JPH02267328A - Controller of gas turbine engine and controlling method - Google Patents

Abstract

PURPOSE: To improve controllability and reliability by forming an error signal representative of the difference between a target engine condition signal and an actual engine condition signal, adjusting the gain of the error signal to be equal to the desired change in the engine parameter, and controlling an actuator. CONSTITUTION: In a controller 300 for controlling the position of a variable exhaust nozzle of a gas turbine engine, a means 320 for receiving the target engine operating temperature is connected to an input of a first comparing means 322, and an error signal representative of the difference to a signal 324 indicative of the actual engine operating temperature is generated. This error signal is input into a gain means 330, and the gain of the error signal is adjusted to be equal to the desired change in the engine parameter. The output of the gain means 330 is input into a first combination means 334 through a first set of dynamics 332 and connected to the output of a means 336 for receiving the position of a target variable exhaust nozzle, and the variable exhaust nozzle is drive-controlled by an actuator 344 on the basis of the output of the means 334.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a gas turbine engine.
In particular, the present invention relates to a control device for controlling the thrust of a gas turbine engine having a variable exhaust nozzle.

BACKGROUND OF THE INVENTION In gas turbine engines, it is typically desirable to control the engine's thrust output. Changes in engine thrust power may occur for a variety of reasons, including sudden transient reductions in thrust power in response to temporary reductions in turbine efficiency. For example, a decrease in turbine efficiency occurs following a period of rapid acceleration. During periods of acceleration, the tip clearance between the engine's turbine and shroud increases for a short period of time due to differential thermal expansion between the engine components. Additionally, the thrust power of the engine gradually decreases over time, corresponding to the gradual deterioration of the engine components. Typically, an engine manufacturer will provide an appropriate thrust margin to allow for this reduction in thrust, and to ensure that the engine does not exceed the minimum thrust that the engine will have over the life of the engine before being overhauled. I'm trying to meet the level.

Thrust margin is achieved by isothermally maintaining the engine turbine temperature at the highest level to provide the required thrust while protecting the engine components from excessive temperatures when the engine is operating at maximum thrust. is representative. By maintaining the turbine temperature isothermally, the operating temperature of the new engine is significantly higher than that required to obtain the required thrust. However, if the turbine temperature is maintained isothermally, the thrust and fan operating lines do not remain constant as degradation occurs. Therefore, as the engine deteriorates, eventually
In order to obtain the maximum thrust levels that are only occasionally required, it becomes necessary to maintain the temperature practically isothermally. Therefore, for most of the engine's operating life, the engine must be operated at a temperature higher than that required to maintain the desired thrust level. As a result of this need to operate at higher temperatures, the engine deteriorates more quickly, thus requiring frequent overhaul and increasing operating costs. An alternative to maintaining turbine temperature isothermally is to monitor the engine pressure ratio. In such a pressure ratio control system, the temperature of 7! is higher than the temperature required to maintain the desired thrust. Although it is not necessary to run the engine at i degrees, this control system requires a pressure sensor to be added to the engine. These sensors increase the cost of the engine and, moreover, the addition of these sensors and associated controls results in additional maintenance and reliability costs associated with adding additional components to the engine. It will be necessary to pay attention.

SUMMARY OF THE INVENTION A gas turbine engine control system of the present invention includes means for receiving a signal representing a first target engine operating condition and means for receiving a signal representing an actual engine condition.

The control system further includes comparison means for generating an error signal representative of the difference between the target signal and the actual engine condition signal, and adjusting the gain of the error signal to equal the desired change in the parameter of the engine to be controlled. and gain means. The output of this gain means is coupled to an activator of the engine which controls the above parameters.

In another form of the invention, a control system for a gas turbine engine includes means for receiving a signal representative of a target engine condition;
and means for receiving a signal representative of actual engine conditions. Comparison means generates an error signal representative of the difference between the target engine condition signal and the actual engine condition signal. Gain means: - adjust the gain of said error signal to equal the desired change in the adjustable engine component;

The controller further couples means for receiving a signal representative of a target position for the adjustable engine component and means for receiving a signal representative of a target position for the adjustable engine component. Have the means. The combination gain means and adjustable engine component target position means are coupled to an engine activator that controls the adjustable engine component.

