JPH02169827A - Control device for gas turbine engine - Google Patents

Abstract

PURPOSE:To maintain normal driving without stopping a vehicle by controlling a gas turbine, when abnormality is detected with a pressure detector, based on the fuel feed rate calculated with a calculation means. CONSTITUTION:An estimated value P3' of an outlet pressure of a compressor is calculated in a control circuit 10 from the revolution N1 of a gas generator shaft 100. When a value P3 measured with a pressure sensor SP3 does not differ much from the calculated value P3', the pressure sensor SP3 is determined to be normal, and when differs much, the pressure sensor is determined to be abnormal. When the pressure sensor SP3 is determined to be normal, the measured value P3 is directly used. In the case of abnormality, the calculated value P3' deducted by a specified value which constitute a nonsensitive zone replaces the pressure value P3. As a gas turbine GT is controlled based on the fuel feed rate calculated from the pressure value P3, abnormality such as the stop or overrunning of the engine is prevented.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention includes a pressure sensor that detects the pressure downstream of a compressor in a gas turbine engine such as a two-shaft gas turbine engine, and adjusts the amount of fuel supplied based on the pressure. This invention relates to fail-safe systems for calculating and controlling gas turbines.

[Conventional technology]

A two-shaft gas turbine engine for automobiles, in which a gas generator including a compressor and a compressor turbine, and a power turbine connected to a vehicle drive shaft are configured by separate shafts, and the compressor turbine from the combustor A system is known in which the combustion gas that drives the power turbine is passed through a variable nozzle to drive a power turbine. During steady state, the gas generator controls the amount of fuel supplied to the combustor and the variable nozzle so that the outlet temperature (T6) of the power turbine becomes the target value T 6 s e t when the rotation speed of the gas generator is kept constant to maximize efficiency. The angle of the constituent blades is controlled.

On the other hand, during transient operation, the responsiveness of the sensor (thermocouple) that detects the outlet temperature of the power turbine becomes a problem, so instead of T6, the control target is changed to the combustor outlet temperature T4.
The amount of fuel is controlled so that the rotational speed of the gas generator is increased to a predetermined value. Since the combustor outlet temperature T4 cannot be directly known, the intake air amount Ga is calculated from the compressor outlet pressure P3 and the target value T of the combustor outlet temperature, 8°, and this intake air amount and combustion The amount of fuel supplied to the engine is calculated from the measured value T3S of the air temperature at the engine inlet. For example, JP-A-60-351
See No. 32.

[Problem to be solved by the invention]

Semiconductor pressure sensors are commonly used as sensors to measure the outlet pressure of a compressor. However, in this type of semiconductor pressure sensor, if its operation becomes abnormal, its output level will be low regardless of pressure changes. signal or flig
It is normal for the device to exhibit an abnormal state of being stuck to the h signal. Therefore, in the case of an abnormality in which the sensor operation remains in the Low state, the fuel supply amount remains at the minimum, and in the case of an abnormality in which the sensor operation remains in the old gh state, the operation continues with the fuel supply amount at the maximum. As a result, the engine may stop or the engine rotation may abnormally increase.

An object of the present invention is to enable normal running of a vehicle to be maintained without stopping the vehicle when there is an abnormality in a pressure sensor.

[Means to solve the problem]

In FIG. 1, the gas turbine engine of the present invention has the following features:
Means B calculates the fuel supply amount to the gas turbine engine from the air pressure downstream of the compressor as one of the condition factors and other condition factors as necessary; A control means B' for controlling the turbine, a pressure detection means C for detecting the pressure downstream of the compressor, a pressure calculation means for calculating the pressure value downstream of the compressor predicted from various state factors of the gas turbine, and pressure a determining means E for determining whether or not the pressure detecting means C is abnormal by comparing the pressure detected by the detecting means C with the pressure calculated by the pressure calculating means; and the controlling means B for determining whether the pressure detecting means C is abnormal or not. The pressure detecting means C and the pressure calculating means are provided with means F for selectively connecting the pressure detecting means C and the pressure calculating means.

