JP2003239764A - Gas turbine device and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine device which makes stable motion without generating the overshoot of the temperature of engine combustion emission gas. <P>SOLUTION: The gas turbine device has a gas turbine engine for driving/ rotating a gas turbine by mixing and burning a fuel, and a generator directly connected to the gas turbine. The gas turbine device also has: a sensor for measuring the temperature of combustion emission gas of the engine; a means for reducing the output of the generator at a low speed when the temperature of the combustion emission gas measured by the sensor exceeds a first set value higher than a target temperature; a means for reducing the output of the generator at a high speed when the temperature of the combustion emission gas exceeds a second set value higher than the first set value; and a means for increasing the output of the generator at a low speed when the temperature of the combustion emission gas is lower than a third set value lower than the target temperature. <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 control method for controlling a fuel control valve of a gas turbine engine.

[0002]

2. Description of the Related Art A gas turbine power generator is basically composed of a generator for generating electric power and a gas turbine engine for driving the generator. A gas turbine engine includes a turbine rotatably mounted via a rotating shaft, a combustor for generating combustion gas, a fuel control valve for controlling the fuel supply amount to the combustor, and an air for compressing air. And a compressor.

In the above structure, the fuel adjusted by the fuel control valve and the air compressed by the air compressor are supplied to the combustor, and the combustor forms a mixture of compressed air and fuel. Then, in the combustor, the air-fuel mixture is combusted to generate combustion gas, and the combustion gas is supplied to the turbine, whereby the turbine rotates at high speed. A generator is attached to one end of the rotating shaft, and power is generated by driving the generator with a turbine via the rotating shaft.

In such a gas turbine power generator, various operation controls such as start-up control or constant speed operation control are performed by controlling the valve opening of the fuel control valve. For example, the engine combustion exhaust gas temperature is detected, and the generated power is adjusted so that it does not exceed a certain value. That is,
The increase in the power generation output is related to the increase in the combustion amount in the gas turbine engine, and the maximum power generation output is determined by the allowable combustion exhaust gas temperature in the gas turbine engine.

The control for keeping the engine combustion exhaust gas temperature at an allowable constant target temperature sets an upper limit value and a lower limit value of a predetermined width with respect to the target value. Then, when the exhaust gas temperature reaches the upper limit value, control is performed to reduce the generator output,
When the exhaust gas temperature falls and reaches the lower limit value, control is performed to increase the generator output. However, the speed of increasing or decreasing the generator output is a problem, and if this speed is increased, hunting occurs and the operation of the engine control system becomes unstable. Further, if the speed of increasing or decreasing the generator output is reduced, it takes time to reach the required value, and there is a problem that the overshoot increases.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is a gas turbine apparatus that does not cause the problem of overshoot of the engine combustion exhaust gas temperature and can perform stable operation. It is intended to provide.

[0007]

In order to solve the above-mentioned problems, a gas turbine apparatus according to the present invention is a gas turbine engine for rotating a gas turbine by mixing air and fuel for combustion. In a gas turbine device including a generator directly connected to the gas turbine, a sensor for measuring a combustion exhaust gas temperature of the engine, and a first set value at which the combustion exhaust gas temperature measured by the sensor is higher than a target temperature. And a means for reducing the output of the generator at a low speed when it exceeds the above, and a means for reducing the output of the generator at a high speed when the second set value higher than the first set value is exceeded And means for increasing the output of the generator at a low speed when the combustion exhaust gas temperature falls below a third set value which is lower than the target temperature.

Further, the control method of the gas turbine apparatus according to the present invention comprises a gas turbine engine for rotationally driving the gas turbine by mixing air and fuel for combustion, and a generator directly connected to the gas turbine. In the provided gas turbine device, measuring the combustion exhaust gas temperature of the engine,
When the flue gas temperature exceeds a first set value higher than the target temperature, the output of the generator is reduced at a low speed, the flue gas temperature further rises, and is higher than the first set value. When the second set value is exceeded, the output of the generator is reduced at a high speed, and when the combustion exhaust gas temperature drops and falls below a third set value that is lower than the target temperature, the output of the generator. Is increased at a low rate.

According to the present invention thus constituted, the generator output is reduced at a low speed when the combustion exhaust gas temperature exceeds the first set value which is higher than the target temperature, and further the first set value is set. If the second set value higher than is exceeded, the output of the generator is reduced at a high speed. Therefore, when the combustion exhaust gas temperature of the engine exceeds the higher second set value, the combustion load is immediately reduced, so that the combustion exhaust gas temperature is rapidly reduced. This prevents the problem of overshoot in which the combustion exhaust gas temperature greatly exceeds the target temperature.

