JP2586623B2 - Control device for gas turbine engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention includes a pressure sensor for detecting a pressure downstream of a compressor in a gas turbine engine such as a two-shaft gas turbine engine, and a fuel supply amount based on the pressure sensor. The present invention relates to a fail-safe device for calculating and controlling a gas turbine.

[Conventional technology]

A two-shaft gas turbine engine for an automobile, wherein a gas generator having a compressor and a compressor turbine and a power turbine connected to a vehicle drive shaft are formed by different shafts, and a compressor turbine from a fuel device is provided. There is known a system in which the combustion gas that drives the power turbine drives a power turbine through a variable nozzle. Under normal conditions, the gas generator configures the fuel supply amount to the combustor and the variable nozzle so that the outlet temperature (T ₆ ) of the power turbine becomes the target value T _6set in a state where the rotation speed is constant and the efficiency is maximized. The angle of the blade is controlled.

On the other hand, during transient operation, the response of the sensor (thermocouple) that detects the outlet temperature of the power turbine becomes a problem, so the outlet temperature T ₄ of the combustor is switched to the control target instead of T ₆ , and the rotation speed of the gas generator is changed. Is controlled so that the speed of the fuel is increased to a predetermined value. And the outlet temperature T ₄ of the combustor
From the compressor outlet pressure P ₃ and the target value T _4set of the combustor outlet temperature, the amount of inhaler G
calculates a, and calculates the amount of fuel supplied to the engine from the measured values T ₃₅ of the intake air amount and the combustion inlet air temperature. For example, see JP-A-60-35132.

[Problems to be solved by the invention]

A semiconductor pressure sensor is generally used as a sensor for measuring the outlet pressure of a compressor.However, when the operation of this type of semiconductor pressure sensor becomes abnormal, the output level of the semiconductor pressure sensor becomes low regardless of the pressure change. It is common to exhibit an abnormal state of sticking to a signal or a high signal.
Therefore, if the operation of the sensor is stuck in the Low state, the operation is continued with the fuel supply amount kept at a minimum, and in the case of an abnormality stuck in the High state, the operation is continued with the fuel supply amount at the maximum. As a result, there is a possibility that the engine stops or the rotation of the engine abnormally increases.

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

[Means for solving the problem]

In FIG. 1, the gas turbine engine of the present invention calculates the fuel supply amount to the gas turbine engine A from the air pressure downstream of the compressor as one of the state factors and, if necessary, other state factors. Means B
Control means B 'for controlling the gas turbine based on the calculated fuel supply amount, pressure detecting means C for detecting the pressure downstream of the compressor, and pressure downstream of the compressor predicted from various state factors of the gas turbine. Pressure calculating means D for calculating a value; determining means E for determining whether the pressure detecting means C is abnormal by comparing the detected value of the pressure by the pressure detecting means C with the calculated value of the pressure by the pressure calculating means D; A means F for switchingly connecting the control means B to a pressure detecting means C and a pressure calculating means D depending on whether the operation is normal or abnormal.

[Action]

In a normal state, the fuel supply amount is calculated based on the value detected by the pressure detecting means C, and the control means B 'controls the gas turbine. In an abnormal state, the fuel supply amount is calculated based on the calculated value by the pressure calculating means D. Control the gas turbine.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail 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, HE is a heat exchanger, CC is a combustor, and CT is a compressor turbine.
The CT is directly connected to the CT via a rotating shaft 100, and fuel is supplied to the combustor CC via the actuator A1. The intake air is compressed by the compressor C and heated by the heat exchanger HE.
The fuel is mixed and burned in the combustor CC, and the combustion gas rotates the compressor turbine CT. The compressor turbine CT and the compressor C may be collectively referred to as a gas generator GG, and the number of revolutions of the compressor turbine CT determines the degree of compression of the compressor C.
The combustion gas that has driven the compressor turbine CT drives the power turbine (output turbine) PT via the variable nozzle VN adjusted by the actuator A2, and then is discharged to the atmosphere as exhaust gas via the heat exchanger HE. A front gear 3 is connected to the rotating shaft 100, and a fuel pump, an oil pump, a starter motor, and the like 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 the automatic transmission A The transmission is transmitted to the transmission mechanism T via a / T torque converter T / C, and is converted into a rotational speed according to the shift state to be an axle drive output. Also, this torque converter T /
C has a lock-up clutch L / C.

