JPH03141830A - Controller of doble axis gas-turbine engine - Google Patents

Abstract

PURPOSE:To improve responsiveness of opening control of a variable nozzle by converting the temperature at inlet of a target compressor turbine to a target pressure ratio, and controlling the opening of the variable nozzle so that a value of the pressure ratio becomes equal to the target pressure ratio. CONSTITUTION:Outlet pressure P3 of a compressor C, outlet pressure P5 of a compressor turbine CT and the number of revolutions N1 of a gas generator GG are detected by respective sensors SP3, SP5, SN1. Temperature T4 is calculated by using the relation between the number of revolutions N1 and the inlet temperature T4 of the compressor turbine CT. When the temperature T4 is not at the target value, and an engine PT is under a normal condition, a pressure ratio P3/P5 is compared with a target value of a memory means 1 and a comparison means 2. The opening of a variation nozzle VN is adjusted by a control means 3 through stably maintaining the number of revolutions N1 of the compressor C so that the temperature T4 becomes the target value. Thereafter the calculation of temperature T4 is not performed, but adjusted only by the pressure P3/P5. In this way, the responsiveness of control can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a two-shaft gas turbine engine, and in particular, to a control device for estimating the outlet temperature of a compressor turbine of a two-shaft gas turbine engine without using a temperature sensor. The present invention relates to a control device that controls an engine.

[Conventional technology]

Two-shaft gas turbine engines have the following characteristics: they can run at high speeds continuously with low vibrations, can use a variety of fuels such as kerosene and methanol, and have large low-speed torque characteristics suitable for automobiles. Therefore, in recent years, practical application as an engine for automobiles has been considered.

FIG. 7 shows an example of a general configuration of a conventional two-shaft gas turbine engine GT installed in an automobile equipped with an automatic transmission.

In the diagram, C is a compressor, HE is a heat exchanger, and CC
is a combustor, CT is a compressor turbine, the combustor C and the combustor turbine CT are directly connected by a rotating shaft, and fuel is supplied to the combustor CC via an actuator ^1. Intake air (intake air) is compressed by a compressor C, heated by a heat exchanger HE, mixed with fuel and combusted in a combustor CC, and the combustion gas rotates a compressor turbine CT. The compressor turbine CT and the compressor C are collectively called a gas generator GG, and the rotation speed N1 determines the degree of compression of the compressor C. The combustion gas that drove the compressor turbine CT passes through a variable nozzle VN adjusted by an actuator 82 to a power turbine (output turbine) PT.
After driving, the gas passes through the heat exchanger HE and becomes exhaust gas.

The rotation of the output turbine PT is decelerated by the reduction gear R/G and transmitted to the automatic transmission aA/T, converted to a rotation speed according to the shift state, and then transmitted to the wheels W via the differential gear.

The control circuit C0NT that drives the actuators AI and A2 receives the accelerator pedal opening and engine operating state parameters from a sensor (not shown).
The control circuit C0NT controls the fuel flow rate and the variable nozzle VN via actuators At and A2 according to the operating state of the engine.
Adjust the O opening.

In addition, in general, the subscripts attached to the intake pressure P and temperature T are the positions of numbers surrounded by circles, such as P3 for the intake pressure at position ■ in Figure 7, and T4 for the temperature at position ■. The rotational speed of the rotational shaft of the gas generator GG is represented by N3, and the rotational speed of the output shaft of the power turbine PT via the reduction gear R/G is represented by N3.

In the two-shaft gas turbine engine configured as described above, during acceleration, deceleration, and steady operation of the gas generator GG, the outlet temperature of the combustor CC (inlet temperature of the compressor turbine) T4 and the outlet temperature of the power turbine T6 are controlled. Combine and control. For example, when the engine shifts from acceleration to steady state, the gas generator G
Conventionally, control is performed to keep the outlet temperature T4 of the combustor CC constant during acceleration of G, and control to keep the outlet temperature T6 of the power turbine or the outlet temperature T of the combustor CC constant when the gas generator GG is steady. .

The inlet temperature T4 of the compressor turbine CT is so high that it is difficult to directly detect it.

Therefore, the inlet temperature T of this compressor turbine CT,
Several methods have been proposed to calculate .

