JPH01193036A - Rotational speed controller for gas turbine engine - Google Patents

Abstract

PURPOSE:To prevent abnormal rise in the rotational speed of a gas turbine at the time of a malfunction in a sensor detecting the rotational speed of a compressor turbine rotated by means of combustion gas by stopping supply of fuel to a combustor. CONSTITUTION:At the time of malfunction of a sensor detecting the rotational speed signal of a compressor turbine in a gas turbine engine, the output voltage from an F-V converter 25 always output according to the rotational speed of engine is abruptly reduced, and the electric potential difference between this output voltage and that from a memory means 26 becomes greater than that upon normal operation. As a result, the potential difference becomes greater than an input signal level on the minus side of a voltage comparator 29 in a fuel supply stopping means 32, and the output is in an ON state, and therefor, a high level output signal is input to an FF circuit 30. The supply of fuel to a combustor through a control circuit 20 is stopped accordingly, so as to stop the rotation of the compressor turbine.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotation control device for a gas turbine engine, and in particular, to a device for preventing the engine rotation speed from becoming abnormally high due to a failure of a rotation speed detection sensor. Regarding a control device.

[Conventional technology]

Japanese Utility Model Application Laid-open No. 60-81236 is known as an example of a rotational speed control device for a two-shaft gas turbine engine having a compressor turbine and a power turbine. In this rotational speed control device, when it is determined that the gas turbine engine is in a predetermined operating state, the target rotational speed of the power turbine and engine is set in accordance with the change in the load of the auxiliary equipment, and the target rotational speed of the power turbine The target rotational speed of the compressor turbine is corrected so that the actual rotational speed of the compressor turbine matches the target rotational speed.

FIGS. 4 and 5 show an example of a conventional rotational speed control device for a gas turbine.

As shown, the compressor 1 is coaxial with the compressor turbine 2, and the power turbine 3 is connected to the load 1). Atmospheric air is sucked and compressed by a compressor 1, passes through a heat exchanger 4, and reaches a combustor 5. The fuel pumped by the fuel pump 8 is delivered to the combustor 5 via the fuel adjustment valve 6 controlled by the fuel adjustment valve drive mechanism 7.
The fuel is supplied to the combustor 5, where it is mixed with the aforementioned air and combusted. The combustion gases generated in the combustor 5 enter the compressor turbine 2, perform work on the power turbine 3 via the barrier pull nozzle 9, and are discharged as exhaust gas through the heat exchanger 4.

The device controlling this system includes a fuel and barrier pull nozzle control device, as shown in the figure, and a rotational speed signal (N,) from the engine detected by each rotational speed detection sensor 13.14.

r'+z), temperature signals output from each temperature sensor 15.16.17.1B (T o, T x, T s, s
, Ti), the pressure signal (P
, ) are input to the control signal calculation circuit 21, and the output of the accelerator pedal 12 is also the human power of the control signal calculation circuit 21. The fuel flow rate command signal Gf of the control signal calculation circuit 21 is sent to the fuel adjustment valve drive mechanism 7 via the driver circuit 23.
sent to. Further, the barrier pull nozzle opening command signal α3, which is the output of the control signal calculation circuit 21, is sent to the barrier pull nozzle drive mechanism IO via the driver circuit 24.

The control circuit shown in FIG. 5 has a function for a gas turbine engine for a vehicle. In other words, when a gas turbine engine is used for a vehicle, the engine output must be variable depending on the amount of depression of the accelerator pedal.The output of the two-shaft gas turbine engine shown in FIG. Since the control device exhibits characteristics that are highly dependent on speed, the target rotation speed of the compressor turbine 2 is determined by the amount of depression of the accelerator pedal, and the actual rotation speed of the compressor turbine shaft is made to effectively follow the target rotation speed of the compressor turbine 2. The increase and decrease of fuel is controlled. In other words, the rotational speed of the engine, particularly the rotational speed of the compressor turbine, is an important factor in controlling the engine.

Since gas turbine engines usually rotate continuously and have higher rotational speeds and higher frequencies than piston engines, electromagnetic pickups are often used as engine rotational speed detection sensors.

[Problem to be solved by the invention]

However, for example, if the electromagnetic pink-up for detecting the engine rotation speed malfunctions, the apparent engine rotation speed signal will usually drop significantly compared to the target engine rotation speed determined by the amount of depression of the accelerator pedal, etc. It will come off. At that time, the following problems occur in the control system.

In other words, as the apparent rotational speed signal decreases relative to the target rotational speed, fuel is increased in order to bring the rotational speed back to the target value, and as a result, the actual engine rotational speed becomes abnormally high. This may cause the engine to rotate and cause damage to the engine.

