JPS62203931A - Fuel injection equipment - Google Patents

Abstract

PURPOSE:To stabilize the quantity of fuel injection and reduce combustion vibrations so as to prevent accidental fires, by restricting the opening degree of a fuel injection opening on a low load time so as to reduce the quantity of the fuel injection and maintain the pressure of the injection fuel simultaneously. CONSTITUTION:Fuel B is streamed from a fuel inlet 5 into an equipment body 6 and injected from a fuel injection opening 2 through the rear hole 8 of the equipment body 6, so that it is mixed with compressed air A and sent into a combustion chamber. Here, when loads are unloaded and the quantity of fuel supply is reduced, a force pressing a fuel inlet adjusting valve 12 is weakened, so that the valve 12 is pressed back by a return spring 19 and the MIN stopper 22 on the rear end surface of a head portion 13 is stopped in contact with a partition wall 9. Thus, the hole 20 of the head portion 13 is closed by a front hole 17, and only the front half of a long hole 21 corresponds with the fuel injection opening 2 at the side of the equipment body 6, so that the quantity of fuel injection is reduced. But the difference between the pressure of the compressed air A and the fuel pressure in the equipment body 6 is ensured, so that combustion vibrations and accidental fires can be held down.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a fuel injection device, and particularly to a fuel injection device for a gas turbine.

(Prior art) The fuel injection device F used in the gas turbine has a sixth fuel injection device F.
As shown in the figure, compressed air A discharged from the air compressor 1 enters from the compressed air inlet passage 1a shown in FIG. 7, mixes with fuel injected from the fuel injection port 2, and is injected. , is ignited by the ignition plug 3 in FIG. 6 and sent to the first stage turbine stationary blade 4, and the energy is used to rotate a turbine rotor (not shown).

(Problems to be Solved by the Invention) In the above, in the conventional fuel injection device for a gas turbine, the fuel B flowing into the fuel injection device F from the fuel population 5 in FIG. 7 is injected from the fuel injection port 2 and compressed. However, since the fuel injection device F is generally designed based on 100% load, the pressure difference between the fuel and compressed air is large during high loads, so the fuel is smoothly injected into the air. However, when the load is low, the amount of fuel injected decreases even though the area of the passage of the fuel injection port 2 is always constant. Therefore, the fuel pressure in the fuel injection device decreases, and the difference between it and the pressure of compressed air A becomes smaller, and as shown in FIG. When looking at the ratio, the pressure ratio falls below the critical pressure ratio at high speeds and low loads, resulting in the problem that the fuel injection pressure at the two fuel injection ports in Figure 7 becomes unstable, which can lead to combustion vibrations and misfires. There was a drawback that caused this.

This invention was made in consideration of the above-mentioned circumstances, and it is possible to stably secure fuel injection pressure according to the load of the gas turbine, prevent combustion vibrations and misfires, and obtain stable combustion. It is an object of the present invention to provide a fuel injection device as described above.

[Structure of the invention]

(Means and effects for solving the problem) This invention makes the opening area of the fuel injection port variable according to the fuel injection pressure,
This system is designed to reduce combustion vibrations that tend to occur at low loads by providing a fuel injection flow rate commensurate with the low load, and a fuel port adjustment valve is inserted into the device body to adjust the fuel port. A fuel injection port that can communicate with the fuel injection port of the device main body is opened on the circumferential surface of the head of the valve, and the fuel port adjustment valve is moved backward in response to a decrease in fuel injection pressure. The matching area with the fuel injection port on the main body side is reduced, so that the fuel injection m is reduced as the fuel injection pressure is reduced.

(Example) Examples of the present invention will be described below with reference to Figures 1 to 5.
The same reference numerals are used to describe the same parts as in the figures.

FIG. 1 is a front view of the fuel injection device shown in FIG.
The figure shows a line cross section. The main body 6 of the device has a cylindrical hole inside, and the partition wall 9 that partitions this hole into a front hole 7 and a rear hole 8 has a keyway shaft hole in the center. 10, and a plurality of fuel passages 11.degree. 11 are opened in parallel to the axial direction around the fuel passage 10.

Around the front hole 7 of the device main body 6, compressed air inlet passages 1a, 1a discharged from an air compressor (not shown) are opened in directions that cross each other at the front position, and the compressed air inlet passages 1a, 1a and the front hole 7 are the fuel injection port 2,
2 is connected.

The fuel port adjustment valve 12 fitted into the hole is a cylindrical cylinder which is fitted into the front hole 7 as tightly as possible and is slidable, as shown in FIG. 1 J3 and FIG. 3. Head 1 having a shaped peripheral surface
3, and the shaft hole 1 of the partition wall 9 that is connected to the head 13.
0, and a shaft 14 that is slidably inserted into the shaft.
A key 15 that fits into the keyway of the shaft hole 10, a MAX collar 16 that determines the maximum forward position of the fuel port adjustment valve 12, and a retaining pin 17 are fixed to the rear end of the shaft 14. A spring stopper 18 is provided, and this spring stopper 1
A return spring 19 is interposed between the fuel port control valve 8 and the partition wall 9 for returning the fuel port adjustment valve 12 to the left in the figure.

A fuel injection port is opened in the head 13 of the fuel port adjustment valve 12, as shown in FIG. . This elongated hole 21 extends toward the distal end of the fuel port adjustment valve 12, and its rear end is positioned to coincide with the circular hole 20. The rear end surface of the peripheral edge of this head 13 serves as a MIN stopper 22 that defines the return limit, and when this stopper 22 hits the partition wall 9, the circular hole 20 is closed by the inner surface of the front hole 7, and the elongated hole 21 Only the front half of the fuel injection port 2 is aligned with the fuel injection port 2 of the device main body 6, and the number of fuel injection ports is halved.

