JPH03271525A - Biaxial gas turbine engine - Google Patents

Abstract

PURPOSE:To improve acceleration performance at the time of abnormality by performing abnormality time control in accordance with accelerative and steady conditions of an engine even when an inlet temperature of a compressor turbine or an outlet temperature of an output turbine of the gas turbine engine is placed in an excessive value. CONSTITUTION:A biaxial gas turbine engine is provided with a gas generator GG, combustor CC, variable nozzle VN and an output turbine PT of a separate shaft. Here an engine acceleration condition is detected in an engine acceleration detecting means 2 by detecting a temperature in a predetermined location of the gas generator GG by an engine temperature detecting means 1. A steady time engine control means 3, in which an engine temperature T is compared with the first preset temperature Ta, controls an opening alphas of a variable nozzle VN in an opening direction, at the time of a relation where T>=Ta, and performs ordinary feedback control of the opening alphas at the time of the relation where T>=Ta continued for less than a predetermined time and at the time of a relation where T<Ta. An acceleration time engine control means 4 controls the opening alphas to a predetermined degree in an opening side, at the time of accelerating the engine, and also compares the engine temperature T with the second preset temperature Tc to perform control of changing the variable nozzle VN further to the opening side from the predetermined opening at the time of a relation T>=Tc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a two-shaft gas turbine engine, and particularly to a two-wheel gas turbine engine mounted on an automobile.

[Conventional technology]

Two-wheel gas turbine engines have recently been considered for practical use as automobile engines due to their low vibration, variety of fuels used, and large constant speed torque. FIG. 5 shows an example of a general configuration of a conventional two-wheel gas turbine engine mounted on an automobile with an automatic transmission.

In a two-shaft gas turbine engine, when the front gear F/G is rotated and started by a starter SM with a built-in clutch, intake air (hereinafter referred to as intake air) is compressed by a compressor C, heated by a heat exchanger HE, Actuator A
The combustion gas is mixed with fuel and combusted in the combustor CC to which fuel is supplied by the combustor CC, and the combustion gas rotates a compressor turbine CT coaxial with the compressor C. The compressor turbine CT and compressor C may be collectively referred to as a gas generator GG, and the rotation speed of the compressor turbine CT determines the degree of compression of the 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 as exhaust gas and is discharged to the atmosphere. Then, the rotation of the power turbine PT is decelerated by the reduction gear R/G and transmitted to the automatic transmission A/T, and after being converted to the rotation speed according to the shift state, it is passed through the differential gear to the wheel W.
transmitted to.

Note that the actuators Al and A2 are the control circuit C0NT.
Therefore, the opening degree of the accelerator pedal AP and engine operating state parameters from a sensor (not shown) are input to the control circuit C0NT. Further, in general, the subscripts attached to the intake pressure P and temperature T shown in FIG. 5 indicate the intake pressure P and temperature T at the position of the number surrounded by circles.

In the two-shaft gas turbine engine configured as described above, conventionally, after the gas generator GG finishes accelerating and transitions to a steady state, the outlet temperature of the output turbine PT is adjusted in order to efficiently extract the output of the engine. Control is performed to operate the variable nozzle VN so that T6 becomes the target value.

That is, in a two-shaft gas turbine engine, the higher the cycle temperature of the engine, the higher the engine output and thermal efficiency.
Conventionally, a method has been used in which the variable nozzle VN is feedback-controlled using the variable nozzle VN so that the outlet temperature T6 of the output turbine PT becomes the target value.

FIG. 6(a) shows the rotational speed Nl of the gas generator GG with the outlet temperature T6 of the output turbine PT as a parameter, where the horizontal axis is the rotational speed Nl of the gas generator GG, and the vertical axis is the variable nozzle VNO opening αs. , - indicates the opening degree αs characteristic of the variable nozzle VN.

However, if the target value is set at normal temperature in this conventional control method, the outlet temperature T6 of the output turbine PT may rise excessively due to changes in atmospheric temperature or engine performance. Therefore, the present applicant has proposed a method of determining whether the outlet temperature T6 of the output turbine PT matches the set value and correcting the opening degree αs of the variable nozzle VN according to the determination result (especially Publication No. 60-47872).