The control circuit 10 for controlling the gas turbine GT and the automatic transmission A / T has an input interface IN for analog signals.
a, an input interface INd for digital signals, an analog-digital converter A / D for digitally converting a signal from the input interface INa, a central processing unit CPU, a random access memory RAM, a read-only memory ROM, and an output circuit OUT. And are connected by a bus line 11, respectively.

The gas generator GG is used for a twin-shaft gas turbine engine.
Speed sensor SN ₁ for detecting a rotational speed N ₁ of the compressor C
Temperature sensor ST ₃ for detecting the outlet temperature T ₃ of the compressor C
Compressor outlet pressure sensor SP that detects the outlet pressure P _3
3 , a temperature sensor ST ₃₅ that detects the outlet temperature T ₃₅ of the heat exchanger HE,
Temperature sensor ST ₆ that detects the outlet temperature of the Pawatabin PT, speed sensor for detecting the rotational speed sensor SN _3, and the axle driving rpm N _P for detecting the rotational speed N ₃ of the gas turbine GT having passed through the reduction gear R / G SN _P and the like are provided. Is a relationship between the character and the subscript wherein the intake pressure of the position of the second view P _3, the temperature of the location of the so called T _4, attached a subscript in the intake pressure P and temperature T, ○ Indicates the intake pressure P and temperature T at the positions enclosed by the circles, the rotation speed of the rotation shaft of the gas generator GG is N ₁ , and the rotation speed of the output shaft of the power turbine PT via the reduction gear R / G is N ₃ Is represented by

The analog signal input interface INa receives the signals N ₁ , N ₃ , N _P , P ₃ , T ₃₅ , and T ₆ from the above-described sensors and analog signals from the accelerator pedal, and the digital signal input interface INd. Are input with 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.

On the other hand, from the output circuit OUT, a signal Gf indicating the fuel flow rate to the actuator A1 of the combustor CC, a signal α _S indicating the opening degree of the variable nozzle VN to the actuator A2,
Signal S ₃ that instructs the on-off of the lock-up clutch L / C of the torque converter T / C, transmission signal S _1, S ₂ and throttle wire signal theta _TH, etc. of the transmission mechanism T is output.

A feature of the present invention is a failure of a compressor outlet pressure sensor SP ₃ , which detects a compressor outlet pressure P _3, which is a state factor for controlling operated factors such as a fuel supply amount and a variable nozzle angle in a gas turbine engine. Be safe. That is, it the current output value of the sensor SP ₃ is regarded as abnormal if it is outside a large sensor SP ₃ and normal if a reasonable range compared with values predicted from the state of the other gas turbine. Hereinafter, control of the gas turbine engine incorporating the fail-safe function will be described. The general flow of this control is the same as that of Japanese Patent Application No. 63-18855, which was filed by the applicant of the present invention. It is determined whether the engine is stationary or not. when the efficiency is maintained near a constant value as a maximum), control based on the outlet temperature T ₆ of the power turbine is performed. The control mainly the inlet temperature T ₄ of the compressor turbine for during transient operation poor response of the sensor ST ₆ for detecting the temperature T ₆ is performed. At the beginning of the return from the transient state to the steady state, the sensor ST
Control a target of T ₄ is briefly run from the response of ₆ is not good. Hereinafter, the outline of the operation of the control circuit 10 for realizing this control will be described with reference to the flowcharts of FIGS.

In step 401, the operating state parameters of the engine are input to the control circuit 10. The operating state parameters include, for example, the rotation speed N ₁ of the gas generator GG, the accelerator opening θ _acc , the outlet temperature T ₆ of the compressor turbine PT, the outlet temperature T ₃₅ of the heat exchanger HE, and the output pressure of the compressor C.
P _3, the input rotational speed N _3, etc. of the automatic transmission A / T.