For example, JP-A-55-12263 and JP-A-57-
49746, the outlet temperature T of the output turbine PT
, and from that temperature the compressor turbine CT
The inlet temperature T4 is estimated.

However, when estimating the inlet temperature T4 of the compressor turbine CT, the conventional method requires a temperature parameter, but measuring the temperature inside the engine is difficult due to the response delay of the thermocouple used as a temperature sensor and the heat exchange Vessel HE
There is a problem in that it is generally difficult to obtain accurate information due to the temperature distribution caused by the combustor CC and the like. In particular, the error increases when the engine accelerates or decelerates, and sometimes the inlet temperature T4 of the compressor/nosa turbine CT exceeds a permissible value, causing problems such as melting of the turbine and damage to the engine.

Therefore, in estimating the inlet temperature T4 of the compressor turbine CT, the present inventor did not use the temperature parameter, but utilized the characteristics of the two-shaft gas turbine engine to estimate the pressure of the intake air or combustion gas and the gas generator GG. Accurately determine the inlet temperature T4 of the compressor turbine CT from only the rotation speed
proposed a control system for a two-shaft gas turbine engine that can estimate

(Problem to be Solved by the Invention) However, in the proposed control device for a two-shaft gas turbine engine, control is performed by comparing the calculated population temperature T4 of the compressor/nosa turbine CT with the target (I!T, ”). Therefore, there is a problem that it takes some time to control to the target value T4'', and the control to reach the target value is delayed.

The present invention does not use temperature parameters, but utilizes the characteristics of a two-shaft gas turbine engine to accurately determine the inlet temperature T4 of the compressor turbine CT from only the pressure of intake air or combustion gas and the rotational speed of the gas generator GG. It is an object of the present invention to provide a control device for a two-shaft gas turbine engine capable of estimating the time required to control the inlet temperature T4 of a compressor turbine CT to a target value T4''.

[Means to solve the problem]

As shown in FIG. 1, the present invention achieves the above object, as shown in FIG.
A control device for a two-shaft gas turbine engine comprising a combustor CC, a variable nozzle VN, and a separate output turbine PT, the control device comprising: a detection means sp for the outlet pressure P of the compressor C; , a detection means SPs for the outlet pressure P of the compressor turbine CT, a detection means SN for the rotational speed N1 of the shaft connecting both C and CT, and a target pressure ratio P3/ which is calculated from the target inlet temperature T411 of the compressor turbine.
A target value storage means 1 for storing "P5", and when the engine is steady,
Pressure ratio comparison means 2 compares the ratio P3/PS of the detected pressure P3゜P, with the target pressure ratio P3/Ps'', and the pressure ratio P, /P is the target pressure ratio P2/Ps'' a variable nozzle opening degree control means 3 which controls the variable nozzle VN in the closing direction when the pressure ratio P 3 / P s is smaller than the target pressure ratio P 3 / ps, and controls the variable nozzle VN in the opening direction when the pressure ratio , a fuel control means 4 for controlling fuel so as to maintain the rotational speed N of the shaft constant in accordance with the control of the variable nozzle opening degree control means 3.

[Effect]

According to the control device for a two-shaft gas turbine engine of the present invention, the outlet pressure P of the microcompressor C, the outlet pressure P of the compressor turbine CT, and the rotation speed N1 of the rotating shaft of the gas generator GG are determined by each sensor. , pressure P
2. The temperature T4 is calculated using the relationship between the rotation speed N, which is uniquely determined from Ps, and the artificial temperature T4 of the compressor turbine CT.

Then, when the temperature T4 is not equal to the target value T4'' and the engine is in a steady state, the pressure ratio P, /P is equal to the target value P2.
/Ps'', and the opening degree α of the variable nozzle VN is adjusted while keeping the rotational speed N1 of the compressor C constant so that T4=T,''. From then on, as long as the steady state is maintained. Without calculating the temperature T4, the pressure P x,
This adjustment operation is repeated only by detecting P s.

〔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 a two-shaft gas turbine engine of the present invention installed in a vehicle with an automatic transmission, and the same components as the two-shaft gas turbine engine shown in FIG. 7 are shown. The same reference numerals (symbols) are given for the above.

