JP2010156308A - Controller for gas turbine engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a two-shaft gas turbine engine capable of carrying out a smooth load-variable operation, by switching combustion while following a load command varied continuously. <P>SOLUTION: This controller for the two-shaft gas turbine engine includes a compressor turbine 3 for driving a compressor 1, a combustor 2 for generating a combustion gas supplied to a compressor turbine 3, and having a plurality of combustion valves 7 for switching the combustion during an operation, and a load turbine 6 for driving an electric power generator 4, and the controller further includes a fuel flow control means 18 for computing a fuel flow rate command value to the combustor 2, a fuel flow rate correcting means 19 for computing a fuel flow rate command value correction value added with a correction signal for compensating the rotation speed fluctuation of the compressor turbine 3, to the fuel flow rate command value computed by the fuel flow control means 18, when switching the combustion, and a fuel valve control means 20 for controlling the openings of a plurality of fuel valves 7, based on the fuel flow rate command value correction value computed by the fuel flow rate correcting means 19. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a two-shaft gas turbine engine including a compressor turbine and a load turbine, and more particularly to a control device for a two-shaft gas turbine engine that requires combustion switching when the load changes. About.

  In order to cope with global warming in recent years, it is desired to prioritize environmental compatibility for a combustion apparatus of a gas turbine engine. Therefore, in many gas turbines and engines in recent years, regardless of whether it is for power generation, for aircraft, for ships, or for mechanical drives, it is possible to reduce carbon dioxide emissions by increasing efficiency and to emit nitrogen oxides called the premixed combustion method. Engines that have achieved a reduction in volume are the mainstream. The premixed combustion method is a combustion method in which air and fuel that can suppress the generation amount of nitrogen oxides are premixed and burned, and generation of nitrogen oxides and other substances that affect the environment can be suppressed. .

  This premixed combustion method is known to have a narrow range of combustion stable conditions because air and combustion are mixed in advance and then combusted. Therefore, as a method for improving combustion stability and enabling load operation, the combustor is composed of a plurality of burners and fuel valves for supplying fuel to the burners, and the premixed combustion of the combustor by these burners and fuel valves. A method has been proposed in which the portion is divided into a plurality of portions and the combustion portion is increased or decreased according to the operating load.

  In this method, the operating load can be changed by a combination of a method of increasing / decreasing the fuel supply to the premixed combustion portion divided into a plurality and a method of increasing / decreasing the premixed combustion portion (hereinafter referred to as combustion switching). However, it is necessary to ignite or extinguish the burner during combustion switching, and there is a problem that the combustion energy fluctuates greatly during this burner point / extinguishing.

  In the gas turbine engine for power generation, with the increase in power demand, the difference in power demand between day and night is increasing, and an engine with high load change width and load following performance is required. The fluctuation of the combustion energy during the combustion switching becomes a cause of load fluctuation, and there is a problem that the realization of a smooth load change operation is hindered.

  As an improvement measure for this problem, in an ordinary power generation gas turbine engine, an operation method has been proposed in which the opening of a fuel valve that controls the fuel flow rate is locked during combustion switching (see, for example, Patent Document 1).

JP-A-10-212976

  In the case of the operation method in which the opening degree of the fuel valve is locked at the time of combustion switching described above, the opening degree of the pressure regulating valve is changed at a predetermined ratio so as to suppress the pressure fluctuation in the fuel pipe, and the inside of the pipe at the time of combustion switching is changed. The fuel supply pressure fluctuation is suppressed in a short time. As a result, it is possible to reduce the load fluctuation at the time of combustion switching.

  However, for example, when combustion switching occurs when the power generation gas turbine engine is operating based on a load increase command, this method cannot supply a load that continuously increases and changes. Absent. That is, there is a problem that it cannot follow a continuously changing load command.