Step 401-406 are routine for failsafe pressure sensor ST _6. Step 402 The expected value from the rotational speed N ₁ of the compressor outlet pressure of the gas generator
P ₃ ′ is calculated. That is, the rotation speed N ₁ of the gas generator
And is related to FIG. 5 between the outlet pressure P ₃ of the compressor C, it can be predicted approximately the outlet pressure P ₃ of the compressor C than the rotational speed N ₁ of the gas generator. Steps
At 403, it is determined whether P ₃ ≧ P ₃ ′ + α, and at step 404, P ₃ <P ₃ ′
-Α is determined. Here α is a suitable value for determining the dead zone, a pressure sensor SP ₃ If the measured value P ₃ of the sensor SP ₃ there is no operation value and P ₃ 'so large difference is judged to be normal, the measurement of the sensor SP ₃ If the value P ₃ there is large discrepancies between calculated values and P ₃ 'it can be determined that there is an abnormality in the pressure sensor SP _3. If the pressure sensor SP ₃ is judged to be normal proceeds to step 406, the detected value P ₃ of the pressure sensor SP ₃ are used as is, in the case of abnormal Step 40
5, the value obtained by subtracting the predetermined value α constituting the dead zone from the expected value P ₃ ′ calculated in step 402, that is, P ₃ ′ −α
There is replaced by a pressure value P _3.

The fuel supply amount Gf as the manipulated factor is obtained after step 407.
And a control routine of the variable nozzle VN. This routine is the same as that of the aforementioned Japanese Patent Application No. 63-188554. Step 302
Then, a target value _N1set of the rotation speed of the gas generator GG, which is a function of the accelerator opening θ _acc , is calculated.

Then, in step 303, it is determined from the operating state parameters of the engine whether or not the gas generator GG is in a steady state. The determination between the transient state and the steady state of the engine may be made based on the amount of depression of the accelerator pedal, the amount of change of the accelerator pedal within a unit time, the rate of change of the rotation speed of the rotating shaft of the gas generator GG, and the like.

When it is determined that the gas generator GG is in the steady state (YES), the process proceeds to step 304. When the steady state control is performed in the subsequent steps 304 to 307, and it is determined that the gas generator GG is in the transient state. (NO) advances to step 308, and in the following step 309 to step 311, the control of the transient state is performed.

In the steady state, the time counter T is set in step 304.
_The time is counted by adding 1 to the _GAC , and it is determined whether or not the time counted in the subsequent step 305 is greater than the reference value Kt, that is, whether or not a predetermined time has elapsed since the transition to the steady state. You. When the predetermined time has elapsed since the transition to the steady state (T _GAC> Kt), that is, when a stable steady state, the process proceeds to step 307, is controlled based on the outlet temperature T ₆ of Pawatabin. At this time, the response of the temperature sensor that measures the outlet temperature of the compressor turbine does not matter, so that the outlet temperature T ₆ of the power turbine is set to the target value T ₆ while the rotation speed N ₁ of the gas generator GG is kept constant. and controls the degree of opening alpha _S of the fuel flow rate Gf and the variable nozzle VN so that _6Set.

On the other hand, when the transient state, the value of the time counter T _GAC at step 308 is cleared and continues at step 309 with respect to the rotational speed of the target value N _1set arithmetic gas generator GG at step 302, the current gas generator GG rotational speed N ₁ whether small, i.e., transients or acceleration state or deceleration state is determined. Then, when accelerating (N _1set
> N ₁ ), proceed to step 310, where the gas generator G
G is controlled based on the outlet temperature T ₄ of the combustor CC. The control at this time is such that the outlet temperature T ₄ of the combustor CC is set to the target value T while accelerating the gas generator GG to increase its rotation speed N _1.
The fuel flow rate Gf is controlled to be 4 sets. Further, when the deceleration state (N _1set ≦ N ₁₎ proceeds to step 311, the control of the deceleration is performed. At this time, since the outlet temperature T ₄ of the CC of the combustor can not be measured well system by the temperature sensor directly to the 1,000 degrees or more high temperature, by measuring the compressor outlet pressure P ₃ by the pressure sensor SP ₃ indirectly know an exit temperature T _4, which is for controlling the fuel flow rate Gf such that the target value T _4set. That is, the intake air amount Ga is obtained from the compressor outlet pressure P ₃ and the combustor outlet temperature target value T _4set, and the obtained intake air amount Ga and T
Can be calculated and _4set, the fuel amount Gf supplied from the air temperature T ₃₅ Metropolitan the engine in the combustion inlet.