Further, even if the generator output is reduced at a high speed, if the temperature falls below the third set value below the target temperature, the generator output increases at a low speed. Therefore, when the generator output is decreased at a high speed, the generator output is not increased again at a high speed in a region lower than the target temperature. Therefore, when the generator output falls below the target temperature, the generator output is controlled so as to gradually increase, the combustion exhaust gas temperature of the engine also gradually rises, and the combustion exhaust gas temperature falls below the target temperature. And converges between the first set value and the third set value.

Therefore, the problem of overshoot of the combustion exhaust gas temperature does not occur, and the combustion exhaust gas temperature can be stably controlled to a predetermined maximum allowable value. As a result, the combustion exhaust gas temperature can be used at the maximum allowable upper limit value, so that the maximum power generation output of the gas turbine engine can be taken out.

[0012]

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 the gas turbine device of this embodiment.

As shown in FIG. 1, the gas turbine device according to this embodiment includes a turbine 1, a generator 5 that is driven to rotate by the turbine 1, and a combustor 2 that supplies combustion gas to the turbine 1. A fuel control valve 14 that regulates the amount of fuel supplied to the combustor 2, an air compressor 3 that supplies compressed air to the combustor 2, and a combustion gas that has been supplied to the turbine 1 are compressed using heat. A regenerative heat exchanger 4 for heating the air,
The control device 13 that controls the turbine 1 is provided.

The turbine 1 has a plurality of rotary blades (not shown) for receiving fluid and rotating, is housed in a casing (not shown), and is rotatably supported 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. A regeneration heat exchanger 4 is installed in the middle of the pipe 7, and the compressed air discharged from the air compressor is heated by the regeneration heat exchanger 4 and then supplied to the combustor 2. Has become.

The fuel control valve 14 is arranged upstream of the combustor 2, and the fuel supplied from a fuel supply source (not shown) is
After passing through the fuel control valve 14, it is supplied to the combustor 2. The fuel control valve 14 is configured such that the opening of the valve is variable, and the amount of fuel supplied to the combustor 2 is adjusted by operating the opening of this valve.

The fuel and compressed air supplied to the combustor 2 form an air-fuel mixture in the combustor 2. In the combustor 2, the air-fuel mixture is ignited by an ignition plug (not shown) 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. The generator 5 is connected to the end of the rotary shaft 6,
The turbine 1 drives the generator 5 to rotate at a high speed via the rotary shaft 6 to generate electric power.

This gas turbine system is equipped with various sensors, and the control unit 13 controls the valve opening of the fuel control valve 14 based on these signals. Rotation sensor 1
Reference numeral 2 detects the rotation speed of the rotary shaft 6, and the valve opening of the fuel control valve is feedback-controlled so that the rotation speed becomes constant during constant speed operation. Further, an EGT (Exhaust Gas Temperature) sensor 16 is provided in the combustion gas discharge portion of the gas turbine to measure the temperature of the combustion exhaust gas discharged from the turbine. Then, the fuel control valve 14 is controlled so that this temperature does not rise above the allowable target temperature.

2 to 4 show examples of control of engine combustion exhaust gas temperature (EGT) and generator output. In each figure, the engine exhaust gas temperature (EGT) is shown by the solid line, and the generator output is shown by the dotted line. Further, these controls are applied, for example, when the generator output is increased from 0 to, for example, the rated output after the gas turbine device is started and the rotation speed of the gas turbine is adjusted to a predetermined operating speed. As described above, the generator output is proportional to the combustion load of the gas turbine engine, and when the generator output increases, the engine combustion exhaust gas temperature also rises.

FIG. 2 shows, as a comparative example, set values (UPPERBAND, LOWER BAND) above and below the target value (TARGET) of the exhaust gas temperature.
It is equipped with. In this control device 13, the engine exhaust gas temperature rises and the upper set value (UPPER BAND)
The generator output decreases at a predetermined speed when Then, when the exhaust gas temperature decreases and reaches the lower set value (LOWER BAND), the generator output is set to increase at a predetermined speed. In this example, the generator output is increased from 0 to, for example, the rated output. At this time, the exhaust gas temperature (EGT) also rises substantially linearly, and the exhaust gas temperature becomes the target temperature (T
Upper limit set value (UPPER
BAND), the controller 13 detects this and reduces the generator output at a predetermined speed. Therefore, the generator output decreases after time t ₁ . Along with this, the exhaust gas temperature also decreases, exceeds the target value (TARGET), and further reaches the lower limit setting value (LOWER BAND), and the generator output again increases at a predetermined speed (time t ₂ ). Then, when the exhaust gas temperature again exceeds the upper limit set value, at that time, the generator output again decreases at the predetermined speed (time t ₃ ). The same applies to time t
_It is repeated in ₄ .