  On the other hand, load fluctuations due to combustion energy fluctuations are prominent in a two-shaft gas turbine engine in which a turbine driving a compressor (compressor turbine) and a turbine generating a load (load turbine) are driven by different shafts. appear. In the two-shaft gas turbine engine, the compressor turbine is driven by the combustion energy from the combustor, and then the load turbine is driven using the exhaust gas of the compressor turbine. For this reason, fluctuations in combustion energy affect both the compressor turbine and the load turbine, and appear as fluctuations in the combustion air pressure in the compressor turbine and fluctuations in the rotational speed and output in the load turbine. Each of these events further causes a decrease in the ability to follow changes in load.

  The present invention has been made on the basis of the above-mentioned matters. The purpose of the present invention is to provide a two-shaft gas turbine that can perform a smooth load change operation by switching combustion in accordance with a load command that changes continuously. It is to provide an engine control device.

  (1) In order to achieve the above object, the present invention generates a compressor turbine that drives a compressor that sucks and pressurizes air, and generates combustion gas to be supplied to the compressor turbine, and performs combustion switching during operation. A control device for a two-shaft gas turbine engine comprising a combustor having a plurality of fuel valves and a load turbine for driving a generator as a load, and calculates a fuel flow rate command value to the combustor A fuel flow rate control means and a fuel for calculating a fuel flow rate command correction value obtained by adding a correction signal for compensating for fluctuations in the rotation speed of the compressor turbine to the fuel flow rate command value calculated by the fuel flow rate control means at the time of combustion switching It is assumed that a flow rate correction unit and a fuel valve control unit for controlling the opening of the plurality of fuel valves based on the fuel flow rate command correction value calculated by the fuel flow rate correction unit.

  (2) In order to achieve the above object, the present invention generates a compressor turbine that drives a compressor that sucks and pressurizes air, and generates combustion gas to be supplied to the compressor turbine, and performs combustion switching during operation. A control apparatus for a two-shaft gas turbine engine comprising a combustor having a plurality of fuel valves and a load turbine for driving a generator as a load, wherein a load command as an output target of the generator is input A fuel flow rate control means for calculating a fuel flow rate command value corresponding to the load command to the combustor, a load change rate is calculated based on the load command, and the load change rate is equal to or higher than a preset set value. In this case, the fuel flow rate correction means for calculating the fuel flow rate command correction value obtained by adding a correction signal for compensating for the fluctuation in the rotation speed of the compressor turbine to the fuel flow rate command value calculated by the fuel flow rate control means. , And that a fuel valve control means for controlling the opening degree of the plurality of fuel valves, based on the fuel flow rate command correction value calculated by the fuel flow rate correction means.

  (3) In the above (1) or (2), preferably, the fuel flow rate correcting means receives a rotational speed of the load turbine, and calculates a time change amount of the load turbine rotational speed; And a function generator for obtaining a correction signal for the fuel flow rate command value based on a time change amount of the load turbine rotation speed from the differential calculator.

  (4) In the above (3), preferably, the function generator of the fuel flow rate correction means adds a correction signal for the fuel flow rate command value when the time change amount of the load turbine speed is equal to or less than a set value. It shall be provided with a dead zone to stop

  (5) In the above (4), preferably, the fuel flow rate correction means outputs a positive dead zone width and a negative dead zone width of the function generator with the fuel flow rate command value as an input. Shall be provided.

  (6) In the above (4), preferably, the fuel flow rate correction means generates a dead zone setting function for outputting a positive dead zone width and a negative dead zone width of the function generator with the load command change rate as an input. It shall be equipped with a vessel.

  According to the control device for a gas turbine engine of the present invention, a fuel flow rate correction signal for controlling in advance the fluctuation in the rotational speed of the load turbine with respect to the fluctuation in the rotational speed of the load turbine that occurs as a load change when switching combustion. Is added to the fuel flow rate command to control the opening of the fuel valve, so that the follow-up performance to the load change at the time of combustion switching can be improved. As a result, a smooth load change operation can be realized even in a two-shaft gas turbine engine that requires combustion switching when the load changes.

