JPS5918239A - Control apparatus for gas-turbine engine - Google Patents

Abstract

PURPOSE:To prevent misfiring of a gas-turbine engine and to improve its performance, by employing such an arrangement that an ignition plug attached to a combustor of the gas-turbine engine is always kept in operation during operation of the engine. CONSTITUTION:In a gas-turbine engine which is equipped with a combustor 6 for burning fuel ejected from a fuel injection valve 48 under supply of air compressed by a compressor and heated by a heat exchanger, the combustor 6 is provided with an ignition plug 51 operable at the time of starting and also at the time of engine operation other than that in addition to a conventional ignition plug 50 used for starting the engine. These ignition plugs 50, 51 are controlled respectively by ignition circuits 43, 44 which are controlled by a microcomputor 38. That is, at the time of starting a gas turbine, spark discharge is produced by the ignition plug 50 by operating the ignition circuit 43. At the time of ordinary operation of the engine, on the other hand, the ignition plug 51 is set into operation. Further, at the time of transient period such as acceleration and deceleration of the engine, both of the above two ignition plugs 50, 51 are operated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a two-shaft gas turbine engine for an automobile, and particularly to an exhaust purification function.

As a control device for a conventional two-shaft gas turbine engine for automobiles (hereinafter referred to as gas turbine).

For example, there is Japanese Patent Application Laid-Open No. 52-47113.

Gas turbine combustion is continuous combustion under low pressure.
The maximum temperature of the flame is low compared to the temperature of the piston engine. Therefore, since the amount of CO, HC, and NOx emitted is small, an exhaust purification device as large as that of a piston engine is not required.

However, as shown in FIG. 6, the amount of NOx emitted is larger than that of CO and HC, so it is necessary to reduce it.

There is a first-order method for reducing NOx.

A. Two-stage combustion method In this method, combustion air is supplied in two stages.In the first stage, combustion is performed at an air ratio of 1 or less, and then in the second stage, the insufficient amount of air is sent in to quickly start the first combustion. This method completes combustion.

B. Water injection method In this method, atomized water or steam is injected near or upstream of the flame in the combustor to lower the temperature of the flame and reduce the number of flames.

C1 Water and fuel emulsion method A large amount of water and fuel are mixed in the form of micron-sized particles, which are then injected and combusted.

D. Catalytic combustor system A device that burns vaporized fuel through a catalytic reaction.

E. Uniform lean mixture system Usually uses a mixture with an air-fuel ratio of about 30 to 40.
However, this method reduces NOx by burning a lean mixture with an air-fuel ratio of about 50 to 60.

] Of the methods A to E, methods A to D (Ma) have difficult countermeasures for automobile gas turbines in terms of cost, reliability, and engine design.

On the other hand, method E is easy to put into practical use.

It is also the most promising because it also has the effect of improving fuel efficiency.

However, if a lean mixture is simply used, there are problems in that misfires tend to occur and drivability during acceleration etc. deteriorates.

The present invention has been made in view of the above problems, and N
It is an object of the present invention to provide a control device that effectively reduces oy and eliminates the risk of misfire.

”-In order to achieve the above-mentioned objects, in the present invention.

The air-fuel mixture is set to be leaner than before, and the dual ignition device is always activated during operation to prevent misfires.

Further, in the present invention, a plurality of ignition devices are provided, and only one of them is activated during normal operation, and a
During sudden acceleration, etc.), all ignition devices are activated and the mixture is controlled to be richer than during normal operation, thereby preventing misfires and improving drivability. There is.

The present invention will be described in detail below based on the drawings.

FIG. 1 is a schematic diagram of a gas turbine to which the present invention is applied.

In FIG. 1, a compressor turbine 2 is shown.

A compressor 1 is driven via a compressor shaft 3. This compressor 1 (not shown) sucks air from an air intake, compresses it, and sends it to the heat exchanger 5. The air preheated by the heat exchanger 5 flows into the combustor 6.

Fuel is injected into the combustor 6 from a fuel injection valve (not shown). This fuel is combusted together with preheated air in the heat exchanger 5. The gas heated by the combustion first drives the compressor turbine 2 to rotate. The gas that rotated the compressor turbine 2 also rotates the power turbine 7 via the variable nozzle 8, passes through the heat exchanger 5,
After warming the air taken in from Compresosa 1, it is released into the atmosphere. The power turbine 7 rotates a transmission gear 10 once through a power turbine shaft 9, and drives wheels 12, which are loads, through a drive shaft 11.

