JPH073188B2 - Variable nozzle control device for gas turbine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas turbine used in a vehicle such as an automobile, and more particularly to a device for controlling a variable nozzle.

[Conventional technology]

In this type of gas turbine, the variable nozzle arranged between the compressor turbine and the power turbine is
As described in JP-A-60-47824, the angle control is performed in order to ensure stable and responsive driving. That is, the angle of the variable nozzle is controlled so that the thermal efficiency of the engine is maximized. Now, as the compressor turbine inlet temperature T ₄ and the power turbine outlet temperature T ₆ are higher, the thermal efficiency of the engine is higher, but these temperatures T ₄ and T ₆ have upper limits due to the material of the turbine and the like. Therefore, conventionally, the compressor turbine inlet temperature T ₄ or the power turbine outlet temperature T ₆ is controlled so as to approach the upper limit value or the set value, where the set value of the power turbine outlet temperature T ₆ is the compressor speed N ₁ and it is determined in accordance with the output shaft speed N _3, the set value of the compressor turbine inlet temperature T ₄ are determined in accordance with only the compressor rotational speed N _1.

[Problems to be solved by the invention]

However, according to the inventor's invention, as shown in FIG. 5, the upper limit value of the compressor turbine inlet temperature T ₄ changes not only with the compressor rotation speed N ₁ but also with the output shaft rotation speed N ₃ . That is, if the angle of the variable nozzle is controlled only by the compressor rotation speed N ₁ , the thermal efficiency of the engine does not always become the highest, and there is a problem that the engine performance cannot be sufficiently enhanced.

The present invention aims to improve the control of the variable nozzle and further increase the thermal efficiency of the engine.

[Means for solving problems]

The present invention has the configuration shown in the configuration diagram of the invention of FIG. 1, and includes a first rotation speed detection means A for detecting the rotation speed of the compressor turbine 102, and an output shaft 109 connected to the power turbine 103.
Second rotation speed detection means B for detecting the rotation speed of the compressor turbine 102, means C for detecting the inlet temperature of the compressor turbine 102, means D for detecting the outlet temperature of the power turbine 103, and the inlet temperature or the outlet temperature of the compressor turbine 103. And a nozzle control means E for controlling the variable nozzle 106 so as to approach a set value determined according to each rotation speed of the output shaft 109.

〔Example〕

 The present invention will be described below with reference to illustrated embodiments.

FIG. 2 shows a gas turbine engine to which an embodiment of the present invention is applied. The gas turbine engine 100 has an electronic control unit (E
CU) 200 controls and rotates, and this rotation is transmitted to wheels 13 via automatic transmission 11 and differential gear 12. The automatic transmission 11 is switched by the actuator 14 controlled by the ECU 200.

The gas turbine engine 100 includes a gas generator having a compressor 101 and a compressor turbine 102, a power turbine 103, and reduction gears 104, 105 meshing with each other.
And a variable nozzle 106, a combustor 107, and a heat exchanger 108. The compressor 101 is for compressing intake air, and is rotationally driven by the compressor turbine 102. The compressor turbine 102 is supplied with combustion gas from a combustor 107 and rotates, and this combustion gas is changed by a variable nozzle 106.
Is supplied to the power turbine 103 via the power turbine 103, the rotation of the power turbine 103 is controlled according to the supply state of the combustion gas, the variable nozzle 106 is adjusted in angle by the actuator 15 controlled by the ECU 200, and the power turbine of the combustion gas is supplied. The reduction gear 104 that changes the supply state to the 103 rotates coaxially with the power turbine 103 to rotationally drive the other reduction gear 105, whereby the rotation of the power turbine 103 is reduced. The rotation of the reduction gear 105 is transmitted to the automatic transmission 11 via the output shaft 109. The heat exchanger 108 is the power turbine 1
The exhaust gas from 03 is used to heat the intake air supplied to the combustor 107. The combustor 107 includes a fuel tank 16 and a light valve 17
The lightweight valve 17 is controlled to be opened and closed by the ECU 200.

