JPS5948294B2 - Control device for twin-shaft gas turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device that adjusts the opening degree of barrier pull vanes in proportion to the magnitude of sudden acceleration and deceleration of a two-shaft gas turbine equipped with a heat exchanger.

A single-shaft gas turbine with a heat exchanger and its control device are constructed as shown in Fig. 1, and the flow of pickled gas in the control device is as follows:
The result is as shown in FIG.

The reference numerals and partial names of each element in FIGS. 1 and 2 are described below.

1... Comple two turbines, 2... Gas generator turbines, 2... Force turbines, 3... Two turbines, 4 ... Heat exchanger, 5 ... Combustor, 6 ... Fuel adjustment valve, 7 ... Fuel adjustment valve drive mechanism, 8 ...・Combustion F pump, 9... Barrier pull vane, 10... Barrier pull vane drive mechanism, 11...
...Load, 12...Accelerator pedal, 13...Gas-zey turbine target rotation speed setting Hot sleep 14...Gas-zey, turbine rotation speed detector, 15. ...Power turbine rotation speed detector, 16
・・・・・・Gas Gene Turbine Human Logus Temperature Detector, 1
7. 18...Converter, 19...Fuel barrier pull vane control device, 20
, 21... Frequency-voltage converter, 22, 25.
32 35.37.38... Comparator, 23...
...Gas general speed governor, 24...Coefficient, 26...Power turbine overspeed.

Protector, 27...Function generator (fuel planning line during steady operation)
, 28...Function generator (maximum fuel line during acceleration),
29... Function generator (gas general population temperature planning line during steady operation), 30, 42.46... Adder, 31... Temperature protector, 33... ...P operation regulator, 34... Phase lead compensation circuit, 36... PI operation regulator, 39... Barrier pull vane opening adjustment at sudden acceleration/deceleration, 40... Barrier pull vane opening degree determiner, 4
1...Minimum value selection circuit, 43...Blowout prevention fuel flow rate setting device, 44.
...Maximum value selection circuit, 44...Gas general inlet temperature margin setting device.

Next, the meanings of the symbols used in FIGS. 1 and 2 will be described below.

N6*: Target value of gas generator rotation speed during steady operation, N6.
Gas general rotation speed at design point, N6: Gas general rotation speed measurement value, N-: Power turbine rotation speed target value during steady operation, NP:
Power turbine rotation speed at the design point, N: Measured power turbine rotation speed, T7REF: Target value of gas general population temperature during steady operation,
T7: Measured gas general temperature, T7MOD: Measured gas general inlet temperature after phase lead compensation, T7maX: Endurance limit temperature of turbine material, ΔT
:Gas general temperature margin, ■NmaX: Barrier pull vane opening during sudden acceleration, VNmi
n: Barrier pull vane opening during sudden deceleration, R6: Barrier pull vane opening (change from design point opening), nGmaX: Barrier pull vane opening upper limit, #Gm1
n: Lower limit of barrier pull vane opening, GfR□: Planned fuel flow rate during steady operation, ΔGf: Fuel flow rate change, ΔGfmaX: Maximum value of fuel flow rate change (preventing overheating and surging), Gfm, n: Sudden deceleration The control device shown in Figure 2 is suitable for gas turbines for vehicles.
It has the following functions.

(1) Fuel planning line determined to maintain low fuel consumption.”
- to perform steady state operation.

(2) Improving rapid acceleration/deceleration performance.

(3) Preventing material overheating due to excessive fuel injection and preventing overspeeding of co-rotating parts due to power imbalance.

In order to satisfy all the functions 1 to 3 above, the fuel flow rate is
GfRE) shown in the figure, the maximum fuel line (Grm
aX-ray) and the minimum fuel line (Gfmin line), and is proportionally controlled with a droop of α% based on the design point.

In addition, Grma X-rays are used to detect overheating during sudden acceleration.
・Alternatively, with the intention of preventing surging, c and m+X-rays are lines set with the intention of maintaining the air-fuel ratio to prevent blowout during rapid events.

During sudden acceleration/deceleration, the regulator 39 opens and closes the barrier pull vane at a constant angle (VNmaX or VNmin) in an on-off manner, but the width 2Δ of the dead zone of the regulator 39 is set to an appropriate value.

Note that Δ is a criterion for determining sudden acceleration/deceleration.

The PI regulator 36 is provided for use during steady operation.

