JP3939197B2 - Gas turbine apparatus starting method and gas turbine apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine apparatus starting method and a gas turbine apparatus, and more particularly, to a starting method for starting a gas turbine apparatus using a starting motor.
[0002]
[Prior art]
In general, a gas turbine device is a turbine that is rotatably mounted via a rotating shaft, a combustor that generates a combustion gas by burning a mixture of fuel and air, and a fuel supply amount to the combustor is adjusted. This is basically composed of a fuel control valve that performs this operation and an air compressor that pumps air to the combustor in conjunction with the turbine. In such a configuration, the air-fuel mixture formed via the fuel control valve and the air compressor is combusted to generate high-temperature and high-pressure combustion gas, and the combustion gas is supplied to the turbine so that the turbine operates at high speed. Is driven to rotate.
[0003]
Such a gas turbine device is usually provided with a motor for starting the gas turbine device, and at the time of starting, the air-fuel mixture is ignited while the turbine is rotationally driven by the motor.
Here, the state at the time of starting of a gas turbine apparatus is demonstrated with reference to FIG.
FIG. 3 is a diagram showing the turbine rotational speed, the exhaust temperature, the fuel supply amount, and the supply current to the motor when the conventional gas turbine apparatus is started. In FIG. 3, NR (Number of Revolution) represents the rotational speed of the turbine, FCV (Fuel Control Valve) represents the opening of the fuel control valve, EGT (Exhaust Gas Temperature) represents the exhaust temperature, and MC ( Motor Current represents the amount of current supplied to the motor.
[0004]
First, the turbine is rotationally driven by a motor, and this rotational speed is maintained when the rotational speed at which the turbine can ignite is reached as shown in FIG. Thereafter, the fuel control valve is opened to start fuel supply (t ₁ ), and the fuel is supplied to the combustor while gradually increasing the supply amount. Simultaneously with the start of fuel supply, the ignition operation of the mixture of fuel and air formed in the combustor is started, and eventually the mixture is ignited (t ₂ ). appear.
[0005]
After the air-fuel mixture is ignited and combustion gas is generated, the combustion gas is supplied to the turbine, and the turbine is rotationally driven by the combustion gas and the motor. Thereafter, the current supply to the motor is stopped (t ₃ ), and thereafter, the turbine is rotationally driven only by supplying the combustion gas. Further, after the mixture is ignited and the supply of the combustion gas is started (from t ₂ ), the acceleration of the fuel control valve is increased or decreased so that the turbine is accelerated at a predetermined target acceleration (ACCsp). Control is performed.
[0006]
[Problems to be solved by the invention]
However, immediately after the start of the acceleration control (t ₂ ), as shown in FIG. 3, the supply of fuel is attempted to quickly increase the acceleration of the turbine from 0 to the target acceleration (ACCsp) as shown in FIG. The amount increases temporarily (see FCV in FIG. 3). For this reason, the exhaust gas temperature rises rapidly, and the gas turbine device, in particular, the combustor suddenly becomes high temperature and suffers great damage (see EGT in FIG. 3).
[0007]
Further, when the rotational drive of the turbine by the motor is stopped, thereafter, the turbine is accelerated only by supplying the combustion gas. Then, immediately after the rotation of the motor stops driving (t ₃ ), there is a problem that the amount of fuel supply increases rapidly due to the control operation for maintaining the target acceleration, and the temperature of the gas turbine device further rises.
[0008]
The present invention has been made in view of such conventional problems, and at the time of start-up, the rapid increase in temperature of the gas turbine apparatus is prevented by preventing a rapid increase in the amount of fuel supplied for combustion. An object of the present invention is to provide a gas turbine device that can be suppressed.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, an embodiment of the present invention is directed to igniting a mixture of fuel and air while rotating a turbine by a motor to burn the mixture, and a combustion gas generated by the combustion In the starting method of the gas turbine device for accelerating the turbine by supplying to the turbine, the supply amount of fuel to be burned is kept constant for a predetermined time after the mixture is ignited. To do.
[0010]
According to the present invention as described above, it is possible to prevent the fuel from being excessively supplied immediately after the ignition by keeping the fuel supply amount constant after the air-fuel mixture is ignited. As a result, it is possible to suppress the temperature rise of the gas turbine device.
[0011]
In one aspect of the present invention , after the predetermined time has elapsed, the amount of fuel supplied for combustion is gradually increased, and the rotational driving force of the turbine by the motor is gradually decreased. .
