JPH10103155A - Fuel supply device for afterburner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply device for an after-urner, having a very small time delay at ignition time and high reliability, which can prevent generation of calking in an injection valve. SOLUTION: A flow divider valve 6 is arranged in the vicinity of an injection valve, also in the flow divider valve, a fuel return pipe 10 returned to a fuel tank side is provided, a fuel circulation flow path 14 via the divider valve with fuel supply pipes 5, 12 is formed. In the fuel circulation flow path, a circulation valve 11 is interposed. The circulation valve is ordinarily placed in an opened condition, fuel is circulated, only when an after-burner device is used, the circulation valve is placed in a closed condition, the fuel circulation flow path is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel supply device for an afterburner.

[0002]

2. Description of the Related Art For example, some jet engines have an afterburner device. The afterburner device is used when a large thrust is required.The afterburner device includes an injection valve for fuel injection downstream of the combustion chamber and a flame holding tube downstream of the combustion chamber. It is to reburn.

[0003]

As described above, the afterburner device is used only at the time of takeoff or when a large thrust such as acceleration from subsonic speed to supersonic speed is required, and is always used. is not. Therefore, in the region from idling to dry max where the afterburner device is not used, no fuel flows to the afterburner fuel supply device. For this reason, the location where the injection valve is disposed is substantially at the center in the exhaust pipe, and since it is exposed to the high-temperature exhaust flow, carbon contained in the fuel is carbonized and the nozzle of the injection valve is closed ( (Hereinafter referred to as coking).

In order to prevent such clogging of the injection valve, it has been practiced to discharge all fuel remaining in a pipe from a branch valve connected to the injection valve.
In this case, it takes a certain amount of time to fill the pipe with fuel again, so that there is a problem that a time delay occurs when the afterburner device is ignited.

Further, in order to prevent such a time delay, it has been considered that the pipe is first filled with fuel promptly, and then a small amount of ignition fuel is caused to flow. Complex and poorly reliable.

[0006] The present invention has been made in view of the above circumstances, has a very small time delay at the time of ignition, high reliability,
Moreover, it is an object of the present invention to provide an afterburner fuel supply device capable of preventing the occurrence of caulking of the injection valve.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, fuel supplied from a fuel supply line is supplied to an afterburner via a metering valve, a throttling valve, and a flow dividing valve. In a fuel supply device for an afterburner, which is guided to an injection valve and is injected therefrom for reburning, the branch valve is arranged near the injection valve, and the branch valve is provided with a fuel return pipe returning to the fuel tank side. To form a fuel circulation passage through a flow dividing valve together with the fuel supply pipe, and the fuel circulation passage is normally opened but closed only when the afterburner device is used. And a circulation valve for closing the valve.

[0008] The invention according to claim 2 is characterized in that the circulation valve is provided integrally with the throttling valve.

According to a third aspect of the present invention, a check valve is provided between the flow dividing valve and the circulation valve of the fuel return pipe so as to allow only the fuel flow in the return direction. I do.

[0010]

According to the first aspect of the present invention, since the flow dividing valve is disposed near the injection valve, all fuel remaining between the flow dividing valve and the injection valve is purged (discharged) in order to prevent occurrence of coking. However, the amount of the purge is small, so that the time for refilling them with fuel is only an extremely short time, so that there is almost no time delay when the afterburner device is fired.

Further, since the branch valve is arranged near the injection valve, the branch valve is easily heated.
From the idle ring to the dry max area,
Since the circulation valve is set to the “open” state and the fuel is caused to flow through the fuel circulation channel to cool the flow dividing valve, the rise in temperature of the flow dividing valve can be suppressed.

According to the second aspect of the present invention, since the circulation valve is provided integrally with the throttling valve, the whole system can be simplified and the size and weight can be reduced. Further, when the fuel supply pipe on the fuel supply side extending from the throttling valve is used as the fuel circulation flow path of the flow dividing valve, the pipe connection is facilitated.

According to the third aspect of the present invention, since the check valve that allows only the fuel flow in the return direction is interposed between the flow dividing valve and the circulation valve of the fuel return pipe, the afterburner device is provided. During operation, the backflow of fuel through the fuel return pipe can be prevented, and the reliability of the device can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a fuel supply device for an afterburner according to the present invention. Symbol 1 in the figure
Represents a fuel supply line extending from a fuel pump (not shown), 2
Is a metering valve, 3 is a differential pressure sensing valve, and 4 is a throttling valve. A fuel supply pipe 5 extends from the throttling valve 4, and a plurality of flow dividing valves 6,. The branch valve 6 is arranged near an injection valve (not shown), and the branch valve 6 and the injection valve are connected by a fuel supply pipe 8.

A fuel return pipe 10 is provided from the flow dividing valve 6 to return to the fuel tank side. The fuel return pipe 10 is provided with a non-return valve 10a for allowing only the fuel flow in the return direction. A circulation valve 11 is formed integrally with the throttle ring valve 4, and the fuel return pipe 10 is connected to the circulation valve 11. The fuel supply pipe 12 extending from the circulation valve 11 joins the fuel supply pipe 5 extending from the throttling valve 4. A check valve 12 a is interposed at the junction of the fuel supply pipe 12. The fuel supply pipes 12 and 5 and the fuel return pipe 10
Forms a fuel circulation channel 13 via the flow dividing valve 6.