In FIG. 1, the reference numeral 23 indicates the shaft 14 and the shaft hole 1 of the partition wall 9.
This is a ◯ ring interposed between 0 and 0.

Next, the operation of the above embodiment will be explained.

In FIG. 2, fuel B flowing in from a fuel injection port 5 is injected from the fuel injection port 2 through the inside of the fuel injection device (1) and the rear hole 8, mixed with compressed air A, and sent into the combustor.

During high loads, there are many instances of fuel injection, so
The fuel pressure inside rises, and this pressure pushes the fuel port adjustment valve 12 against the force of the return spring 19, causing the MAX stopper 16
When the fuel is stopped against the partition wall 9, fuel flows out from all the fuel injection ports (holes 20 and elongated holes 21) of the head 13, mixes with the compressed air A, and is sent as moist fuel.

On the other hand, when the load is removed and the fuel supply amount is reduced, the force pushing the fuel port adjustment valve 12 becomes weaker, so the fuel port adjustment valve 12 is pushed back by the force of the return spring 19, and the MIN The stopper 22 hits the partition wall 9 and is stopped. As a result, the circular hole 20 opening on the circumferential surface of the head 13 is closed by the inner circumferential surface of the front hole 7, and the elongated hole 21
Only the front half of matches the fuel injection port 2 on the device main body 6 side,
Although the frontage area is halved and the fuel injection flow rate is reduced, the difference between the pressure of compressed air A and the fuel pressure inside the device body 6 is maintained, and this prevents combustion problems and misfires that tend to occur at low loads. This will reduce the occurrence of defects. Further, slight movement of the fuel port adjustment valve 12 due to small fluctuations in the fuel supply pressure and compressed air pressure is caused by the O ring 2
3, sufficient absorption can be achieved. Therefore, when the load is low, the opening degree of the fuel injection port is restricted to maintain the fuel injection pressure while reducing the amount of fuel injected.As shown in Figure 5, the fuel pressure and combustor internal pressure are It is possible to reliably prevent the pressure ratio π from becoming lower than the limit pressure ratio. Furthermore, for alignment of the fuel injection port between the device main body 6 and the fuel port adjustment valve 12, @14 of the fuel port adjustment valve 12 is required.
This is ensured by the key 15 provided at the top, but it goes without saying that this can be done not only by the key but also by a spline connection.

In the illustrated embodiment, circular holes 20 and elongated holes 21 are alternately provided in the head 13 of the fuel port adjustment valve 12, and the circular holes 20 are closed when the fuel port adjustment valve 12 retreats. Although a case has been described in which the opening degrees of the fuel injection ports are made variable, it is also possible to have a configuration in which all the holes have the same structure and the opening degrees of the holes are narrowed all at once by retracting the fuel port adjustment valve 12. In addition, the specific structure of each part is not limited to the illustrated embodiment, and other shapes and structures may be adopted as long as they have the same function.

〔Effect of the invention〕

As explained above, this invention is configured to maintain the injection fuel pressure while reducing the fuel injection Dj ffi by limiting the opening degree of the fuel injection port during low load, so that the fuel injection G can be stabilized. Together, combustion vibrations can be reduced and misfires can be prevented.

This has various effects such as extending the service life of the combustor, preventing trips due to misfires, protecting the bearing and vibration meter attached to the casing due to combustion vibration, and preventing trips due to exceeding tolerance values. is obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a front view, Fig. 3 is a side view of the fuel port adjustment valve in Fig. 2, and Fig. 4 is Fig. 3B-[3 line enlarged 5 is a diagram showing improvements made by the present invention, and FIG. 6 is a cross-sectional view of a fuel injection device in a gas turbine. FIG. 7 is a cross-sectional view of a conventional fuel injection device, and FIG. 8 is a diagram showing problems with the conventional fuel injection device. 1a...Compressed air inlet passage, 2...Fuel injection port, 6
...Device main body, 7.. Front hole, 8.. Rear hole, 9.
... partition wall, 10 ... shaft hole, 11 ... fuel passage,
12...Fuel port adjustment valve, 13...Head, 14...
Shaft, 16...MAX stopper, 19... Return spring,
20...Circular hole, 21...Long hole, 22...MI
N stopper, 23...O ring, A...compressed air,
B...Fuel. Figure 6 Shizuka 7 Figure 6 Figure 6

Claims (1)

[Scope of Claims] 1. A fuel injection device for a gas turbine, consisting of a device main body and a fuel port adjustment valve slidably fitted into a cylindrical hole in the device main body as tightly as possible. A plurality of fuel injection ports that can communicate with the fuel injection ports of the main body of the device are opened on the circumferential surface of the head of the fuel port adjustment valve, and the fuel port adjustment valve is movable as the fuel injection pressure decreases. 1. A fuel injection device characterized in that the opening degree of a fuel injection port is limited according to a decrease in fuel injection pressure. 2. The fuel injection ports of the fuel port adjustment valve are configured by an alternating arrangement of circular holes and ellipses, and when the fuel port adjustment valve is retracted, the circular holes are closed to the inner surface of the device body to reduce the number of injection ports. The fuel injection device according to claim 1, characterized in that the opening degree is limited.