JPS5847231Y2 - gas turbine - Google Patents

Description

[Detailed description of the invention] The present invention turns off the power to the control device to stop the control device when an abnormality occurs in the gas turbine control device, such as the gas turbine engine starting control device or rotation speed control device. It concerns safety equipment.

A gas turbine engine startup control device is a device that controls the fuel flow rate during startup.

In other words, when starting a gas turbine engine,
It is necessary to provide the amount of fuel necessary for ignition, but the fuel flow rate required for ignition varies depending on the temperature of the engine at the time of starting.When the engine temperature is low, the required fuel flow rate is large, and when the engine temperature is high, the required fuel flow rate is large. (Hot start) requires small fuel flow rate.

For this reason, if a constant fuel flow rate is always given during startup, it may not be possible to ignite or damage the turbine blades due to sudden ignition of the casing. It is emitted as unburned gas and causes air pollution, and this unburned fuel adheres to the heat exchanger and burns inside the heat exchanger due to the temperature rise after the engine ignites, damaging the heat exchanger. This can lead to various negative effects, such as:

Therefore, it is possible to configure the engine to measure the temperature of the engine at startup and provide the optimum flow rate for that temperature, or to set the fuel flow rate to the engine at startup to be low at first and increase over time as a function of time. There is an engine start control device that is configured to give a certain amount of heat to the engine, thereby reliably igniting the engine while eliminating the various adverse effects mentioned above.

In addition, the rotation speed control device for a gas turbine engine sets a target value for the rotation speed, and controls the fuel flow rate based on the difference signal between the signal corresponding to the set rotation speed and the signal corresponding to the actual rotation speed. It is.

In the gas turbine control device described above, if an abnormality occurs in the temperature detector or rotation speed detector as a sensor, or the fuel control valve or its drive mechanism as an actuator, the effect will not only affect the control device but also the gas turbine itself. There is a risk that this could lead to a major accident.

In order to cope with this problem, safety devices have been conventionally provided in gas turbine control devices.

That is, (1) Detects an abnormality in the control device and issues an alarm (however, the operation is performed by the operator).

(2) Detects an abnormality and reduces the amount of fuel supplied to bring it into a safe operating range.

(3) Detects an abnormality and cuts off the fuel supply to stop it.

Either one or a combination of these was done.

However, in the conventional system as described above, safety operations were performed by the operator, which caused inconveniences such as uncertainty and delays in operations.

The above-mentioned methods (2) and (3) have the disadvantage that they cannot be effective if the fuel flow rate regulating device becomes abnormal.

The present invention was developed with an eye on these points, and provides a safety device that eliminates the above-mentioned inconveniences, operates reliably without time delay, and operates even if actuators such as the fuel adjustment device are abnormal. The purpose is to

In order to achieve the above objectives, the present invention is characterized by automatically shutting off the power supply when an abnormality in the control device is detected, and
The purpose is to forcibly turn on the power in priority to the above-mentioned power cut-off in the event of instability before and immediately after starting.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a block diagram of the present invention.

11ri are sensors such as a temperature detector and a rotation speed detector, and 2 is actuators such as a fuel control valve drive mechanism.

Reference numeral 3 denotes an abnormality detection circuit which monitors signals from the sensors 1 and actuators 2 and issues a power cutoff signal S1 when an abnormality is detected.

4(/'i) The prohibition circuit receives the engine stop signal 41, start signal 42, etc. as input, and issues a power cut-off prohibition signal S2 that prohibits turning off the power while the engine is stopped and for a certain period of time after the engine has been started.

5 is a drive circuit, which receives the power cutoff signal S from the abnormality detection circuit 3.
1 and the power cut-off prohibition signal S2 from the prohibition circuit 4, the power supply relay 6 of the next stage is driven and controlled with priority given to the power cut-off prohibition signal S2.

In other words, power is supplied to the control device through the power relay 6 for a certain period of time before and after startup, and after that, if the control device is normal, the power is continued to be supplied, and if an abnormality occurs, the power relay 6 , then turn off the power.

FIG. 2 is a circuit diagram showing a specific embodiment of the present invention.

This is the case for a control device that performs control to keep the engine speed constant, and uses a pulse pickup PPU for detecting the rotation speed as a sensor and a fuel flow rate adjustment valve as an actuator.

COMP1 to coMP5 are voltage comparators, and when the + side terminal voltage is higher than the one side terminal voltage, the output is the power supply voltage 1 B, and when the opposite is the case, the output is zero.

First, the abnormality detection circuit will be explained.

Pulse pickup PPUU emits pulses with a frequency proportional to the rotation speed of the gas turbine.

Under normal conditions, this pulse charges capacitor C1 through diode D1.

Therefore, the voltage at one side of the voltage comparator COMP 1 is higher than the + side reference voltage 1, and the output is zero.

When the pulse pickup PPU becomes abnormal, the capacitor C1 is discharged through the resistor R1, and since there is no pulse, the voltage at one terminal of the voltage comparator COMP1 becomes zero, and the output becomes the power supply voltage 1B.

This detects an abnormality in the pulse pickup PPU.

Actuator abnormality detection is performed as follows.

With the set voltage of the VSETU actuator, the actuator normally moves such that the feedback voltage vFB detected by the potentiometer POT becomes VFB2VSET.

If the case is R2R3, R4-R5, R6-R7, one side terminal voltage of voltage comparator COMP2 (ri(VsET+v
2)/2, and the + side terminal voltage is VF'13/2.

Therefore, when VFR is greater than (VsET+v2), the output of voltage comparator COMP2 becomes the power supply voltage 10B.