In the circulation valve 11, the fuel supply pipe 12 is connected to a port 11a.
The port 11b is connected to a low-pressure side fuel return pipe 16 communicating with the fuel tank, the port 11c is connected to a high-pressure side fuel supply pipe 17 for supplying circulating fuel, and the port 11d.
Is connected to the fuel return pipe 10. A spool 11e is built in the circulation valve 11, and the spool 11e normally moves to the left to be in an "open" state, and connects the fuel supply pipes 17 and 12, and also connects the fuel return pipes 10 and 16. However, when the afterburner device is operated, the spool 11e moves rightward as shown in the figure, and becomes "closed" to close the fuel circulation flow path 14.

Next, the operation of the afterburner fuel supply device having the above configuration will be described. When a large thrust is required to operate the afterburner device, the circulation valve is closed and the fuel circulation passage 14 is closed.
Close. Therefore, in this case, when an injection valve (not shown) is opened, the fuel supplied from the fuel supply line 1 through the metering valve 2 and the stirring ring valve 4 is supplied to the fuel supply line as shown by a solid line arrow in the figure. The fuel is injected from the injection valve through the pipe 5, the branch valve 6, and the fuel supply pipe 8 into the hot exhaust stream in the central part of the exhaust pipe. As a result, the fuel is reburned, and a large thrust is obtained.

On the other hand, when the afterburner device is stopped as in a normal operation, the injection valve is closed, and a purge valve (not shown) is opened to remain in the fuel supply pipe 8 connecting the branch valve 6 and the injection valve. Purge (discharge) fuel to prevent caulking of injection valves. At the same time, the spool 11e is moved to the left from the position shown in the figure to bring the circulation valve 11 into the "open" state. Thus, the fuel supply pipes 17 and 12 communicate with each other, and the fuel return pipes 10 and 16 communicate with each other. The fuel supplied from the fuel supply pipe 17 on the high pressure side reaches the branch valve 6 through the fuel supply pipes 12 and 5 as shown by the dashed arrows in the drawing, and from there the circulation valve through the fuel return pipe 10. To the fuel return pipe 16
And return to the tank side. As described above, since the fuel can be caused to flow through the fuel circulation flow path and the fuel can be used to cool the flow dividing valve, it is possible to suppress a rise in the temperature of the flow dividing valve disposed near the injection valve and under a condition that is easily heated.

In the above embodiment, the afterburner device of the jet engine has been described as an example. However, it goes without saying that the present invention can be applied to a fuel injector device used in a ramjet engine.

[0020]

According to the first aspect of the present invention, since the flow dividing valve is disposed near the injection valve, all fuel remaining between the flow dividing valve and the injection valve is purged in order to prevent the occurrence of coking. (Discharge), the purge amount is small, so that there is almost no time delay at the time of ignition of the afterburner device. That is, it is possible to simultaneously prevent the occurrence of coking and eliminate the time delay at the time of ignition of the afterburner device. In addition, since the shunt valve is arranged near the injection valve, when the afterburner device is stopped from the idle ring to the dry max region, the circulation valve is set to the `` open '' state,
Since the fuel can flow through the fuel circulation channel to cool the flow dividing valve, the temperature rise of the flow dividing valve can be suppressed.

According to the second aspect of the present invention, since the circulation valve is provided integrally with the throttling valve, the whole system can be simplified and reduced in size and weight, and the fuel supply side extending from the throttling valve can be provided. When the fuel supply pipe is used as a fuel circulation flow path of the flow dividing valve, pipe connection is facilitated.

According to the third aspect of the present invention, since the check valve that allows only the fuel flow in the return direction is interposed between the diversion valve and the circulation valve of the fuel return pipe, the afterburner device is provided. During operation, the backflow of fuel through the fuel return pipe can be prevented, and the reliability of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of an afterburner fuel supply device showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel supply line 2 Metering valve 3 Differential pressure sensing valve 4 Circulation valve 5 Fuel supply pipe 6 Divide valve 10 Fuel return pipe 10a Check valve 12 Fuel supply pipe 14 Fuel circulation flow path

Claims (3)

[Claims] 1. A fuel supplied from a fuel supply line (1) is guided to an injection valve for an afterburner via a metering valve (2), a throttling valve (4), and a flow dividing valve (6), and from there. In a fuel supply device for an afterburner that is injected for re-burning, a fuel return pipe (1) that returns the fuel flow to a fuel tank side while arranging the flow dividing valve near the injection valve.
0) to form a fuel circulation flow path (14) that passes through a flow dividing valve together with the fuel supply pipes (5, 12).
An afterburner, wherein a circulation valve (11), which is normally open but is closed only when the afterburner device is used and closes the fuel circulation channel, is interposed in the fuel circulation channel. For fuel supply. 2. The after-burner fuel supply device according to claim 1, wherein the circulation valve is provided integrally with the throttling valve. 3. The after-burner fuel supply device according to claim 1, wherein the fuel return pipe is provided between the diverter valve and the circulation valve of the fuel return pipe to allow only a fuel flow in a return direction. A fuel supply device for an afterburner, comprising a valve (10a) interposed.