[Effect]

During normal operation, the fuel supply amount is calculated based on the value detected by the pressure detection means C, and the control means B' controls the gas turbine.
In the event of an abnormality, the fuel supply amount is calculated based on a value calculated by the pressure calculation means, and the control means B' controls the gas turbine.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 shows the configuration of an embodiment of the present invention mounted on a vehicle with an automatic transmission. In the figure, C is a compressor, Hε is a heat exchanger, CC is a combustor, and CT is a compressor turbine. The compressor C and compressor turbine CT are directly connected by a rotating shaft 100, and the combustor CC is connected to an actuator via fuel is being supplied.

The intake air is compressed by compressor C, and then transferred to heat exchanger T1.
It is heated at ε, mixed with fuel and combusted in the combustor CC, and the combustion gas rotates the compressor turbine CT. This compressor turbine CT and compressor C
are sometimes collectively referred to as gas generators GG, and the rotation speed of this compressor turbine CT determines the degree of compression of the compressor C. compressor turbine CT
The combustion gas that drives the power turbine (output turbine) PT passes through a variable nozzle VN adjusted by an actuator A2, and then passes through a heat exchanger 11ε as exhaust gas and is discharged to the atmosphere. A front gear 3 is connected to the rotating shaft 100, and a fuel pump, an oil pump, a starter motor, etc. are connected to the front gear 3. The rotating shaft 101 of the power turbine PT is connected to an automatic transmission A/T via a reduction gear R/G, and the rotation of the power turbine PT of the gas turbine GT is reduced by the reduction gear R/G and connected to the automatic transmission A. /T is transmitted to the transmission mechanism T via the torque converter T/C, and is converted to a rotational speed according to the shift state, and becomes an axle drive output. Further, this torque converter T/C is provided with a lock-up clutch L/C.

The control circuit 10 that controls the gas turbine GT and the automatic transmission A7T includes an input interface INa for analog signals and an input interface INd for digital signals.
, an analog-to-digital converter A/D that digitally converts the signal from the input interface INa.

Central processing unit CPU, random access memory RA
M, read-only memory ROM, and output circuit O
There are UTs, etc., and each is connected by a pass line 11.

In addition, a gas generator GG is used for a two-shaft gas turbine engine.
A rotation speed sensor SN, which detects the rotation speed N1 of.

Temperature sensor S that detects the outlet temperature T of the compressor C
Compressor outlet pressure sensor sp, which detects the outlet pressure P of the compressor C, and the outlet temperature T3 of the heat exchanger O
Temperature sensor 5T3S detects the outlet temperature of the power turbine PT, temperature sensor STs detects the outlet temperature of the power turbine PT, rotation speed sensor SN3. and a rotation speed sensor SN for detecting the axle drive rotation speed N, and the like. Regarding the relationship between letters and subscripts, the subscripts attached to the intake pressure P and temperature T are as follows: In Fig. 2, the intake pressure at the position of ■ is P3, the temperature at the position of ■ is T, and so on. It shows the intake pressure P and temperature T at the position of the number surrounded by O, the rotation speed of the rotating shaft of the gas generator GG is expressed as Nl, and the rotation speed of the output shaft of the power turbine PT via the reduction gear R/G is expressed as N. It will be done.

The analog signal input interface INa receives signals N, , N, , N, , P3 . T33. T.

Analog signals from the engine and accelerator pedal are input, and digital signals such as an on/off signal from a key switch, a shift position signal from a shift lever, and a brake signal from a brake are input to an input interface INd for digital signals.

On the other hand, from the output circuit OUT, a signal Gf instructs the fuel flow rate to the actuator A1 of the combustor CC.

A signal α5 that instructs the opening degree of the variable nozzle VN to the actuator A2, a signal S3 that instructs the on/off of the lock-up clutch L/C of the torque converter T/C, a shift signal S, S2 of the transmission mechanism T, and a throttle wire. signal θ
T11 etc. are output.