Embodiments of a control apparatus for a gas turbine engine according to the present invention will be described below with reference to the drawings.
1 to 3 show a first embodiment of a control apparatus for a gas turbine engine according to the present invention. FIG. 1 shows a first embodiment of a control apparatus for a gas turbine engine according to the present invention. FIG. 2 is a control block diagram of the fuel flow rate control means in the first embodiment of the control apparatus for the gas turbine engine of the present invention, and FIG. 3 is the present invention. FIG. 3 is a control block diagram of fuel flow rate correction means in the first embodiment of the control apparatus for the gas turbine engine of FIG.

  In FIG. 1, a two-shaft gas turbine engine compresses the intake air cooled by the intake air cooling device 8 to obtain compressed air for combustion, and the compressed air from the air compressor 1 A combustor 2 that burns with fuel to generate high-temperature and high-pressure combustion gas; a compressor turbine 3 that drives the compressor 1 by obtaining rotational power of the drive shaft 16 by the combustion gas from the combustor 2; The plant includes a load 4 corresponding to a generator, and a load turbine 6 that drives the load 4 by obtaining the rotational power of the drive shaft 17 by the exhaust gas of the compressor turbine 3. The combustor 2 includes a burner 21 that enables load operation by switching combustion. Further, the exhaust gas after driving the load turbine 6 is discharged to the outside through the exhaust duct 9.

  The two-shaft gas turbine engine has a rotation speed meter 10, a compressed air pressure gauge 12, a compressed air thermometer 13 on the compressor turbine side as a measuring means, a rotation speed meter 11, a power output meter 14 on the load turbine side, and An exhaust gas thermometer 15 is provided.

  For example, a load command (MWD) from a power supply station and a measurement signal from each of the measuring means are input to the control device 5 of the gas turbine engine. The control device 5 calculates the fuel valve opening command CGCV based on these information and outputs it to the fuel valve 7 to control the start / stop / load operation of the two-shaft gas turbine engine. Yes.

The control device 5 of the gas turbine engine has a plurality of functions such as a safety protection function and an auxiliary machine control function in addition to starting / stopping / load operation. However, in the description of the present embodiment, only functions necessary for load operation are shown and described.
The control device 5 in FIG. 1 includes a fuel flow rate control means 18, a fuel flow rate correction means 19, and a fuel valve control means 20.

  The fuel flow rate control means 18 inputs a load command MWD, a compressor turbine rotational speed NHPT, a compressor outlet pressure PC, a compressor outlet temperature TC, a load turbine rotational speed NLPT, a load MW, and a turbine exhaust temperature TX, and a gas turbine. -Determine the fuel flow control command value (fuel flow rate command) FFD when the engine starts, stops, and loads.

  In FIG. 2, which is a control block diagram of the fuel flow rate control means 18, the fuel flow rate control means 18 calculates a start flow control means 36 for calculating the fuel flow rate FFD0 when the engine is started, and calculates a fuel flow rate FFD1 for when the engine is started / accelerated. Acceleration control means 37, stop control means 38 for calculating fuel flow rate FFD2 when the engine is stopped, speed / load control means 39 for calculating fuel flow rate FFD3 during load operation, and exhaust gas for calculating fuel flow rate FFD4 during exhaust temperature control A temperature control means 40 is provided. Further, in the low value selection 41, the lowest value among these fuel flow rates is output as the fuel flow rate command FFD.

  In general, as a characteristic of a two-shaft gas turbine engine, the rotational speed NHPT of the compressor turbine 3 is controlled when the engine is started, accelerated, and stopped, and the rotational speed NLPT of the load turbine 6 is controlled when the engine is loaded. A point is mentioned. Therefore, also in the present embodiment, the compressor turbine rotational speed NHPT is used as the input to the start control means 36, the acceleration control means 37, and the stop control means 38 as shown in FIG. The load turbine speed NLPT is used.

