JPH02233833A - Controller for two-shaft gas turbine engine - Google Patents

Abstract

PURPOSE:To calculated the inlet temperature of a compressor turbine by installing each detecting means for outlet pressure of a compressor and that of the compressor turbine and rotational speed of a shaft connecting both and an operational means, respectively. CONSTITUTION:In a two-shaft gas turbine engine, turbine corrected speed N1/theta and a relationship of ratio P3/P between outlet pressure P3 of a compressor C and outlet pressure P5 of a compressor turbine CT are primarily determined from the engine characteristic, and the relation is approximately with one curve. theta4 makes reference atmospheric temperature (15 deg.C) as a criterion, and it is one that makes inlet temperature of the compressor turbine CT into dimensionaless and is defined by a specified formula. Accordingly, the curve is found in advance and stored in memory. At time of engine driving, N1/theta is secured from P3/P5 and the said curve by speed N1 by the output pressure P3 of the compressor C by a pressure detecting means SP3 and speed N1 by a speed detecting means SN1 and the outlet pressure P5 of the compressor turbine CT by a pressure detecting means SP5, thus inlet temperature T4 of the compressor turbine CT is found out of the specified formula.

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. This relates to a control device that controls an engine. (Conventional technology) Two-shaft gas turbine engines are capable of continuous high rotation with low vibration, can use many types of fuel such as kerosene and methanol, and have large low-speed torque characteristics suitable for automobiles. Because of these characteristics, practical application as an engine for automobiles has been considered in recent years.

FIG. 6 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 compressor C and the compressor turbine CT are directly connected through a rotating shaft, and fuel is supplied to the combustor CC via an actuator AI. Intake air (intake air) is compressed by a compressor C, heated by a heat exchanger IE, 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 sometimes collectively called a gas generator GG, and the rotation speed N. influences the degree of compression of compressor C. The combustion gas that has driven the compressor turbine CT passes through a variable nozzle VN adjusted by an actuator A2, drives a power turbine (output turbine) PT, and then passes through a heat exchanger HE to become exhaust gas. The rotation of the output turbine PT is decelerated by the reduction gear R/G and transmitted to the automatic transmission A/T, and after being converted to a rotation speed according to the shift state, it is transmitted to the wheels W via the differential gear D. ．． Note that actuator AI. The control circuit CONT that drives A2 receives the accelerator pedal opening and engine operating state parameters from a sensor (not shown).
The control circuit CONT 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 the numbers surrounded by O, such as the intake pressure at the position ■ in Figure 6 is P3, and the temperature at the position ■ is T4. , the rotational speed of the rotational shaft of the gas generator GG is represented by N, 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 (compressor turbine inlet temperature) T4 and the outlet temperature of the power turbine are controlled. controlled in combination. For example, when the engine shifts from acceleration to steady state, as shown in FIG. Conventionally, control is performed to keep the outlet temperature T constant.

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

Therefore, the inlet temperature T4 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 of the output turbine PT
The inlet temperature T4 of one bottle CT can be estimated at two T. From this temperature, the inlet temperature T4 of the compressor turbine CT, which provides the control system for the shaft-type gas turbine engine, is estimated. It is in. [Problem to be Solved by the Invention] However, when estimating the inlet temperature T of the compressor turbine CT, the temperature parameter is absolutely necessary in the conventional method, but the temperature inside the engine cannot be measured using a temperature sensor. The response delay of the thermocouple used and the heat exchanger 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 turbine CT exceeds the allowable value.
This causes problems such as damage to the engine due to melting of the turbine.

An object of the present invention is to estimate the inlet temperature T4 of the compressor turbine CT by using the characteristics of a two-shaft gas turbine engine without using temperature parameters to estimate the pressure of intake air or combustion gas and the rotation of the gas generator GG. [Means for Solving the Problem] 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, comprising means SP for detecting outlet pressure P3 of the compressor C; A detection means SP for the outlet pressure P of the compressor turbine CT, a detection means SN+ for the rotation speed N of the shaft connecting both C and CT, and a rotation speed N, which is uniquely determined from the pressures p, p, and compressor turbine C
Relationship between outlet temperature T4 of T and the detection means SP3, SPS
, a means 1 for calculating the outlet temperature T4 from the detected values of SNI.
It is equipped with

[Effect]

According to the control device for a two-shaft gas turbine engine of the present invention,
When the outlet pressure P3 of the compressor C, the outlet pressure P of the compressor turbine CT, and the rotation speed N of the rotating shaft of the gas generator GG are determined by each sensor, the pressure P
al. The rotation speed N. which is uniquely determined from Pi. The inlet temperature T4 of the compressor turbine CT is calculated using the relationship between the outlet temperature T4 of the compressor turbine CT and the outlet temperature T4 of the compressor turbine CT. [Examples] Examples 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. 6 are shown. The same reference numerals (symbols) are given to the above.