The invention also provides a method for controlling a gas turbine engine, the method comprising: receiving a signal representing a target engine condition; receiving a signal representing an actual engine condition; and combining the target engine condition signal and the actual engine condition signal. An error signal representative of the difference is generated. Adjust the gain of the error signal to be equal to the desired change in the engine components. further receiving a signal representative of a target position for the adjustable engine component and combining the output of the gain means with means for receiving a signal representative of the target position for the adjustable engine component;
The outputs of the combined gain means and adjustable engine component target position means are then coupled to an engine activator for controlling the adjustable engine component.

Specific Configuration First, FIG. 1 shows one form of a gas turbine engine to which the present invention relates, generally designated by 10. This gas turbine engine 10 includes a first compressor 20 that generates downstream flow.
, the second compressor 28 is located downstream of the first compressor 20, the combustor region 32 is located downstream of the second compressor 28, and
A first turbine 36 and a second turbine 38 are each located downstream of the combustor region 32 and a variable exhaust nozzle 4
0 is located downstream of the first turbine 36 and the second turbine 38. The control device 50 includes, for example, a temperature sensor 52,
The controller 50 receives inputs such as from a fan speed sensor 54 and an input indicative of a power level angle (PLA).
The output of the variable exhaust nozzle 40 and the combustor region 3
Controls the amount of fuel flow to 2.

FIG. 2 shows a control system 200 that does not have the advantages of the present invention. This controller 200 partially controls the position of the variable exhaust nozzle 40. The controller 200 includes means 210 for receiving the PLA demand signal and means 212 for generating a variable exhaust nozzle demand signal based on the value of the signal received by the receiving means 210. Variable exhaust nozzle demand signal generating means 212 is coupled to means 214 for combining the various signals. The controller 200 further comprises means 220 for receiving a maximum allowable engine operating temperature, which is coupled to an input of the first comparison means 222. Means 224 for receiving the actual engine operating temperature is also coupled to the human power of first comparing means 222 . The first comparing means 222 includes means for generating a temperature error signal representing the difference between the signal received from the actual temperature receiving means 224 minus the signal received from the maximum temperature receiving means 220. The output of the first comparing means 222 is coupled to an integrator 230 .
The output of is coupled to one of the signal combining means 214. The output of the signal combining means 214 is transmitted to the second comparing means 240.
and the output of the latter is coupled to a set of dynamics 242
The output of dynamics 242 is coupled to engine 2
Actuator 244 for moving 46 variable exhaust nozzles
An engine sensor 248 coupled to and sensing the position of the variable exhaust nozzle is coupled to an input of the second comparing means 240 .

In operation, controller 200 receives a PLA demand signal from PLA signal receiving means 210, and the control system generates a variable exhaust nozzle demand signal based on the PLA signal. Typically, the maximum level of thrust (
thrust) and without afterburner, the variable exhaust nozzle indicates that the nozzle should be in its narrowest position.

The variable exhaust demand signal is adjusted to prevent the engine from exceeding the maximum allowable temperature. To effectuate this adjustment, a signal representative of the actual engine temperature is obtained from the actual temperature receiving means 224 and a signal representative of the maximum allowable engine operating temperature is obtained from the maximum engine temperature receiving means 220. These signals are sent to comparison means 222 which generates a temperature error signal which is sent to integrator 230 which adjusts the signal. Integrator 23 of the control device
0 attempts to bring the temperature error to zero, thus causing the combination means 214 to adjust the variable exhaust demand signal such that the engine operates at the highest allowable temperature. The adjusted variable exhaust demand signal is sent to the dynamics set 242;
The dynamics condition the signal into a form appropriate for control of the exhaust nozzle by actuator 244. Actuator 244 moves the nozzle position of engine 246 and sensor 248 generates feedback information regarding the position of the exhaust nozzle. Therefore, the control device 200 controls the engine such that at maximum thrust without afterburner, the engine temperature is equal to the maximum allowable value. Operating at the maximum permissible temperature results in operating a new, undegraded engine at a temperature significantly higher than that required to achieve the required thrust level. Operating the engine at such elevated temperatures results in the engine deteriorating more quickly, thus requiring more frequent overhauls and increasing operating costs.

FIG. 3 illustrates one embodiment of the invention in which a portion of controller 300 controls the position of a variable exhaust nozzle. In this control system 300, a means 320 for receiving a target engine operating temperature is coupled to an input of a first comparison means 322.