The ECU 200 includes a microcomputer, and a read only memory (ROM) 201 that stores various control programs and the like.
A random access memory (RAM) 202 for storing various data and the like, a central processing unit (CPU) 203 for executing arithmetic processing according to a control program, and a reference clock pulse for various arithmetic operations including a crystal oscillator 204. A clock generation circuit 205 that generates a signal, an AD converter 206 that converts an analog signal from various sensors described below into a digital signal, a sensor that outputs a digital signal, an input / output to which the actuators 14 and 15 and the lightweight valve 17 are connected. It has a port (I / O) 207. The ECU 200 has a fuel flow rate G _f input to the lightweight valve 17,
Each control command signal of the shift position S _p input to the actuator 14 and the variable nozzle angle command value α _s input to the actuator 15 is output.

For such control, ECU 200 receives detection signals from various sensors. The accelerator sensor 21 outputs an output signal corresponding to the depression amount of the accelerator pedal 18, that is, a signal corresponding to a set value N _1set of the rotation speed of the gas generator. The gas generator rotation speed sensor 22 outputs a signal corresponding to the rotation speed N ₁ of a gas generator including a compressor and a compressor turbine. The engine output shaft rotation speed sensor 23 outputs a signal corresponding to the rotation speed N ₃ of the reduction gear 105, that is, the engine output shaft 109. The pressure sensor 24 outputs a signal corresponding to the outlet pressure COP of the compressor 101. The combustion air temperature sensor 25 is composed of a thermocouple and an amplifier.
The signal corresponding to the inlet air temperature T ₃₅ of is output. The turbine inlet temperature sensor 26 comprises a thermocouple and an amplifier, and outputs a signal corresponding to the inlet temperature T ₄ of the compressor turbine 102. The turbine outlet temperature sensor 27 includes a thermocouple and an amplifier, and outputs a signal corresponding to the outlet temperature T ₆ of the power turbine 103. Variable nozzle angle sensor
28 consists of potentiometer and amplifier, variable nozzle 10
The signal corresponding to the angle α _f of 6 is output. The shift position sensor 29 outputs a signal corresponding to the shift position S _p of the automatic transmission 11.

As shown in FIG. 3, the gas generator rotation speed sensor 22 includes a gear 22 made of a magnetic material which is interlocked with the rotation of the gas generator.
The rotation of a is detected by the electromagnetic pickup 22b, and the pickup 22b detects the rotation of the gear 22a as an AC signal having a frequency proportional to the rotation speed N ₁ of the gas generator. This signal is amplified by the amplifier 22c and shaped into a rectangular wave, and this rectangular wave signal is converted into an analog voltage signal by the frequency-voltage conversion circuit 22d and input to the AD converter 206.

When the vehicle is started, the ECU 200 receives power from a stabilizing power supply circuit (not shown) and starts operating when the engine key is turned on.

FIG. 4 shows a schematic flowchart of control by the ECU 200. In Step 301, the gas generator speed setting N
_lset , gas generator speed N ₁ , engine output shaft speed
N ₃ , compressor outlet pressure CDP, combustor inlet temperature T ₃₅ , compressor turbine inlet temperature T ₄ , turbine outlet temperature T ₆ ,
Various signals of the variable nozzle angle α _f and the shift position S _pi are input. In step 302, from the various signals input in step 301 and the data stored in RAM 202,
Determine if the engine is in steady state. Step
At 303, the fuel flow rate G _f is calculated from various signals and the data stored in the RAM 202, and the result is output. Step
In 304, the variable nozzle angle α _s is calculated from various signals and the data stored in the RAM 202, and the result is output.
Then, in step 305, the shift position S _p is calculated and the result is output. Finally, in step 306, various signals and R
A failure diagnosis is performed using the data stored in AM202. That is, the accelerator sensor 21, the gas generator rotation speed sensor 22, the engine output shaft rotation speed sensor 23, the pressure sensor 24, the air temperature sensor 25, the turbine outlet temperature sensor 26,
It is determined whether or not the variable nozzle angle sensor 27, the shift position sensor 28, the actuators 14, 15 and the like are operating normally. After the end of step 306, the process returns to step 301 again, and the above-described operation is repeated.