  As described above, in the two-shaft gas turbine engine, both the compressor turbine rotational speed NHPT and the load turbine rotational speed NLPT change due to increase / decrease in the fuel flow rate. Changes to each.

  Therefore, in the present embodiment, only the load turbine speed NLPT is input to the speed / load control means 39, and the fuel flow rate correction means 19 described later compensates for fluctuations in the compressor turbine speed NHPT in the fuel flow rate command FFD. Both the compressor turbine rotational speed NHPT and the load turbine rotational speed NLPT are set by taking into account the correction amount for fuel (fuel bias) and setting the dead zone for the correction amount based on the rate of change of the fuel flow rate command FFD and the load command MWD. Load operation considering fluctuations is realized.

  Returning to FIG. 1, the fuel flow rate correction means 19 determines a correction value FFDC of the fuel flow rate command FFD from the fuel flow rate command FFD and the load turbine rotational speed NLPT, and is driven by combustion energy fluctuation at the time of combustion switching. The fluctuation of the rotational speed of the shaft 17 is suppressed.

  In FIG. 3, which is a control block diagram of the fuel flow rate correction means 19, the fuel flow rate correction means 19 includes a differential calculator 30, a function generator 31, a gain setting device 36, a function generator 32, a signal for obtaining a time change rate of the signal. Are provided with an integration computing unit 33 for obtaining the time integration, a change rate limiter 34 for limiting the time change rate of the signal, and an adder 35.

  The differential calculator 30 inputs the load turbine speed NLPT and calculates the time change rate dNLPT / dt of the load turbine speed NLPT. Further, the function generator 31 inputs the time change rate dNLPT / dt and calculates the time change rate control amount dNHPT / dt of the compressor turbine 3. The time change rate control amount dNHPT / dt corresponds to the change rate of the compressor turbine rotational speed NHPT generated when the load turbine rotational speed NLPT changes. The function generator 31 sets a dead zone so that the output value in the input section DB1 becomes 0, and the control amount from the function generator 31 is not generated when the load turbine rotational speed NLPT is minutely changed.

  The function generator 42 calculates the dead band ranges HH (positive side dead band width) and HL (negative side dead band width) of the function generator 31 from the input fuel flow rate command FFD. In the present embodiment, the width of the fuel flow rate command FFD in the combustion state switching range is set to Δx, and when the fuel flow rate command FFD is within the range of Δx, the dead zone ranges HH and HL are output small. As a result, the function generator 31 outputs a non-zero value as the time change rate control amount dNHPT / dt even for a minute change in the input value dNLPT / dt.

  The fluctuation of the load turbine speed NLPT is most noticeable at the time of combustion switching. The function generators 31 and 42 can detect fluctuations in the load turbine speed NLPT at the time of combustion switching.

  The gain setting unit 36 multiplies the time change rate control amount dNHPT / dt obtained previously by a negative number, inverts the sign of the time change rate control amount dNHPT / dt, and corrects it with an arbitrary adjustment parameter using the control gain. After that, it is output as a correction time change rate control amount dNHPT '/ dt. Further, the function generator 32 inputs the correction time change rate control amount dNHPT ′ / dt, and calculates the fuel flow rate change rate dFuel / dt corresponding to the load turbine rotation speed change rate dNLPT / dt. A dead zone is set in the function generator 32 so that the output value in the input value section DB2 becomes 0, and the control amount from the function 32 is not generated when the compressor turbine rotational speed control amount is minutely changed.

  The integral calculator 33 integrates the fuel flow rate change rate dFuel / dt obtained previously to calculate the fuel flow rate command bias FFDB. Further, the change rate limiter 34 limits the change rate so that the fuel flow rate command bias FFDB does not change rapidly, and outputs a fuel flow rate command bias correction value FFDBC. The adder 35 adds the fuel flow rate command bias correction value FFDBC to the fuel flow rate command FFD, and outputs the fuel flow rate command correction value FFDC as a new fuel flow rate command.