In the figure, GT is a gas turbine, and this gas turbine GT includes a fuel pump, an oil pump, etc. Front gear F/G to which the starter motor etc. are connected, compressor C,
Heat exchanger HE, combustor CC, compressor turbine CT directly connected to the 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 11E, 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
A2 is an actuator that supplies fuel to the combustor CC, and A2 is an actuator that adjusts the opening degree αS 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 1t9A/T, and the rotation of the output turbine PT of the gas turbine GT is transmitted to the transmission mechanism via the torque converter built in the automatic transmission 1t9A/T. This is converted to the rotational 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 ink interface INa for analog signals, an input interface INd for digital signals, and an input interface I.
There is an analog-to-digital converter A/D for digitally converting the signal from Na, a central processing unit CPU, a random access memory RAM, a read-only memory ROM, an output circuit OUT, etc., and each bus line 11
It is connected with In addition, a gas generator G is used for a two-shaft gas turbine engine.
A rotation speed sensor SN.G detects the rotation speed N1 of G. ．． A rotation speed sensor SN. detects the rotation speed N3 of the gas turbine GT via the reduction gear R/G. , a rotation speed sensor SN, which detects the axle drive rotation speed N, and a temperature sensor ST. which detects the atmospheric temperature. , a temperature sensor ST3 that detects the outlet temperature T3 of the compressor C, a heat exchanger 11
Temperature sensor ST3S detects the outlet temperature Tzs of power pin PT, Temperature sensor S detects the outlet temperature T of power pin PT.
A temperature sensor such as T&, a pressure sensor SP3 that detects the outlet pressure P of the compressor C, a pressure sensor SPS that detects the outlet pressure P of the compressor turbine CT, and the like are provided. The input interface INa for analog signals receives signals N+, Nz, Np, P:+ . Ps.
To, Tss. T, and analog signals θacc from the accelerator pedal are input, and the digital signal input interface INd receives on/off signals from the key switch,
Digital signals such as a shift position signal from the shift lever and a brake signal from the brake are input.

On the other hand, from the output circuit OUT, a signal Gf instructing the fuel flow rate to the actuator A1 of the combustor CC, a signal α instructing the variable nozzle VNO opening degree to the actuator 82, and a signal α, A signal S for instructing on/off, and a speed change signal S for the speed change mechanism.
, S2 and throttle wire signal θ. etc. are output.

In the two-shaft gas turbine engine configured as described above, the control circuit 10 calculates the output of the combustor CC from the outlet pressure P3 of the compressor C, the outlet pressure P of the compressor turbine CT, and the rotational speed N of the gas generator GG. Outlet temperature T
4 is calculated and the engine is controlled. Therefore, here, first, the pressure P3, the pressure P, and the rotation speed N. The process of calculating the outlet temperature T4 of the combustor CC from . In a two-shaft gas turbine engine whose load is controlled by a variable nozzle VN, the corrected turbine rotation speed N +
/ fT4, the ratio of the outlet pressure P of the compressor C, and the outlet pressure PS of the compressor turbine CT P 3 /
The relationship between Ps is uniquely determined, and the relationship can be approximated by a single curve as shown in FIG. Here, θ4 is the inlet temperature T4 of the compressor turbine CT, which is made dimensionless based on the standard atmospheric temperature (15°C) 4.
It is defined by the following formula ■.

θ4=T. /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 IO, P 3 can be obtained as a detected value during engine operation. / P
s and this characteristic curve, NI/fT4 is obtained, and the inlet temperature T4 of the compressor turbine CT can be calculated from equation (2). In addition, what is stored in the control circuit 10 is P 3 / P s and N + / f"'i"'
Not the relationship with a, but P:l/PS and N,/J″r′
It may be related to 4.

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, a value P 3 / P of the ratio between the outlet pressure P3 of the compressor C and the outlet pressure P of the compressor turbine CT is determined.
s is calculated, and the inlet temperature T4 of the compressor turbine CT is calculated from the characteristic curve (FIG. 4) previously stored in the read-only memory ROI1 and the above-mentioned equation (2).