The present invention is characterized by a compressor outlet pressure sensor SP3. It is fail-safe. That is, if the current output value of sensor SP3 is within a reasonable range compared to values predicted from other gas turbine conditions, sensor SP3 is considered normal (if it is out of the range, it is considered abnormal). The control of a gas turbine engine incorporating this fail-safe function will be explained below.The general flow of this control is the same as that of Japanese Patent Application No. 63-485547, which is the earlier application filed by this applicant.
It is determined whether the engine is stationary or not, and when the engine is stationary (the rotational speed of the gas generator is maintained near a constant value that maximizes the efficiency of the compressor), control is performed based on the outlet temperature T6 of the power turbine. It will be done. On the other hand, during transient operation, the response of the sensor ST that detects the temperature T6 is not good, so control is performed mainly based on the inlet temperature T4 of the compressor turbine. Since the responsiveness of the sensor STs is not good at the beginning of the return from the transient state to the steady state, control aiming at T4 is executed for a while. below,
An overview of the operation of the control circuit 10 that implements this control will be explained using the flowcharts of FIGS. 3 and 4.

In step 401, engine operating state parameters are input to the control circuit 10. These operating state parameters include, for example, the rotational speed Nl of the gas generator CG, the accelerator opening θ5cc-t, the outlet temperature T6 of the compressor turbine PT, the outlet temperature T35 of the heat exchanger HE, the outlet pressure Pj of the compressor C, and the automatic transmission A. /T input rotation speed N
It is 3rd prize.

Steps 401-406 are a fail-safe routine for the pressure sensor STa. In step 402, an estimated value P,1 of the compressor outlet pressure is calculated from the rotational speed N1 of the gas generator. That is, there is a relationship shown in FIG. 5 between the rotational speed N1 of the gas generator and the outlet pressure P of the compressor C, and the rotational speed N1 of the gas generator,
Therefore, the outlet pressure P of the compressor C can be approximately predicted.

In step 403, it is determined whether P, ≧P, '+α, and in step 404, it is determined whether Ps<P3'-α. Here α is an appropriate value that determines the dead zone, and the sensor S
If the measured value P of P3 is not significantly different from the calculated value P,', the pressure sensor SP3 is judged to be normal.If the measured value P3 of sensor SP3 is significantly different from the calculated value P,', the pressure sensor SP3 is judged to be normal. It can be determined that there is an abnormality in the pressure sensor SP.

If the pressure sensor SP is determined to be normal, proceed to step 4.
The process proceeds to step 06, where the detected value P3 of the pressure sensor SP is used as is, and in the case of an abnormality, the process proceeds to step 405, where the value obtained by subtracting the predetermined value α constituting the dead zone from the expected value P3' calculated in step 402, i.e. P, -α is replaced by the pressure value P,.

Step 407 and subsequent steps are the fuel supply amount G as the operated factor.
The control routine for the variable nozzle VN and the variable nozzle VN is shown.

This routine is the same as that of the above-mentioned Japanese Patent Application No. 185547/1983. In step 302, a target value N of the rotation speed of the gas generator GG, which is a function of the accelerator opening degree θacc, is determined.
+s. , is calculated.

Then, in step 30i, it is determined from the operating state parameters of the engine whether the gas generator GG is in a steady state. The transient state and steady state of the engine may be determined based on the amount of depression of the accelerator pedal, the amount of change in the accelerator pedal within a unit time, the rate of change in the rotational speed of the rotating shaft of the gas generator CG, and the like.

When it is determined that the gas generator CG is in a steady state (YES), the process advances to step 304, followed by step 30.
Steady state control is performed from step 4 to step 307, and when it is determined that the gas generator GG is in a transient state (NO), the process proceeds to step 308, and the subsequent step 30
From step 9 to step 311, transient state control is performed.

In the steady state, the time counter T is set in step 304.
. Add 1 to AC to count time, followed by step 30
It is determined whether the time counted in step 5 is greater than the reference value Kt, that is, whether a predetermined time has elapsed since the transition to the steady state. When a predetermined time has elapsed since the transition to the steady state (TCAC>Kt), that is, when the steady state is stable, the process proceeds to step 307, where control is performed based on the outlet temperature T6 of the power turbine. In this control, the responsiveness of the temperature sensor that measures the outlet temperature of the compressor turbine is not a problem, so the outlet temperature T6 of the power turbine is set to the target value of 76 m with the rotational speed N of the gas generator CG constant. Fuel flow ff so that g +
1Gf and the opening degree α of the variable nozzle VN.