  The fuel flow rate correcting means 19 of the present embodiment is configured to perform integral control by using the integral calculator 33. However, instead of the integral calculator 33, a proportional control may be configured using a gain setter.

  Returning to FIG. 1, the fuel valve control means 20 calculates and controls output of the fuel valve opening commands CGCV of the plurality of fuel valves 7 based on the fuel flow rate command correction value FFDC. The fuel flow rate to the burner 21 changes according to the fuel valve opening command CGCV.

  In the present embodiment, the function generator 42 is used to detect a change in the rotational speed NLPT of the load turbine 6 at the time of combustion switching. However, the function generator 42 determines the rotational speed NLPT of the load turbine 6 at the time of load parallel / disconnection. The function generator 42 may be set to detect fluctuations.

  Next, operation characteristics of the two-shaft gas turbine engine to which the above-described first embodiment of the gas turbine engine control device of the present invention is applied will be described with reference to FIGS. FIG. 4 is a characteristic diagram showing planned values of operating characteristics of the two-shaft gas turbine engine in the first embodiment of the control apparatus for the gas turbine engine of the present invention, and FIG. 5 is a characteristic diagram of the gas turbine engine of the present invention. It is a characteristic view which shows the driving | operation characteristic of the 2-shaft type gas turbine engine in 1st Embodiment of the control apparatus of an engine. In FIGS. 4 and 5, the same reference numerals as those shown in FIGS. 1 to 3 are the same or corresponding components, and the description thereof is omitted.

In FIG. 4, the horizontal axis represents time, and the vertical axis represents the plan values of the load command MWD, the fuel flow rate command FFD, the compressor turbine rotational speed NHPT, and the load turbine rotational speed NLPT from the top.
First, at time t0, the gas turbine engine is started, and after the load turbine rotational speed NLPT reaches the rated rotational speed, a uniform speed operation is performed, and at time t1, a generator as a load is placed in parallel with the power system. When the generator is arranged in parallel with the power system, the load turbine speed NLPT is operated at the rated speed almost according to the power system frequency. After load parallel, the load command MWD increases to the rated load, but combustion switching occurs at time t2 when the fuel flow rate command FFD reaches point B. In the present embodiment, the number of burners before combustion switching is B1 (pieces), and the number of burners after combustion switching is B2 (pieces). The load continues to increase after switching to combustion, and reaches the rated load at time t3. In this embodiment, it is assumed that combustion switching occurs only at one point B before reaching the rated load. However, these switching points may be set at a plurality of locations until the rated load is reached.

  Before and after combustion switching, the fuel flow rate per burner varies due to the change in the number of burners, and the fuel-air ratio changes greatly. Specifically, when the number of burners increases (when the load increases), the fuel flow rate per burner decreases, so the fuel-air ratio relatively decreases. When the number of burners decreases (when the load is reduced), the fuel flow rate per burner increases, so the fuel-air ratio increases relatively.

  FIG. 5 shows engine operating characteristics before and after time t2 when combustion switching occurs. In FIG. 5, the horizontal axis indicates time, the vertical axis indicates from the top the fuel flow rate command FFD, the compressor turbine rotational speed NHPT, the load turbine rotational speed NLPT, and the load MW, and the dotted line indicates when the load is increased by the conventional control device. The engine operating characteristics and the solid line represent the engine operating characteristics when the load is increased by the control device of the present invention.

  When combustion switching occurs at time t2 and point B, the fuel-air ratio decreases as the number of burners increases, and the combustion gas temperature decreases. Further, the combustion energy flowing into the compressor turbine 3 and the load turbine 6 decreases, and the compressor turbine rotational speed NHPT and the load turbine rotational speed NLPT decrease as shown by dotted lines. Furthermore, the load MW also decreases as the load turbine speed NLPT decreases.