Next, control of the gas turbine will be explained using FIGS. 2 and 3.

FIG. 2 is a conceptual diagram of closed loop control.

In FIG. 2, 13 is a gas turbine main body.

In closed-loop control, the target rotation speed setter 14 first determines the target rotation speed based on the amount of accelerator pedal depression, which is the required value for the rotation speed, and then sets the fuel value corresponding to the target value to the controller 1.
5 and drives the fuel system 16 including the fuel injection valve to rotate the compressor turbine (not shown, 2 in FIG. 1). This rotational speed is detected by the rotation sensor 17, the deviation from the aforementioned target rotational speed is calculated, and the deviation is controlled to be zero.

On the other hand, the target temperature setting device 18 sets a predetermined target temperature value to be the most efficient according to the number of rotations.

Generated and output by a function generator. The controller 19 outputs a control signal according to this target temperature value, ii
The opening degree of the J-variable nozzle 20 (corresponding to 8 in FIG. 1) is controlled.

The opening degree of this variable nozzle 20 is also the same as in the fuel system described above.
Feedback control is performed so that the deviation between the actual temperature detected by the gas temperature sensor 21 (for example, the combustor output temperature) and the target temperature value becomes zero.

Next, FIG. 3 is a diagram showing the conceptual diagram shown in FIG. 2 in more detail.

In Fig. 3, +N81 is a signal that gives the target rotation speed immediately after starting, and N82 is a signal that gives the target rotation speed during low-speed idling immediately after starting.
Either one is selected by Wl, and -next delay circuit 2
2 and is sent to the adder 23.

Further, Nsa is a signal that gives a target rotational speed during idling that is higher than the above-mentioned NSI + NS2, and Ac is a signal that gives a target rotational speed corresponding to the accelerator pedal opening.

These signals NS3. AC is also switch sw2
．． It is sent to the adder 23 via SW, 3. These switches SW, -SW, 3 are opened and closed depending on the operating state.

After the above signals are added by an adder 23, they pass through a limiter 24 that determines the maximum rotation speed and are sent to the deviation detection circuit 25 as a target rotation speed signal S1.

The deviation detection circuit 25 outputs a deviation signal S3 corresponding to the deviation between the actual rotational speed signal S2 sent from the 9th rotation sensor 17 and the target rotational speed signal S1.

The minimum value priority circuit 26 selects the smaller of the temperature deviation signal S8 (to be described later) and the deviation signal S3 (described above) as the minimum value signal S.
Output as 4.

The PID circuit 27 adds a value proportional to the minimum value signal S4, an integrated value, and a differentiated value to generate a control signal S5.
make.

This control signal S5 is sent to the drive circuit 29 via the switch SW4. The drive circuit 29 outputs a drive signal S7 corresponding to the control signal S5, thereby causing the fuel injection valve 30 to
The amount of fuel necessary to drive the engine to the target rotation speed is supplied to the gas turbine J3.

Note that the switch SW4 is connected to the PIDM path 27 side during normal operation, but is switched to the starting fuel setting circuit 28 side for a certain period of time at the time of starting.

The starting fuel setting circuit 28 outputs a signal S6 that provides an appropriate fuel injection amount at starting. The value of this signal S6 is determined depending on the temperature and other operating parameters, and changes depending on the elapsed time from the start of the engine.

On the other hand, temperature control is performed by controlling the opening degree of the -DJ variable nozzle 37.

First, the function generator 31 calculates a target temperature signal according to a predetermined function according to the value of the actual rotation speed signal S2,
The target temperature signal S9 is outputted by adding correction based on the atmospheric temperature To, etc. to the target temperature signal S9. This target temperature signal S9 is the operational amplifier 3
2.

The target temperature signal S9 is sent to the deviation detection circuit 34 through a limiter 33 that determines the maximum temperature.

The deviation detection circuit 34 outputs a deviation signal S8 corresponding to the deviation between the actual temperature signal S+o (value corresponding to the gas temperature) sent from the gas temperature sensor 21 and the output of the limiter 33 described above. This is sent to the minimum value priority circuit 26 mentioned above.

The target temperature signal S9 is also sent to the deviation detection circuit 35, where a deviation signal SO corresponding to the deviation from the actual temperature signal SIO is detected.