A feedback loop composed of an adder 46 and a barrier pull vane opening degree determiner 40 sets the barrier pull vane opening degree signal W6 to an upper limit value Δvcmax and a lower limit value IVGm+.

It functions as a limiter to keep it within the range.

Note that, when the barrier pull vane opening lV6 exceeds the upper limit 'Vcmax or the lower limit Δv6min, the determiner 40 outputs a signal proportional to the excess.

The proportional gain of the determiner 40 at this time is assumed to be KE.

Furthermore, the barrier pull vane opening degree Δ■6 increases, and the adder 46
In order to prevent the regulator 36 from exceeding its operating range due to an excessive signal being applied to the output signal, the upper and lower limits of the output signal ΔVE, -
Δ■o is set.

For overheat prevention, the target value T7REF of the gas generator inlet temperature during steady operation is determined by the gas generator rotation speed N6.
Cut the upper limit of the line by adding the margin ΔT to the maximum durability temperature of the material, and get 7N below the measured gas generator inlet temperature.

1. This is done by reducing the fuel flow rate in proportion to the amount that exceeds this set line.

Note that the converters 1 and 18 are for converting signals within the control device into operation signals for the fuel adjustment valve drive mechanism 7 and the barrier pull vane drive mechanism 10, respectively.

Regarding the operation of the two-shaft gas turbine with a heat exchanger shown in FIG. 1 during sudden acceleration and deceleration, conventionally the barrier pull vane 9 was turned on and off at a constant angle (VNm) using the regulator 39 shown in FIG.
A method of opening and closing with aX or vNmill was considered.

According to this method, a vibration phenomenon as shown in FIG. 3 occurs particularly during sudden acceleration, and depending on the characteristics of the gas turbine to be controlled, a limit cycle may occur, resulting in unstable operating conditions.

This is because the barrier pull vane 9 is suddenly opened due to a sudden acceleration command (N, "-NC: > Δ), and at the same time, fuel injection starts, and the gas temperature and population temperature rise. -7On the other hand,
The rotational speed of the gas-sey turbine 2 increases as the temperature of the incoming combustion gas increases, but the rotational speed does not increase to the sigh speed where there is a moment of inertia.

As the rotational speed N of the gas generator turbine 2 increases, the effect of the barrier pull vane opening degree adjuster 36 for steady operation wears off, and the opening degree 6 of the barrier pull vane 9 gradually decreases.

As the gas general rotation speed ■6 increases, the deviation of the gas general rotation speed (N6''-N6) gradually decreases, and finally,
At the same time as NC, "-N6-Δ, the output of the regulator 39 becomes zero and the barrier pull vane 9 is abruptly closed.

By closing the barrier pull vane 9, the gas generator turbine 2 enters a deceleration state, and the deviation of the gas generator rotational speed is again N6''-N.

> Δ, the output of the regulator 39 becomes VNmaX, and the gas generator turbine 2 enters the re-acceleration state.

As a result of the repower target speed of the gas generator turbine 2, the deviation (N6''-N6) of the gas turbine and rotational speed decreases, and N,,''-N6
<Δ, and the vehicle enters a deceleration state again.

In this way, the gas generator turbine 2 repeatedly accelerates and decelerates, resulting in an unstable operating state.Furthermore, due to fluctuations in the opening degree of the barrier pull vanes 9, the output I/Lux of the power turbine 3 also fluctuates. There were drawbacks.

As a control device for a two-shaft gas turbine, a hunting phenomenon (opening degree of the barrier pull vane 9, same rotation speed of the gas generator turbine 2, output torque of the power turbine 3, etc.) occurs during the seventh sudden deceleration. Therefore, it is necessary to quickly make the gas generator rotational speed N6 follow its target value N6''.

The present invention was made based on this idea, and instead of conventionally using an on-off operation adjuster 39 to adjust the opening degree of the barrier pull vane 9 during sudden acceleration/deceleration. By replacing the regulator 47 with a proportional action with a dead band, continuous control is performed that reflects the magnitude of sudden acceleration/deceleration, and the deviation (N,,,,,”-NG) of the gas generator rotation speed is reduced to NG*-N6. ==-
The gist of this invention is to quickly make the gas general rotation number N6 follow its target value N♂ without causing a hunting phenomenon when the value becomes Δ.

Next, a specific embodiment of the present invention will be described in detail with reference to the accompanying drawings. A control device in which the signal path shown in FIG. 4 is replaced with the circuit shown in FIG. 4 has the structure of the present invention.

Incidentally, Fig. 4 also includes peripheral elements to make it easier to understand the improved areas.

