JP2005351196A - Method for controlling fuel supplying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling a fuel supplying device capable of satisfactorily removing fuel in a fuel injection nozzle at the time of stopping the operation and considerably reducing generation of the after-dripping of the fuel in the fuel supplying device equipped with a return type fuel injection nozzle. <P>SOLUTION: The fuel supplying device comprises a fuel supplying passage 4 communicated with the fuel injection nozzle 3 of a combustor 2 from a fuel tank 9 through a fuel pump 1, a fuel passage 5 communicated with the fuel tank 9 through a three-way solenoid valve 8 provided at a branching part diverged from a fuel supplying passage 4, and a return passage 7 communicated with the fuel tank 9 side from the fuel injection nozzle 3 through a flow adjustment valve 6. At the time of stopping the operation, the fuel pump 1 is stopped after fully opening the flow adjustment valve 6, and the three-way solenoid valve 8 is switched to a state in which the fuel injection nozzle 3 and the fuel supplying passage 4 are communicated with each other, which increases a difference in pressure between in the combustor 2 and in each passage. The fuel in the fuel injection nozzle 3 is blown away and removed by the pressure in the combustor 2, which considerably reduces the generation of the after-dropping of the fuel and coking of the fuel at an injection hole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control method used in, for example, a fuel supply device that supplies fuel to a gas turbine engine.

  Conventionally, as a fuel supply device of a gas turbine engine, a fuel supply passage communicating with a fuel injection nozzle in a combustor from a fuel tank via a fuel pump, a fuel passage branched from the fuel supply passage and communicated with the fuel tank, A three-way switch with a return passage communicating from the fuel injection nozzle to the fuel tank side via a flow rate adjusting valve, and switching between the fuel pump side and the fuel passage side with respect to the fuel injection nozzle at the branch portion of the fuel supply passage and the fuel passage Some were equipped with valves.

  This fuel supply device switches the three-way valve to the fuel pump side during operation of the gas turbine engine so that the fuel injection nozzle and the fuel pump communicate with each other. Then, the fuel in the fuel tank is supplied to the fuel injection nozzle by the fuel pump, the fuel is injected from the fuel injection nozzle into the combustor, and the flow rate of the return fuel from the fuel injection nozzle is adjusted by the flow rate adjustment valve. Thus, the fuel injection amount from the fuel injection nozzle is controlled.

When the gas turbine engine is stopped, the fuel pump is stopped and the three-way valve is switched to the fuel passage side so that the fuel injection nozzle and the fuel passage communicate with each other, and at the same time, the flow rate adjusting valve is fully opened. As a result, the fuel in the fuel injection nozzle is swept away to the fuel passage side and the return passage side by the pressure in the combustor, preventing leakage of fuel from the fuel injection nozzle into the combustor, generating white smoke and starting ignition Prevent mistakes.
JP-A-9-79565

  However, in the conventional fuel supply apparatus described above, when the gas turbine engine is stopped, the leakage of fuel from the fuel injection nozzle into the combustor can be significantly reduced. When the pressure decreases, a slight fuel sag occurs in the fuel injection nozzle, and the injection hole may be filled with the fuel.

  Then, when the injection hole is filled with fuel, the fuel is caulked by the heat of the engine and adheres to the injection hole, and coking proceeds by repeating start and stop, resulting in a decrease in fuel injection performance. Therefore, in the past, there has been a demand for an improvement in preventing the fuel from drooping in the fuel injection nozzle after the operation is stopped.

  The present invention has been made paying attention to the above-described conventional problems, and in the fuel supply device including the return type fuel injection nozzle, the fuel in the fuel injection nozzle can be sufficiently removed when the operation is stopped. It is an object of the present invention to provide a control method for a fuel supply apparatus that can significantly reduce the occurrence of fuel sag.

  The fuel supply device control method of the present invention includes a fuel supply passage that communicates from a fuel tank via a fuel pump to a fuel injection nozzle in a combustor, a fuel passage that branches from the fuel supply passage and communicates with the fuel tank, And a return passage communicating from the fuel injection nozzle to the fuel tank side via the flow rate adjusting valve, and switching between the fuel pump side and the fuel passage side with respect to the fuel injection nozzle at a branch portion of the fuel supply passage and the fuel passage In the fuel supply device having a three-way valve, when the operation is stopped, the flow rate adjustment valve is fully opened, the fuel pump is stopped, and the three-way valve is switched to a state where the fuel injection nozzle and the fuel passage communicate with each other. The configuration is a means for solving the conventional problems.

  According to the control method of the fuel supply apparatus of the present invention, when the operation is stopped, the pressure in each passage is lowered by first fully opening the flow rate adjustment valve. Thus, after that, when the fuel pump is stopped and the three-way valve is switched to a state where the fuel injection nozzle and the fuel passage communicate with each other, the pressure difference between the combustor and each passage becomes larger. The fuel in the fuel injection nozzle is blown off by the internal pressure, and the fuel can be sufficiently removed. As a result, after the pressure in the combustor has dropped, the fuel drooping in the fuel injection nozzle and the occurrence of fuel coking in the injection hole can be greatly reduced, and as a result, good injection performance and ignition performance. Can be maintained over a long period of time.