This deviation signal 811 is sent to the drive circuit 36 via switch SW5.

The drive circuit 36 generates a drive signal 8 corresponding to the deviation signal 811.
12, thereby controlling the opening degree of the variable nozzle 37 so that the gas temperature matches the target temperature.

Note that TR is a signal for controlling the opening degree of the variable nozzle 37 to a specific position suitable for the conditions when accelerating, TR2 when decelerating, ST when starting, and RE when avoiding surging. Switch S in each case
The corresponding one of W6 to SW9 is turned on, and a necessary signal is sent to the drive circuit 36.

Note that at this time, the switch SWs is turned off.

Furthermore, by providing a variable guide vane at the inlet of the compressor 1 shown in Fig. 1 and giving appropriate swirl to the air entering the compressor 1, fuel consumption at the same rotation speed of the compressor can be reduced and fuel consumption during idling can be improved. It is also practiced to make

Next, FIG. 4 is a diagram showing an embodiment of the present invention.

In FIG. 4, the control microcomputer 38 includes a CPU 39. Input/output device 40. RAM41. R
Consists of OM42, two igniters 43.4
One ignition signal S13.4 controlling the ignition signal S13. Output S14.

Further, the accelerator position signal 815 is a signal corresponding to the depression angle of the accelerator pedal, and the neutral signal 816 indicates that the transmission (corresponding to 10 in Fig. 1) connected between the gas turbine and the load is neutral. This is a signal indicating that

Furthermore, in the combustor 6, air (indicated by broken lines in the figure) that has been compressed by the compressor 1 in FIG.

On the other hand, fuel supplied through the fuel pipe 49 is injected from the fuel injection valve 48, swirled while being mixed with intake air by the swirler 47, and ignited by the spark plug 50 to be combusted. The resulting high-temperature, high-pressure combustion gas 45 is passed through a variable nozzle 8 to a compressor turbine 7.
sent to.

In a gas turbine, once 7 ignition occurs.

After that, combustion will continue automatically without the need to activate the spark plug. For this reason, conventional ignition systems are designed to operate only at the time of starting.

The ignition circuit 43 and the spark plug 50 (hereinafter referred to as the first ignition device) in FIG. 4 are the ignition device for starting as described in 1. It can be operated at all times even during normal operation.

The ignition circuit 44 and the ignition plug 51 (hereinafter both will be referred to as a second ignition device) are provided for the first time in the present invention.

The control according to the present invention will be explained below.

FIG. 5 is a flowchart showing an embodiment of control according to the present invention.

In Fig. 5, first, in order to start the gas turbine,
Turn on the starter switch with Pl.

At P1, it is determined whether the transmission is in neutral, and at P3, it is determined whether the rotation speed of the compressor turbine is O (ie, stopped). This determination is made according to the neutral signal 816 and the actual rotational speed signal S2 shown in FIG.

If at least one of Pl and P3 is NO, the process goes to P4, and starting is prohibited. At this time, a lamp, buzzer, etc. may be used to indicate that starting is prohibited.

Next, when Pl and P3 are both YES, that is, the transmission is in neutral (neutral position for manual transmissions, neutral range or parking range for automatic transmissions), and the compressor turbine has stopped. If so, the process goes to P5, where the starter motor is activated and the ignition circuit 43 of the first ignition device is activated to cause the first ignition plug 50 to generate a spark discharge.

Next, in P6, time is counted and it is determined whether or not the elapsed time since the start of the above operation has reached a predetermined time t1.

The above elapsed time is 1. When it reaches Pl, it starts injecting the starting fuel.

As a result, when ignition is successful and the gas turbine starts self-sustaining operation, the process goes to P8 and normal control of the fuel injection amount and variable nozzle opening degree is performed.

This normal control is basically the same as the explanation in FIG. 3, but the following two points are different in the present invention.

First, in the conventional control device, the ignition device stops when the second ignition is successful, but in the case of the present invention, the first ignition device continues to operate even after ignition, and always ignites. .

Further, the conventional air-fuel mixture (during normal operation) has an air-fuel ratio of about 30 to 40, but in the case of the present invention, the air-fuel ratio is set to about 50 to 60. Even if such a lean mixture is used, there is no risk of misfire because the fuel is always ignited.

Next, while the gas turbine is operating, acceleration/deceleration of the rotational speed is determined at predetermined intervals (P9).

