JP2007255815A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve combustion performance by efficiently injecting fuel into a combustion chamber by adjusting a flow rate of fuel while keeping a fuel injection pressure at a given pressure. <P>SOLUTION: This fuel injection valve 1 comprises a fuel injection valve body 2 having a fuel injection hole 2a at its tip in a state of being communicated to a fuel inflow port 2b through an annular space 2f and the like, a needle valve 3 axially movably fitted to a valve supporting member 6 disposed in the fuel injection valve body 2 in a state that a tapered shaft 3a is faced to the fuel injection hole 2a, and an electromagnetic actuator 4 disposed on the rear end of the fuel injection valve body 2, and adjusting an axial moving position of the needle valve 3 to change an opening of the fuel injection hole 2a by the needle valve 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel injection valve that injects fuel into a combustion chamber of a continuous combustion apparatus such as a combustor of a gas turbine.

In a gas turbine combustor, it is necessary to spray fuel from a fuel injection valve with a fuel injection pressure kept constant as much as possible at the time of ignition and a wide flow range corresponding to the load from low load to high load. is there. Therefore, conventionally, fuel having two types of large and small fuel injection holes corresponding to the size of the load range and having the pressure and flow rate adjusted respectively by being sent from the fuel pump is selected according to the size of the load or 2. Description of the Related Art There is known a fuel injection valve that sprays into a combustion chamber of a combustor through both fuel injection holes (see, for example, Patent Document 1 and Patent Document 2).
JP 11-159757 A JP 2000-193242 A

  However, in the conventional fuel injection valve, since the size of the opening of the fuel injection hole is a fixed orifice, when the flow rate of the fuel supplied to the fuel injection valve is reduced, the pressure control valve Even if the pressure is adjusted to the set value by the fuel, the fuel injection pressure at the opening of the fuel injection hole is lowered, so that the combustion spray state for the combustor of the gas turbine is deteriorated, resulting in the ignition of the combustor. There is a problem of deteriorating performance, flame holding performance, combustion efficiency, emission, exhaust concentration and the like.

  The present invention has been made in view of the above circumstances, and the fuel flow rate can be adjusted while maintaining the fuel injection pressure at an arbitrary pressure so that the fuel can be efficiently injected into the combustion chamber, and the combustion performance is improved. An object of the present invention is to provide a simple fuel injection valve having a structure that can be made to operate.

A fuel injection valve according to the present invention includes a fuel injection valve main body provided with a fuel injection hole communicating with a fuel passage at the tip, and a tapered tapered shaft portion facing the fuel injection hole. A needle valve provided in the main body so as to be movable in the axial direction and a base end of the fuel injection valve main body, and the position of the fuel injection hole by the needle valve is adjusted by adjusting the movement position of the needle valve in the axial direction. It is characterized by having a configuration including an actuator for changing the opening degree.
In this fuel injection valve, the fuel injection hole of the fuel injection valve main body is configured as a variable orifice by the taper shaft portion of the needle valve, and the opening area of the variable orifice is adjusted by adjusting the position of the needle valve by an actuator. Is done. Thus, the injection amount from the fuel injection hole is adjusted in a state in which the fuel supplied to the fuel inlet of the fuel injection valve body maintains a predetermined pressure.

  In the fuel injection valve, if the actuator is an electromagnetic actuator that adjusts a moving position of a movable iron core connected to the needle valve by changing an electromagnetic attraction force in accordance with an amount of electricity, a needle valve position adjusting mechanism This makes the configuration simple and easy to implement.

  Further, in the fuel injection valve, when the fuel injection valve body is configured to be attached to the combustor with the fuel injection hole directed toward the combustion chamber of the combustor of the gas turbine, the combustion performance in the combustor is greatly increased. It can be improved, and stable operation of the gas turbine can be ensured.

