JPS5948296B2 - Variable vane control circuit at startup of two-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 more particularly to a start-up barrier pull vane control circuit for this type of system for automobiles.

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

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

Fuel from a combustion pump 8 is supplied to the combustor 5 via a fuel regulating valve 6 controlled by a fuel regulating valve drive mechanism 7, where it is combusted.

The combustion gas generated in the combustor 5 first passes through the gas generator turbine (
After driving a power turbine 3 (hereinafter abbreviated as gas generator) 2 and then a power turbine 3 via a barrier pull vane 9, the gas is discharged via a heat exchanger 4.

The output shaft of the power turbine 3 is linked to a load 11 .

Reference numeral 14 is a gas generator rotation speed detector, 15 is a power turbine rotation speed detector, 16 is a gas generator inlet temperature detector, 17 is a compressor intake air temperature detector, and 10 is a barrier pull vane drive mechanism.

This two-shaft gas turbine is controlled by the above-mentioned fuel adjustment valve drive mechanism 7 and barrier pull vane drive mechanism 10, and the control device, that is, the fuel/barrier pull vane control device is designated by reference number 20, and its details are It is shown in FIG.

The fuel/barrier pull vane control device 20 controls the gas general rotation speed set value N6* during steady operation, which is output from the gas rotation speed setting device 13 according to the degree of depression of the accelerator pedal 12 (see Fig. 1), and the gas general rotation speed. The gas general rotation speed measurement value N6 obtained from the detector 14, the power turbine rotation speed measurement value N obtained from the power turbine rotation speed detector 15, and the gas general inlet temperature T obtained from the gas general inlet temperature detector 16.
After inputting the measured value 〒7 of 7 and the measured value ↑1 of the compressor intake air temperature T1 obtained from the compressor intake air temperature detector 17, and performing appropriate control calculations including intake air temperature correction, Barrier pull vane opening command■
6 and a fuel flow rate command Gf.

These command signals are transmitted to converters 19 and 18, respectively.
It is converted into an operation signal by the barrier pull vane drive mechanism 1.
0 and the fuel regulating valve drive mechanism 7.

This fuel/barrier vane control device 20 has the function of outputting the two fingers as described above, but is particularly suitable for gas turbines for vehicles and is equipped with the following functions.

That is, (1) steady-state operation is performed on the gas generator inlet temperature and fuel plan line planned so as to maintain low fuel consumption.

(2) Improving sudden acceleration/deceleration performance.

(3) Preventing gas turbine materials from overheating due to excessive fuel input, and preventing overspeeding of rotating parts due to power imbalance.

As shown in FIG. 2, the fuel/barrier vane control device 20 includes a startup barrier pull vane opening setting device 21 that outputs a startup barrier pull vane opening command G8, and a gas generator inlet temperature measurement value T7. gas general inlet temperature T after phase advance compensation.

and the lead compensation circuit 22 that outputs the measured values N6 and T″
1 and outputs the gas general inlet temperature planned value T7* during steady operation (gas general inlet temperature planned line during steady operation), the set value N*, measured value N6, temperature T7o, and planned value T7*. The barrier pull vane control circuit 24 during normal operation receives and outputs the barrier pull vane opening command during normal operation ■GA, and the barrier pull vane opening command during normal operation ■GA and the barrier pull vane opening command during startup ■G8 and an operation mode changeover switch 26 that selectively switches between the two to obtain the barrier pull vane opening command VG, and an operation mode that receives the measured value N6, compares it with the operation mode switching rotation speed N6T, and outputs the operation mode switching signal S6T. Switching judgment circuit 2
5, set value N6″, measured value N6, N1, temperature plan value T
7* and temperature T7o and outputs a fuel flow rate command G, a startup/normal operation fuel control circuit 27 is included.

Below, a control method for the barrier pull vane opening degree of the fuel/barrier pull vane control device 20 will be described.

At startup, in order to reduce the load on the gas generator 2 and promote speed up to idling speed, the barrier pull vane 9 is set to the fully open position, which is further opened from the normal operating range, by the barrier pull vane opening setting device 21 at startup. Set.

The operation mode switching judgment circuit 25 manually inputs the rotational speed measurement value N6 and compares it with the predetermined mode switching rotational speed N6□, and when N6<N6□, S6□-0, and when N6 - N6□ , S6□=1 is output.

