JPS5947140B2 - Variable vane control device for twin-shaft gas turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a barrier pull vane control system for a two-shaft gas turbine, and in particular to an improvement in this type of system for motor vehicles.

1 and 2 show a conventional two-shaft gas turbine with a heat exchanger and its control device.

That is, in the conventional two-shaft gas turbine, air from the atmosphere is compressed by the compressor 1, heated by the heat of the exhaust gas by the heat exchanger 4, and guided to the combustor 5.

Fuel from a fuel pump 8 is supplied to the combustor 5 via a fuel adjustment valve 6 controlled by a fuel adjustment valve drive mechanism I, where it is combusted.

The combustion gas generated in the combustor 5 first passes through the gas generator turbine (
After driving a gas generator (hereinafter abbreviated as gas generator) 2 and then driving a power turbine 3 via a barrier pull vane 8, the gas is discharged through a heat exchanger 4.

Power turbine 3 is linked to load 11rc.

In addition, reference number 16 is a log gas temperature detector with gas generator, 1
4 is a gas generator rotation speed detector, 1sti power-turbine rotation speed detector, and 10 is a barrier pull vane drive mechanism.

Control of this two-shaft cast turbine is performed by the above-mentioned fuel adjustment valve drive mechanism 7 and barrier pull vane drive mechanism 10, and the control device is designated by reference numeral 19, and its details are shown in FIG. be.

As shown in FIG. Rotation speed measurement value No.
The power turbine rotation speed measurement value NP obtained from the power turbine rotation speed detector 15 and the measurement value 〒7 of the gas generator inlet temperature T7 obtained from the gas generator logger and 2 temperature detector 16 are input.

After this rill device 1 appropriately controls and calculates these,
A fuel flow rate command value G and a barrier pull vane opening command value Vo are outputted and applied to the aforementioned fuel control valve drive mechanism 7 and barrier pull vane drive mechanism 10 via converters 17 and 18, respectively.

In the control device 19 shown in FIG. 2, reference number 20 is a phase lead compensation circuit, 21 is a function generator (gas gene inlet temperature planning line during steady operation), 22 is a fuel flow rate control calculation circuit, 2
3, 2γ, 28 are comparators, 24 is an adder, 25 is a PI adjuster, 26 is a barrier pull vane opening determiner, 29 is a barrier pull vane opening adjuster during sudden acceleration/deceleration, 30-piece proportional gain setter It is.

In this figure, the symbol T7* is the gas general inlet temperature target value during steady operation, T2C is the gas general inlet temperature measurement value after phase lead compensation, VT is the barrier pull vane opening command signal during steady operation, and vN is the barrier during sudden acceleration/deceleration. Pull vane opening command signal, VG is barrier pull vane opening command signal (change from design point opening), VGmaX is barrier pull vane opening upper limit, VGmin is barrier pull vane opening lower limit, Δke This shows the acceleration/deceleration determination criteria.

To briefly describe the calculation circuit for the barrier pull vane 1 command value vG of the control device 19, during steady operation, the P I adjustment is performed so that the gas generator inlet temperature T7 is controlled along the planned line T7* in order to maintain low fuel consumption. At step 125, a barrier pull vane opening command value VG is calculated.

On the other hand, during sudden acceleration and deceleration, the barrier pull vane 9 is opened and closed in a N-OF manner by the regulator 29.

Note that the dead zone 4 of the regulator 29, which serves as a criterion for sudden acceleration/deceleration, is set to an appropriate value.

The output of the regulator 29 is zero during steady operation.

A feedback loop composed of an adder 24 and a barrier pull vane opening degree determiner 26 sets the barrier pull vane opening degree command signal VG to an upper limit value VGmax1 a lower limit value VGm i
It functions as a limiter to keep it within a thin range of n.

Note that the converters 17 and 18 each have a control device 19.
This is for converting the signals Gf and vG from the fuel adjustment valve drive mechanism I and the barrier pull vane drive mechanism 10 into operation signals.

Regarding the operation of the two-shaft gas turbine with a heat exchanger shown in FIG. 1 during sudden acceleration/deceleration, conventionally the barrier pull vane 9 was set at a constant angle (VNm
aX, VNmin) was used.

According to this method, a vibration phenomenon as shown in FIG. 3 is caused during sudden acceleration/deceleration, and depending on the custom-made gas turbine to be controlled, a limit cycle may occur and the operating state may become unstable.