A means 324 for receiving the actual engine operating temperature is also coupled to an input of the first comparison means 322. First comparison means 32
2 includes means for generating a temperature error signal representing the difference between the signal received from the actual temperature receiving means 324 minus the signal received from the target temperature receiving means 320. The output of the first comparison means 322 is coupled to a gain means 330, the output of the gain means 330 being coupled to a first set of dynamics 332. The output of the first dynamics 332 is coupled to a first combining means 334 for combining the various signals. Means 336 for receiving the position of the target variable exhaust nozzle is also coupled to the second input of signal combining means 334 .

The output of the first signal combining means 334 is output from the second comparing means 340.
the output of the second comparison means 340 is coupled to a second set of dynamics 342, the output of the second dynamics 342 is coupled to an actuator 344 for moving a variable exhaust nozzle of an engine 346, and An engine sensor 348 , such as a linear differential transformer, that senses the position of the exhaust nozzle is coupled to an input of the second comparing means 340 .

This control device is typically a digital electronic control (D
E C) or full digital electronic control (FADEC)
). Target engine operating temperature receiving means 320 typically receives a number of inputs such as fan inlet temperature and ambient pressure.

Typically, these inputs are compared to a schedule for a new, undegraded engine and a target engine operating temperature is obtained based on that schedule. Schedules are typically obtained by examining performance under various conditions using an engine performance model. Alternatively, an adjustable controller may be used to analyze actual engine performance.

Target variable exhaust nozzle position receiving means 336 also typically receives a number of human inputs, such as fan inlet temperature and ambient pressure. Typically, these manpower forces are compared to a schedule for a new, undegraded engine and a target engine exhaust nozzle position is obtained based on that schedule. Therefore, like the 7R degree schedule, the variable exhaust nozzle position schedule is typically obtained using a cycle model or by analyzing actual engine performance.

Preferably, the means 324 for receiving the actual engine operating temperature is an input port of the electronic control unit that receives an output from an engine temperature sensor. Typically, the second
The exhaust gas temperature of the turbine 38 or the low pressure turbine temperature is detected. As shown in FIG. 3, the means 324 for receiving the actual engine operating temperature is coupled to a temperature lead compensation network 360 that compensates for delays in temperature sensing, and the output of the lead compensation network 360 is coupled to a lead compensation network 360 that compensates for delays in temperature sensing. 1 comparison means 322.

Gain means 330 is typically selected to produce a constant thrust. Gains are based on engine data or cycle estimates and are used to determine how much the variable exhaust nozzle position must open as engine temperature increases to keep thrust constant.

As shown in FIG. 4, the appropriate gain can be obtained by testing the engine to identify a line of constant thrust and taking the slope of this line. For example, for a change in temperature above the target temperature (down) versus a change in variable nozzle position (in square inches), the constant thrust line has a slope of about 0.0971 n2/down, so the gain is 0.097. However, it must be understood that the gain is also a complex function or schedule that requires human effort for various engine conditions to achieve the correct gain for a given set of conditions.

In operation, the control system 300 receives the actual temperature receiving means 32.
4, which is processed by advance compensation network 360 to compensate for delays in temperature sensing. A signal representative of the target engine operating temperature for the base engine is transmitted to the target engine temperature receiving means 320.
get by.

The first comparison means 322 generates a temperature error signal representative of the difference between the actual engine temperature and the target temperature. This temperature error signal is sent to gain means 330 which adjusts the value of the error signal to obtain a signal representative of the proportional change in the variable exhaust nozzle. The output of the gain means 330 is routed to a first set of dynamics 332 which provide compensation to ensure stability while maintaining the appropriate gain (this can be done using standard techniques). Means 336 for receiving the target variable exhaust nozzle position includes:
A signal is generated representing a target nozzle position representative of a base or standard engine, eg, a new engine. This variable exhaust target signal is then combined with the output of the first set of dynamics 332 in a first signal combining means 334 . The output of the first signal combining means 334 provides an exhaust nozzle control signal based on the target position adjusted by the difference between the actual temperature and the target temperature. The output of the combining means 334 is sent to a second set of dynamics 342, which dynamics 342
adjusts signals for control of the exhaust nozzle by actuator 344 that adjusts the position of engine component 346;
The engine sensor 348 then provides feedback information regarding the position of the exhaust nozzle, after which the second comparison means 34
Subtract this feedback information from the desired signal by 0.