In the figure, GT is a gas turbine, and this gas turbine GT includes a front gear F/G to which a fuel pump, an oil pump, a starter motor, etc. are connected, and a compressor C1.
Heat exchanger HE, combustor CC, compressor turbine CT directly connected to compressor C by a rotating shaft, variable nozzle VN
, an output turbine PT, a reduction gear R/G, etc. Intake air is compressed by a compressor C, heated by a heat exchanger HE, mixed with fuel and combusted in a combustor CC, and the combustion gas rotates a compressor turbine CT. The combustion gas that has driven the compressor turbine CT passes through the variable nozzle VN to drive the output turbine PT, and then passes through the heat exchanger HE and is discharged into the atmosphere as exhaust gas. A1 is an actuator that supplies fuel to the combustor CC, and A2 is an actuator that adjusts the opening degree α of the variable nozzle VN.

The reduction gear R/G of the gas turbine GT is equipped with an automatic transmission A/
The rotation of the output turbine PT of the gas turbine GT is reduced by the reduction gear R/G and transmitted to the transmission mechanism via the torque converter built in the automatic transmission A/T, and the shift state is changed. It is converted into a rotation speed corresponding to the rotation speed and becomes the axle drive output.

The control circuit 10 that controls the gas turbine GT and the automatic transmission A/T 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 human interface INa, a central processing unit CPU, a random access memory RAM, Ef
E-only memory ROM and output circuit 0tlT
etc., and each is connected by a pass line II.

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

a rotation speed sensor SN that detects the rotation speed N3 of the gas turbine GT via the reduction gear R/G, and an axle drive rotation speed N;
A rotation speed sensor such as a rotation speed sensor SNP that detects the temperature, a temperature sensor ST that detects the atmospheric temperature, and a temperature sensor ST that detects the outlet temperature T3 of the compressor C! , the outlet temperature of the heat exchanger HE T3. a temperature sensor Shs that detects
A temperature sensor such as a temperature sensor ST that detects the outlet temperature T of the power turbine PT, and a pressure sensor SP3 that detects the outlet pressure P of the compressor C. A pressure sensor such as a pressure sensor SP for detecting the outlet pressure P of the compressor turbine CT is provided.

The human interface INa for analog signals includes signals Nl, Nx+Np, and P3 from the aforementioned sensors. P.S.
, T.O.

Txs, analog signal θa from T6 and accelerator pedal
cc, etc. 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 a human input interface INd for digital signals.

On the other hand, from the output circuit 0tlT, a signal Gf instructs the fuel flow rate to the actuator A1 of the combustor CC, a signal α8 instructs the opening degree of the variable nozzle VN to the actuator A2, and an on/off of the lock-up clutch of the torque converter. A signal S3 instructing the
,, S2 and throttle wire signal θ. etc. are output.

In the two-shaft gas turbine engine configured as described above, the control circuit 10 controls the outlet pressure P3 of the compressor C and the outlet pressure P of the compressor turbine CT.

The outlet temperature T4 of the combustor CC is calculated from the rotational speed N of the gas generator GG, and the engine is controlled.

Therefore, here, first, pressure P3, pressure P, and rotation speed N
The process of calculating the outlet temperature T4 of the combustor CC from 1 and 1 will be explained.

In a two-shaft gas turbine engine whose load is controlled by a variable nozzle VN, the corrected turbine rotation speed N,
/JT, the outlet pressure P of the compressor C, and the ratio Pi/Ps of the outlet pressure Ps of the compressor turbine CT are uniquely determined, and the relationship is expressed by a single curve as shown in Figure 4. Can be approximated.

Here, θ4 is based on standard atmospheric temperature (15°C),
It is a dimensionless version of the inlet temperature T4 of the compressor turbine CT, and is defined by the following equation.

θ, =74/273.16+15...■
Therefore, in each two-shaft gas turbine engine, if the characteristic curve shown in FIG. 4 is determined in advance and stored in the control circuit 10, the P3/P% obtained as a detected value during engine operation
From this characteristic curve, N, /J'T can be obtained, and the inlet temperature T4 of the compressor turbine CT can be calculated from equation (2). Note that PI/Ps, N, and /J'T are stored in the control circuit 10.

Rather than the relationship between P, /P5 and N, /17. It may be related to

Then, using the above relationship between PI/P and N, /JT, if the rotation speed N1 is detected, N I / j77V1), which can be obtained from the target inlet temperature T4' of the compressor turbine CT, is obtained. , the target engine state (P, /PS)" can be obtained by calculation.

