 4 is a sectional view of a combustor showing another embodiment.

FIG. 5 is a sectional view of the swirler cylinder.

FIG. 6 is a sectional view of a combustion cylinder showing still another embodiment.

FIG. 7 is a sectional view of a swirler cylinder showing still another embodiment.

FIG. 8 is a diagram showing experimental results.

[Explanation of symbols]

 1 Combustor 2 Combustion Cylinder 3 Swirler Cylinder 4 Fuel Injection Valve 6 Blades 7 Radial Flow Swirler 9 Auxiliary Air Supply Hole (Auxiliary Air Supply Means) 21 Auxiliary Air Supply Hole (Auxiliary Air Supply Means)

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[Procedure amendment]

[Submission date] October 29, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

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[Procedure amendment]

[Submission date] December 20, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

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Claims (1)

[Claims] 1. A swirler cylinder having a diameter smaller than that of the combustion cylinder is connected to an upstream side of the combustion cylinder, a fuel injection valve is arranged inside the swirler cylinder, and the swirler cylinder swirls in a circumferential direction around the fuel injection valve. A gas comprising a radial swirler for supplying an air flow, and an auxiliary air supply means for supplying an air flow toward the fuel injection valve at a position separated from the radial swirler in the axial direction of the swirler cylinder. Turbine combustor.