[0012]
According to the present invention, the rotational driving of the turbine by the motor is stopped after the rotational driving of the turbine is gradually shifted from the driving by the motor to the driving by the combustion gas. As a result, when the rotation drive by the motor is stopped, the control operation to supply fuel to maintain the target acceleration can be relaxed, and the rapid increase in temperature of the gas turbine device can be prevented by suppressing the fuel supply amount. It becomes possible to do.
[0013]
Further, when the fuel supply amount after ignition is kept constant while the rotational speed of the turbine rises, only the amount of air supplied to the combustor increases, and the air-fuel mixture formed in the combustor. The ratio of fuel to the amount of air in the interior will be low. Then, in some cases, a phenomenon called flame-out in which the combustion flame disappears may occur. According to the present invention, since the fuel supply amount is gradually increased after the fuel supply amount is kept constant, the temperature increase of the gas turbine device can be suppressed while preventing the occurrence of such flameout. It becomes possible.
[0014]
Another aspect of the present invention is a gas turbine apparatus that rotates a turbine by burning a mixture of air and fuel and supplying combustion gas generated by the combustion to the turbine. Ignition means for igniting the air-fuel mixture while rotating the turbine by a motor, a fuel control valve having a variable opening for adjusting the amount of fuel supplied for combustion, and ignition for detecting the ignition of the air-fuel mixture A detection means and an opening degree holding means for holding the opening degree of the fuel control valve constant for a predetermined time from the time when the ignition of the air-fuel mixture is detected by the ignition detection means are provided.
[0015]
Another embodiment of the present invention, after the predetermined time further comprises it was gradually driving force adjusting means for increasing the opening degree of the fuel adjusting valve with gradually decreasing the amount of supply of current to the motor It is characterized by.
[0016]
In this case, the driving force adjusting means controls an air-fuel ratio control unit that controls an air-fuel ratio of air and fuel in the air-fuel mixture by operating an opening of the fuel control valve, and controls a current supply amount to the motor. A current supply amount control unit for controlling the motor so that the turbine maintains a predetermined target acceleration by the current supply amount control unit, and the fuel adjustment valve by the air-fuel ratio control unit after the predetermined time has elapsed. It is preferable to gradually increase the opening degree.
[0017]
Alternatively, the driving force adjusting means includes: a current supply amount control unit that controls a supply amount of current to the motor; and an acceleration control unit that controls the acceleration of the turbine by operating the opening of the fuel control valve. It is preferable that the supply amount of current to the motor be gradually decreased by the current supply amount control unit after the predetermined time has elapsed, while maintaining the turbine at a predetermined target acceleration by the acceleration control unit.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a gas turbine apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing an overall configuration of a gas turbine apparatus according to the present embodiment.
[0019]
As shown in FIG. 1, the gas turbine apparatus according to the present embodiment includes a turbine 1, a combustor 2 that combusts a mixture of fuel and air, and a fuel adjustment that adjusts the amount of fuel supplied to the combustor 2. It is basically composed of a valve 19 and an air compressor 3 that pumps air to the combustor 2 in conjunction with the turbine 1.
[0020]
The turbine 1 has a plurality of rotating blades (not shown) for receiving fluid and rotating, and is rotatably supported in a casing (not shown) via a rotating 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 through a pipe 7, and the air compressed by the air compressor 3 is supplied to the combustor 2 through the pipe 7.
[0021]
The fuel control valve 19 is disposed on the upstream side of the combustor 2, and fuel supplied from a fuel supply source (not shown) is supplied to the combustor 2 through the fuel control valve 19. The fuel adjustment valve 19 is configured so that the opening degree of the valve is variable, and the amount of fuel supplied to the combustor 2 is adjusted by operating this opening degree.
[0022]
The fuel and 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. The combustion gas is supplied to the turbine 1 so that the turbine 1 is rotationally driven at a high speed. The rotational speed of the turbine 1 is detected by a rotational speed detection unit 12 disposed in the vicinity of the shaft end of the rotary shaft 6, and the rotational speed of the turbine 1 detected by the rotational speed detection unit 12 is sent to the acceleration control unit 11. .
[0023]
The acceleration control unit 11 calculates the acceleration of the turbine 1 by differentiating the rotation number of the turbine 1 sent from the rotation number detection unit 12, and adjusts the fuel so that the calculated acceleration approaches a preset target acceleration. The acceleration of the turbine 1 is controlled by operating the opening degree of the valve 19.
[0024]
A generator 5 is connected in the vicinity of the end of the rotating shaft 6, and the generator 5 is rotationally driven by the turbine 1 via the rotating shaft 6 to generate electric power. In the present embodiment, the generator 5 is used as a starting motor at the time of starting. In the following description, the generator is appropriately referred to as a motor.