Furthermore, when looking at this as an operating line on a compressor map, as shown in FIG. 4, conventionally it becomes an oscillating operating line.

First, considering the behavior during sudden acceleration, the sudden acceleration command (
Due to N G *NG > Δ), barrier pull vane 9
At the same time as the gas generator is suddenly opened, fuel injection begins and the gas generator inlet temperature rises.

On the other hand, the rotational speed of the two gas generator turbines increases as the temperature of the incoming combustion gas increases, but the rotational speed does not increase rapidly because of the moment of inertia.

As the rotational speed NG of the gas generator turbine 2 increases, the effect of the barrier pull vane opening degree determination device 26 for steady operation becomes less effective, and the opening degree vG of the barrier pull vane 9 gradually decreases.

As the gas general rotational speed NG increases, the deviation (NG*-NG)ViL of the gas general rotational speed gradually decreases and finally becomes NG*-NG-Δ.

At the same time, the output of the regulator 29 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 N again.

Since the state is such that *NG>Δ, the output of the regulator 29 becomes vNmax, and the gas generator turbine 2 enters the re-acceleration state.

As a result of the re-acceleration of the gas generator turbine 2, the deviation (NG*-NG) of the gas generator rotational speed decreases to NG*-NG Δ, and the system falls into 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 torque of the power turbine 3 also decreases. There was a variable drawback.

Also, during sudden deceleration, vibrations occur in the same way,
It had the disadvantage of causing surging.

The object of the present invention is to improve the drawbacks of this conventional device.

That is, during sudden acceleration/deceleration, no hunting phenomenon (opening degree of barrier pull vane 9, gas generator 20 rotation speed, output torque of power turbine 3, etc.) occurs, and
Promptly and stably reduce the gas gener- ation speed NG to its target value N without the compressor 1 entering the surge region.
The purpose is to follow G*.

The present invention uses a proportional action regulator with a dead band that can independently set the acceleration side proportional gain and deceleration side proportional gain to adjust the opening of the barrier pull vane during sudden acceleration/deceleration. There is provided a barrier pull vane control device for a two-shaft gas turbine, characterized in that the deceleration side proportional gain is set to be large in an area where the rotational speed deviation is large and small in an area where the rotational speed deviation is small.

As a result, according to the present invention, the proportional gain on the acceleration/deceleration side replaces the conventional regulator 29 with 0N-OFF operation used to adjust the opening degree of the barrier pull vane 9 during sudden acceleration/deceleration. Since the controller 31 is replaced with a proportional action regulator 31 with a dead band that can be set independently, and continuous control is performed that reflects the degree of sudden acceleration/deceleration, the deviation of the gas generator rotation speed (NGI - NG
) decreases to Δ1, the gas generator rotational speed NG quickly follows its target value NG* without causing a pinching phenomenon or without compressor 1 entering the surge region. It is possible to do so.

A barrier-pull vane control device that is a preferred embodiment of the present invention includes (1) a circuit that generates a signal to command the opening degree of the barrier-pull vane according to the degree of sudden acceleration/deceleration during sudden acceleration/deceleration; The circuit can independently set the proportional gain on the acceleration side and the deceleration side, and furthermore, in the deceleration side region, the proportional gain can be set high in the section where the rotation speed deviation is large, and the proportional gain can be set small in the section where the rotation speed deviation is small.

Also, the output during steady operation is zero.

) and (2) During steady operation, the gas general inlet temperature plan value determined by the gas general and pin rotation speed is the target value, and the gas general inlet temperature (however, the result of phase advance compensation for the measured value) is the controlled variable. a circuit that generates a command signal for the opening of the barrier pull vane by proportionally and integrally adjusting the deviation of the
) Said circuit 1).

A circuit that adds the outputs of (2) and generates a signal to command the opening degree of the barrier pull vane, and (4) determines whether the output of circuit 3) is within the upper and lower limits and generates a limit value. and a circuit that limits the output of the circuit 3) by sending a feedback signal to the input part of the proportional-integral regulator of the circuit 2) when the acceleration is increased, thereby preventing surging without impairing acceleration performance. The barrier pull vane opening degree is adjusted according to the magnitude of sudden acceleration/deceleration so that the speed can be decelerated quickly without any problems. Also, when the deviation of the gas generator rotation speed becomes small, the control operation during steady operation is continuously performed. We are making it possible to migrate.