The operation mode changeover switch 26 receives the operation mode changeover signal S.
When receiving GT, connect the contact point and C when 56T-〇,
When S,=1, a and C are connected.

However, at startup, the contact point C of the operation mode changeover switch 26 is connected, and the output of the opening setting device 21 is sent to the barrier pull vane drive mechanism 10 via the converter 19, and the barrier pull vane 9 is controlled.

When the gas generator rotation speed measurement value N6 increases and becomes N6≧N6□, contacts a and C of the changeover switch 26 are connected, and the output of the barrier pull vane control circuit 24 during normal operation passes through the converter 19 to the barrier pull vane. The signal is sent to the drive mechanism 10, and the panoramic vane is controlled during normal operation.

The lead compensation circuit 22 inputs the measured gas genera inlet temperature value T7, performs phase lead compensation for the detection delay, and sends it to the barrier pull vane control circuit 24 during normal operation.

The function generator 23 inputs the gas general rotational speed measurement value N6 and the compressor intake air temperature measurement value T1, and generates the gas general inlet temperature plan value T7'1 during steady operation with intake air temperature correction.
′ is calculated, and the barrier pull vane control circuit 24 during normal operation is
Send to.

The barrier pull vane control circuit 24 calculates the barrier pull vane opening command value so as to control the gas generator inlet temperature T7 to a value T7'A along the planned line in order to maintain low fuel consumption during steady operation.

On the other hand, during sudden acceleration/deceleration, in order to improve sudden acceleration/deceleration performance, a barrier pull vane opening command value is calculated to open/close the barrier pull vane 9 according to the degree of sudden acceleration/deceleration.

In conventional control devices, during startup of a two-shaft gas turbine, the barrier pull vane opening degree is set to the fully open position to promote speed increase, and as shown in Fig. 4, the rotation measurement value N, increases and the operation mode is switched from startup to normal operation, there is a large difference in the operating range of the barrier pull vane between the barrier pull vane opening during startup and the opening during normal operation. 9 caused bunching, which caused a delay in settling the idling speed to N6□.

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

In other words, when starting a two-shaft gas turbine, the speed increase of the gas generator shaft is not impaired, and when the rotational speed increases and the operation mode is switched from startup to normal operation, bunching of the barrier pull vane opening can be caused. The purpose is to make the transition continuous.

According to the present invention, the barrier pull vane opening degree is controlled as a function of the gas generator rotational speed measurement value N6, whereas the barrier pull vane opening degree was conventionally kept constant at the fully open position at startup, and this function is changed to zero. From rotation to starter/cut I/out rotation speeds N and C.

It is kept constant at the fully open position, and when the rotation speed is above NSC, the barrier pull vane is closed as the rotation speed measurement value N6 increases by 1. When switching the operation mode, the barrier pull vane opening is set to the same as when idling. When closing the barrier pull vane, the rising speed of the measured rotational speed N6 is detected and compared with the preset rising speed. If the detected rising speed is small, the amount by which the barrier pull vane is closed is reduced and the rising speed is I try not to lose speed.

Thereby, when switching the operation mode, the barrier pull vanes can be continuously shifted without causing bunching.

That is, the present invention provides a barrier pull vane control circuit for a two-shaft gas turbine, which includes a circuit that outputs a planned opening value at startup as a function of the gas generator rotation speed;
A circuit that detects the rising speed of the gas general rotation speed, compares it with a preset 1L rise speed, and outputs a correction signal for the barrier pull vane opening if the detected 1L rise speed is small, and a circuit that outputs a correction signal for the barrier pull vane opening. Comparing with the starter cut-out rotation speed, if the gas general rotation speed is small, only the output of the opening planned value output circuit is output, and if the gas general rotation speed is equal or larger, the opening planned value output circuit and correction are performed. A circuit that adds the output of the signal output circuit and outputs a barrier pull vane opening command at startup, and compares the gas general rotation speed with the operation mode switching rotation speed, and if the gas general rotation speed is small, outputs the opening command. It consists of a circuit that uses the output of the circuit as a barrier pull vane opening command, and when the gas generator rotation speed is equal or larger, the output of the barrier pull vane control circuit during normal operation is used as a barrier pull vane opening command to switch the operation mode. A barrier pull vane control circuit at startup of a two-shaft gas turbine is characterized in that: 1, the barrier pull vane is continuously shifted without impairing speed increase during startup, and without causing bunching when switching operation modes; I can do it.