  In the conventional control device, the fuel flow rate command FFD is increased so as to compensate for the decrease in the load turbine rotational speed NLPT at the time of combustion switching. However, since the load turbine 6 and the load 4 are connected to the system, the decrease range of the load turbine rotational speed NLPT is smaller than the compressor turbine rotational speed NHPT, which causes a control delay in the fuel flow rate command FFD. As a result, the fuel flow rate command FFD greatly vibrates, and the response waveforms of the compressor turbine rotational speed NHPT, the load turbine rotational speed NLPT, and the load MW also vibrate accordingly. If the load turbine speed NLPT decreases to a point that deviates from the system frequency, the engine is disconnected from the system. Further, when the fuel flow rate command FFD is greatly reduced due to the vibration of the fuel flow rate command FFD, the flame of the burner 21 may be lost due to the reduction of the fuel-air ratio.

  On the other hand, in the gas turbine engine control apparatus 5 of the present invention, as shown by the solid line in FIG. 5, a decrease in the load turbine rotation speed NLPT at the time of combustion switching is detected in advance by a differential calculator, and the load turbine rotation is detected. The fuel flow rate command bias correction value FFDBC for minimizing the fluctuation of the number NLPT and the compressor turbine rotational speed NHPT is obtained. Further, the correction value FFDBC is added to the fuel flow rate command FFD to calculate the fuel flow rate command correction value FFDC, and then the fuel valve 7 is controlled based on the FFDC.

  The fuel flow rate command correction value FFDC prevents a decrease in the load turbine speed NLPT and suppresses a decrease in the fuel-air ratio at the time of combustion switching, thereby suppressing fluctuations in the compressor turbine speed NHPT and the load turbine speed NLPT. Can do. As a result, the fluctuation of the load MW accompanying the fluctuation of the load turbine speed NLPT can be minimized, and the load following performance of the gas turbine engine in the load change can be improved.

  According to the first embodiment of the control device for a gas turbine engine of the present invention described above, the rotation of the load turbine 6 against the fluctuation of the rotational speed NLPT of the load turbine 6 that occurs as a load change at the time of combustion switching. Since the fuel flow rate command bias correction value FFDBC for controlling the number fluctuation in advance is added to the fuel flow rate command FFD, it is possible to improve the follow-up performance to the load change at the time of combustion switching. As a result, a smooth load change operation can be realized even in a two-shaft gas turbine engine that requires combustion switching when the load changes.

  Next, a second embodiment of the gas turbine engine control apparatus of the present invention will be described with reference to FIG. FIG. 6 is a control block diagram of the fuel flow rate correcting means in the second embodiment of the control apparatus for the gas turbine engine of the present invention. In the following description, the same components as those in the first embodiment of the present invention described above are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 6, the fuel flow rate correcting means 19 obtains the dead zone ranges HH and HL of the function generator 31 from the time change rate dMWD / dt (load change rate) of the load command MWD. The differential calculator 43 receives the load command MWD and calculates a time change rate dMWD / dt (load change rate) of the load command MWD. The function generator 44 calculates the dead band ranges HH (positive side dead band width) and HL (negative side dead band width) of the function generator 31 from the input load change rate. In the present embodiment, as shown in FIG. 6, the dead zone ranges HH and HL are output smaller as the load change rate increases. As a result, when the load change rate is large, the function generator 31 outputs a non-zero value as the time change rate control amount dNHPT / dt even for a minute change in the input value dNLPT / dt.

  The function generators 31 and 44 predict the rate of change in the rotational speed of the load turbine 6 when the load command changes, thereby enabling load change operation with suppressed fluctuations in the rotational speed of the load turbine 6.