The present invention focuses on the above problem and provides a control device that can prevent the engine rotation speed from becoming abnormally high even if the rotation speed detection sensor fails and can reliably protect the engine from damage. The purpose is to

(1!1) Means for Solving 1] A rotational speed control device for a gas turbine engine according to the present invention that meets this objective detects the rotational speed of a compressor turbine rotationally driven by combustion gas generated in a combustor. a rotational speed detection sensor; a failure detection means for determining failure of the rotational speed detection sensor from a change in a rotational speed signal from the rotational speed detection sensor; and stopping supply of fuel to the combustor when a failure is determined. and fuel supply stop means.

[Effect]

In the gas turbine engine rotational speed control device configured in this way, if the rotational speed detection sensor that detects the engine rotational speed fails during engine operation, the output signal that is constantly output according to the engine rotational speed will be interrupted. In this case, it is determined that the rotational speed detection sensor is malfunctioning, and fuel supply to the combustor is automatically stopped to prevent engine damage.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a rotational speed control device for a gas turbine engine according to the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention. The present invention provides a new control function for controlling the fuel regulating valve in the devices shown in FIGS. 4 and 5 shown in the prior art. The basic configuration is similar to that shown in FIGS. 4 and 5. Therefore, the present invention will also be explained based on FIGS. 4 and 5.

FIG. 1 shows a rotational speed control device for a gas turbine engine, in which a rotational speed signal N1 of the shaft of a compressor turbine 2 is detected by an electromagnetic pinup 13 as a rotational speed detection sensor. As is well known, this rotational speed signal N captures the rotational speed of the engine as a frequency, so an F-V converter 25 is provided to convert it into a voltage signal for use in control. F-V
The converter 25 is connected to a sample/hold circuit 26 as storage means. The F-V converter 25 serves to detect and memorize the value of the output voltage V as a rotational speed signal using ON-OFF pulses periodically generated from the pulse oscillator 27.
When the output pulse of 27 is ON (High level), F-
Output voltage V of V converter 25 and sample/hold circuit 2
6 become equal, and the output pulse of the pulse oscillator 27 becomes 0FF (L.

W level), the output voltage V at that point becomes the output voltage V', and the next output pulse turns ON (High level).
It is held and output until . FIG. 3 shows the relationship between the output voltage V and the output voltage V', with time plotted on the horizontal axis. As shown in FIG. 2, the period T of the pulse oscillator is determined by the characteristics of the engine, and in this embodiment is set to about 100 ssec.

The F-V converter 25 is connected to a negative input terminal of an operational amplifier 28 as a calculation means via a resistor R1. Negative input terminal of operational amplifier 28 and operational amplifier 28
The output side of is connected via a resistor R2. The output side of the sample/hold circuit 26 is connected to the positive input terminal of an operational amplifier 28 via a resistor R1. Further, the positive input terminal of this operational amplifier 28 is connected to a resistor R4.
It is grounded through. In other words, in this example, F
The potential difference between the output voltage V of the -V converter 25 and the output voltage V' of the sample/hold circuit 26 is calculated by an operational amplifier 28, and the result is output as an output voltage ΔV. The operational amplifier 28 used here has a resistor R8”R
Since t −Rx = R4, the output voltage is Δ
It is well known that V-V'-V.

The operational amplifier 28 is connected to a fuel supply stop means 32 . The fuel supply stop means 32 is roughly composed of a voltage comparator 29 and a flip-flop circuit 30. A positive input terminal of the voltage comparator 29 is connected to the output side of the operational amplifier 28 via a resistor R3, and a negative input terminal of the voltage comparator 29 is connected to a variable resistor 29a via a resistor R&. There is. That is, here, the output voltage ΔV from the operational amplifier 28 is applied to the positive input terminal of the voltage comparator 29, and the zero voltage of the variable resistor 29a for setting the reference voltage is applied to the negative input terminal. An output Vset is applied. Here, the reference voltage Vset signal is determined in consideration of the maximum value of the amount of change in rotational speed within the period T of the output pulse of the pulse oscillator 27 during normal operation of the engine. In other words, a signal corresponding to a range of change in rotational speed that cannot occur under normal engine operating conditions is set in advance.

The output side of the voltage comparator 29 is connected to a set input terminal S of a flip-flop circuit 30 via a resistor R. The output terminal of the flip-flop circuit 30 is connected to the above-mentioned control circuit 20, and the other terminals C are both grounded. And the flip-flop circuit 30
The reset terminal R of the control circuit 20 is connected to the reset terminal R of the reset circuit 31 of the control circuit 20.
It is connected to the. Here, the reset circuit 31 is activated and the flip-flop 30 is reset only when the control system is powered on before engine operation. Further, the operation of the flip-flop is such that the output signal Q outputted from the output terminal is reset to a low level state by the operation of the reset circuit 31 immediately after the power of the control system is turned on. After that, the output of the voltage comparator 29 becomes High.
As long as it does not reach the level state, the output signal Q ha Low
maintain level status. Here, the condition for the output signal Q of the flip-flop circuit 30 to be at a high level is when the output of the voltage comparator f29 described above is at a high level. As is well known, when a high level signal is applied to the -degree set input terminal of the flip-flop circuit 30 and the output signal Q becomes high level, the output signal remains unchanged until a high level signal is inputted to the reset input terminal. Q maintains its state.