Similarly, the output of voltage comparator COMP3 indicates that VFB is VSE
When the voltage is smaller than T+V3, the power supply voltage becomes 10B.

Here, if V2 is a positive voltage and V3 is a negative voltage, VFB is VS
When Vpm is V2 or more thicker than ET, the output of COMP2 is 10B, and when Vpm is V3 or more smaller than VSET, COM
The output of P3 is 10B.

That is, when the actuator is moving normally according to VSET, the voltage comparator COMP2. COMP
Both outputs of 3 are zero, and if the actuator becomes abnormal and stops moving according to the set voltage VSET,
An output signal of 10 B is generated from either of the voltage comparators COMP2 and COMP3.

When any one of the outputs of the voltage comparators COMP1 to COMP3 reaches 10 B, a voltage of 10 B is applied to the resistor R8 by the diodes D2 to D4.

The circuit consisting of resistor R8, capacitor c2, and voltage comparator COMP4 is a timer circuit. When all the inputs to resistor R8 are zero, the output of voltage comparator COMP4 becomes U+B, and when a voltage of 10 B is applied to resistor R8, capacitor C2 When it is charged and the charging voltage becomes higher than the positive reference voltage v4, the output becomes zero.

This output is the output S1 of the abnormality detection circuit.

That is, when both the sensor button and the actuator are normal, the output is 10 B, and when an abnormality occurs, the output becomes zero.

The above timer circuit is installed so that even if it malfunctions for a short time due to noise etc., it will not be judged as abnormal.
This is not necessary if noise countermeasures are taken in the previous stage.

Next, the prohibition circuit will be explained.

The switch SW is a switch that issues a signal to start and stop the gas turbine, and when it is on the upper side, it starts, and when it is on the lower side, it stops.

When stopped, the voltage across resistor R9 is zero, and voltage comparator COM
The positive terminal voltage of P5 is lower than the reference voltage V5, so the output of the voltage comparator COMP5 is zero.

When starting, the capacitor C3 is charged to the power supply voltage terminal B through the resistor R9)V5<+B, so after a certain period of time after starting, the voltage at the + side terminal of the voltage comparator COMP5 becomes higher than V5, and the output becomes the power supply voltage terminal B.

This output is the power cutoff prohibition signal S2.

i.e. 52 during stoppage and immediately after start-up;
-0, then S2-10B.

Next, the drive circuit button and power relay will be explained.

A power cutoff signal S1 is applied to the base of the transistor Q through the U resistor R1.

The collector terminal is connected to the power cutoff prohibition signal S2 through a forward diode D5.

When S2 is 10B, no current flows through diode D5, so power supply relay RY is driven only by transistor Q.

When the power cutoff signal S1 is a voltage element B, the transistor Q is turned on, the relay RY is energized, the contacts are closed, and power is supplied to the control device.

When the power cutoff signal S1 is zero, the transistor Q is turned off, and the power supply to the control device is cut off.

Next, when the power cut-off prohibition signal S2 is zero, the relay RY is driven through the diode D5, so power is supplied to the control device regardless of the power cut-off signal S1.

That is, the power cut-off prohibition signal S2 takes priority and the control device is forcibly turned on during a stop and a certain period of time after starting, and thereafter the power is turned off when an abnormality occurs according to the power cut-off signal S1. become.

When the power is turned off, not only does the fuel adjustment valve close, but all the fuel pumps, fuel cutoff valves, etc. operate to stop the fuel supply, ensuring that the gas turbine stops.

In addition to the above-mentioned embodiments, abnormality detection can be performed in the same way for temperature sensors, pressure sensors, variable nozzle actuators, etc. Also, if the power supply current is detected and an abnormally large current flows, It is also possible to turn off the power and replace it with a fuse.

As explained above, according to the present invention, when an abnormality occurs, it is possible to automatically cut off the power supply to the control device to reliably stop the gas turbine and ensure safe operation. Since the power is forcibly turned on for a certain period of time before and after startup, the power supply will not be cut off due to unstable operation during startup, and if a motor is used as an actuator, If an abnormality occurred, the motor would stop and an overcurrent would flow, potentially damaging the motor or motor drive circuit, but according to the present invention, the power can be automatically turned off in such cases. Since it has a sturdy case, it can prevent damage.
In addition to the safety of the gas turbine itself, it is also possible to protect the electrical system of the control device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, and FIG. 2 is a circuit diagram showing a specific embodiment of the present invention. 1... Sensors, 2... Actuators, 3... Abnormality detection circuit, 4... Prohibition circuit, 41... Stop signal , 42...
Starting signal, 5... Drive circuit, 6... Power relay, Sl... Power cutoff signal, S2...
...Power cutoff prohibition signal, C0AiP 1 to COMP5
...Voltage comparator, PPU...Pulse
Pick up, POT...Potentiometer, RY...Power supply relay, VSET...Actuator setting voltage, VFR...Feedback voltage.

Claims (1)

[Scope of utility model registration request] An abnormality detection circuit that detects abnormalities in the sensors and actuators of the gas turbine control device and issues a power cutoff signal to turn off the power to the control device, and a gas turbine start/stop control switch that performs a certain A prohibition circuit that emits a power cut-off prohibition signal that prohibits turning off the power, and when both of the above signals are received, the power supply circuit is controlled by giving priority to the power cut-off prohibition signal, and the power is cut off without outputting the power cut-off prohibition signal. A safety device for a gas turbine control device, comprising: a drive circuit that controls a power circuit to turn off the power when a signal is output.