JP2900371B2 - Two-shaft gas turbine engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a two-shaft gas turbine engine, and more particularly to a two-shaft gas turbine engine mounted on an automobile.

[Conventional technology]

The two-shaft gas turbine engine (1) can rotate continuously with high speed because of only the rotary motion. (2) Because it is a continuous combustion engine, it uses not only gasoline and light oil, but also various fuels such as kerosene and methanol. (3) It has characteristics such as having a large low-speed torque and suitable torque characteristics for automobiles. Therefore, in recent years, practical application as an automobile engine has been studied.

FIG. 10 shows an example of a general configuration of a conventional two-shaft gas turbine engine mounted on an automobile having 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 compressor C and the compressor turbine CT are directly connected by a rotating shaft, and the combustor CC is connected to the combustor CC via an actuator A1. Fuel is being supplied. The intake air (hereinafter referred to as “intake”) is compressed by the compressor C, heated by the heat exchanger HE, and is heated by the combustor CC.
The fuel is mixed with fuel and burned, and the combustion gas rotates the compressor turbine CT. The compressor turbine CT and the compressor C are collectively referred to as a gas generator GG.
The rotation speed of the compressor turbine CT affects the degree of compression of the compressor C. The combustion gas that drives the compressor turbine CT is
After driving the power turbine (output turbine) PT through the variable nozzle VN adjusted to A2, the gas is exhausted into the atmosphere via the heat exchanger HE and discharged to the atmosphere.

The configuration of the two-shaft gas turbine GT is as described above. The rotation of the power turbine PT is reduced by the reduction gear R / G, transmitted to the automatic transmission A / T, and converted into a rotational speed corresponding to the shift state. The power is transmitted to the wheels W via the dynamic gear D.

The actuator A1 supplies fuel to the combustor CC according to a command from the control circuit CONT, and the actuator A2 adjusts the opening of the variable nozzle VN according to a command from the control circuit CONT. The opening degree of the accelerator pedal and the operating state parameters of the engine from a sensor (not shown) are input to the control circuit CONT, and the control circuit CONT drives the actuators A1 and A2 according to the operating state of the engine.

In general the intake pressure of the position of the FIG. 10 P _3, the temperature of the location of the so called T _4, subscript attached to the intake air pressure P and temperature T, the position of the enclosed numbers ○ Shows intake pressure P and temperature T.

Conventionally, in the two-shaft gas turbine engine configured as described above, in order to shorten the acceleration time t _acc of the gas generator GG and improve the acceleration performance of the vehicle, a variable nozzle is used when accelerating the gas generator GG. the degree of opening α _S of VN has been fully opened. This is because, as shown in FIG. 11, the combustor if the outlet temperature T ₄ is the same in CC, full-opening the opening alpha _S of the variable nozzle VN, i.e., toward the voltage applied to the variable nozzle VN is small gas This is because the acceleration time t _acc of the turbine GT is short.

Normally, when the gas generator GG is idling, the variable nozzle is controlled to be fully opened in order to reduce the fuel consumption.

[Problems to be solved by the invention]

However, as in the prior art, when fully opening the opening alpha _S of the variable nozzle VN in accelerating the gas generator GG, indeed, the acceleration time t _acc to the gas generator GG reaches a maximum acceleration is small, its The acceleration characteristic has a problem that the acceleration in the initial stage of acceleration is small and the acceleration rapidly increases after a predetermined time, so that the feeling of acceleration as expected in the initial stage of acceleration cannot be obtained and the driving feeling is poor.

An object of the present invention is to provide a two-shaft gas turbine engine in which a sufficient acceleration feeling can be obtained in the initial stage of acceleration of the gas generator GG and the operation feeling is improved.

[Means for solving the problem]

The two-shaft gas turbine engine of the present invention that achieves the above object is directly connected to a compressor C as shown in FIG.
A compressor turbine CT driven by combustion gas from the combustor CC, and an output turbine PT connected to a load;
In a two-shaft gas turbine engine including a variable nozzle VN provided between the output turbine PT and the compressor turbine CT, an acceleration state detecting means 1 for detecting an acceleration state of the engine from an operation state parameter of the engine; Variable nozzle drive means 2 is provided for executing control for closing the variable nozzle VN at the beginning of the acceleration of the engine, and executing control for opening the variable nozzle VN during the latter half of the acceleration period of the engine.