By the way, Fig. 6 shows the pressure ratio P3/PS and the variable nozzle VNO opening α obtained by adjusting the engine performance based on the characteristics of each component of a two-shaft gas turbine engine with a variable nozzle VIJ. This shows the characteristics of From this figure, at a predetermined rotation speed N, the opening degree α3 of the variable nozzle VN and the pressure ratio P3/P.

There is a one-to-one correspondence between the rotation speed N and the variable nozzle V.
It can be seen that the pressure ratio P3/PS is determined by the opening degree α3 of N. Therefore, the pressure ratio P2/PS is compared with the target pressure ratio (P3/PS), and the pressure ratio P3/PS is determined.
The opening degree α8 of the variable nozzle VN can be determined by controlling the variable nozzle VN to the target value (P3/P3) and (P5).This target value (P:l/PS) is calculated in advance and read-only. It may be stored in the memory ROM or calculated from the target value T4'' of the inlet temperature T4 of the compressor turbine CT.

By doing the above, the target pressure ratio (P3/P
5)" By controlling the opening degree α8 of the variable nozzle VN, as a result, the compressor turbine CT
The inlet temperature T4 is controlled to the target value T41.

Next, the control operation of the control circuit 10 during acceleration and steady state of the engine will be explained using the flowchart shown in FIG.

In step 301, the rotational speed N of the gas generator GG is detected, and in step 302, the outlet pressure P of the compressor C and the outlet pressure P of the compressor turbine CT are detected. Then, in step 303, the outlet pressure P3 of the compressor C and the outlet pressure P of the compressor turbine CT.

Calculate the ratio value P3/Ps of Find it by Further, in this embodiment, a target pressure ratio (P3/P5) is calculated from the rotational speed N+ detected in step 301 and the target inlet temperature T4' of the compressor turbine CT.

In step 304, it is compared whether the inlet temperature T4 of the compressor turbine CT calculated in step 303 is equal to the target value T4'', and if they are equal (YES), this routine is terminated, but if they are not equal (NO), it is compared. Proceeding to step 305, it is determined whether the gas generator GG is in an acceleration state.Discrimination between an acceleration state and a steady state of the gas generator GG is made based on the amount of depression of the accelerator pedal and the amount of change in the accelerator pedal within a unit time. The determination may be made based on the rate of change in the rotational speed of the rotating shaft.

When it is determined that the gas generator GG is in a steady state (NO), the process proceeds to step 309, and the subsequent step 309
Then, in step 311, the target pressure ratio (P2/P5) calculated in step 303 is compared with the pressure ratio P3/PS, and (Pi/P3), (P5)"≦P)/P
In the case of S (NO>, step 309 to step 310
Then, control is performed to close the opening degree α of the variable nozzle VN, and if (Pz/P3), (P5) ">P3/PS (
If YES), the process proceeds from step 309 to step 311, where control is performed to open the opening degree α of the variable nozzle VN.

When step 310 or step 311 is completed, the process proceeds to step 312, where the rotation speed N of the rotation shaft of the gas generator GG is detected, and in the subsequent step 313, control is performed to keep the rotation speed Nt of the rotation shaft of the gas generator GG constant. . This rotation speed N.

In step 310, the variable nozzle VN is controlled to be constant.
If the variable nozzle VN is opened in step 311, the rotational speed N increases, so the fuel flow rate Gf is decreased, and if the variable nozzle VN is closed in step 311, the rotational speed N+ decreases, so the fuel flow rate Gf is increased. Then, in step 314, the outlet pressure P, , P
, the process returns to step 305 and steps 309 to 314 described above are performed as long as the engine is in a steady state.
Repeat the action.

On the other hand, when it is determined in step 305 that the gas generator GG is in the acceleration state (YES), step 3
06, and in subsequent steps 307 and 308, the increase or decrease in fuel is calculated from the difference between the inlet temperature T4 of the compressor turbine CT calculated in step 303 and the target value T4''. The difference ΔT between the inlet temperature T4 and the target value T,* is calculated, and in step 307, the target fuel flow rate G
The difference ΔGf between "f" and the current fuel flow MGf is calculated, and the current fuel flow rate Gf is corrected using this ΔGf in step 308. At this time, the combustion gas flow IG is determined based on the flow rate characteristics of the compressor turbine CT. p shown in Figure 5.
It can be determined from the s/p sc 4-'T4/P3 characteristics. Furthermore, if H is the enthalpy, ηee is the combustion efficiency of the combustor CC, and LIIV is the low calorific value indicating how many calories are produced per 1 kg, then the following equations To establish.