Further, the names of each element are the same as those in FIGS. 1 and 2, except for the following 47 and 48.

47... Sudden force [1 deceleration barrier pull vane opening adjuster, 48... Proportional gain setting device, here the width 2Δ of the dead zone of the regulator 47, the gain of the proportional adjustment section, The I-lower limit value and the gain of the proportional gain setter 48 shall be set appropriately.

The regulator 47 adjusts the deviation (N, "-N6) of the gas generator rotation speed.
According to the magnitude of the sudden acceleration/deceleration judgment criterion (Δ), when sudden acceleration/deceleration occurs, the barrier pull vane is instructed to open according to the magnitude of the sudden acceleration/deceleration (1.h [JIJ
A gain setter 48 adjusts the output of the regulator 47.

Also, IN6*-N1. When l<Δ, the output of regulator 47 is zero.

Now, when the gas turbine is operating at steady state, the 7' accelerator pedal 12 is suddenly depressed due to sudden acceleration.
Consider the state where it is kept as is.

That is, since the setting device 13 operates in conjunction with the accelerator pedal 12, the output N6* of the setting device 13 changes in a stepwise manner.

As a result, the deviation (N, ”-NG) of the gas general rotation speed is
Since N6*-N6>Δ, the regulator 47 outputs a signal VN' instructing the opening degree of the barrier pull vane in proportion to the magnitude of the sudden acceleration (IN6*-N61-Δ).

The output VN' of the regulator 47 is gain-adjusted by the proportional gain setter 48, and then inputted to the comparator 37 as a signal (2).

Since the output Δ■6 of the comparator 37 increases by the addition of the signal ■, the barrier vane 9 is opened.

On the other hand, in the fuel control system as well, since N6"N6>O, the fuel flow rate to be added is calculated by the governor 23, and the fuel flow rate supplied to the fuel device 5 increases, and the gas general temperature T7 continues to rise.

The gas generator turbine 2 increases its rotational speed as the temperature of the inflowing combustion gas increases, but the rotational speed does not increase rapidly because of the moment of inertia.

As the rotational speed N6 of the gas generator turbine 2 increases, the deviation (N6'', -N,) of the gas generator rotational speed gradually decreases, and accordingly, the output ■, ' of the regulator 47 increases
7, the sudden closing action of the barrier pull vane 9, which was seen in the case of the conventional on-off type regulator 39, does not occur.

The output of the regulator 47 is sent to the comparator 3 via the gain setter 48.
7 and combined with the output of the regulator 36 for steady operation, the deviation of the gas generator rotation speed (N6” -NG)
During steady operation (IN6”-N6
It is possible to shift to the adjustment operation of the barrier pull vane opening degree where 1<Δ).

The control operation of the control device according to the present invention during sudden acceleration has been described above, but the control operation during sudden deceleration is also performed in the same manner.

Next, during steady operation, the output of the regulator 47 is zero, so
The opening degree of the barrier pull vane 9 is adjusted only by the regulator 36.

Now, the measured value of the gas general inlet temperature (result of phase lead compensation) T7MOD is the gas general inlet "-1 temperature planned value T7R".
Consider the case where it is lower than EF.

The output of the comparator 35 is positive and is input to the regulator 36 via the summing heat 6.

Note that the other input signal of the addition@decoder 6 is the comparator 37.
If the output Δv6 is within the lower limit value, it is zero.

Proportional-integral adjustment is performed by the regulator 36, and the output signal □ increases.

Since the output ■1 of the regulator 36 is inputted to the (-) side terminal of the comparator 37, the output Δ■6 of the comparator 37 decreases.

Therefore, the barrier pull vane 9 is operated in the closing direction via the converter 18 and the barrier pull vane drive mechanism 10.

When the opening degree of the barrier pull vane 9 decreases, the flow rate of the combustion gas passing through the gas general turbine 2 decreases, so the gas general population temperature T7 increases.

Conversely, when T7MOD>T7REF, the output (1) of the regulator 36 decreases, acting in the direction of increasing the opening degree of the barrier pull vane 9, and the gas generator inlet temperature T7 decreases.

Here, the barrier pull vane opening degree determiner 40 and the adder 46
We will now explain the limiter function for Δ■6 of the feedback loop composed of .If Δ■6 exceeds the upper limit value ΔVGma
Exceeding the upper limit of Δ■6 (Δ■6−ΔVcmax
) is input to the adder 46.