In this method, when there is an abnormality in which the outlet temperature T of the output turbine PT exceeds a set value, the opening degree α3 of the variable nozzle VN is
The value of is changed from the state shown in FIG. 6(a) to 172 as shown in FIG. 6(b), and the variable nozzle VN is controlled to the open side.

[Problem to be solved by the invention] However, the measures against abnormalities proposed by the applicant do not
There is a problem in that the control in the acceleration state of the engine and the control in the steady state are the same, and it is unreasonable to perform the same control during acceleration when the outlet temperature T6 of the output turbine PT is high and during steady state when it is not. . In other words, with conventional countermeasures, there is no clear distinction between control when an abnormal engine is accelerating and when the engine is in steady state.
The rise time of the rotational speed N3 of the output shaft of the engine during acceleration is delayed, and acceleration performance is deteriorated.

In addition, in the above explanation, the outlet temperature T6 of the output turbine PT
Although an example of controlling the inlet temperature T4 of the compressor turbine CT has been described, similar problems arise when controlling the inlet temperature T4 of the compressor turbine CT.

An object of the present invention is to solve the problem in controlling a conventional two-shaft gas turbine engine in the event of an abnormality, and to prevent the inlet temperature T4 of the compressor turbine CT or the outlet temperature T6 of the output turbine PT of the gas turbine engine from becoming overtemperature. Another object of the present invention is to provide a two-shaft gas turbine engine that can improve acceleration performance during abnormal conditions by performing abnormal control according to the acceleration state and steady state of the engine.

[Means to solve the problem]

The configuration of a two-wheeled gas turbine engine according to the present invention that achieves the above object is shown in FIG. A two-shaft gas turbine engine to which the present invention is applied includes a gas generator GG having a coaxial compressor C and a compressor turbine CT, a combustor CC, a variable nozzle VN, and a separate output turbine PT.
The engine temperature detection means 1 detects the temperature of a predetermined part of the gas generator GG, and the engine acceleration detection means 2
detects the acceleration state of the engine. Then, the steady state engine control means 3 sets the engine temperature T to the first set temperature T when the engine is in a steady state.
When the state of T≧・Ta continues for a predetermined time, the variable nozzle VN is controlled in the direction of opening αs, and T≧T
When the continuation of a is less than a predetermined time and when T<Ta, normal feedback control of the opening degree αs of the variable nozzle VN is performed, and the acceleration engine control means 4 controls the variable nozzle V when the engine accelerates.
The opening α8 of N is set to a predetermined opening on the open side, and the engine temperature T is set to a second set temperature Tc that is higher than the first set temperature Ta.
When T≧Tc, the variable nozzle VN is controlled to be opened further than the predetermined opening.

[Effect]

According to the two-wheeled gas turbine engine of the present invention, when the engine is in a steady state, the engine temperature T is compared with the first set temperature Ta. When the state of T≧Tb continues for a predetermined time, the opening degree α8 of the variable nozzle VN is controlled in the direction of opening, and T≧
When the shape of Ta is less than a predetermined time and when T<Ta, the opening degree αS of the variable nozzle VN is normally feedback-controlled. On the other hand, when the engine is in an accelerating state, the opening degree α8 of the variable nozzle VN is set to a predetermined opening degree on the open side, and the engine temperature T is compared with a second set temperature Tc which is higher than the temperature Ta.
When ≧Tc, the variable nozzle VN is changed to be further open than the predetermined opening.

〔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 shows the same components as the two-shaft gas turbine engine shown in FIG. 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, a compressor C and a compressor turbine to which a rotating shaft is directly connected and constitutes a gas generator GG. CT, heat exchanger HE, combustor CC,
Variable nozzle VN on compressor C.

There is a power 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 injected from a fuel injection valve in a combustor CC, and combusted, and the combustion gas rotates a compressor turbine CT. The combustion gas that has driven the compressor turbine CT passes through the variable nozzle νN to drive the power turbine PT, and then passes through the heat exchanger fE as exhaust gas and is discharged to the atmosphere.