In this embodiment, the variable nozzle angle α _s is the compressor turbine inlet temperature T ₄ or the power turbine outlet temperature T ₆
Is controlled to be the set value. FIG. 5 shows the variable nozzle 1 for obtaining the set value T _4set of the compressor turbine inlet temperature and the set value T _6set of the turbine outlet temperature with respect to the gas generator rotational speed N ₁ and the engine output shaft rotational speed N ₃ .
The channel area A _{5 of} 06 (corresponding to the angle α _s ) is shown. As can be seen from this figure, in the region where the variable nozzle flow passage area A ₅ is controlled to bring the power turbine outlet temperature T ₆ close to the set value, that is, in the T ₆ region, the flow passage area A ₅ is the gas generator rotation speed. It increases as N ₁ increases, and increases as engine output shaft speed N ₃ decreases. On the other hand, the variable nozzle channel area A ₅ is the compressor turbine inlet temperature T ₄
Region or T ₄ region is controlled so as to approach the set value, the rotational speed N _1, N ₃ is limited to both high portion, the T ₄
In the region, the flow passage area A ₅ is the gas generator rotation speed N ₁
Becomes higher, and becomes larger, and the engine output shaft speed
The lower N ₃ is, the larger it is. Therefore, in this embodiment, the variable nozzle flow passage area A ₅ is the fifth with respect to the rotation speeds N ₁ and N ₃ .
It is controlled so as to change as indicated by a symbol R in the figure. The region where the rotation speed N ₁ is lower than about 52000 rpm is the surge region.

FIG. 6 shows a curved horizontal plane (N ₁ -N ₃
Projection onto a plane). From this figure, it is understood that the T ₆ region has a pentagonal shape as shown by a broken line, while the T ₄ region has a triangular shape as shown by a chain line. Now, in the present embodiment, the N ₁ -N ₃ plane shown in FIG. 6 is partitioned into a grid by straight lines parallel to the N ₁ axis and the N ₃ axis, and the data of the variable nozzle channel area A ₅ at each grid point is obtained. It is stored in RAM201. Thus when the rotational speed N _1, N ₃ are given, the flow passage area A ₅ which corresponds to the rotational speed N _1, N ₃ using the data of the flow passage area A ₅ in a suitable grid points are calculated.

FIG. 7 shows a calculation routine for the variable nozzle angle α _s, that is, the variable nozzle passage area A ₅ when the rotational speeds N ₁ and N ₃ are given. This routine is interrupted every predetermined time.
First, in step 311, the gas generator speed N ₁ and the engine output shaft speed N ₃ are read. In step 312, it is determined which of the meshes shown in FIG. 6 the rotation speeds N ₁ and N ₃ correspond to. That is, in FIG.
Determine the mesh containing N ₁ and N ₃ . The mesh determined here is illustrated in FIG. In step 313, the coordinates of the _four vertices P ₁ , P ₂ , P ₃ , P ₄ of this mesh, that is, the rotation speeds N ₁ , N ₃ at each vertex are read. Here, the coordinates at the vertex P ₁ are (N ₁₁ , N ₃₁ ), the coordinates at the vertex P ₂ are (N ₁₂ , N ₃₂ ), the coordinates at the vertex P ₃ are (N _13,31 ),
Let the coordinates at P _{4 be} (N ₁₄ , N ₃₂ ). Then step
At 314, the flow path area A ₅ at each vertex P ₁ , P ₂ , P ₃ , P _4, that is, the vertical coordinate of FIG. ₅ is read. Here, the vertical coordinate at vertex P ₁ is (A ₅₁ ), the vertical coordinate at vertex P ₂ is (A ₅₂ ), the vertical coordinate at vertex P ₃ is (A ₅₃ ), and the vertical coordinate at vertex P ₄ is (A ₅₄ ). To do.