[Action]

According to the two-shaft gas turbine engine of the present invention, when the acceleration state of the vehicle equipped with the two-shaft gas turbine engine is detected, the variable nozzle is closed at the start of acceleration, so that the expansion ratio of the output turbine PT increases. As a result, the output increases, the output of the engine increases, and the vehicle acceleration in the initial stage of acceleration increases. Then, since the variable nozzle is opened in the latter half of the acceleration period, the output of the gas turbine itself is secured, the acceleration time is shortened, and the occurrence of surge during acceleration is reduced.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 shows a configuration of an embodiment of a two-shaft gas turbine engine of the present invention mounted on a vehicle with an automatic transmission, and has the same components as those of the two-shaft gas turbine engine shown in FIG. Are given the same symbols (symbols).

In the figure, GT is a gas turbine. The gas turbine GT has a front gear 3, a compressor C, a heat exchanger to which a fuel pump, an oil pump, a starter motor, etc. are connected.
There are a compressor turbine CT, a variable nozzle VN, a power turbine (output turbine) PT, a reduction gear R / G, etc., which are directly connected to the HE, the combustor CC, and the compressor C via a rotating shaft. The intake air is compressed by the compressor C, heated by the heat exchanger HE, mixed with fuel in the combustor CC and burned, and the combustion gas rotates the compressor turbine CT. The combustion gas that has driven the compressor turbine CT drives the power turbine PT via the variable nozzle VN, and then is discharged to the atmosphere as exhaust gas via the heat exchanger HE. A1 is an actuator for supplying fuel to the combustor CC, and A2 is an actuator for adjusting the opening of the variable nozzle VN.

The automatic transmission A / T is connected to the reduction gear R / G of the gas turbine GT, and the rotation of the power turbine PT of the gas turbine GT is reduced by the reduction gear R / G and the torque converter of the automatic transmission A / T. The transmission is transmitted to the transmission mechanism T via the T / C, and is converted into a rotational speed according to the shift state to be an axle drive output. The torque converter T / C is provided with 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.

An analog signal input interface INa receives a signal from a sensor (not shown) provided in the gas turbine GT.
N ₁ , N ₃ , N _p , P ₃ , T ₃₅ , T ₆ , analog signals from the accelerator pedal, etc. are input. The input interface INd for digital signals is an on / off signal from a key switch, and a shift from a shift lever. Digital signals such as a position signal and a brake signal from a brake are input. Where N ₁
Is the rotational speed of the rotating shaft of the gas generator GG, N ₃ is the reduction gear
R / G output shaft rotation speed, N _p is output shaft rotation speed of transmission mechanism T, P ₃ is compressor C outlet temperature, T ₃₅ is combustor CC inlet temperature, T ₆ is power turbine PT outlet temperature Is shown.

On the other hand, from the output circuit OUT, a signal Gf for instructing the fuel flow rate to the actuator A1 of the combustor CC, a signal α _S for instructing the actuator A2 of the opening degree of the variable nozzle VN,
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.

Next, the operation of the control circuit 10 in the two-shaft gas turbine engine configured as described above will be described with reference to the flowchart of FIG. 3 and the characteristic diagrams of FIGS. In addition,
Two in-shaft gas turbine engine, it is possible to control the engine by the outlet temperature T ₆ of Pawatabin PT in the steady state of the engine, the transient state of the engine, immediately after ie engine acceleration or acceleration, the outlet temperature of Pawatabin PT for the thermocouple to measure T ₆ is follow-up delay, the engine transient state is controlled by the combustor exit temperature T _4.

In step 301, the operating state parameters of the engine are input to the control circuit 10, and in step 302, the fuel flow rate Gf according to the operating state of the engine is calculated. Then, in step 303, it is determined from the operating state parameters of the engine whether the engine is in an acceleration state. The acceleration state of the engine may be determined based on the increase amount of the depression amount of the accelerator pedal within a unit time, the increase rate of the rotation speed of the rotation shaft of the gas generator GG, and the like.

Engine when it is determined that the acceleration state (YES), the process proceeds to step 305, the variable nozzle VN during acceleration opening degree alpha _S is the rotational speed N ₁ and the reduction gear R / G of the rotating shaft of the gas generator GG It is calculated as a function of the rotational speed N ₃ of the output shaft. The calculation in step 305, the opening degree alpha _S of the variable nozzle VN during acceleration in the present invention is closed is controlled so.