The acceleration/deceleration can be determined according to the accelerator position signal 815 and the actual rotational speed signal S2.

If the accelerator position l signal 815 is an analog voltage signal corresponding to the depression angle of the accelerator pedal as described above, acceleration or deceleration can be determined from the value of the voltage or the rate of change of the voltage.

If the master accelerator position signal SI5 is a switch signal that turns on and off depending on the depression angle of the accelerator pedal,
It may be configured such that a predetermined period of time from turning on the switch is determined as acceleration, and a predetermined period of time from turning off the switch is determined to be deceleration.

Further, it can also be determined based on the degree of increase or decrease in the rotation speed of the compressor turbine given by the actual rotation speed signal S2.

If YES in P9, that is, during acceleration/deceleration, the air-fuel ratio fluctuates transiently and misfires are likely to occur, so PIO also activates the ignition circuit 44 of the second ignition device, and both the first and second ignition devices ignite. Do the following.

When igniting with both ignition devices like this.

Even if the air-fuel ratio fluctuates, there is less risk of misfire.

Note that the ignition circuit 43 for starting normally operates at a relatively low voltage (
A high energy (about 3kV) and high energy (05 to 2J) CDI ignition system is used. When the voltage is low and the energy is high as described above, the life of the spark plug 50 tends to be shortened.

Therefore, when starting is completed with the first ignition device, the 11th ignition device is stopped and the second ignition device is activated. 7. During normal operation, the second ignition device is always activated.

The configuration may be such that both the first and second ignition devices are activated during acceleration and deceleration.

As the above-mentioned second ignition device, if the ignition energy is the same, using a high-pressure device will extend the life of the ignition plug 51 and is suitable for constant operation.

FIG. 7 is an example of a CDI ignition system.

In FIG. 7, the DC-AC converter 53 is connected to the NOTSUTTE!
J 52 converts direct current to alternating current. The alternating current is boosted by a step-up transformer 54, rectified by a diode 55, and stored in a capacitor 56. Trigger circuit 58 receives ignition signal SI3. from microcomputer 38. When SI4 (occurs at a predetermined period) is applied, the bird outputs signal SI7. When the trigger signal 817 is applied to the thyristor 57, the thyristor 57 becomes conductive, whereby a current due to the charge in the capacitor 56 flows to the step-up transformer 59, and a high voltage is generated on the secondary side. The high voltage causes a spark discharge at the ignition plug 50 or 51, causing ignition.

Normally, an ignition device with an output voltage of about 3 kV is used as a starting ignition device, but in the case of an ignition device that constantly ignites according to the present invention, a high voltage of 5 kV or more is better.

In addition, in the case of high pressure and high energy, the above CDI
Instead of an ignition system, it is also possible to use an ignition coil type ignition system that is used in ordinary gasoline engines, but whose energy is increased to a desired value.

Note that the value of the type 1 ignition energy of the ignition device (it may be appropriately selected according to the characteristics of the gas turbine, the value of the air-fuel ratio, the cost, etc.).

In addition, in the embodiments shown in FIGS. 4 and 5, a case is illustrated in which there are two ignition devices, a first and second ignition device, and the operation of the ignition devices is controlled according to the operating condition, but the embodiments have only one ignition device. , it may be configured to operate constantly from the time of startup.

Furthermore, in the embodiment shown in FIG. 5, both ignition devices are configured to operate only during acceleration and deceleration, but there are other operating conditions in which misfires are particularly likely to occur, such as during startup, or when the outside temperature is extremely low. Both ignition devices are configured to operate even when the battery voltage is low (the ignition energy is less than the energy needed to turn the starter, and the probability of saving a misfire can be increased). It's okay.

Also, depending on various parameters indicating the operating state of the gas turbine, such as the target rotation speed and actual rotation speed of the compressor turbine, the target value and actual temperature of the inlet temperature of the compressor turbine, and the target value and actual temperature of the outlet temperature of the power turbine. The configuration may be such that the operation of the ignition device is switched.

Next, FIG. 8 is a flowchart 1 showing another embodiment of the control of the present invention.

The embodiment shown in FIG. 8 is obtained by adding pH and PI2 to the embodiment shown in FIG. 5, and increases the fuel injection amount by detecting sudden acceleration.

That is, in the present invention, since a leaner air-fuel mixture is used in the large II engine than in the past, an increase in 9 ignition energy alone inevitably leads to poor acceleration and drivability during sudden acceleration.