  FIG. 1 is a diagram for explaining a fuel supply apparatus to which a control method for a fuel supply apparatus according to the present invention can be applied, and a sequence when the operation of the fuel supply apparatus is stopped.

  The fuel supply device shown in FIG. 1 (a) is used for a gas turbine engine, and includes a fuel supply passage 4 communicating with a fuel injection nozzle 3 in a combustor 2 from a fuel tank 9 via a fuel pump 1, and a fuel. A fuel passage 5 branched from the supply passage 4 and communicated with the fuel tank 9 and a return passage 7 communicated from the fuel injection nozzle 3 to the fuel tank 9 via the flow rate adjustment valve 6 are provided. A three-way solenoid valve 8, which is a three-way valve that switches between the fuel pump 1 side and the fuel passage 5 side with respect to the fuel injection nozzle 3, is provided at a branch portion of the passage 5. Although the return passage 7 is connected to the fuel supply passage 4 between the fuel pump 1 and the fuel tank 9 in the illustrated example, it may be directly connected to the fuel tank 9, and in any case, the fuel tank 9 Communicate indirectly or directly to the side.

  As shown in FIG. 2, the fuel injection nozzle 3 includes a distal end side block 12 having an injection hole 11 and a proximal end side block 14 provided with a return channel 13 on the axis. Both blocks 12 and 14 are joined in a coaxial state via tapered surfaces that are in a concave-convex relationship, and a fuel supply groove 15 is formed between the tapered surfaces, and a swirl chamber 16 is formed at the center. The fuel supply passage 4 communicates with the fuel supply groove 15, and the return passage 7 communicates with the return passage 13. The combustion injection nozzle 3 injects fuel into the combustor 2 from the injection hole 11 while rotating the fuel (light oil) introduced from the fuel supply groove 15 in the swirl chamber 16.

  In addition to the configuration shown in the figure, the fuel supply device includes a control device that operates the fuel pump 1, adjusts the opening of the flow rate adjustment valve 6, and switches the three-way electromagnetic valve 8. In addition, the gas turbine engine is conventionally known, and the combustion air is mixed with the air from the compressor and the fuel from the fuel supply device, and the turbine is rotated with the combustion gas to obtain the rotational output. Keep the compressor rotating.

  The fuel supply device having the above configuration switches the three-way solenoid valve 8 to the fuel pump 1 side (ON) when the gas turbine engine is in operation, so that the fuel injection nozzle 3 and the fuel pump 1 communicate with each other. Then, the fuel in the fuel tank 9 is supplied to the fuel injection nozzle 3 by the fuel pump 1 and the fuel supply passage 4 to inject fuel into the combustor 2 from the fuel injection nozzle 3, and the flow rate adjustment valve in the return passage 7. The fuel injection amount from the fuel injection nozzle 3 is controlled by adjusting the flow rate of the return fuel from the fuel injection nozzle 3 by 6.

  Further, as a control method of the fuel supply device, when the gas turbine engine is stopped, the flow rate adjustment valve 6 is fully opened as shown in FIG. 1B, and when the predetermined time t1 has elapsed, the fuel pump 1 is stopped. The three-way solenoid valve 8 is switched to the fuel passage 5 side (OFF) to bring the fuel injection nozzle 3 and the fuel passage 5 into communication.

  As described above, when the flow rate adjustment valve 6 is first fully opened when the operation is stopped, the pressure in each passage is reduced in a short time, and then the fuel pump 1 is stopped and the three-way solenoid valve 8 is connected to the fuel injection nozzle. When the fuel passage is switched to the state in which the fuel passage is communicated, the pressure difference between the combustor 2 and each passage becomes larger.

  As a result, the fuel in the fuel injection nozzle 3 is blown off by the pressure in the combustor 2, and the fuel is pushed away to the fuel passage 5 side and the return passage 7 side, so that the fuel in the fuel injection nozzle 3 is sufficient. Can be removed. Therefore, even if the pressure in the combustor 2 subsequently decreases, the trailing of the fuel in the fuel injection nozzle 3 and the coking of the fuel in the injection hole 11 are greatly reduced, and good injection performance is achieved. And the ignition performance can be maintained over a long period of time.

It is explanatory drawing (a) which shows the fuel supply apparatus which can apply the control method of the fuel supply apparatus concerning this invention, and a timing chart (b) explaining the sequence at the time of an operation stop. It is sectional drawing explaining the specific example of a fuel-injection nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel pump 2 Combustor 3 Fuel injection nozzle 4 Fuel supply passage 5 Fuel passage 6 Flow control valve 7 Return passage 8 Three-way solenoid valve (three-way valve)
9 Fuel tank

Claims (1)

  A fuel supply passage communicating with the fuel injection nozzle in the combustor from the fuel tank via the fuel pump, a fuel passage branched from the fuel supply passage and communicating with the fuel tank, and a fuel tank from the fuel injection nozzle via the flow rate adjusting valve A fuel supply device having a return passage communicating with the fuel supply passage and a three-way valve that switches between the fuel pump side and the fuel passage side with respect to the fuel injection nozzle at a branch portion of the fuel supply passage and the fuel passage. A control method for a fuel supply device, wherein after the flow rate adjustment valve is fully opened, the fuel pump is stopped and the three-way valve is switched to a state in which the fuel injection nozzle and the fuel passage are in communication.

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