AI is an actuator that supplies fuel to the combustor CC, and has a built-in metering valve. Further, A2 is an actuator that adjusts the opening degree αs of the variable nozzle VN.

The reduction gear RIG of the gas turbine GT is equipped with an automatic transmission A/
The rotation of the power turbine PT of the gas turbine GT is decelerated 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 reached. It is converted to the corresponding 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 interface lNa- for analog signals and an input interface INd for digital signals.
, an analog-to-digital converter A/D for digitally converting the signal from the input interface INa, a central processing unit CPU, a random access memory RAM, a read-only memory ROM, an output circuit OUT, etc., each connected by a pass line 11. ing.

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

A rotation speed sensor SN3. detects the rotation speed N3 of the gas turbine GT via the reduction gear R/G. and 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, a temperature sensor STY that detects the outlet temperature T3 of the compressor C, and a temperature sensor that detects the outlet temperature 73S of the heat exchanger HE. sensor 5Tzs
, a temperature sensor such as a temperature sensor ST6 that detects the 00 temperature T6 of the power turbine PT, and a pressure sensor SP3 that detects the outlet pressure P3 of the compressor C. Pressure sensor SPS that detects outlet pressure P5 of compressor turbine CT
A pressure sensor such as this is provided.

The analog signal input interface INa receives signals N, , N, , N, , P, , P6 . T
,.

Analog signals θSCe, etc. from T, ..., T and accelerator pedal AP are input, and the digital signal input interface INd receives on/off signals from the key switch, shift position signals from the shift lever, brake signals from the brake, etc. digital signal is input.

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 α8 instructs the variable nozzle VNO opening to the actuator A2, and a signal α8 instructs the lock-up clutch of the torque converter to turn on and off. a signal S4 for instructing, a speed change signal S for the speed change mechanism,
, S2 and throttle wire signal θ. etc. are output. Furthermore, in this embodiment, an alarm AL such as a warning lamp or a buzzer is connected to the output circuit OUT, and when the detected value of the temperature sensor ST6 that detects the outlet temperature Tb of the output turbine PT is higher than the set value, light or sound is emitted. temperature sensor ST,
It is now possible to notify vehicle occupants of any abnormalities.

Next, the operation of the control circuit 10 in the two-shaft gas turbine engine configured as described above will be explained using the flowchart of FIG. 3 and the characteristic diagram of FIG. 4.

In this embodiment, the engine temperature in the two-wheeled gas turbine engine is the outlet temperature T of the power turbine PT.

It will be explained as follows.

First, in step 301, the gas generator G
It is determined whether the rotational speed N1 of G is 240 Orpm or more. If NI<240 Orpm (NO), the process does not proceed to the next step; if N1≧2400rprrl (YES), the process proceeds to step 302 and time is counted. Then, in step 303, it is determined whether 10 seconds have elapsed.

Steps 301 to 303 are for confirming that the engine is not starting.

In the following step 304, it is determined whether the engine is in an acceleration state. This determination is made based on the amount of depression of the accelerator pedal AP. If the engine is in a steady state (NO), the process proceeds to step 305, and if the engine is in an accelerated state (YES), the process proceeds to step 313. Since the subsequent control is completely different between the steady state of the engine and the accelerated state, the control of the engine in the steady state will be explained first, and then the control of the engine in the accelerated state will be explained.

(1) Steady state control of the engine When the engine is in a steady state, the first judgment temperature is set to 800.
With the second determination temperature of °C1 being 1200 °C, three types of control are performed depending on which range the value of the outlet temperature T6 of the output turbine PT is in. Steps 305 and 306 include the detected outlet temperature T of the output turbine PT.
This is to determine the area to which 6 belongs, 1621200
If it is °C, YES in step 305 and step 3
15, if 800°C≦T and <1200°C, NO in step 305, YES in step 306, and proceed to step 307; if Tb <800''C, NO in step 305, and YES in step 307. If NO, the process proceeds to step 310.

If the temperature is 1,621,200° C., this is an overtemperature in the steady state, which is a dangerous condition, so in step 315, the fuel flow rate Gf is set to 0, fuel canting is performed, and control is performed to lower the engine temperature.