[0025]
The gas turbine apparatus according to the present embodiment includes ignition means for igniting the air-fuel mixture while rotating the turbine 1 by the motor 5 at startup, ignition detection means 22 for detecting the air-fuel mixture, and fuel adjustment. An air-fuel ratio control unit 15 that controls the air-fuel ratio of air and fuel in the air-fuel mixture by operating the opening of the valve 19 and a current supply amount control unit 16 that controls the amount of current supplied to the motor 5 are further provided. ing.
[0026]
In the present embodiment, the ignition means refers to an ignition plug (not shown) provided in the combustor 2. In the present embodiment, the ignition detection means 22 includes an exhaust temperature sensor 20 that measures the temperature of the combustion gas after being supplied to the turbine 1, and an exhaust temperature measured by the exhaust temperature sensor 20 indicates a predetermined rate of increase. The ignition determination unit 21 determines that the air-fuel mixture has been ignited.
[0027]
The air-fuel ratio control unit 15 is configured to keep the opening of the fuel control valve 19 constant for a predetermined time from when the ignition detection means 22 detects ignition of the air-fuel mixture. That is, the air-fuel ratio control unit 15 functions as an opening degree holding unit. Further, the air-fuel ratio control unit 15 gradually increases the opening degree of the fuel control valve 19 after the above-described predetermined time has elapsed.
[0028]
The current supply amount control unit 16 controls the amount of current supplied to the motor 5 to control the turbine 1 at the time of startup to a desired rotational speed and acceleration. The current supply amount control unit 16 is set so that the turbine 1 maintains a predetermined number of revolutions preferable for ignition while the ignition means performs the ignition operation on the mixture, and further, after the mixture is ignited The turbine 1 is set to be accelerated at a predetermined target acceleration while the fuel supply amount is kept constant by the air-fuel ratio control unit 15.
[0029]
According to the air-fuel ratio control unit 15 and the current supply amount control unit 16 configured as described above, after the fuel supply amount is made constant for a predetermined time after the mixture is ignited, the fuel supply is performed by the air-fuel ratio control unit 15. Since the amount is gradually increased, the rotational driving force of the turbine 1 by the combustion gas is increased. At this time, the current supply amount control unit 16 controls the current supply amount to the motor 5 so that the turbine 1 is accelerated at the target acceleration. Therefore, the current supply amount control unit 16 supplies the motor 5 with the increase in the rotational driving force by the combustion gas. This reduces the amount of current supplied.
[0030]
That is, in the case where the acceleration of the turbine 1 is kept constant via the motor 5, when the rotational driving force of the turbine 1 by the combustion gas increases, the rotational driving of the turbine 1 by the motor 5 is interlocked with this. The power will be reduced. Therefore, in the present embodiment, the air-fuel ratio control unit 15 and the current supply amount control unit 16 constitute driving force adjusting means.
[0031]
Here, operations of the opening degree holding means and the driving force adjusting means will be described with reference to FIG. FIG. 2 is a diagram showing the turbine rotation speed, fuel supply amount, exhaust temperature, and current supply amount to the motor when the gas turbine apparatus according to the present embodiment is started. In FIG. 2, NR represents the rotational speed of the turbine 1, FCV represents the opening of the fuel control valve 19, EGT represents the exhaust temperature, and MC represents the amount of current supplied to the motor 5. As a comparative example, a value shown in a conventional gas turbine apparatus is indicated by a dotted line.
[0032]
As shown in FIG. 2, first, the turbine 1 is rotationally driven by the motor 5, and when the turbine 1 reaches a rotational speed preferable for ignition, the current supply amount control unit 16 maintains the rotational speed. Thereafter, the fuel adjustment valve 19 is opened to start the supply of fuel (t ₁ ), and the fuel is supplied to the combustor 2 while gradually increasing the supply amount. Simultaneously with the start of fuel supply, the combustor 2 starts an ignition operation for the air-fuel mixture by the ignition means.
[0033]
Eventually, when the air-fuel mixture is ignited (t ₂ ), the air-fuel mixture is combusted and combustion gas is generated, and the turbine 1 is accelerated by obtaining driving force by the combustion gas in addition to the motor 5. Since the exhaust gas temperature rises when the mixture is ignited, the ignition detection means 22 detects that the ignition operation for the mixture has been completed.