  According to the fuel injection valve of the present invention, since the fuel injection hole of the fuel injection valve body is configured as a variable orifice whose opening degree is adjusted by the axial movement position of the needle valve, the fuel injection hole is opened. The fuel flow rate can be easily adjusted by changing the degree, and even if the fuel flow rate is changed, the fuel supplied to the fuel injection valve body with the pressure adjusted is changed like a conventional fixed orifice type fuel injection hole. The fuel injection pressure is always set arbitrarily, regardless of the range of adjustment of the fuel flow rate, without causing the problem of lowering the fuel injection pressure from the fuel injection hole, especially when the flow rate is changed to a small amount. The fuel can be injected efficiently while maintaining the above.

For this reason, in a continuous combustion apparatus, a favorable improvement effect can be obtained with respect to combustion performance such as good ignition performance, flame holding performance, combustion efficiency, emission, and exhaust concentration.
In addition, since the fuel injection hole of the fuel injection valve itself has a fuel flow control function as a variable orifice, the fuel flow control valve that has been conventionally installed in the fuel supply line becomes unnecessary, and the fuel supply piping to the fuel injection valve Therefore, the fuel system can be simplified, the device can be downsized, and the manufacturing cost can be reduced.

Hereinafter, a fuel injection valve according to an embodiment of the present invention will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes a fuel injection valve according to an embodiment of the present invention. The fuel injection valve 1 is disposed in a fuel injection valve main body 2 having a fuel injection hole 2a at the tip, and is movable in the axial direction within the fuel injection valve main body 2, and adjusts the opening area of the fuel injection hole 2a. The needle valve 3 and a linear electromagnetic actuator 4 for controlling the movement position of the needle valve 3, the fuel injection valve body 2 is attached to a combustor 5 of a gas turbine, and the fuel injection hole 2 a It is provided in the combustion chamber 5 a of the combustor 5.

  The fuel injection valve main body 2 is formed in a cylindrical shape, and the fuel injection hole 2a is provided through the tip of the fuel injection valve main body 2, and the fuel inlet 2b is provided in the side wall on the base end side (upper end side in FIG. 1). The front end side is attached to the combustor 5 of the gas turbine, and the fuel injection hole 2 a is opened to the combustion chamber 5 a of the combustor 5. The fuel injection hole 2a includes a parallel hole portion 2d on the inner side of the fuel injection valve main body 2, and a tapered hole portion 2e whose outer side is wider than the parallel hole portion 2d.

  A cylindrical valve support member 6 having a valve insertion hole 6a whose axis coincides with the inside 2c of the fuel injection valve body 2 is provided with a flange 6b provided at the upper end thereof. (The upper end in FIG. 1) is fixedly provided, and the valve support member 6 is in liquid-tight contact with the bottom of the fuel injection valve main body 2, and the valve insertion hole 6 a is the fuel injection hole. It communicates with the parallel hole 2d of 2a. An annular space (fuel passage) 2 f is formed between the outer periphery of the valve support member 6 and the inner wall of the fuel injection valve body 2, and the annular support 2 f is formed at the tip of the valve support member 6. A plurality of communication holes (fuel passages) 6c that connect the parallel hole portion 2d of the fuel injection hole 2a via the tip end portion (fuel passage) of the valve insertion hole 6a are predetermined in the circumferential direction toward the diametrical direction. It is provided at intervals.

  The needle valve 3 is made of a non-magnetic member, has a tapered shaft portion 3 a that is tapered on the distal end side, and a parallel shaft portion 3 b that is provided on the proximal end side. A parallel shaft portion 3b is slidably fitted in the hole 6a in the axial direction (vertical direction in FIG. 1), and the tip end portion of the tapered shaft portion 3a is inserted into the fuel injection hole 2a in the fuel injection valve main body 2. It is made to come. An O-ring 7 is attached to the upper end portion of the valve insertion hole 6a of the valve support member 6 to keep the fitting gap between the needle valve 3 and the valve insertion hole 6a fluid-tight. The electromagnetic actuator 4 is fixed to the upper end of the flange 6b of the valve support member 6, and the base end (upper end in FIG. 1) of the parallel shaft portion 3b of the needle valve 3 is connected to the rod-shaped movable iron core. ing.