  The first embodiment is intended to detect a fluctuation in the rotational speed NLPT of the load turbine 6 at the time of combustion switching and to calculate a fuel flow rate command bias correction value FFDBC that controls the rotational speed fluctuation in advance. On the other hand, the second embodiment differs in that attention is paid to the rotational speed fluctuation of the load turbine 6 when the load command changes. When the gas turbine engine performs the load operation, the rotational speed of the load turbine 6 also varies according to the load balance on both the system and the engine side, and particularly in the rapid load change operation, the load of the gas turbine engine The rotational speed fluctuation of the load turbine 6 increases due to the response delay. On the other hand, the fuel flow rate correcting means of the present embodiment can detect the load change rate to control the fluctuation in the rotational speed of the load turbine in advance to improve the load followability of the engine in the rapid load operation. it can.

  According to the above-described second embodiment of the control device for a gas turbine engine of the present invention, when the time change rate of the load command is large, this load is detected against the fluctuation in the rotational speed NLPT of the load turbine 6 that increases. Since the fuel flow rate command bias correction value FFDBC for pre-controlling the rotational speed fluctuation of the turbine 6 is added to the fuel flow rate command FFD, even when the time change rate of the load command is large, the load changes. The following performance can be improved. As a result, for example, even in a two-shaft gas turbine engine that requires rapid load operation, smooth load change operation can be realized.

  Next, a third embodiment of the gas turbine engine control apparatus of the present invention will be described with reference to FIG. FIG. 7 is a control block diagram of the fuel flow rate correcting means in the third embodiment of the control apparatus for the gas turbine engine of the present invention. In the following description, the same components as those in the first and second embodiments of the present invention described above are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 7, the function generator 42 calculates dead bands (1) HH1 and HL1 of the function generator 31 from the fuel flow rate command FFD, and the differential calculator 43 and the function generator 44 calculate the rate of change dMWD / dt of the load command MWD. Dead band of function generator 31 (2) HH2 and HL2 are calculated. The outputs HH1 and HL1 of the function generator 42 and the outputs HH2 and HL2 of the function generator 44 are input to the signal switch 45. In the signal switch 45, the outputs HH1 and HL1 of the function generator 42 and the outputs of the function generator 44 One of HH2 and HL2 is selected, and this is output to the function generator 31 as a positive dead zone width and a negative dead zone width HH and HL. The function generator 31 uses the positive dead zone width and the negative dead zone widths HH and HL as the dead zone setting values.

  In the present embodiment, the load change rate dMWD / dt is used to select the outputs HH1, HL1 of the function generator 42 and the outputs HH2, HL2 of the function generator 44 in the signal switch 45. When the load change rate dMWD / dt is greater than or equal to the set value (or greater than the set load change rate), the signal switch 45 uses the outputs HH2 and HL2 of the function generator 44 as the dead zone set values HH and HL. The rapid load following described in the embodiment is made possible.

  On the other hand, when the load change rate dMWD / dt is less than the set value, the outputs HH1 and HL1 of the function generator 42 are adopted as the dead zone set values HH and HL, and the combustion switching described in the first embodiment is performed. Controls fluctuations in the load turbine over time.

  According to the third embodiment of the control device for a gas turbine engine of the present invention described above, when the time change rate of the load command is large, or when the combustion speed is changed, the rotational speed NLPT of the load turbine 6 increases. On the other hand, since the fuel flow rate command bias correction value FFDBC for controlling the rotational speed fluctuation of the load turbine 6 is added to the fuel flow rate command FFD, the time change rate of the load command is large or when the combustion is switched. Even so, it is possible to improve the follow-up performance to the load change. As a result, the load followability of the gas turbine engine can be improved, and fluctuations in the rotational speed of the load turbine during combustion switching can be prevented.