[0034]
When it is detected by the ignition detection means 22 that the air-fuel mixture has been ignited, the air-fuel ratio control unit 15 opens the fuel control valve 19 for a predetermined time (from t ₂ to t ₃ ) starting from this detection time. The degree of fuel is kept constant, and the amount of fuel supplied to the combustor 2 is kept constant (see FCV in FIG. 2). Conventionally, the control is switched to the acceleration control by the acceleration control unit 11 immediately after ignition, and the exhaust gas temperature has risen rapidly as shown by the dotted line in FIG. 2. In the present embodiment, however, the air-fuel ratio control unit 15 provides the combustion. Since the fuel supply amount is kept constant, the exhaust temperature is prevented from rising.
[0035]
After the ignition detection means 22 detects the ignition of the air-fuel mixture, the turbine 1 is driven by the combustion gas and the motor 5 and the turbine 1 is accelerated. At this time, the motor 5 is controlled by the current supply amount control unit 16 so that the turbine 1 is accelerated while maintaining a predetermined target acceleration (ACCsp) set in advance. As a result, the turbine 1 is accelerated at the target acceleration (ACCsp) while the opening of the fuel control valve 19 is kept constant.
[0036]
After the opening of the fuel control valve 19 is kept constant for a predetermined time, the air-fuel ratio control unit 15 then gradually increases the opening of the fuel control valve 19 at a predetermined increase rate (t _3- ). Then, as described above, since the turbine 1 is held at a predetermined target acceleration by the current supply amount control unit 16, the rotational driving force of the turbine 1 by the motor 5, that is, the amount of current supplied to the motor 5 gradually increases. (Refer to MC in FIG. 2). That is, when the fuel control valve 19 is increased to increase the rotational driving force by the combustion gas, the amount of current supplied to the motor 5 is automatically reduced and the rotational driving force by the motor 5 is decreased.
[0037]
When the amount of current supplied to the motor 5 decreases to some extent and the amount of fuel supplied for combustion increases, the amount of current supplied to the motor 5 is completely reduced to 0 (t ₄ ). If it does so, the subsequent turbine 1 will accelerate only by supplying combustion gas. After the amount of current supplied to the motor 5 becomes zero, the air-fuel ratio control unit 15 is switched to the acceleration control unit 11, and the subsequent turbine 1 is subjected to acceleration control by the acceleration control unit 11.
[0038]
In this way, before the current supply to the motor 5 is stopped, the combustor 2 immediately after the supply current to the motor 5 is completely stopped by gradually shifting from driving by the motor 5 to driving by combustion gas. Therefore, it is possible to prevent excessive fuel from being supplied. Further, if the fuel supply amount supplied for combustion is kept constant while the turbine 1 is accelerated after the air-fuel mixture is ignited, the ratio of the fuel to the air amount in the air-fuel mixture decreases, and in some cases, the flame Out may occur. In this embodiment, the fuel supply amount after ignition is kept constant, and then the fuel supply amount is gradually increased. Therefore, it is possible to suppress the rise in the temperature of the gas turbine device while preventing the occurrence of flameout. Become.
[0039]
Next, a second embodiment of the present invention will be described.
The overall configuration of the gas turbine apparatus in the present embodiment is exactly the same as in the first embodiment described above. In addition, the present embodiment is also the same as the first embodiment in the movements of the turbine rotation speed, the fuel supply amount, the exhaust temperature, and the current supply amount to the motor, which are shown when the gas turbine device is started up. Accordingly, since the configuration and operation not specifically described are the same as those in the first embodiment, description thereof will be omitted.
[0040]
This embodiment is the same as the first embodiment in that an air-fuel ratio control unit 15 is provided as an opening degree holding means of the fuel control valve 19. The difference between the present embodiment and the first embodiment is that the driving force adjusting means for reducing the current supply amount to the motor 5 while increasing the fuel supply amount is different. In other words, in the present embodiment, the driving force adjusting means includes the current supply amount control unit 16 and the acceleration control unit 11.
[0041]
In this embodiment, after the fuel supply amount is kept constant for a predetermined time by the air-fuel ratio control unit 15, the current supply amount control unit 16 supplies the motor 5 to the motor 5 while maintaining the turbine 1 at a predetermined target acceleration by the acceleration control unit 11. The current supply amount is gradually decreased. When the current supply amount is decreased by the current supply amount control unit 16, the rotational driving force of the turbine 1 by the motor 5 is decreased. Then, the acceleration control unit 11 increases the opening degree of the fuel control valve 19 to maintain the turbine 1 at the target acceleration and increases the rotational driving force by the combustion gas.
[0042]
That is, when the acceleration of the turbine 1 is kept constant by the acceleration control unit 11, if the current supply amount to the motor 5 is decreased, the supply amount of fuel provided for combustion by the acceleration control unit 11 Will increase. As a result, the amount of current supplied to the motor 5 and the opening of the fuel control valve 19 show the same movement as in the first embodiment described above.