In step 315, the flow passage area A ₅ at the rotation speeds N ₁ and N ₃ is calculated from the coordinates of the vertices P ₁ , P ₂ , P ₃ and P ₄ . First, in FIG. 8, draw a straight line that passes through the rotation speed N ₃ and is parallel to the horizontal axis, and define the straight lines at the intersections with the right and left sides of the mesh, respectively.
And P _34, P _12. Similarly, draw straight lines that pass through the rotation speed N ₁ and are parallel to each other in the vertical and horizontal directions, and set the intersections of this straight line and the upper and lower sides of the mesh as P ₂₄ and P ₁₃ , respectively. The vertical coordinate (A ₅₁₂ ) at the point P ₁₂ is the vertical coordinate (A ₅₁ ), (A ₅₁ ) at the points P ₁ and P ₂ .
₅₂ ) From Similarly, the vertical coordinates at points P ₃₄ , P ₁₃ , and P ₂₄ are Becomes Next, from the vertical coordinates (A ₅₁₂ ) and (A ₅₃₄ ) at the points P ₁₂ and P ₃₄ , the flow passage area A ₅ ′ at the rotation speeds N ₁ and N ₃ is However, N ₁₃₄ and N ₁₁₂ are rotation speeds N ₁ at points P ₁₂ and P ₃₄ . Then, by substituting the equations (1) and (2) into the equation (5), A ₅ ′ can be obtained. Similarly, from the vertical coordinates (A ₅₁₃ ) and (A ₅₂₄ ) at the points P ₁₃ and P ₂₄ , the flow passage area A ₅ ″ at the rotation speeds N ₁ and N ₃ is Then, by substituting the equations (1) and (2) into the equation (6), A ₅ ″ is obtained. Then, the average value of A ₅ ′ and A ₅ ″ is taken, and the obtained flow path area A ₅ is obtained. To do. That is, Is the variable nozzle channel area A ₅ at the rotation speeds N ₁ and N ₃ .

In this way, when the rotation speeds N ₁ and N ₃ are determined, the flow passage area A ₅ of the variable nozzle, that is, the angle α _s is obtained in step 304 of FIG. 4, and the variable nozzle 106 is controlled based on this. . Here, when the rotational speeds N ₁ and N ₃ are in the T ₄ region of FIG. 5, the set value T of the compressor turbine inlet temperature T ₄ is set.
_{The 4set} is not determined only by the gas generator rotational speed N ₁ as in the conventional case, but changes according to the gas generator rotational speed N ₁ and the engine output shaft rotational speed N ₃ . That is, the compressor turbine inlet temperature T ₄ and power turbine outlet temperature T ₆ is always accurately kept to a permissible temperature for the material of each component, thereby the heat efficiency of the engine is improved.

〔The invention's effect〕

As described above, according to the present invention, the variable nozzle is controlled so that the inlet temperature of the compressor turbine or the outlet temperature of the power turbine approaches a set value determined depending on each rotation speed of the compressor turbine and the power turbine. The effect that the thermal efficiency of the engine is improved and the engine output is increased is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of the present invention, FIG. 2 is a block diagram showing a gas turbine engine to which an embodiment of the present invention is applied, FIG. 3 is a block diagram of a gas generator speed sensor, and FIG. 4 is an ECU. Fig. 5 is a graph showing the change in the set value of the flow passage area of the variable nozzle with respect to the gas generator speed and the engine output shaft speed, and Fig. 6 is the T ₆ region in the N ₁ -N ₃ plane. and T ₄ illustrates a region, flow calculation routine of FIG. 7 is a variable nozzle flow area, FIG. 8 is an enlarged view of a mesh of N ₁ -N ₃ plane of FIG. 6. 22 …… Gas generator speed sensor, 23 …… Engine output shaft speed sensor, 102 …… Compressor turbine, 1
03 …… Power turbine, 106 …… Variable nozzle.

Claims (1)

[Claims] 1. A compressor turbine is rotatably driven by combustion gas supplied from a combustor, and combustion gas discharged from the compressor turbine is supplied to a power turbine under the control of a variable nozzle. In a gas turbine that heats intake air supplied to the combustor, first rotation speed detecting means for detecting the rotation speed of the compressor turbine, and second rotation speed detecting means for detecting the rotation speed of an output shaft connected to the power turbine. Rotation speed detection means, means for detecting the inlet temperature of the compressor turbine, means for detecting the outlet temperature of the power turbine, and the inlet temperature or the outlet temperature depending on the rotation speed of the compressor turbine and the output shaft Nozzle control means for controlling the variable nozzle so as to approach a fixed set value. Variable nozzle control apparatus for a gas turbine to symptoms.