Hereinafter, a preferred embodiment of the present invention illustrated in FIG. 3 will be described in detail.

The gist of the present invention is that, in the control device 20, the startup barrier pull vane opening setting device 21 shown in FIG. 2 is replaced with a startup barrier pull vane control circuit consisting of elements 51 to 58 shown in FIG. be.

In addition, in FIG. 3, peripheral elements are also shown to clarify the connection relationship between the elements related to the present invention and other elements, and the same elements are indicated by the same reference numbers as the elements in FIG. 2. be.

At startup, the barrier pull vane control circuit differentiates the gas general rotation speed measurement value N6 to obtain the gas general rotation speed change rate dN6/dt.
and a differentiator 51 that obtains the gas generator rotational speed change rate set value (d
Rotation speed change rate setter 5 that outputs NG/dt) set
2 and a comparator 5 that compares these change rates and set values.
3, and a barrier pull vane opening adjuster 54 with a gain of 1 to obtain a barrier pull vane opening correction value G81 based on the rate of change in rotation speed, form an opening correction signal output circuit A, and the gas gener- ate rotation speed measurement value N6 Starter cutout rotation speed NSC
Compared with the starter cutter 1~out rotation speed judgment signal S
Starter cut-off I/rotation speed determination circuit to obtain sc (hysteresis characteristic (Nso) shown at the top of this circuit in Figure 3)
>N5o).

This hysteresis characteristic is caused by fluctuations in the gas generator rotation number.
Judgment signal S.

In order to prevent the output of the adder 58 from fluctuating due to repeated states 1 and O, once the starter is cut out, the determination signal S is set.

This is to maintain state 1.

The width of N5o and NsD takes into account the amount of variation when the gas generator rotational speed increases.

) 55, a changeover switch 56 controlled by this starter cutout rotation speed determination signal SSC, and an adder 5.
8 forms an opening command output circuit B that outputs the barrier pull vane opening command ■G5 at startup, and further outputs the barrier pull vane opening planned value ■G5o at startup as a function of the gas generator rotational speed measurement value N6. The barrier pull vane opening command (G8) at start-up is applied to a circuit C for switching the operating mode, which includes an operating mode switching determination circuit 25 and an operating mode changeover switch 26.

In terms of operation, the measured gas generator rotational speed N6 is led to the starter/cutout rotational speed determination circuit 55, where it is compared with the starter/cutout rotational speed N5o,
When the measured value N6 is rising and N6<N5°, the starter cutout rotation speed judgment signal 58o-1 indicates that N6≧N8o.
At this time, 58o=0 is sent to the changeover switch 56.

The changeover switch 56 closes the contact when 55o=1 and sends the output of the barrier-pull vane opening adjuster 54 to the adder 58, but when 55C=0, the contact is opened and the barrier-pull vane opening is adjusted. The circuit from the adder 54 to the adder 58 is disconnected.

The function generator 57 manually inputs the measured gas generator rotational speed value N6 and outputs the barrier pull vane opening planned value ■G5° at startup, and when 0<N6<N8o, the barrier pull vane 9
is kept constant at the fully open position, and closes as the rotational speed measurement value N6 increases at N6-N5o, and is set so that the opening degree of the barrier pull vane is approximately at the attrition time at the operating mode switching rotational speed N61.

Therefore, when N6<N5C, the output of the function generator 57 commands the fully open position, thereby reducing the load on the gas generator 2 and promoting an increase in the rotational speed measurement value N6.

When the measured rotational speed N6 increases and the turbine is able to speed up on its own, the starter motor is cut out.

Next, after the starter motor is cut out (Nc
>N5o) The method for controlling the barrier pull vane opening will be described.

The differentiator 51 inputs the gas general rotational speed measurement value N6, calculates the gas general rotational speed change rate dN6/dt, and sends it to the comparator 53.