In such control of exhaust gas temperature and generator output, the combustion exhaust gas temperature (EGT) is set to the target value (TARGE
It is possible to keep near T). However, there is a problem in reducing the generator output and setting the increasing speed at the upper limit setting value and the lower limit setting value. When the generator output is reduced and the speed of increase is increased, when the generator output exceeds the upper limit set value, the generator output is immediately reduced, so that the exhaust gas temperature is immediately lowered. Therefore, the problem of so-called overshoot in which the engine combustion exhaust gas temperature rises significantly above the upper limit setting value is prevented, but the combustion exhaust gas temperature and the generator output hunt and the operation becomes unstable. There is.

On the other hand, if the reduction rate and the increase rate of the generator output at the upper limit setting value and the lower limit setting value are set to be small, even if the upper limit setting value is exceeded when increasing the generator output from 0 to near the rated output, Since the reduction rate of the generator output is small, the combustion exhaust gas temperature continues to rise more gradually due to thermal inertia. Further, although the combustion exhaust gas temperature drops after overshooting, the decrease rate of the generator output is slow, so the combustion exhaust gas temperature also falls slowly. Then, when the lower limit set value equal to or lower than the target temperature is reached, the generator output again increases at a predetermined speed. Therefore, if the generator output is reduced and the increasing speed is reduced, there is a problem that the overshoot increases and the time required for convergence increases.

FIG. 3 shows another comparative example. This is because the upper and lower limit values of Fig. 2 are set to the outer set value (OUTE
R BAND) and inner set value (INNER BAND), the generator output is reduced at a lower speed when the combustion exhaust gas temperature exceeds the target set temperature, and the combustion exhaust gas temperature is set inside. When the outside set value higher than the above value is exceeded, the generator output is reduced at a high speed. Similarly, the generator output is increased at a low speed when the flue gas temperature exceeds the inner set value lower than the target temperature, and the generator output is increased at a higher speed when the flue gas temperature exceeds the lower outer set value. It is the one.

By thus setting the upper limit value and the lower limit value in two stages of the inner set value and the outer set value, it is possible to control both the high speed and the low speed of the generator output shown in FIG. Becomes That is, at the outside set value, the generator output decreases or rises at a high speed, so when the combustion exhaust gas temperature exceeds this set value, the generator output immediately decreases or increases rapidly. Therefore, there is no problem of overshoot that greatly exceeds the upper limit set value,
Further, when the inner set value is exceeded, the generator output is reduced or increased at a low speed, which increases the stability of operation. However, even if such an upper limit value and a lower limit value are set in two stages, the problem that the exhaust gas temperature and the generator output vibrate as shown in FIG. 3 cannot be avoided.

FIG. 4 shows the control of the embodiment of the present invention.
In this embodiment, when the flue gas temperature exceeds the inner set value (INNER BAND) higher than the target temperature (TARGET), the generator output is reduced at a low speed, and the outer set value (OUTER BAND) higher than that is set. ) Is exceeded, the generator output is reduced at a high speed, and the generator output is increased at a low speed when the combustion exhaust gas temperature decreases and falls below an inside set value lower than the target temperature. It is a thing. Therefore, as compared with the control method shown in FIG. 3, the lower limit set value of the lower limit value at which the generator output increases at a high speed is not provided.

Here, it is preferable that the temperature difference between the target temperature and the inner set value on the upper limit side and the inner set value on the lower limit side is substantially equal. In addition, the speed at which the generator output is reduced when the combustion exhaust gas temperature exceeds the upper set value inside the upper limit value and the speed at which the generator output is increased when it falls below the lower set inner value below the target temperature It is preferable to make them equal.
As a result, the combustion exhaust gas temperature can be converged between the relatively narrow inner set values centered around the target temperature.

Next, the operation of this control device will be described. It is assumed that the generator output is increased from 0 to near the rated output. The combustion exhaust gas temperature rises as the generator output rises. When the combustion exhaust gas temperature exceeds the upper limit set value, the generator output decreases at a low speed (time t ₁ ). Further, when the combustion exhaust gas temperature rises due to thermal inertia and reaches the set value outside the upper limit value (time t ₂ ), the generator output decreases at a high speed. This suppresses the overshoot of the combustion exhaust gas temperature, and the combustion exhaust gas temperature rapidly drops. When the combustion exhaust gas temperature falls below the lower limit set value, the generator output increases at a low speed. Although not shown in the figure, the temperature gradually converges between the upper limit inner setting value and the lower limit inner setting value with the target temperature as the center.