A preferred embodiment of the present invention illustrated in FIG. 5 of the accompanying drawings will be described in detail below.

The gist of the present invention is that, in the control device 19, the regulator 29 shown in FIG. This is because it was replaced with the container 31.

In addition, this regulator 31 can set the proportional gain to be large when the rotational speed deviation is large and to be small when the deviation rate is large in the deceleration side region.

In FIG. 5, elements that are the same as in FIG. 2 are designated by the same reference numerals.

Here, the width of the dead zone of the regulator 31 (2Δ1), the gain of the proportional adjustment section (at acceleration...KNO? At deceleration...KNl
1KN2; KNl<KH2), the proportional gain change point (-Δ2) in the deceleration side region, the upper and lower limit values, and the gain of the proportional gain setter 30 maintain the predetermined acceleration performance and the compressor 1 enters the surge region. The speed should be set at an appropriate speed so that the speed can be decelerated quickly without any problems.

Next, to describe the operation with reference to FIGS. 4 and 6, the regulator 31 controls the deviation (NGI) of the gas
-NG) and the sudden acceleration/deceleration judgment criterion (Δl), the magnitude of the sudden deceleration will be ING*-NG during sudden acceleration/deceleration.
1-Δ1), and the proportional gain setter 30 adjusts the output of the regulator 31.

Further, when lNG*-NGI<Δ1, the output of the regulator 31 is zero.

Now, consider a situation in which the gas turbine is operated steadily, and the accelerator pedal 12 is suddenly released due to sudden deceleration and is held as it is.

That is, since the setting device 13 is interlocked with the accelerator pedal 12 vc, the output of the setting device 13 decreases in steps of NG*.

As a result, the deviation of the gas generation number (NGI-NG) is
Since ING*-NG1>Δ1, the regulator 31 outputs the opening command signal vN (vNkuO) of the barrier pull vane 9 in accordance with the thickness of the sudden deceleration (1NG*NGI-Δl).

While the rotation speed deviation is large (ING*-NG1>Δ2),
The proportional gain is increased (KN2) to close the barrier pull vane 9 as quickly as possible to promote deceleration of the gas generator turbine 2.

On the other hand, the fuel flow rate calculation circuit 22 calculates a predetermined fuel flow rate Gf, and as the fuel supplied to the combustor decreases, the gas generator inlet temperature T7 decreases.

As a result, the rotational speed NG of the gas generator turbine 2 decreases, and the rotational speed deviation ING*-NG+ gradually decreases accordingly.

When the rotation speed deviation becomes smaller, (Δ1(lNG*-NGI(
Δ2), reduce the proportional gain (KN r ; KN 1
<KN 2 ), it is possible to prevent the compressor from entering the surge region during deceleration.

Then, the speed is further reduced and I N G *NG 14
When it becomes 1, it is possible to continuously shift to the adjustment operation of the barrier pull vane opening degree during steady operation.

The control operation during sudden acceleration is performed in the same way, but the controller 3
The acceleration proportional gain KNO of 1 is the deceleration proportional gain (K
(N 1 , KN 2 ) can be set independently, so acceleration performance will not be impaired.

Next, during steady operation (the deviation of the gas generator rotation speed is ING*-N)
Since the output of the regulator 31 is zero for GI (Δl), the opening degree of the barrier pull vane 9 is adjusted only by the adjustment 525.

Now, consider a case where the gas general inlet temperature measurement value (result of phase lead compensation) T7C is lower than the gas general inlet temperature planned value T7*.

The output of the comparator 23 becomes positive and is input to the regulator 25 via the adder 24.

The other input signal of the adder 24 is zero if the output VG of the comparator 27 is within the upper and lower limit values.

The output signal VT is increased by proportional-integral adjustment from the adjustment 125VC.

Since the output vT of the regulator 25 is input to the Q-) side terminal of the comparator 27, the output vG of the comparator 27 decreases.

Therefore, the converter 18, the barrier pull vane drive mechanism 1
0, the barrier pull vane 9 is operated in the closing direction.

When the opening degree of the barrier pull vane 9 decreases, the flow rate of combustion gas passing through the gas generator turbine 2 decreases, and thus the gas generator inlet temperature T7 increases.