As a result, the human power value of the regulator 36 increases, and the proportional-integral adjusted output ■□ also increases, so the output Δ■6 of the comparator 37 decreases by the amount exceeding the -L limit value, and Δ (2) In 6, the upper limit value Δvcma is suppressed by x.

However, strictly speaking, Δ■6 can be suppressed to a value that slightly exceeds the limit value Δvcmax;
It is determined by the gain of 0, the gain of the regulator 36, and the integration time.

According to the device of the present invention, in addition to the barrier pull vane opening adjuster during steady operation, a barrier pull vane opening adjuster with a proportional adjustment operation with a dead band for sudden acceleration/deceleration is provided, and the outputs of both regulators are added. As a result, by changing the opening degree of the barrier pull vane, it is now possible to adjust the opening degree of the barrier pull vane in proportion to the magnitude of sudden acceleration/deceleration. In addition, the control operation during steady operation can be continuously performed without causing bunching phenomena in various parts of the gas turbine due to the opening degree of the barrier pull vanes.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing a conventional control device for a two-shaft gas turbine, and Fig. 2 is a system diagram showing the flow of signals within the control device.
Figure 3 is a diagram showing the vibration phenomenon caused during sudden acceleration and deceleration.
FIG. 4 is a system diagram showing the configuration of essential parts of the device of the present invention, and FIG. 5 is a chart showing that the device of the present invention does not cause bunching during sudden acceleration/deceleration. 1... Compressor, 2... Gas generator turbine, 3... Power turbine, 4...
...Heat exchanger, 5... Combustor, 6...
Fuel adjustment valve, 7...Fuel adjustment valve drive mechanism, 8.
... Fuel pump, 9 ... Barrier pull vane, 10 ... Barrier pull vane drive mechanism, 11
......Load, 12...Accelerator pedal, 13...Gas general turbine target rotation speed setter, 14...Gas general Turbine rotation speed detector, 15... Power turbine rotation speed detector, 16... Gas generator turbine gas temperature detector, 1 Otsu 18... Converter, 19 ...
...Fuel variable vane control device, 20.21...
...Frequency-voltage converter, 22.25.32.35
．． 37.38...Comparator, 23...Gas general rotation speed governor, 24...Coefficient unit, 26.
... Power turbine overspeed protector, 27 ... Function generator (fuel planning line during steady operation), 28 ... Function generator (maximum fuel line during acceleration), 29...Function generator (gas general population temperature planning line during steady operation), 30;...42, 46...
・Adder, 31...Temperature protector, 33...
...P operation adjuster, 34 ... Phase lead compensation circuit, 36 ... PI operation adjuster, 39 ...
・・Barrier pull vane opening adjuster during sudden acceleration/deceleration, 40・・
...Barrier pull vane opening degree determiner, 41...
・Minimum value selection circuit, 43...Blowout prevention fuel flow rate setting device, 44...Maximum value selection circuit, 45.
...Gas general inlet temperature margin setting device, 47...
... Barrier pull vane opening adjuster during sudden acceleration/deceleration, 48.
...Proportional gain setting device.

Claims (1)

[Claims] 1 Go to the control device of the two-shaft gas turbine with heat exchanger and set the Katsuko 1st speed + 1. %: Only t, a Proportional to the magnitude of deceleration [-7 generates a signal to instruct the opening of the barrier pull vane, 7e, the circuit advances the acceleration/deceleration by fJN, and during steady operation,
The gas temperature determined by the turbine rotation speed is determined by the temperature plan value as the target value, the measured value of the gas temperature temperature as the control variable, and the deviation between the two is adjusted proportionally and integrally to determine the opening degree of the barrier pull vane. Generates an instruction signal to improve fuel efficiency F1
A circuit that adds the outputs of both of the above circuits and generates a signal instructing the opening degree of the barrier pull vane, and a circuit that determines whether the output of this circuit is within the lower limit range. ,
When the limit value is exceeded, a feedback signal proportional to the excessive amount is sent to the input part of the proportional-integral regulator of the circuit that performs the proportional-integral adjustment and generates an instruction signal for the opening degree of the barrier pull vane. This circuit calculates the output of the above two circuits in terms of force and limits the output of the circuit that generates the signal instructing the opening degree of the barrier pull vane. Adjusting the barrier pull vane opening in proportion to By continuously changing the opening of the barrier pull vane for acceleration/deceleration, the opening of the barrier pull vane can be continuously shifted to the control operation during steady operation without causing unstable operation. Gas turbine control device.