The electromagnetic actuator 4 changes an electromagnetic attractive force by controlling a current (electric quantity) flowing through the electromagnetic coil, and moves the movable iron core or an output shaft connected to the movable iron core in a movement stroke in the axial direction thereof. It is a conventionally well-known one that is stably displaced over the entire area.
A fuel supply source is connected to the fuel inlet 2b of the fuel injection valve body 2 through a fuel supply line 9 provided with a fuel pump 8, and the fuel supply line 9a downstream of the fuel pump 8 is connected to the fuel supply line 9a. A pressure control valve 10 such as a pressure adjustment valve or a proportional pressure adjustment valve is provided for controlling the pressure of the fuel flowing into the fuel inlet 2b while returning a part of the fuel in the fuel supply line 9a to the fuel supply source side. ing.

  The pressure control valve 10 is electrically connected to the control device 11 and is operated by the control unit 13 based on the set value of the pressure setting device 12 provided in the control device 11 to thereby control the pressure of the fuel flowing through the fuel supply line 9a. It is designed to control arbitrarily. The electromagnetic actuator 4 is connected to a current regulator 14 for passing a current through the electromagnetic coil. The current regulator 14 is electrically connected to the control device 11 and a needle position provided in the control device 11. Based on the set value of the setting device 15, the control unit 13 operates to adjust the amount of current flowing through the electromagnetic coil of the electromagnetic actuator 4, and the needle valve 3 corresponds to the current set value by the needle position setting device 15. The moving position in the axial direction is changed based on a predetermined relationship. That is, the amount of current by the needle position setting device 15 and the size of the opening area of the fuel injection hole 2a based on the axial movement position of the needle valve 3 (fuel flow rate (fuel injection amount)) have a fixed relationship. It can change. The current adjuster 14, the needle position setting device 15, and the control unit 13 constitute a needle position controller 16.

  In the fuel injection valve 1 according to the embodiment, required fuel is drawn from the fuel supply source by the fuel pump 8 and supplied to the fuel inlet 2b of the fuel injection valve body 2 through the fuel supply line 9. The The fuel supplied to the fuel inlet 2b passes through the annular passage 2c, reaches the bottom thereof, passes through the communication hole 6c at the tip of the valve support member 6, and enters the valve insertion hole 6a of the valve support member 6. The fuel injection valve 2a is injected into the combustion chamber 5a of the combustor 5 of the gas turbine from a variable orifice formed by the parallel hole portion 2d of the fuel injection hole 2a and the tapered shaft portion 3a of the needle valve 3. Combustion is performed by compressed air introduced into the combustion chamber 5 a of the combustor 5 from the outer peripheral side of the main body 2.

  At that time, the pressure of the fuel supplied from the fuel inlet 2b of the fuel injection valve main body 2 to the parallel hole portion 2d of the fuel injection hole 2a is preliminarily set by the pressure setting valve 12 of the control device 11 by the pressure control valve 10. It is adjusted to the set pressure. The flow rate of the fuel passing through the opening (variable orifice) formed between the tapered shaft portion 3a and the parallel hole portion 2d of the fuel injection hole 2a depending on the moving position of the needle valve 3 is determined by the control device 11. The moving position of the needle valve 3 is adjusted by changing the current supplied from the current adjuster 14 to the electromagnetic coil of the electromagnetic actuator 4 based on the set value of the needle position setting device 15.

  When adjusting the flow rate of fuel injected from the fuel injection hole 2a of the fuel injection valve 1 into the combustion chamber 5a of the fuel injection valve 1 in response to a change in the load of the gas turbine, control is performed according to the needle position setting device 15. It can be arbitrarily adjusted according to the moving position of the needle valve 3 by the current regulator 14 operated by the section 13. Since the fuel flow rate is adjusted at the variable orifice of the fuel injection hole 2a of the fuel injection valve body 2, the pressure control valve 10 operated by the control unit 13 according to the pressure setter 12 of the control device 11 is used in advance. The adjusted pressure is stably maintained as set value without being affected by the fuel adjustment.