G4H4" = G*s"H25+Gf"* 7
7 cc*LHV −■G4+14 = G3
s*)I3s +Gf*ηc-L)IV-
The formula ■■ is the energy balance during the calculation in step 303, and the formula ■ is the energy balance when the target value T4'' is reached.Enthalpy H is a function of temperature and air-fuel ratio, and H4=f ( F/A, T4) ... ■ holds true. Therefore, from the formula ■ to the formula ■, ΔGf = *G4 *Δ
T4 is determined and a fuel correction value can be calculated.

(Effects of the Invention) As explained above, according to the control device for a two-shaft gas turbine engine of the present invention, the target compressor turbine CT
Convert the inlet temperature T4' to the target pressure ratio (P3/P, > 0, and the value of the pressure ratio P, /P,
By controlling the opening degree α of the variable nozzle VN so as to achieve PS), the opening degree α of the variable nozzle VN can be controlled in a shorter time using pressure with better response than when controlling it by temperature. In addition, although there is a temperature distribution in each part of a two-shaft gas turbine engine due to the combustor CC, etc., there is little distribution in pressure, and this provides more accurate information than control based on temperature. This has the effect of being able to reliably prevent problems such as turbine melting damage.

[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 a two-shaft gas turbine engine of the present invention, and FIG. 3 is a control procedure of the control circuit shown in FIG. 2. A flow chart showing the outline of P:l/Pi Nl is shown in Fig. 4.
/ je a characteristic diagram showing the relationship, Figure 5 is P3/PS
G4jT</P: Characteristic diagram showing the + characteristic, Fig. 6 shows the variable nozzle ν corresponding to the rotation speed N of the gas generator GG.
Fig. 7 is a diagram showing the general configuration of a conventional two-shaft gas turbine engine; Fig. 8 is a diagram showing a conventional gas generator. FIG. 3 is a diagram showing control characteristics when the vehicle shifts from an acceleration state to a transient state. 1... Target value storage means, 2... Pressure ratio comparison means, 3
...Variable nozzle opening control means, 4. Fuel control means, 10. Control circuit, C. Compressor, CC.
...Combustor, CT...Compressor turbine, HE...
...Heat exchanger, PT...Power turbine, SN,...
Rotation speed sensor, ST: 1.5T3S, ST6...Temperature sensor, spi, sps...Pressure sensor, VN・
...Variable nozzle.

Claims (1)

[Claims] A compressor (C), a compressor turbine (CT) coaxial with the compressor, a combustor (CC), and a variable nozzle (VN).
A control device for a two-shaft gas turbine engine, comprising: a pressure means (SP_3) for detecting an outlet pressure (P_3) of the compressor (C); and a separate shaft output turbine (PT); Turbine (CT) outlet pressure (P_3
), a rotation speed detection means (SN_1) that detects the rotation speed (N_1) of the shaft connecting both (C) and (CT), and a target inlet temperature (T_4^) of the compressor turbine. *) Target value storage means (1) that stores the target pressure ratio (P_3/P_5^*) calculated from
The ratio (P_3/P_5) of the target pressure ratio (P_3/P_5
The pressure ratio comparison means (2) compares the pressure ratio (P_3/P_5) with the target pressure ratio (P_3/P_
5^*), the variable nozzle (VN) is controlled in the closing direction, and the pressure ratio (P_3/P_5) becomes the target pressure ratio (
P_3/P_5^*) Variable nozzle (VN) in the following cases
a variable nozzle opening degree control means (3) for controlling the opening direction of the nozzle; and a variable nozzle opening degree control means (3) for controlling the fuel so as to keep the rotational speed (N_1) of the shaft constant according to the control of the variable nozzle opening degree control means (3). A control device for a two-shaft gas turbine engine, comprising: a fuel control means (4) for controlling the fuel;