If the engine rotational speed signal N1 is lost due to some reason such as a failure of the electromagnetic pickup, the output voltage Δ■ exceeds the reference voltage Vset, so the voltage comparator 29 and the flip-flop circuit 3o are operated, and the flip-flop circuit 30 is activated. Output signal Q becomes High level. After that, even if the output voltage ΔV falls below the reference voltage Vset, the output signal Q of the flip-flop circuit 30 remains High.
This will maintain the h level condition. The output signal Q of this flip-flop circuit 30 is sent to the control circuit 20 as a fuel stop signal.

The control circuit 20 is a circuit that controls the fuel supplied to the combustor 5 and the opening degree of the barrier pull nozzle, and here, the fuel stop signal Q, which is the output signal of the flip-flop circuit 30, is
The circuit configuration is such that conventional fuel control is performed when the signal is at the OW level, and fuel is stopped when the fuel stop signal Q is at the High level.

Next, the operation of the above-mentioned gas turbine engine rotational speed control device will be explained.

In this rotational speed control device, for example, if the electromagnetic pickup as a rotational speed detection sensor that detects a rotational speed signal during engine operation fails, the F-V conversion that is constantly output according to the engine rotational speed is Vessel 25
Since the output voltage V from the sample/hold circuit 26 rapidly decreases, the potential difference ΔV between the output voltage V and the output voltage V' output from the sample/hold circuit 26 takes on a larger value than during normal operation.

Therefore, this potential difference (output voltage) ΔV is the negative input signal of the voltage comparator 29, which is set in advance.
signal, and the output of the voltage comparator 29 turns ON (H
high level) state.

In other words, if a potential difference ΔV corresponding to a range of change in rotational speed that is impossible under normal engine operating conditions occurs, it is determined that the electromagnetic pickup 13 has failed, and the high level output signal, which is a failure occurrence signal, is used for voltage comparison. The signal is input from the circuit 29 to the flip-flop circuit 3°. This results in
The output signal Q is output from the flip-flop circuit 30 as a fuel stop signal, and the fuel adjustment valve drive mechanism 7 is operated via the control circuit 20. Then, by the operation of this fuel adjustment valve drive mechanism 7, the fuel adjustment valve 6 is shut off, and the combustor 5
Fuel supply to the vehicle will be cut off. That is, the generation of combustion gas is stopped and the rotation of the compressor turbine 2 is stopped.

Therefore, even if the electromagnetic pickup fails during engine operation, the rotational speed of the compressor turbine 2 will not increase abnormally, making it possible to reliably protect the engine from damage.

〔Effect of the invention〕

As explained above, when using the gas turbine engine rotational speed control device of the present invention, when it is determined that the rotational speed detection sensor is malfunctioning, the supply of fuel to the combustor is stopped. Abnormally high speeds are prevented and the gas turbine engine can be reliably protected from damage.

[Brief explanation of the drawing]

FIG. 1 is a control diagram of a rotational speed control device for a gas turbine engine according to an embodiment of the present invention, FIG. 2 is a waveform diagram of output pulses output from the pulse oscillator of the device shown in FIG. 1, and FIG. A relationship diagram showing the relationship between the output voltage output from the F-V converter and the output voltage output from the sample/hold circuit in the device shown in FIG. 1, and FIG. 4 is a rotation speed control device in a conventional gas turbine engine. FIG. 5 is an electric circuit diagram of fuel adjustment valve control and barrier pull nozzle opening degree control in the device of FIG. 4. 2...Compressor turbine 5...Combustor 13...Engine rotation speed detection sensor (electromagnetic pickup) 25...F-V converter 26... ...Storage means (sample/hold circuit)
27... Pulse oscillator 28... Arithmetic means (operational amplifier) 29...
... Voltage comparator 30 ... Flip-flop circuit 32 ...
・Fuel supply stop means

Claims (1)

[Claims] (1) A rotation speed detection sensor detects the rotation speed of the compressor turbine that is rotationally driven by the combustion gas generated in the combustor, and a failure of the rotation speed detection sensor is detected from a change in the rotation speed signal from the rotation speed detection sensor. A rotational speed control device for a gas turbine engine, comprising: a failure detection means for determining a failure; and a fuel supply stop means for stopping the supply of fuel to the combustor when a failure is determined.