JP2003201864A - Starting method of gas turbine device and gas turbine device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine device and a starting method thereof which improves reliability of start by surely igniting mixture even under various conditions and restrains temperature rise of the gas turbine device immediately after the ignition. <P>SOLUTION: A turbine 1 is rotary-driven by a motor 5 connected with the turbine 1, and air is pressure-transferred to a combustor by an air compressor 3 interlocking with the turbine 1. When the turbine 1 reaches a predetermined rotational frequency, the supply of fuel to a combustor 2 is started, and an ignition action of fuel-air mixture is started in the combustor 2. While the ignition action of the mixture is performed at least in the combustor 2, the rotational frequency of the turbine 1 is increased, and the supply volume of the fuel to the combustor 2 is increased. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine device, and more particularly to a method of starting a gas turbine device using a starter motor.

[0002]

2. Description of the Related Art A general gas turbine apparatus includes a turbine rotatably mounted via a rotary shaft, a combustor for generating combustion gas, and a fuel adjustment for adjusting a fuel supply amount to the combustor. It is provided with a valve and an air compressor for sending compressed air (hereinafter, appropriately referred to as compressed air) to the combustor. Then, the air-fuel mixture formed in the combustor burns to generate high-temperature, high-pressure combustion gas, and the combustion gas is supplied to the turbine to rotate the turbine. .

This type of gas turbine apparatus employs a method of starting the gas turbine apparatus by driving the turbine with a starting motor at the time of starting. That is, first, the turbine is rotationally driven by the motor, and the air compressor is driven by the motor via the rotary shaft to start the supply of the compressed air to the combustor. Then, the fuel control valve is opened to supply the fuel to the combustor, and the mixture of compressed air and fuel is formed in the combustor. When the ignition operation of the air-fuel mixture is started in the combustor, the air-fuel mixture is burned to generate combustion gas, and the combustion gas is supplied to the turbine so that the turbine rotates at high speed. There is.

Here, one of the conditions under which the air-fuel mixture ignites is the mass ratio (or weight ratio) of air and fuel in the air-fuel mixture, that is, the air-fuel ratio (air fuel ratio, A /
(Also referred to as F). The air-fuel ratio is a mass ratio of air and fuel used for combustion, that is, a mixing ratio, and can be obtained by dividing the flow rate of air per unit time by the flow rate of fuel per unit time. As described above, air is compressed by the air compressor and sent to the combustor, and this air compressor is driven in conjunction with the turbine. Therefore, the flow rate of air can be calculated from the rotational speed of the turbine. it can. Further, the flow rate of fuel can be calculated from the opening of the fuel control valve. Therefore, the air-fuel ratio can be derived from the rotational speed of the turbine and the opening degree of the fuel control valve.

FIG. 3 is a graph showing the state of the turbine speed, the opening of the fuel control valve, and the exhaust temperature at the time of starting the conventional gas turbine apparatus over time. As shown in FIG. 3, first, the turbine is rotationally driven by the motor (see the dotted line in FIG. 3) to rotate the turbine at a rotational speed NR ₁ required for ignition.
After reaching 0, the motor is controlled so as to maintain this rotation speed NR ₁ . After that, the supply of the fuel to the combustor is started to form the air-fuel mixture, and at the same time, the ignition operation for the air-fuel mixture is started (t ₁ ). At this time, the fuel supply amount (opening of the fuel control valve) is maintained at a predetermined supply amount (fcv ₁ ) preferable for ignition, as shown in FIG.

Eventually, the air-fuel mixture is ignited to generate combustion gas (t ₂ ), and this combustion gas is supplied to the turbine, whereby power is obtained from the combustion gas to accelerate the turbine. Then, the rotational drive of the motor is stopped. Then, at the same time when the rotational drive by the combustion gas is started, the turbine is controlled by adjusting the supply amount of the combustion gas supplied to the turbine. That is, the speed-up control is performed in which the opening of the fuel control valve is operated so that the turbine acceleration reaches a predetermined target acceleration that is set in advance, thereby increasing the rotation speed of the turbine.

As described above, during the ignition operation (from t ₁ to t
₍ Up to ₂ ), the air-fuel ratio is set to a value that is preferable for ignition. Therefore, as shown in FIG. 3, the rotational speed of the turbine (flow rate of compressed air) and the opening degree of the fuel control valve are set. (Fuel supply amount) is constant. In this way, the air-fuel mixture is quickly ignited by performing the ignition operation with the air-fuel ratio that is preferable for ignition.

[0008]

However, the air-fuel ratio preferable for ignition varies depending on various conditions at the time of starting. For example, it is difficult to ignite when the temperature of the surrounding environment is low, and easy to ignite when the gas turbine apparatus main body is restarted in a high temperature after the operation is stopped. That is, the air-fuel ratio does not necessarily ignite with the same air-fuel ratio, and therefore, the air-fuel mixture may not be ignited well and the startup may fail.