When the prescribed time has shifted to the steady state not expired (T _GAC ≦ Kt), the process proceeds to step 306 from step 305, the control gas generator GG is based on the outlet temperature T ₄ of the combustor CC Is done. That is, since at this time there is a problem in the response of the temperature sensor T ₆ similarly to the time of acceleration, briefly,
Control of opening alpha _S of the variable nozzle VN is performed in addition to the fuel flow rate Gf of the outlet temperature T ₄ of the combustor CC in the base. Fuel flow
The control of Gf is as described above. As described in detail in the earlier application, the control of the variable nozzle VN calculates a target value Gf1 of the fuel flow rate according to the rotation speed of the gas generator, compares this target value Gf1 with the actual fuel flow rate Gf, closing control of the opening degree alpha _S of the variable nozzle VN is performed according to the magnitude.

Step 306, Step 307 proceeds to step 312 when step 310 or step 311 is completed, the opening degree alpha _S and the fuel flow rate Gf, etc. computed variable nozzle VN is outputted to the gas turbine GT. Then, the time is adjusted by a predetermined cycle time in step 313 of FIG. 3, and after the time adjustment, the process returns to step 408 to repeat the above-described control.

〔The invention's effect〕

In the present invention, the pressure at the compressor outlet is calculated based on the state factor of the gas turbine, for example, the rotation speed of the gas generator, and the calculated value is compared with the measured value of the pressure sensor.
When it is determined that there is an abnormality, the fuel supply amount is calculated based on the calculated value without using the sensor value, and the gas turbine is controlled based on the calculated fuel supply amount. It is possible to prevent abnormalities such as the occurrence of an error.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is an overall schematic diagram showing a configuration of a control device for a two-shaft gas turbine engine of the present invention, and FIGS. 3 and 4 are control diagrams of FIG. FIG. 5 is a flowchart showing an outline of a control procedure of the circuit, and FIG. 5 is a diagram showing a relationship between the number of revolutions of the gas generator and a compressor outlet pressure. 10 Control circuit, 100 Gas generator shaft 101 Power turbine shaft, C Compressor CC Combustor, CT Compressor turbine HE Heat exchanger A / T Automatic transmission A1, A2 ...... actuator, VN ...... variable nozzle PT ...... Pawatabin, SP ₃ ...... pressure sensor _{SN 1; SN 3, SN P} ...... speed sensor _{ST 3, ST 35, ST 6} ...... temperature sensor, VN ...... Variable nozzle

Claims (1)

(57) [Claims] 1. A gas turbine engine, comprising means for calculating a fuel supply amount to a gas turbine engine from an air pressure downstream of a compressor as one of the state factors and other state factors as required. Control means for controlling the gas turbine from the calculated fuel supply amount, pressure detecting means for detecting the pressure downstream of the compressor, and calculating a pressure value downstream of the compressor predicted from various state factors of the gas turbine. Pressure calculating means; means for determining whether the pressure detecting means is abnormal by comparing the detected value of the pressure by the pressure detecting means with the calculated value of the pressure by the pressure calculating means; A means for selectively connecting the amount calculating means to the pressure detecting means and the pressure calculating means, and calculating a fuel supply amount based on a value detected by the pressure detecting means in a normal state Te controls the gas turbine, abnormality control apparatus for a gas turbine engine and controlling the gas turbine by calculating the fuel supply amount by calculation value by the pressure calculating means for.