Therefore, according to this control device, when the combustion exhaust gas temperature reaches the set value outside the upper limit value, the generator output is reduced at a high speed, so that the problem of the combustion exhaust gas temperature overshoot is prevented. Since the lower limit value does not have an outer set value for increasing the generator output at a high speed, the generator output gradually increases from the lower limit value toward the target temperature so that the combustion exhaust gas temperature rises. . This enhances operational stability and prevents problems of combustion exhaust gas temperature and generator output oscillations.

According to the gas turbine device equipped with such a control device, the combustion exhaust gas temperature can be suppressed to the vicinity of the set value outside the upper limit value without causing an overshoot, so the combustion exhaust gas temperature target value is set to the combustion exhaust gas temperature. Can be set near the trip temperature. The combustion exhaust gas trip temperature is a preset temperature for safety in which the generator output trips when the combustion exhaust gas temperature reaches this temperature and the output is stopped. In this way, since the combustion exhaust gas temperature can be set as the target temperature up to the maximum allowable temperature of the device, the maximum power generation output of the device can be taken out. Also, since there is no problem of overshoot of the combustion exhaust gas temperature, it is possible to increase the rising speed of the generator output. Therefore, it is possible to start the gas turbine power generator in a short time.

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

[0030]

As described above, according to the present invention,
It becomes possible to control the combustion exhaust gas temperature stably so that the maximum output of the gas turbine device is obtained. As a result, hunting of the combustion exhaust gas temperature is prevented and high convergence to the target temperature is obtained.

[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 diagram showing a relationship between combustion exhaust gas temperature and generator output as a comparative example, in which solid line shows combustion exhaust gas temperature and dotted line shows generator output.

FIG. 3 is a diagram showing a relationship between combustion exhaust gas temperature and generator output as still another comparative example, in which solid line shows combustion exhaust gas temperature and dotted line shows generator output.

FIG. 4 is a diagram showing the operation of the gas turbine device of the embodiment of the present invention, showing the relationship between the combustion exhaust gas temperature and the generator output. In the figure, the solid line shows the temperature of the combustion exhaust gas, and the dotted line shows the generator output.

[Explanation of symbols]

1 turbine 2 Combustor 3 air compressor 4 Regenerative heat exchanger 5 generator 6 rotation axes 7 piping 12 Rotation sensor 13 Control device 14 Fuel control valve 16 EGT sensor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Miyamoto             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 (72) Inventor Masafumi Kataoka             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION F-term (reference) 5H590 AA02 AA13 AA23 BB09 CA08                       CC01 CE02 EA07 EA14 EB14                       EB21 FA01 FA05 FB01 GA10                       HA06 HA18

Claims (4)

[Claims] 1. A gas turbine apparatus comprising a gas turbine engine that rotationally drives a gas turbine by mixing air and fuel for combustion, and a generator directly connected to the gas turbine. A sensor for measuring the exhaust gas temperature; a means for reducing the output of the generator at a low speed when the combustion exhaust gas temperature measured by the sensor exceeds a first set value higher than the target temperature; Means for reducing the output of the generator at a high speed when a second set value higher than the set value of, and a case where the combustion exhaust gas temperature falls below a third set value lower than the target temperature. And a means for increasing the output of the generator at a low speed. 2. The gas turbine apparatus according to claim 1, wherein a temperature difference between the first set value and the target temperature is substantially equal to a temperature difference between the target temperature and the third set value. . 3. The speed at which the output of the generator is reduced when the combustion exhaust gas temperature exceeds a first set value that is higher than the target temperature is set to a third setting when the combustion exhaust gas temperature is lower than the target temperature. The gas turbine apparatus according to claim 1, wherein the speed is substantially equal to the speed at which the output of the generator is increased when the value falls below the value. 4. A gas turbine device comprising a gas turbine engine for rotating and driving a gas turbine by mixing air and fuel for combustion, and a generator directly connected to the gas turbine. The exhaust gas temperature is measured, and when the combustion exhaust gas temperature exceeds a first set value higher than the target temperature, the output of the generator is reduced at a low speed, the combustion exhaust gas temperature further rises, and the first exhaust gas temperature increases. Second higher than the set value of
The output of the generator is reduced at a high speed when the set value is exceeded, and the output of the generator is decreased when the combustion exhaust gas temperature drops and falls below a third set value lower than the target temperature. A method for controlling a gas turbine device, which is characterized by increasing at a speed.