In order to solve this problem, in the prior art, as shown in FIG. 4, while keeping the turbine speed constant,
Attempts have been made to follow changes in ignition conditions by increasing the opening of the fuel control valve and varying the air-fuel ratio. However, in this case, the following problems occur. Immediately after the ignition (t ₂ ), as described above, the control of the turbine is switched from the drive by the motor to the speed-up control by the supply of the combustion gas. At this time, the rotational speed of the turbine immediately after ignition is kept constant and the acceleration is 0, so that the deviation between the target acceleration and the acceleration of the turbine immediately after switching is large.

Then, immediately after switching to the speed-up control, the fuel control valve opens greatly due to the control operation for minimizing this deviation. For this reason, excessive fuel is supplied from the fuel control valve to the combustor, and the temperature of the gas turbine device, particularly the combustor, suddenly rises to a high temperature immediately after ignition (Fig. 4). Exhaust temperature reference). This problem also occurs when the activation method shown in FIG. 3 is adopted.

The present invention has been made in view of the above problems, and it is possible to reliably ignite an air-fuel mixture even under various conditions to improve the reliability of starting, and immediately after ignition. It is an object of the present invention to provide a gas turbine device capable of suppressing the temperature rise of the gas turbine device and the starting method thereof.

[0012]

In order to solve the above problems, the present invention rotatably drives the turbine by a motor connected to the turbine, and burns air by an air compressor linked to the turbine. The fuel to the combustor when the turbine reaches a predetermined rotational speed, and at the same time, the ignition operation of the mixture of fuel and air is started in the combustor, and at least the combustion is performed. While the air-fuel mixture is being ignited in the burner, the rotational speed of the turbine is increased and the amount of fuel supplied to the combustor is increased.

Further, according to the present invention, a motor for rotationally driving a turbine, a motor control unit for controlling the rotational speed of the motor, a combustor for combusting a mixture of fuel and air to generate combustion gas, In a gas turbine device provided with an air compressor that pumps air to the combustor in conjunction with the turbine, and a fuel control valve that adjusts the amount of fuel supplied to the combustor, a gas mixture in at least the combustor While the ignition operation is being performed on the engine, the motor control unit increases the rotation speed of the turbine via the motor and increases the amount of fuel supplied to the combustor via the fuel control valve. It is characterized by

According to the present invention, the air-fuel ratio can be made to follow the variation of the ignition condition, so that the ignition can be reliably performed. Moreover, since the turbine is accelerated to some extent at the time of ignition, the deviation between the acceleration of the turbine at the time of ignition and the target acceleration is small. Therefore, it is possible to prevent the excessive supply of fuel immediately after ignition and switching to the speed-up control, and thereby to prevent the temperature of the gas turbine device from rising immediately after ignition.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a gas turbine device according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of a gas turbine device according to this embodiment.

As shown in FIG. 1, the gas turbine device according to the present embodiment has a turbine 1, a combustor 2 for supplying combustion gas to the turbine 1, and a fuel adjustment for adjusting the amount of fuel supplied to the combustor 2. The valve 19 includes an air compressor 3 that sends air to the combustor 2 under pressure, and a turbine control unit 11 that controls the turbine 1.

The turbine 1 has a plurality of rotary blades (not shown) for receiving a fluid and rotating, and is rotatably supported in a casing (not shown) via a rotary shaft 6. The air compressor 3 is configured to be driven by the turbine 1 via the rotating shaft 6 to compress air. The air compressor 3 is connected to the combustor 2 via a pipe 7, and the air compressed by the air compressor 3 is supplied to the combustor 2 via the pipe 7.

The fuel control valve 19 is arranged on the upstream side of the combustor 2, and the fuel supplied from a fuel supply source (not shown) is supplied to the combustor 2 after passing through the fuel control valve 19. The fuel control valve 19 has a variable opening, and the amount of fuel supplied to the combustor 2 is adjusted by operating the opening. The turbine control unit 11
Controls the turbine 1 by operating the opening of the fuel control valve 19 so that the acceleration of the turbine 1 approaches a preset target acceleration.

The fuel and the compressed air supplied to the combustor 2 form an air-fuel mixture in the combustor 2, and the air-fuel mixture burns in the combustor 2 to generate high-temperature and high-pressure combustion gas.
Then, by supplying this combustion gas to the turbine 1, the turbine 1 rotates at high speed. A rotation speed detection unit 12 that detects the rotation speed of the turbine 1 is installed near the shaft end of the rotation shaft 6 on the motor 5 side.

Further, the gas turbine device according to the present embodiment, as shown in FIG. 1, has a motor 5 connected to a rotary shaft 6.
And a motor controller 8 that controls the number of rotations of the motor 5. Then, in the present embodiment, the motor 5 functions as a starting motor for the gas turbine device, and the rotation speed control of the motor 5 at this time is performed by the motor control unit 8.