[0043]
As described above, in this embodiment, although the driving force adjusting means is different from that of the first embodiment, the movement of the fuel supply amount to the combustor 2 and the current supply amount to the motor 5 shown at the time of startup is the first. This is exactly the same as the embodiment. Therefore, also in the present embodiment, similarly to the first embodiment, it is possible to suppress the temperature increase of the gas turbine device while preventing flameout at the time of startup.
[0044]
In addition, the gas turbine apparatus of this invention is not limited only to the above-mentioned embodiment, Of course, various changes can be added within the range which does not deviate from the summary of this invention.
[0045]
【The invention's effect】
As described above, according to the present invention, the fuel supply amount is kept constant after ignition of the air-fuel mixture, thereby preventing the fuel from being excessively supplied immediately after ignition. As a result, it is possible to suppress the temperature rise of the gas turbine device.
[0046]
In addition, according to the present invention, the rotational drive of the turbine by the motor is stopped after the rotational drive of the turbine is gradually shifted from the drive by the motor to the drive by the combustion gas. As a result, when the rotation drive by the motor is stopped, the control operation to supply fuel to maintain the target acceleration can be relaxed, and the rapid increase in temperature of the gas turbine device can be prevented by suppressing the fuel supply amount. It becomes possible to do.
[0047]
Furthermore, according to the present invention, the fuel supply amount is gradually increased after the fuel supply amount is kept constant, so that it is possible to suppress the temperature rise of the gas turbine device while preventing the occurrence of flameout. become.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of a gas turbine apparatus according to first and second embodiments of the present invention.
FIG. 2 is a diagram showing a turbine rotational speed, a fuel supply amount, an exhaust temperature, and a current supply amount to a motor when the gas turbine apparatus according to the first and second embodiments of the present invention is started.
FIG. 3 is a diagram showing turbine rotation speed, fuel supply amount, exhaust temperature, and current supplied to a motor when a conventional gas turbine device is started.
[Explanation of symbols]
1 Turbine 2 Combustor 3 Air compressor 5 Generator (motor)
6 Rotating shaft 7 Piping 11 Acceleration control unit 12 Rotational speed detection unit 15 Air-fuel ratio control unit 16 Current supply amount control unit 19 Fuel control valve 20 Exhaust temperature sensor 21 Ignition judgment unit 22 Ignition detection means

Claims (4)

A gas turbine device that accelerates the turbine by igniting a mixture of fuel and air while rotating the turbine by a motor, burning the mixture, and supplying combustion gas generated by the combustion to the turbine In the starting method of
For a predetermined time after the mixture is ignited, the amount of fuel supplied for combustion is kept constant ,
A starting method for a gas turbine device , wherein after the predetermined time has elapsed, the amount of fuel supplied for combustion is gradually increased and the rotational driving force of the turbine by the motor is gradually decreased . In a gas turbine device that rotates a turbine by burning a mixture of air and fuel and supplying combustion gas generated by the combustion to the turbine,
Ignition means for igniting the air-fuel mixture while rotationally driving the turbine by a motor at startup;
A variable opening fuel control valve that adjusts the amount of fuel supplied for combustion;
Ignition detection means for detecting the ignition of the air-fuel mixture;
An opening degree holding means for holding the opening degree of the fuel control valve constant for a predetermined time from the time when the ignition of the air-fuel mixture is detected by the ignition detection means ;
A gas turbine apparatus comprising: driving force adjusting means for gradually decreasing the amount of current supplied to the motor after the predetermined time has elapsed and gradually increasing the opening of the fuel control valve . The driving force adjusting means controls the air-fuel ratio of air and fuel in the air-fuel mixture by operating the opening of the fuel control valve, and current supply for controlling the amount of current supplied to the motor An amount control unit, and the current supply amount control unit controls the motor so that the turbine maintains a predetermined target acceleration, and the air-fuel ratio control unit opens the fuel control valve after the predetermined time has elapsed. The gas turbine apparatus according to claim 2 , wherein the gas turbine apparatus is gradually increased. The driving force adjusting means includes a current supply amount control unit that controls the supply amount of current to the motor, and an acceleration control unit that controls the acceleration of the turbine by operating the opening of the fuel control valve, while maintaining the turbine to a predetermined target acceleration by the acceleration control unit, by the current supply amount control unit after the predetermined time period elapses in claim 2, wherein the gradually reducing the amount of supply of current to the motor The gas turbine apparatus described.

Images