If 800°C≦Tb<1200”C, the engine temperature is overtemperature in the steady state but not in a dangerous state, so first, in step 307, the fuel flow rate Gf is reduced and controlled to the value at idle, A counter counts time.In step 308, it is determined whether the count value of the counter is greater than or equal to I sec.

That is, it is determined whether this temperature state has continued for I sec or more. If the continuation of the temperature state of 800°C≦T and <1200°C is I sec and there is no drop (No), step 3
Proceed to step 11 and change the opening αs of the variable nozzle VN, which was done previously.
control is performed. That is, if the opening degree α5 of the variable nozzle VN follows the normal VNINT map shown in FIG. 6(a),
It is set according to the rotational speed N of the gas generator GG. Then, in step 312, feedback control of the opening degree α3 of the variable nozzle VN is performed.

On the other hand, if the temperature state of 800'C≦T6<1200°C continues for 1 sec or more (YES), step 30
9, the opening degree αs of the variable nozzle VN is set to half the value set according to the rotational speed N1 of the gas generator GG according to the normal VNINT map shown in FIG. 6(a), and the opening degree αs of the variable nozzle νN is The opening degree αs is controlled to the opening side.

This control is the same as the map-based control shown in FIG. 6@).

If T is <800°C, the engine temperature is normal in the steady state, so the value of the time counter is cleared in step 310, and the opening degree αs of the variable nozzle VN is changed to the value shown in FIG. 6 in step 311. It is set according to the rotational speed N of the gas generator GG according to the normal VNINT map shown in (a). And step 31
2, variable nozzle VNO opening degree α.

feedback control is executed.

(2) Control of the Acceleration State of the Engine When the engine is in the acceleration state, first, in step 313, the opening degree αs of the variable nozzle VN is fixed at 2.0. The value αs=2.0 is the value on the opening side of the variable nozzle VN (fully closed when αs=10, fully open when αs=0). Next, the first judgment temperature is set to 850°C, which is higher than the normal temperature.
The determination temperature of T is set at 1250° C., which is higher than the steady state, and it is determined in step 314 and step 316 which region the value of the outlet temperature T of the output turbine PT is in, and three types of control are performed.

In the case of 1621200°C, which is YES in step 314, it is a dangerous situation due to overtemperature in the acceleration state.
In step 315, the fuel flow rate Gf is set to 0, a fuel cut is performed, and control is performed to lower the engine temperature.

If 850°C≦T6<1250°C (No in step 314 and YES in step 316), the engine temperature is overtemperature in the acceleration state, but it is not dangerous, so proceed to step 317 and turn on the variable nozzle VN. The opening degree αs is set to O, the variable nozzle VN is fully opened, and further temperature rise is prevented.

If Tb<850'C, which is No in step 314 and No in step 316, the engine temperature is normal in the acceleration state, so the opening degree α3 of variable nozzle VN is
is held at 2.0.

The reason why the first determination temperature and the second determination temperature are set to higher temperatures than in the steady state is that the parts of the output turbine PT and the main housing have a large heat capacity. That is, even if the fuel flow rate Gf is suddenly increased, the actual temperature does not rise suddenly. Therefore, even if the temperature is such that the output turbine PT may melt during steady state,
During acceleration (usually several seconds), the output turbine PT will not melt even if the temperature is slightly higher than this temperature, as long as it is within several seconds. It is clear that if the outlet temperature T6 of the output turbine PT is increased, the rotational speed N3 of the output shaft will be increased, and therefore the acceleration performance will be improved.

FIG. 4 shows that the engine which was in an idle state at time t0 accelerates, and at time t, the outlet temperature of the output turbine PT is T6.
temporarily becomes between 850°C and 1250°C, and at time t2, the outlet temperature T of the output turbine PT becomes 850°C.
'C or below, the acceleration transitions to a steady state at time t3, and the outlet temperature T6 of the output turbine PT becomes between 800°C and 1200'C at time t4 for 1 s.
3 shows changes in each parameter of the two-shaft gas turbine engine according to the procedure shown in FIG. 3, assuming a model operating state in which the same state continues at time t after ec.