Engine when it is determined that no acceleration state (NO), the process proceeds to step 304, where whether or not the control is T ₄ control the current of the gas generator GG, i.e., whether the steady state immediately after acceleration is determined You. When steady state immediately after acceleration (YES), the routine proceeds to step 306 the combustor outlet temperature T ₄ is the target combustor outlet temperature T
Opening alpha _S of the variable nozzle VN is calculated to be _4set,
When acceleration is not in a steady state immediately after (NO), i.e. T ₆ when the control is variable nozzle V as Pawatabin outlet temperature T ₆ becomes the target Pawatabin outlet temperature T _6Set proceeds to step 307
Opening alpha _S of N is calculated.

When Step 305, Step 306, or Step 307 is completed, the process proceeds to Step 308, where the calculated variable nozzle VN is calculated.
Opening alpha _S and the fuel flow rate Gf, etc. is output to the gas turbine GT. Then, in step 309, the time is adjusted by a predetermined cycle time, and after the time adjustment, the process returns to step 301 and the above-described control is repeated.

Next, the gas generator G in the aforementioned step 305
It will be described an example of opening α how to determine the _S of the variable nozzle VN in acceleration G.

FIG. 4 shows the state of the combustor CC during steady operation of the engine.
Maximum temperature and the outlet temperature of Pawatabin PT of the outlet temperature T ₄
And the maximum temperature of T _6, the opening degree of the variable nozzle VN by surge α
_This shows the limit at which _S can be closed, and the closing limit value of the opening degree α _S of the variable nozzle VN is α _{S (M)} . During engine acceleration, and it assumed to be constant rotational speed N ₃ of Pawatabin PT (actual N ₃ changes to), during engine acceleration fifth
Controls the opening alpha _S of the variable nozzle VN as shown by bold lines in FIG. For example, the rotation speed N ₁ of the rotation shaft of the gas generator GG is
When accelerating from N _idle to N _rated , that is, from point A to point D
When accelerating to, as is conventional indicated by a broken line, the rotational speed N ₁
The variable nozzle VN was kept open from N _idle to N _rated , and the control was performed in the order of point A → point E → point D. In this embodiment, the variable nozzle VN is controlled when the rotation speed N ₁ is N _idle. controlled in the closing direction the opening alpha _S of VN from the point a to the opening indicated at point B, then to maintain this opening, the variable nozzle VN at point C
After overlapping the closed limit alpha _{S (M)} is controlled so as not to close beyond the closed limit value of the variable nozzle VN α _{S (M).} Then, the opening degree α _S of the variable nozzle VN is controlled to open in a direction to a point D at which the rotation speed N ₁ becomes N _rated .

As a result, the acceleration characteristic of the gas generator GG with respect to time is as shown in FIG. 6, and according to the control of this embodiment, the gas generator acceleration becomes the characteristic (α
_ST = 2.4), and according to the conventional control,
The acceleration of the gas generator GG is indicated by the broken line (α _ST = 1.
2) Looking only at the time until the acceleration reaches the maximum, the conventional control indicated by the broken line is shorter,
In the conventional control, the acceleration is small in the initial stage of acceleration, whereas in the control of this embodiment, the acceleration is large in the initial stage of acceleration, and the apparatus of this embodiment is better in acceleration feeling in the initial stage of acceleration.

FIG. 8 shows a further example of how to determine the degree of opening alpha _S of the variable nozzle VN during acceleration of the gas generator GG in step 305 described above. In this example, the opening α _S of the variable nozzle VN is controlled only by the upper limit opening α _{S6 (M)} of the variable nozzle VN at which the power turbine outlet temperature T ₆ reaches the maximum temperature in the steady state,
Opening alpha _S of the variable nozzle VN when the rotational speed N ₁ is N _idle, point A
From the upper limit opening _{αS6 (M) of the} variable nozzle VN indicated by point B from Δ
It is controlled in the closing direction until lower by alpha _S opening. After that, this opening changes in the opening direction while maintaining the opening lower by Δα _S from the closing limit value α _{S6 (M) of the} variable nozzle VN, and the rotation speed N ₁ becomes N _rated.
Is controlled from point C to point D. The opening degree Δα _S in this figure is a constant that can take a negative value to a positive value.