FIG. 2 is a graph showing the rotational speed of the turbine, the opening degree of the fuel control valve, and the exhaust gas temperature at the time of starting the gas turbine system according to this embodiment over time.
As shown in FIG. 2, when starting the activation of the gas turbine device, first, electric power is supplied to the motor 5, and the motor 5 rotationally drives the turbine 1 (see the dotted line in FIG. 2). Eventually,
After the rotation speed of the turbine 1 reaches the rotation speed (NR ₁ ) at which ignition is possible, the motor controller 8 controls the motor 5 to gradually increase the rotation speed of the turbine 1. Then,
As shown in, since the motor 5 and the air compressor 3 are interlocked via the rotary shaft 6, the supply amount of compressed air to the combustor 2 at this time also gradually increases.

Almost at the same time when the motor controller 8 starts to increase the rotational speed of the turbine 1, the fuel control valve 19 is opened to start the supply of fuel to the combustor 2 (t ₁ ). Further, at the same time when the fuel supply to the combustor 2 is started, the opening of the fuel control valve 19 is gradually increased to increase the fuel supply amount to the combustor 2.

In the combustor 2, the air-fuel mixture is formed by the compressed air and the fuel, and the ignition operation to the air-fuel mixture is started almost at the same time as the supply of the fuel to the combustor 2. The air-fuel ratio that is preferable for igniting the air-fuel mixture varies depending on the temperature of the gas turbine apparatus main body, etc.
_{(Between 1} and t ₂ ), as described above, the supply amount of the compressed air and the fuel to the combustor 2 increases, so that the air-fuel ratio changes. Therefore, when the air-fuel ratio meets the conditions preferable for ignition at that time, the mixture is ignited.

After the ignition operation of the air-fuel mixture is completed, the combustion gas is supplied to the turbine 1, and the combustion gas obtains a driving force to accelerate the turbine 1. After the rotational driving of the turbine 1 by the combustion gas is started (after t ₂ ), the turbine control unit 11 switches to the speed increasing control. In addition, in the combustor 2, it is possible to confirm whether or not the ignition operation of the air-fuel mixture is completed.
This is performed by measuring the exhaust temperature with an exhaust temperature measuring device 17 provided in the pipe.

Immediately after switching to the speed increasing control,
As shown in FIG. 2, since the turbine 1 has already been driven by the motor 5 and has accelerated to some extent, the deviation between the acceleration of the turbine 1 and the target acceleration at this time is not so large. Therefore, as shown in FIG. 2, the opening of the fuel control valve 19 does not open excessively in order to bring the acceleration of the turbine 1 closer to the target acceleration, and as a result, the excessive fuel is supplied to the combustor 2. As a result, it is possible to prevent the temperature of the gas turbine device immediately after ignition from becoming high.

The gas turbine device of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0027]

As described above, according to the present invention,
Since the air-fuel ratio can be made to follow the change in the ignition condition, it is possible to reliably ignite. Moreover, since the turbine is accelerated to some extent at the time of ignition, the deviation between the acceleration of the turbine at the time of ignition and the target acceleration is small. Therefore, it is possible to prevent excessive supply of fuel immediately after ignition and switching to speed-up control.
It is possible to prevent the temperature of the gas turbine device from rising immediately after ignition.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a gas turbine device according to an embodiment of the present invention.

FIG. 2 is a turbine rotation speed, a fuel control valve opening degree, and
It is a graph showing the appearance of the exhaust temperature over time.

FIG. 3 is a graph showing the rotational speed of the turbine, the opening degree of the fuel control valve, and the exhaust gas temperature at the time of starting the conventional gas turbine device over time.

FIG. 4 is a graph showing the state of the rotational speed of the turbine, the opening degree of the fuel control valve, and the exhaust temperature at the time of startup of another conventional gas turbine device over time.

[Explanation of symbols]

1 turbine 2 Combustor 3 air compressor 5 motor 6 rotation axes 7 piping 8 Motor control unit 11 Turbine controller 12 Rotation speed detector 17 Exhaust gas temperature measuring device 19 Fuel control valve

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Miyamoto             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Masafumi Kataoka             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Yasushi Furuya             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION

Claims (2)

[Claims] 1. A turbine connected to a turbine to drive the turbine to rotate, and an air compressor linked to the turbine pumps air to a combustor. When the turbine reaches a predetermined rotation speed, the combustion is performed. While starting the supply of fuel to the burner, start the ignition operation of the mixture of fuel and air in the combustor, at least while the ignition operation of the mixture is performed in the combustor,
A method of starting a gas turbine device, comprising increasing the rotational speed of the turbine and increasing the amount of fuel supplied to the combustor. 2. A motor for rotationally driving a turbine, a motor control unit for controlling the rotational speed of the motor, a combustor for combusting a mixture of fuel and air to generate combustion gas, and an interlock with the turbine. In a gas turbine device including an air compressor for compressing and sending air to the combustor, and a fuel control valve for controlling the amount of fuel supplied to the combustor, at least an ignition operation of an air-fuel mixture in the combustor While the above is being performed, the motor control unit increases the rotational speed of the turbine via the motor and increases the amount of fuel supplied to the combustor via the fuel control valve. Gas turbine equipment.