Conversely, if T2C>T7*, the output vT of the regulator 25
decreases, acting in the direction of increasing the opening degree of the barrier pull vane 9, and the gas generator inlet temperature T7Vi decreases.

Next, the limiter function for vG of the feedback loop composed of the barrier vane opening degree determiner 26 and the adder 24 will be explained.

Now, the barrier pull vane opening signal vG is the upper limit value vGma
If X is exceeded, the opening degree determiner 26 sends to the adder 24 a positive feedback amount proportional to the excess amount (vG'cmax) of the signal vG from the upper limit value.

As a result, the input value of the regulator 25 increases, and the proportional-integral-adjusted output ■T also increases, so that the output vG of the comparator 27 decreases by the amount exceeding the upper limit, and the signal vG equals the upper limit. It can be held down by vGmaX.

However, strictly speaking, the VG value can be suppressed to a value slightly exceeding the upper limit value vGmax, but this is determined by the gain of the determiner 26, the gain of the regulator 25, and the integration time.

According to the above configuration, in addition to the barrier pull vane opening adjuster during steady operation, there is a proportional adjustment operation with a dead band for sudden acceleration/deceleration (acceleration side proportional gain KNO and deceleration side proportional gain KN).
ltKN2 can be set independently.

) is installed, the proportional gains on the rapid acceleration side and the sudden deceleration side are set to appropriate values independently, and the outputs of both regulators are added to determine the opening of the barrier pull vane. change.

As a result, the opening degree of the barrier pull vane can be adjusted in accordance with the magnitude of sudden acceleration/deceleration so that acceleration performance is not impaired and the compressor can be decelerated quickly without entering the surge region.

Furthermore, when the deviation in the gas generator rotational speed becomes small, it is possible to continuously shift to the control operation during steady operation.

[Brief explanation of drawings]

Figure 1 is a system diagram of a two-shaft gas turbine with a heat exchanger, Figure 2 is a system diagram of its control circuit, Figure 3 is a diagram showing waveforms at various parts of the control circuit in Figure 2, and Figure 4 is a compressor modification. FIG. 5 is a diagram of flow rate ratio versus compressor compression ratio, FIG. 5 is a system diagram of a control circuit according to the present invention, and FIG. 6 is a diagram showing waveforms at various parts of the control circuit of FIG. 1... Compressor, 2... Gas generator turbine, 3... Power turbine, 4...
- Heat exchanger, 5... Combustor, 6...
Fuel adjustment valve, γ...Fuel adjustment valve drive mechanism, 8.
... Fuel pump, 9-...- Barrier pull vane, 10-... Barrier pull vane drive mechanism, 11.
...Load, 12 ...Accelerator pedal, 1
3... Gas generator rotation speed setting device, 14...
・Gas general rotation speed detector, 15...Power turbine rotation speed detector, 16...Gas general input log gas temperature detection U17, 18...Converter, 19.
...Fuel/barrier pull vane control device, 20...
-...Phase lead compensation circuit, 21...Function generator (gas generator inlet temperature planning line during steady operation), 22...
・・Fuel flow rate control calculation circuit, 23°27.28・・・・
... Comparator, 24 ... Addition 25 ...
・PI adjuster, 26... To judge barrier pull vane opening 29... Barrier pull vane opening adjuster during sudden acceleration/deceleration, 30... Proportional gain setting device.

Claims (1)

[Claims] 1 The barrier pull vane during steady operation is adjusted by proportional-integral adjustment of the deviation between the gas generator inlet temperature plan value set as a function of the gas generator rotation speed and the gas generator turbine inlet actual measured value in the control device of the two-shaft gas turbine. A circuit that calculates the opening command value, a circuit that calculates the barrier pull vane opening command value during sudden acceleration/deceleration based on the deviation between the set value and the measured value of the gas gene turbine rotation speed, and all output signals of the former and latter circuits. In a barrier pull vane control device consisting of a circuit that calculates the barrier pull vane opening command value by adding the value, the acceleration side proportional control is used to adjust the opening of the barrier pull vane according to the magnitude of the sudden acceleration/deceleration during sudden acceleration/deceleration. A proportional action regulator with a dead band that can independently set the gain and the reduction side cylinder 1 and second proportional gains is used. A barrier pull vane control device for a two-shaft gas turbine, wherein the first proportional gain is set to be smaller than the second proportional gain in an area where the numerical deviation is small.