Therefore, during sudden acceleration, both the first and second ignition devices are activated, and the fuel injection amount is also increased to make the air-fuel mixture somewhat richer, thereby improving acceleration performance.

Further, it is preferable that Pal be configured to detect not only sudden acceleration but also all operating conditions in which it is particularly preferable to enrich the air-fuel mixture, such as during acceleration from idling, at startup, and at the start of running.

Furthermore, if the amount of increase in fuel for PI2 is determined as a function of engine temperature, acceleration, etc. can be effectively improved without significantly increasing the amount of exhaust from PI2.

As explained above (in the present invention, the air-fuel mixture is set leaner than before, and the ignition device is configured to operate at all times, so the NOx components in the exhaust gas can be removed to a large extent without the risk of misfire. It is possible to reduce the fuel consumption and also improve fuel efficiency.

Also, especially during operating conditions where misfires are likely to occur.

By configuring the engine to operate a plurality of ignition devices, misfires can be more effectively prevented.Furthermore, in certain operating conditions, the configuration is configured to operate a plurality of ignition devices and increase the amount of fuel injection. This makes it possible to prevent acceleration and drivability from deteriorating even when a lean mixture is used.

[Brief explanation of the drawing]

Figure 1 is an example of a gas turbine to which the present invention is applied;
The figure is a schematic block diagram of closed-loop control. Fig. 3 is a detailed block diagram of closed loop control, Fig. 4 is an embodiment of the present invention, Fig. 5 is a flow chart showing an embodiment of the control of the present invention, and Fig. 6 is an exhaust gas component concentration characteristic diagram. 7 is an example of an ignition system, and FIG. 8 is a flowchart showing another embodiment of the control of the present invention. Explanation of symbols 1...Compressor 2...Compressor turbine 3...Compressor shaft 5...Heat exchanger 6...Combustor 7...Power turbine 8...Variable nozzle 9...Power turbine Shaft 10...Transmission gear 11...Drive shaft 12...Axle
13... Gas turbine main body 14... Target rotation speed setting device 15... Controller 16... Fuel system 17...
Rotation sensor 18...Target temperature setting device 19...
Controller 20...Variable nozzle 21...Cast temperature sensor 22...-Next lag circuit 23...Adder 24...Limiter 25...Deviation detection circuit 26...Minimum value priority circuit 27... ... PII) circuit 28... Starting fuel setting circuit 29... Drive circuit 30... Fuel injection valve 31... Function generator 32... Operational amplifier 33... Limiter
34.35... Deviation detection circuit 36... Drive circuit
37...Variable nozzle 38...Microcomputer 39...CPU 40...I/O device 41...R, AM 42...ROM43
, 44... Ignition circuit 45... Combustion gas 46...
・Liner 47...Swirer 48...Fuel injection valve 49...Fuel pipes 50, 51...Spark plug attorney Junnosuke Nakamura Figure 4

Claims (1)

[Scope of Claims] ] A control device for a gas turbine engine configured to operate a spark plug provided in a combustor of the gas turbine engine at all times during engine operation. 2. A means for detecting a plurality of spark plugs provided in the combustor and a specific operating condition in which a misfire is particularly likely to occur; and 2. Activating one spark plug during normal operation. 9. The gas turbine engine control device according to claim 1, further comprising means for operating all the spark plugs during the specified operation. 3゜ The gas turbine engine according to claim 2, characterized in that the number of spark plugs to be operated is switched according to the rotational speed value of the compressor turbine, the actual rotational speed, or the temperature of each part of the engine. H-equipment F
t. 4 In a gas turbine engine, a combustor is equipped with multiple spark plugs.9 During normal operation, one spark plug is activated and the air-fuel ratio of the air-fuel mixture is lean to about 50 to 60, and during specific operating conditions all spark plugs are activated. A control device for a gas turbine engine configured to operate a spark plug and increase the amount of fuel to make the air-fuel ratio of the air-fuel mixture smaller than the value indicated in the figure. 5. The gas turbine engine according to claim 4, characterized in that the specific operating conditions in item 1 are at startup, at the start of running, at sudden acceleration, and at acceleration from an idling state. Control device. 6. The control device for a Tsukas turbine engine according to claim 4, characterized in that the amount of fuel increase in the specific operating state is set in accordance with the engine temperature.