Figure 9 shows a further example of how to determine the degree of opening alpha _S of the variable nozzle VN during acceleration of the gas generator GG in step 305 described above. Opening alpha _S upper opening alpha _{S4 (M)} only variable nozzle VN of the variable nozzle VN combustor outlet temperature T ₄ in the steady state in the same manner in this example is the maximum temperature the rotational speed N ₁
Is N _idle, the closing direction is controlled from the point A to the opening degree lower by Δα _S from the closing limit value α _{S4 (M) of the} variable nozzle VN indicated by the point B. Then the opening is kept lower opening only [Delta] [alpha] _S varies in the opening direction from the variable nozzle VN closed limit α _{S4 (M),} the point from the point C when the rotational speed N ₁ becomes N _rated D is controlled. The opening degree Δα _S in this figure is also a constant that can take a negative value to a positive value. Further, the opening degree alpha _S of the variable nozzle VN, as indicated by a broken line, may be controlled so that the point A → point B → point E → point D.

As described above, at the start acceleration during acceleration of the gas generator GG running close controlling the opening alpha _S of the variable nozzle VN, the second half of the acceleration period is when executing a control to open the opening alpha _S of the variable nozzle VN , fuel flow rate Gf for opening alpha _S of the variable nozzle VN, the rotational speed N ₁ of the rotating shaft of the gas generator GG,
Time course of the rotational speed N ₃ of the output shaft is as Figure 7.
The broken line in this figure, performs control to open the opening alpha _S of the variable nozzle VN during acceleration of the gas generator GG.
Fuel flow rate Gf for opening alpha _S of a conventional variable nozzle VN, the rotational speed N ₁ of the rotating shaft of the gas generator GG, the rotational speed of the output shaft
Shows the time course of N _3. As described above, in the device of the present embodiment, the acceleration time of the gas generator GG is longer than that of the conventional device, but the rotation speed N ₃ of the output shaft is
Higher values are obtained than in the conventional device. That is, in the engine of the present invention including this embodiment, as shown in FIG. 6, the rise of the vehicle acceleration at the time of acceleration of the gas generator GG is accelerated, and the acceleration feeling of the vehicle is improved.

In this manner, the vehicle acceleration rises faster when the gas generator GG is accelerated because the closer the variable nozzle VN, the larger the expansion ratio P ₅ / P ₆ of the power turbine PT and the larger the output of the power turbine PT. As a result, the engine output increases and the vehicle acceleration G increases.

〔The invention's effect〕

As described above, according to the two-shaft gas turbine engine of the present invention, at the start of acceleration, control is performed to close the opening α _S of the variable nozzle VN, and during the second half of the acceleration period, the opening α _{S of the} variable nozzle VN is controlled. By executing the control to open the power, the expansion ratio of the power turbine increases in the initial stage of acceleration, and the output increases,
Since the output of the engine is increased and the vehicle acceleration is increased, the rise of the vehicle acceleration is accelerated and the driving feeling of the vehicle is improved.

[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 two-shaft gas turbine engine of the present invention,
FIG. 3 is a flowchart showing an example of a control procedure of the control circuit of FIG. 2, and FIG. 4 is a maximum temperature of a combustor outlet temperature and a power turbine outlet temperature during steady engine operation, and a limit of a variable nozzle opening due to a surge. FIG. 5 is a diagram showing an example of control of the variable nozzle according to the present invention at the time of engine acceleration, FIG. 6 is a diagram showing acceleration characteristics by the control of FIG. 7 Figure fuel flow to the variable nozzle control according to the present invention, the gas generator speed and diagrams showing the Pawatabin rotational speed characteristic with time, Figure 8 and Figure 9 is N ₁ showing a modified embodiment of FIG. 5 - α _S characteristic diagram, 10th
FIG. 11 is a diagram showing a general configuration of a conventional two-shaft gas turbine engine, and FIG. 11 is a diagram showing a combustor outlet temperature-acceleration characteristic. 1 ... Acceleration state detecting means, 2 ... Variable nozzle driving means, C ...
Compressor, CC: Combustor, CT: Compressor turbine, HE: Heat exchanger, PT: Power turbine, VN: Variable nozzle.

Claims (1)

(57) [Claims] 1. A compressor turbine (CT) directly connected to a compressor (C) and driven by combustion gas from a combustor (CC), and a power turbine (P) connected to a load.
T) and a variable nozzle (VN) provided between the output turbine (PT) and the compressor turbine (CT). Acceleration state detection means (1) for detecting a state; control for closing the variable nozzle (VN) in the initial stage of engine acceleration; and control for opening the variable nozzle (VN) in the latter half of the engine acceleration period. And a variable nozzle drive means (2) for performing.