When acceleration is started, the opening degree αs of the variable nozzle νN is maintained at 2.0 in step 313, and the opening degree αs of the variable nozzle νN is maintained at 2.0 at time tl.
When the temperature reaches 2850°C, the opening degree αs of the variable nozzle VN is set to 0 in step 317, and the opening degree αs of the variable nozzle VN is set to 0 at time t2.

<When the temperature reaches 850°C, the opening degree αs of the variable nozzle VN returns to 2.0 in step 313. And time t3
After the steady state is reached, the opening degree of variable nozzle VN is α.

is feedback-controlled, and at time t4 the output turbine P
Even if the outlet temperature T6 of T exceeds 800°C, step 3
Variable nozzle VNO opening α on the path 08 → 311 → 312
The feedback control of s is maintained, and at a time after I sec, a process of reducing the opening degree αs of the variable nozzle VN to 1/2 is performed in step 309.

As a result, the rotational speed N of the output shaft of the gas turbine engine rises smoothly during acceleration, improving acceleration performance.

In addition, in the above-mentioned embodiment, in step 315, the fuel flow rate Gf is set to O to perform a fuel cut, but the control may also be performed to significantly reduce the fuel amount. Also, in step 317, the opening degree αs of the variable nozzle VN is fully opened;
The opening degree αs of the variable nozzle VN in this step 317
It is sufficiently effective even if it is suppressed to about 90% of full opening.

〔Effect of the invention〕

As explained above, according to the two-wheeled gas turbine engine of the present invention, the compressor turbine C of the gas turbine engine
The inlet temperature T4 of T or the outlet temperature T of the power turbine PT
6 becomes overtemperature, by performing abnormality control according to the acceleration state and steady state of the engine, acceleration performance in abnormality can be improved and hunting of the variable nozzle VN can be prevented. There is an effect.

[Brief explanation of drawings]

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 two-wheeled gas turbine engine of the present invention, and Fig. 3 shows an example of the control procedure of the control circuit in Fig. 2. Flowchart, Figure 4 is a characteristic diagram showing changes in each parameter of a two-wheel gas turbine engine according to the procedure shown in Figure 3 under a certain model operating state, and Figure 5 shows the general configuration of a conventional two-wheel gas turbine engine. Figure 6(a) is a control characteristic diagram according to the outlet temperature T6 of the output turbine PT for the opening degree αs of the variable nozzle VN when the conventional engine is normal, and Figure 6(a) is the control characteristic diagram when the engine is abnormal. It is a control characteristic diagram according to the outlet temperature T6 of the output turbine PT of the opening degree αs of the variable nozzle VN. 10...Control circuit, AL...Alarm, C...Compressor, CC...Combustor, CT...Compressor turbine, GG...Gas generator, PT...Power turbine, Si2... Temperature sensor, VN...variable nozzle.

Claims (1)

[Claims] Coaxial compressor (C) and compressor turbine (C
A gas generator (GG) equipped with a gas generator (T) and a combustor (C
C), a variable nozzle (VN), and a separate shaft output turbine (
In a two-shaft gas turbine engine equipped with a two-shaft gas turbine engine (PT), the engine temperature detection means (1) detects the temperature (T) of a predetermined part of the gas generator (GG), and the engine acceleration detection means (1) detects the acceleration state of the engine. 2), and when the engine is steady, the engine temperature (T) is set to the first set temperature (Ta
), when the state of T≧Ta continues for a predetermined time, the opening degree (α_s) of the variable nozzle (VN) is controlled in the direction of opening, and when the state of T≧Ta continues for less than the predetermined time and when T<Ta a steady-state engine control means (3) that performs normal feedback control of the opening degree (α_s) of the variable nozzle (VN) when the engine is accelerating; degree, and compares the engine temperature (T) with a second set temperature (Tc) that is higher than the first set temperature (Ta), and when T≧Tc, the variable nozzle (VN) is opened at a temperature higher than the predetermined opening degree. A two-shaft gas turbine engine further comprising: acceleration engine control means (4) for performing control to change the engine to the open side.