1 is a schematic view of a two-shaft gas turbine engine provided with a first embodiment of a control device for a gas turbine engine of the present invention. It is a control block diagram of the fuel flow rate control means in the first embodiment of the control device for the gas turbine engine of the present invention. It is a control block diagram of the fuel flow rate correction means in the first embodiment of the control device for the gas turbine engine of the present invention. It is a characteristic view which shows the plan value of the driving | running characteristic of the 2-shaft type gas turbine engine in 1st Embodiment of the control apparatus of the gas turbine engine of this invention. It is a characteristic view which shows the operating characteristic of the 2-shaft type gas turbine engine in 1st Embodiment of the control apparatus of the gas turbine engine of this invention. It is a control block diagram of the fuel flow volume correction | amendment means in 2nd Embodiment of the control apparatus of the gas turbine engine of this invention. It is a control block diagram of the fuel flow volume correction | amendment means in 3rd Embodiment of the control apparatus of the gas turbine engine of this invention.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Combustor 3 Compressor turbine 4 Load 5 Controller 6 Load turbine 7 Fuel valve 10 Revolution meter 11 Revolution meter 16 Drive shaft 17 Drive shaft 18 Fuel flow control means 19 Fuel flow correction means 20 Fuel valve control means 21 Burner 30 Differentiation operator 31 Function generator 32 Function generator 33 Integration operator 34 Change rate limiter 35 Adder 36 Gain setting device

Claims (6)

A compressor turbine that drives a compressor that sucks and pressurizes air; a combustor that generates a combustion gas to be supplied to the compressor turbine, and that switches a combustion during operation; and a generator that is a load A control device for a two-shaft gas turbine engine comprising a load turbine for driving
Fuel flow rate control means for calculating a fuel flow rate command value to the combustor;
Fuel flow rate correction means for calculating a fuel flow rate command correction value obtained by adding a correction signal for compensating for fluctuations in the rotation speed of the compressor turbine to the fuel flow rate command value calculated by the fuel flow rate control means at the time of the combustion switching;
And a fuel valve control means for controlling the opening degree of the plurality of fuel valves based on the fuel flow rate command correction value calculated by the fuel flow rate correction means. apparatus. A compressor turbine that drives a compressor that sucks and pressurizes air; a combustor that generates a combustion gas to be supplied to the compressor turbine and that performs combustion switching during operation; and a generator that is a load A control device for a two-shaft gas turbine engine comprising a load turbine for driving
A fuel flow rate control means for inputting a load command which is an output target of the generator and calculating a fuel flow rate command value corresponding to the load command to the combustor;
The load change rate is calculated based on the load command, and when the load change rate is equal to or higher than a preset value, the rotation of the compressor turbine is changed to the fuel flow rate command value calculated by the fuel flow rate control means. Fuel flow rate correction means for calculating a fuel flow rate command correction value to which a correction signal for compensating for the number variation is added;
And a fuel valve control means for controlling the opening degree of the plurality of fuel valves based on the fuel flow rate command correction value calculated by the fuel flow rate correction means. apparatus. The control apparatus for a two-shaft gas turbine engine according to claim 1 or 2,
The fuel flow rate correcting means receives a rotational speed of the load turbine, and calculates a time change amount of the load turbine rotational speed;
A control device for a two-shaft gas turbine engine, comprising: a function generator for obtaining a correction signal for the fuel flow rate command value based on a time variation amount of the load turbine rotation speed from the differential calculator. The control apparatus for a two-shaft gas turbine engine according to claim 3,
The function generator of the fuel flow rate correcting means includes a dead zone for stopping the addition of a correction signal for the fuel flow rate command value when the time change amount of the load turbine rotational speed is equal to or less than a set value. A control device for a two-shaft gas turbine engine. The control apparatus for a two-shaft gas turbine engine according to claim 4,
The fuel flow rate correction means includes a dead zone setting function generator that outputs the positive dead zone width and the negative dead zone width of the function generator with the fuel flow rate command value as an input. Turbine engine controller. The control apparatus for a two-shaft gas turbine engine according to claim 4,
The fuel flow rate correction means includes a function generator for setting a dead zone that outputs a positive dead zone width and a negative dead zone width of the function generator with the rate of change of the load command as an input. Control device for gas turbine engine.

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