  As described above, the fuel injection valve 1 according to the embodiment has the fuel injection hole 2a communicating with the fuel passage including the fuel inlet 2b, the annular space 2f, the communication hole 6c of the valve support member 6 and the like at the tip. The fuel injection valve main body 2 provided to be open and the tapered taper shaft portion 3a face the fuel injection hole 2a and are fitted into the valve insertion hole 6a of the valve support member 6 so as to be fitted to the fuel injection valve main body 2. The needle valve 3 provided in the axial direction so as to be movable in the inside thereof, and provided at the base end of the fuel injection valve main body 2, the moving position of the needle valve 3 in the axial direction is adjusted by a needle position controller 16. An electromagnetic actuator 4 for changing the opening of the fuel injection hole 2a by the needle valve 3 is provided.

  Therefore, according to the fuel injection valve 1 according to the embodiment, the fuel injection hole 2a of the fuel injection valve body 2 is configured as a variable orifice whose opening degree is adjusted by the axial movement position of the needle valve 3. Therefore, even if the flow rate of the fuel is changed by changing the opening of the fuel injection hole 2a, the fuel supplied to the fuel injection valve main body 2 with the pressure adjusted by the pressure control valve 10 is the conventional fixed orifice type. As in the case of the fuel injection hole, the problem that the fuel injection pressure from the fuel injection hole 2a decreases particularly when the flow rate is changed to a small amount does not occur, and regardless of the adjustment range of the fuel flow rate, always, It is possible to efficiently inject fuel while maintaining an arbitrarily set fuel injection pressure.

For this reason, in the combustor 5 of the gas turbine, a favorable improvement effect can be obtained with respect to the combustion performance such as good ignition performance, flame holding performance, combustion efficiency, emission, exhaust concentration and the like.
When the pressure control valve 10 is a proportional pressure control valve, the fuel flow rate and the fuel injection pressure can be changed steplessly and freely, so that the optimum fuel injection pressure can be controlled at any fuel flow rate. Such combustion performance can be further improved.
Further, since the fuel injection hole 2a itself of the fuel injection valve 1 has a fuel flow rate control function as a variable orifice, the fuel flow rate control valve that has been conventionally installed in the fuel supply line becomes unnecessary, and the fuel injection valve 1 is connected to the fuel injection valve 1. Since only one fuel supply pipe is required, the fuel system is simplified, and the apparatus can be downsized and the manufacturing cost can be reduced.

In the fuel injection valve 1 according to the embodiment, a linear electromagnetic actuator is used as an actuator for adjusting the moving position of the needle valve 3, but the present invention is not limited thereto, and hydraulic and pneumatic cylinders are used. It may be used, and may be of a type having a mechanism for converting rotational motion into linear motion instead of the linear type.
The fuel injection valve 1 according to the embodiment is an example of a case where the fuel injection valve 1 is applied to a fuel injection valve that sprays fuel into a combustor 5 of a gas turbine. However, the present invention is not limited to this, and a boiler and an incinerator are used. The present invention can be applied to a burner of a continuous combustion apparatus such as a drying furnace, and the same effects can be obtained.

It is a longitudinal cross-sectional view which shows the fuel injection valve which concerns on one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection valve 2 Fuel injection valve main body 2a Fuel injection hole 2b Fuel inlet 3 Needle valve 3a Tapered shaft part 4 Electromagnetic actuator 5 Gas turbine combustor 6 Valve support member 8 Fuel pump 9, 9a Fuel supply line 10 Pressure control valve 11 Control Device 16 Needle Position Controller

Claims (3)

  A fuel injection valve main body provided with a fuel injection hole communicating with the fuel passage opened at the tip, and a tapered tapered shaft portion facing the fuel injection hole so as to be movable in the axial direction within the fuel injection valve main body A needle valve provided; and an actuator provided at a base end of the fuel injection valve main body and adjusting an opening position of the fuel injection hole by the needle valve by adjusting a movement position of the needle valve in an axial direction. A fuel injection valve characterized by comprising:   2. The fuel injection valve according to claim 1, wherein the actuator is an electromagnetic actuator that adjusts a moving position of a movable iron core connected to the needle valve by changing an electromagnetic attraction force in accordance with an amount of electricity. 3. . The fuel injection valve according to claim 1 or 2, wherein the fuel injection valve body is attached to the combustor with the fuel injection hole directed toward a combustion chamber of a combustor of a gas turbine.

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