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) The process proceeds to step 305, where it is determined whether the gas generator GG is in an accelerating state. The acceleration state and steady state of the gas generator GG 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 GG, and the like.

When it is determined that the gas generator GG is in a steady state (NO), the process proceeds to step 309, and continues to <<step 309
In step 311, the inlet temperature T4 of the compressor turbine CT calculated in step 303 and the target value T4 are calculated in step 303.
``1'', and if T4≦T4', the process proceeds from step 309 to step 310, where control is performed to close the opening degree α, of the variable nozzle VN, and if T.>74'', the process proceeds from step 309 to step 310. Proceeding to step 311, the opening degree α of the variable nozzle VN is opened.
Returning to , feedback control is performed so that the inlet temperature T4 of the compressor turbine CT becomes the target value T41.

On the other hand, when it is determined in step 305 that the gas generator GG is in an accelerated state (YES), step 3
06, and in subsequent steps 307 to 30H, an increase or decrease in fuel is calculated from the difference between the inlet temperature T of the compressor turbine CT calculated in step 303 and the target value 7411. That is, in step 306, the inlet temperature T4 of the compressor turbine CT and the target value T411
In step 307, the difference ΔGf between the target fuel flow rate Gf and the current fuel flow rate Gf is calculated, and in step 308, the current fuel flow rate IGf is corrected using this 8Gf. At this time, the combustion gas flow ffi
c a can be determined from the P3/P5 Galπ/P+ characteristic shown in FIG. 5 from the flow rate characteristic of the compressor turbine CT. In addition, if H is the enthalbi, ηCC is the combustion efficiency of the combustor CC, and LIIV is the low calorific value indicating how many calories are produced in 1kg, then the following equations ■ and ■ are established by the energy balance of the input and output of the combustor CC. do. G4H4" = G3S*H3S+Gf"* η
cc * LHV − ■GaHa =
Gss book}13s+Gf * ηcc*LHV
... Equation (1) is the energy balance at the time of calculation in step 303, and Equation (2) is the energy balance at the time of the target value T4*. Further, enthalpy H is a function of temperature and air-fuel ratio, and the following holds true: H,=f (F/A, T4)... (2). Therefore, from the formula ■ to the formula ■, ΔGf=K*G, *Δ
T4 is determined and a fuel correction value can be calculated.

〔Effect of the invention〕

As explained above, according to the control device for a two-wheel gas turbine engine of the present invention, the pressure distribution is smaller than the temperature distribution by using the characteristics of the two-shaft gas turbine engine without using the temperature parameter. It is possible to accurately calculate the inlet temperature T4 of the compressor turbine CT only from the pressure of intake air or combustion gas obtained using a pressure sensor with better response than a temperature sensor and the rotational speed of the gas generator GG. As a result, due to conventional thermal balance, the compressor turbine CT
Compared to the method of calculating the inlet temperature T4 of the compressor turbine CT by detecting the temperature of each part of the engine, errors due to temperature distribution and response delay of thermocouples can be eliminated, and the inlet temperature T4 of the compressor turbine CT can be estimated more accurately. Since the engine can be controlled using the temperature T4, it is possible to reliably prevent problems such as turbine melting.

[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 flowchart showing the outline of P3/Ps-N+/f is shown in FIG.
Characteristic diagram showing the relationship of T4, 71. 51m ha pz/ps
-c4fr;/ps Characteristic diagram, Figure 6 shows the general configuration of a conventional two-shaft gas turbine engine, Figure 7 shows a conventional gas generator transitioning from an acceleration state to a transient state. FIG. DESCRIPTION OF SYMBOLS 1... Temperature calculation means, 10... Control circuit, C.
...Compressor, CC...Combustor, CT...
Compressor turbine, HE...heat exchanger, PT...
・Power pin, SN, ... rotation speed sensor, ST
3.ST! s. ST &”'Temperature sensor, Sh,
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 power turbine (PT) having a separate shaft; and a detection means (SP_3) for the outlet pressure (P_3) of the compressor (C); CT) outlet pressure (P_5
) detection means (SP_5), detection means (SN_1) for the rotation speed (N_1) of the shaft connecting both (C) and (CT), and the detection means (SP_3), (SP_5), (SN_1).
) A control device for a two-shaft gas turbine engine, comprising: temperature calculation means (1) that calculates an outlet temperature (T_4) from a detected value of the temperature (T_4).