At the same time, a signal of the rotation speed change rate (dN6/dt) set preset by the rotation speed change rate setter 52 is also sent to the comparator 53, where the output dN of the differentiator 51 is
6/dt and the deviation signal dN6/dt) se
t - dN6/dt by barrier pull vane opening adjuster 54
Send to.

The barrier pull vane opening adjuster 54 is (dN6/dt)
When set > dN6/dt, the rising speed of the measured rotational speed value N6 is smaller than the preset rising speed, so a barrier is created based on the rotational speed change rate according to the magnitude of the deviation signal to promote speed increase. Pull vane opening correction value VGS
I (> 0) is output and added to the barrier pull vane opening planned value ■GSo at startup, which is the output of the function generator 57.

In this way, by correcting the opening correction value ■GS0 to the opening planned value G8o, which is the standard opening, it is possible to give the optimum opening command ■G5 based on the actual barrier vane opening versus rotation speed. .

On the other hand, when (dN6/dt) set≦dN6/dt, the rising speed of the measured value N6 is greater than the preset rising speed, so there is no need to correct the barrier pull vane opening planned value ■G5o at startup. The barrier pull vane opening degree regulator 54 outputs ■GS□-〇.

In this way, in the range N61>N6nN5o,
The barrier pull vane 9 is controlled according to a planned value determined by the function generator 57, and at Nc #NGT, the barrier pull vane 9 has approximately the opening degree of the barrier pull vane during idling.

Therefore, by configuring the barrier pull vane control circuit at startup as described above, the speed increase of the gas generator shaft is promoted, and after the starter motor is cut out, the barrier pull vane is activated as the rotation speed increases without impairing the speed increase. When the barrier pull vane is closed and the operating mode is switched from startup to normal operation, it is possible to continuously shift to the barrier pull vane opening during idling without causing hunting (see Fig. 4).

[Brief explanation of drawings]

Fig. 1 is a system diagram of a two-shaft gas turbine with a heat exchanger, Fig. 2 is a diagram showing a conventional example of its control circuit, Fig. 3 is a diagram showing a control circuit according to the present invention, and Fig. 4 is a diagram showing the gas generator rotation speed. FIG. 3 is a diagram showing measured values and barrier pull vane opening commands as a function of time. 11... 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 structure, 1
1... Load, 12... Accelerator pedal, 13... Gas generator M rotation speed setting device, 14...
...Gas-see/rotation speed detector, 15...Power turbine rotation speed detector, 16...Gas general inlet temperature detector, 17...Compressor intake air temperature detector , 18.19...Converter, 20.
...Fuel/barrier pull vane control device゛21...
...Barrier pull vane opening setting device at startup, 22...
...Advance compensation circuit, 23...Function generator,
24... Barrier pull vane control circuit during normal operation, 25... Operation mode switching judgment circuit, 26...
...Operation mode selector switch, 27...
Starting/normal operation fuel control circuit, 51...Differentiator, 52...Circuit number change rate setting device, 53...
: Comparator, 54... Barrier pull vane opening adjuster, 55... Starter cutout... Function generator, 58... Adder.

Claims (1)

[Claims] 1. A barrier pull vane control device for a two-shaft gas turbine includes a circuit 57 that outputs a planned barrier pull vane opening value at startup as a function of the gas general turbine rotation speed, and a circuit 57 that detects the rate of increase in the gas general turbine rotation speed. , a circuit A that compares the rising speed set in advance and outputs a correction signal for the barrier pull vane opening if the detected rising speed is small, and a circuit A that outputs a correction signal for the barrier pull vane opening when the detected rising speed is small;
・Compared to the out rotation speed, when the gas general turbine rotation speed is small, only the output of the opening planned value output circuit is output, and when the gas general turbine rotation speed is equal to or larger, the output of the opening planned value output circuit and Compare circuit B that outputs the barrier pull vane opening command at startup by adding the outputs of the and correction signal output circuits, and the gas general turbine rotation speed with the operation mode switching rotation speed, and find that the gas general turbine rotation speed is small. In this case, the output of the opening command output circuit is used as the barrier pull vane opening command, and when the gas generator rotation speed is equal to or larger, the output of the barrier pull vane control circuit 24 during normal operation is used as the barrier pull vane opening command. A barrier pull vane system at the time of startup of a two-rotation gas turbine, which is characterized by a circuit C that switches the operation mode as follows! in circuit.