Therefore, the control system of FIG. 3 has many advantages over the control system of FIG. The control system of FIG. 3 does not operate continuously at the maximum allowable temperature. Instead, the engine is controlled to maintain constant thrust. Therefore, this result:
The engine operates at significantly lower temperatures for most of its operating life, and as the engine gradually ages, the engine operating temperature increases and the variable exhaust nozzle changes from its nominal position to produce constant thrust power. . Typically, the engine of the present invention is overhauled when the operating temperature reaches the maximum operating temperature, which is the normal operating temperature of the engine of FIG. Operating the engine at lower temperatures increases the time interval between overhauls, thus reducing operating costs. Furthermore, unlike the control system of FIG. 2, the control system of FIG. 3 can compensate for sudden transient decreases in engine efficiency by operating at constant thrust. These advantages are achieved without additional sensors or associated controls by simply incorporating sensors and controls typically used in gas turbine engines.

In FIG. 5, a portion of the control device 500 is shown as
Another embodiment of the present invention is shown for controlling the position of zero. This control device 500 includes means 5 for receiving a PLA demand signal.
10 and a means 512 for generating a variable exhaust nozzle demand signal based on the PLA signal 510. The controller 500 further includes means 520 for receiving a target engine operating temperature coupled to an input of a comparing means 522 .

Means 524 for receiving the actual engine operating temperature is also coupled to an input of comparison means 522. The output of the first comparing means 522 is coupled to a gain means 530 .
The output of is coupled to a first set of dynamics 532. The output of the first dynamics 532 is coupled to signal combining and comparing means 533. Means for receiving target variable exhaust nozzle position 536 and variable exhaust signal means 512
are also respectively coupled to inputs of signal combining and comparing means 533. The signal combination and comparison means 533 is connected to the first dynamics 532 and the target nozzle position receiving means 53.
6 is added, and the output of variable exhaust signal means 512 is subtracted. The output of combination and comparison means 533 is coupled to the input of augmentor fuel comparison means 537. The output of the fuel comparison means 537 is coupled to the engine's augmentor fuel control (WFR), and the output of the fuel comparison means 537 and the output of the variable exhaust signal means 512 are both coupled to a second comparison means 540, which The output of 540 is coupled to a second set of dynamics 542, the output of second dynamics 542 is coupled to an actuator 544 that moves a variable exhaust nozzle of engine 546, and an engine sensor 548 that senses the position of the variable exhaust nozzle. ,
For example, a linear differential transformer is coupled to the input of a fuel comparison means 537, which fuel comparison means 537 is connected to the engine sensor 5.
The output of the combination/comparison means 533 is subtracted from the output of 48.

The control device of FIG. 5 is typically implemented similarly to the embodiment of FIG. In operation, controller 500 controls P
The controller receives the PLA demand signal by the LA signal receiving means 510 and generates a variable exhaust demand signal based on the PLA signal. Typically, at maximum levels of thrust and without afterburner, a variable exhaust nozzle indicates that the nozzle should be in its narrowest position. This signal is then adjusted to compensate for engine temperature. Therefore, a signal representing the actual engine temperature is received from the actual temperature receiving means 524 and a signal representing the target engine operating temperature is obtained from the target engine temperature receiving means 520.

These signals are fed to a first comparing means 522, a gain means 530 making appropriate adjustments to the signals in response to proportional changes in variable exhaust nozzle position, and a first dynamics 532 making necessary compensations to ensure stability. and the combination/comparison means 533 receives the target variable exhaust position receiving means 53.
6. Match the outputs of the first dynamics 532 and the variable exhaust signal means 512. Comparison means 537 subtracts the output of combination and comparison means 533 from the output of engine sensor 548 to generate a signal to the augmentor fuel control system. Comparison means 540 subtracts this augmentor fuel signal from the output of variable exhaust signal means 512 to generate an exhaust nozzle control signal, which is processed by a second set of dynamics 542 to output an exhaust nozzle control signal via actuator 544. is the control signal.

Therefore, the control device of FIG. 5 also controls the exhaust nozzle position to maintain a constant thrust based on, for example, the deviation of the characteristics of the new, undegraded engine from the target position. Note that although the position of the PLA provides input to the augmentor fuel control system, at maximum thrust the exhaust nozzle position is independent of the PLA. Similar to FIG. 3, the controller senses the position of the PLA and energizes the controller of FIG. 5 when the PLA is set to maximum thrust.

Although preferred features of the invention have been described, the invention is equally applicable to other embodiments. For example, the controller could control other engine components, such as a variable core, in which case the schedule and gain means would be modified accordingly, eg, to include a target core position.