On the other hand, in a transient state, the time counter T is counted in step 308. After the value of AC is cleared, in the following step 309, it is determined whether the current rotation speed NI of the gas generator CG is smaller than the target value N l * e l of the rotation speed of the gas generator GG calculated in step 302. That is, it is determined whether the transient state is an acceleration state or a deceleration state. If the acceleration state is present (Nl-7>Nl), the process proceeds to step 310, and the gas generator CG is controlled based on the outlet temperature T4 of the combustor CC. The control at this time is to accelerate the gas generator GG and increase its rotational speed N, while increasing the outlet temperature T4 of the combustor CC to the target value T41.
This is to control the fuel flow rate G' so that it becomes .

Further, when the vehicle is in a deceleration state (N l m s +≦N), the process proceeds to step 311, and control during deceleration is performed. At this time, since the outlet temperature T4 of the CC of the combustor becomes a high temperature of i,ooo degrees or higher, it cannot be directly measured accurately with a temperature sensor, so by measuring the compressor outlet pressure P with a pressure sensor SP3. The outlet temperature T4 is indirectly known and the fuel flow ff1Gf is controlled so that this becomes the target value T4xsl. That is, compressor outlet pressure P3 and combustor outlet temperature target value T4□
6. Calculate the intake air amount Ga from and, and calculate the intake air ff
The amount of fuel Gf supplied to the engine can be calculated from 1G&, T 4 m e L, and the air temperature T35 at the combustor inlet.

If a predetermined period of time has not yet passed since the transition to the steady state (ToAC≦Kt), the process proceeds from step 305 to step 306, where the gas generator GG is controlled based on the outlet temperature T4 of the combustor CC. . That is, at this time, there is a problem in the responsiveness of the temperature sensor T6 as in the case of acceleration, so for a while, the opening degree α of the variable nozzle VN is adjusted based on the outlet temperature T4 of the combustor CC in addition to the fuel flow ff1Gf.
, is controlled. The control of the fuel flow fflGf is as described above.

In addition, the control of the variable nozzle VN is as detailed in the previous application.
Target value G of fuel flow rate according to the rotation speed of the gas generator
fl is calculated, this target value Gfl is compared with the actual fuel flow rate Gf, and the opening degree α of the variable nozzle is adjusted depending on the magnitude of the target value Gfl.
, opening/closing control is executed.

When step 306, step 307, step 310 or step 311 is completed, proceed to step 312,
The calculated opening degree α of the variable nozzle VN, fuel flow rate G, etc. are output to the gas turbine GT.Then, the time is adjusted by a predetermined cycle time in step 313 of FIG. Returning to step 408, the aforementioned control is repeated.

〔Effect of the invention〕

In this invention, the pressure at the compressor outlet is calculated based on the state factors of the gas turbine, such as the rotational speed of the gas generator, and the calculated value is compared with the measured value of the pressure sensor, and if it is determined that there is an abnormality, the sensor value is not used. In addition, since the fuel supply amount is calculated based on the calculated value and the gas turbine is controlled based on the calculated fuel supply amount, it is possible to prevent abnormalities such as the engine stopping or over-speeding.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is an overall schematic diagram showing the configuration of the control device for the two-shaft gas turbine engine of the present invention, and FIGS. 3 and 4 are the control shown in FIG. FIG. 5 is a flowchart showing an outline of the circuit control procedure, and FIG. 5 is a diagram showing the relationship between the rotation speed of the gas generator and the compressor outlet pressure.

Claims (1)

[Claims] 1. Means for calculating the amount of fuel supplied to the gas turbine engine from the air pressure downstream of the compressor as one of its condition factors and other condition factors as necessary, and this calculation. a control means for controlling the gas turbine based on the fuel supply amount; a pressure detection means for detecting the pressure downstream of the compressor; and a pressure calculation means for calculating the pressure value downstream of the compressor predicted from various state factors of the gas turbine. a means for determining whether or not the pressure detecting means is abnormal by comparing the pressure detected by the pressure detecting means with the pressure calculated by the pressure calculating means; and the fuel supply amount calculating means depending on whether the pressure is normal or abnormal. has means for selectively connecting the fuel supply to the pressure detection means and the pressure calculation means, and when normal, the gas turbine is controlled by calculating the fuel supply amount based on the value detected by the pressure detection means, and when abnormal, the amount calculated by the pressure calculation means is calculated. 1. A gas turbine engine control device that controls a gas turbine by calculating a fuel supply amount.