The components expressed by the means of this invention may also be realized by separate components or concretely realized as a plurality of components of a single program. Therefore, such changes and modifications are also included within the scope of the present invention.

[Brief explanation of drawings]

Fig. 1 is a schematic cross-sectional view of a typical gas turbine engine to which the control device of the present invention is applied, Fig. 2 is a block diagram of the control device, and Figs. 3 and 5 show the body length of the control device of the invention. A block diagram showing different embodiments, and FIG. 4 is a graph showing the relationship between temperature change and exhaust nozzle area. Description of main symbols 300, soo: control device, 320.520: target engine operating lH degree receiving means, 322.522-first comparison means, 324.5247 actual temperature receiving means, 332.532: first set of dynamic 334: Signal combining means, 336.536: Target variable exhaust nozzle position receiving means, 340.540: Second comparison means, 342.542: Second set of dynamics, 344.5
44: Actuator, 346.546: Engine, 348.548: Engine sensor, 360: Advance circuitry, 510: PLA. 512: Variable exhaust demand signal, 533: Combination and comparison means, 537: Augmentor fuel comparison means. FIG. FIG. FIG.

Claims (1)

[Scope of Claims] 1. Means for receiving a signal representing a first target engine operating condition, means for receiving a signal representing an actual engine condition, and an error signal representing a difference between the target signal and the actual engine condition signal. gain means for adjusting the gain of said error signal to equal a desired change in the parameter of the engine to be controlled; and coupling the output of said gain means to an activator of the engine for controlling said parameter. A control device for a gas turbine engine, comprising means for controlling a gas turbine engine. 2. The control system of claim 1, wherein said means for receiving a signal representative of actual engine conditions is means for receiving actual engine temperature. 3. The control device according to claim 2, wherein the means for receiving the actual engine temperature is means for receiving the temperature of the low pressure turbine. 4. Further comprising: means for receiving a signal representing a target position for said parameter to be controlled; and means for coupling the output of said gain means to said means for receiving a signal representing a target position for said parameter to be controlled. The control device according to item 1. 5. The control device according to claim 4, wherein the means for receiving a signal representing a target position for the parameter to be controlled is means for receiving a signal representing a target position for a variable exhaust nozzle of the engine. 6. A control device for a gas turbine engine having a variable exhaust nozzle, comprising means for receiving a signal representing a target engine temperature, means for receiving a signal representing an actual engine temperature, and a combination of the target temperature signal and the actual engine temperature signal. a comparison means for generating an error signal representative of the difference; gain means for adjusting the gain of the error signal to equal a desired change in position of the variable exhaust nozzle; and a signal representative of the target position for the variable exhaust nozzle. means for receiving; and means for receiving a signal representing a target position for the variable exhaust nozzle; and coupling the combined gain means and variable exhaust nozzle target means to an activator of the engine for controlling the variable exhaust nozzle. A control device for a gas turbine engine, comprising means. 7. The control device according to claim 6, wherein the means for receiving the actual engine temperature is means for receiving the temperature of the low pressure turbine. 8. means for receiving a signal representative of a target engine condition; means for receiving a signal representative of an actual engine condition; and comparison means for generating an error signal representative of the difference between the target engine condition signal and the actual engine condition signal; gain means for adjusting the gain of the error signal to equal a desired change in the adjustable engine component; means for receiving a signal representative of a target position for the adjustable engine component; an engine activator for combining an output with means for receiving a signal representative of a target position for said adjustable engine component, said combination gain means and said adjustable engine component target position means for controlling said adjustable engine component; and means for coupling to a gas turbine engine. 9. The control device according to claim 8, wherein the target engine condition is an engine temperature, and the actual engine condition is an actual engine temperature. 10. The control system of claim 9, wherein the means for receiving the actual engine temperature is means for receiving the temperature of the low pressure turbine. 11. The control system of claim 8, wherein the adjustable engine component is a variable exhaust nozzle. 12. receiving a signal representing a target engine condition, receiving a signal representing an actual engine condition, generating an error signal representing a difference between the target engine condition signal and the actual engine condition signal, and adjusting a gain of the error signal; adjusting the output of the gain means to equal a desired change in the adjustable engine component and receiving a signal representative of a target position for the adjustable engine component; a gas turbine engine comprising: a means for receiving a signal indicative of position; and coupling the output of the combined gain means and adjustable engine component target position means to an activator of the engine for controlling the adjustable engine component. control method.