RU2466287C1 - Control method of gas-turbine engine with afterburner, and system used for its implementation - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: control of gas-turbine engine (GTE) with afterburner is performed as per one of three control loops; individual control programme is specified on each loop and corrected as per certain group of sensors the readings of which are the most essential for operation exactly in that mode.

EFFECT: invention allows improving operating reliability and safety of GTE with afterburner of airborne vehicle due to reducing the time of augmented and full acceleration of GTE and expansion of safe startup area of afterburner, and providing GTE operation in wide range in optimum modes.

2 cl, 1 dwg

Description

The group of inventions relates to the field of aircraft engine manufacturing and can be used in electronic-hydromechanical systems for automatic control of multimode gas turbine engines (GTE) with afterburner combustion chamber (FCC).

There is a known method of controlling a gas turbine engine with an FCC, which consists in the fact that the fuel consumption in the FCC is controlled by the measured air temperature at the inlet of the gas turbine engine, the air pressure behind the compressor, the position of the engine control lever (ORE) and the fuel consumption in the main combustion chamber (ACS), by the position of the throttle and the pressure drop across the turbine form the specified position of the valves of the critical section of the jet nozzle (PC) of the gas turbine engine, compare it with the measured position of the valves of the PC valve and, using the magnitude of the mismatch between the set and measured values, form the control yayuschee impact on the PC drive valves.

(see Shlyakhtenko S. M. "Theory of jet engines", Moscow, Engineering, 1975, p.305-308).

As a result of the analysis of this method, it should be noted that it is characterized by insufficient speed of the pressure ratio control loop in the given cross sections of the gas turbine engine, and therefore, the deviation of the gas turbine engine parameters in transition modes, especially when igniting the FCS, is very significant. This, in turn, leads to a decrease in the reliability of the gas turbine engine and, as a consequence, to a decrease in the flight safety of the aircraft. In addition, when starting the engine, positioning the PC leads to large fuel withdrawals from the pump, which reduces the frequency of autorotation of the compressor rotor and the pressure behind the fuel pump.

A known GTE control system comprising two control loops, the first of which includes a speed sensor connected to a main speed controller, the output of which is connected to a servo-drive of the fuel control valve. This circuit also contains a master controller. The second control loop regulates the gas temperature in front of the turbine and contains a temperature sensor connected to the first input of the regulator, the second input of which is connected to the limit temperature setter. The system also contains a second speed sensor, the output of which is connected to the first input of an additional speed controller, the second input of which is connected to the output of a nonlinear link associated with the output of the process parameter controller. The outputs of the speed controllers are connected to the inputs of the selector, the output of the selector is connected to the first input of the adder, the second input of which is connected to the feedback sensor by the position of the fuel regulating body (dispenser).

During the operation of the system, the controller output signal, which represents the difference between the output signal of the nonlinear link and the speed sensor signal, passes through the selector (until the temperature limit value is reached), goes to the adder, where it is summed up with the feedback sensor signal and fed to the input of the set point, which controls the servo speed controller. When the gas temperature in front of the turbine is reached, the signal from the temperature controller, which is fed to the selector, and the speed signal, the control signal from the selector, are fed to the adder and then to the regulator and control of the fuel control valve.

(see USSR AS No. 591024, class F02C 9/00, 1979).

As a result of the analysis of the known gas turbine engine control system, it should be noted that it regulates the gas turbine engine according to two parameters - the rotor speed and the gas temperature in front of the turbine. However, this system is very complex, has a fairly large inertia, which does not allow its effective use in the operation of gas turbine engines in transient limit and afterburner modes.

A known method of debugging a gas turbine engine with a FCS, implemented by a system that is equipped with a temperature sensor (T _t ) of gases behind the turbine, a differential pressure sensor of gases on the turbine (π _t ), an automatic control _device (F _gf ) by a signal (π _t ), a hydraulic cylinder position sensor ( GC) nozzles, automatic afterburner fuel with a tuning element.

The system also contains a control panel connected by inputs to the sensors named above. The remote control includes a signal converter, a calculator connected to the converter, a comparison element associated with the outputs of the converter and the calculator.

In operation of the system to the input signals from the sensor signal transmitter receives temperature (T _m) for the gas turbine and the hydraulic cylinders with the position of the nozzle probe. At the output of the signal converter, a single digital code of sensor signals is generated, which is fed to the input of the calculator. The signals from the output of the signal converter are supplied to the computing device for calculating the required value of the PC area according to the formula

,

,

where F _gf and F _gm are the areas of PC in afterburner and afterburner modes, respectively, T _t and T _fzad are the measured and set values of the gas temperature behind the turbine. When debugging dual-circuit gas turbine engines, the required value of the PC area is determined by the formula

,

,

where T _2t is the temperature of the gases behind the turbine after mixing both flows.

The signal from the output of the computing device characterizing a given area of the PC is fed to the input of the comparison element, where a control signal is generated.

During the operation of the gas turbine engine in afterburner mode, signals from the gas temperature sensor of the nozzle and the position sensor of the hydraulic cylinders of the nozzle are input to the signal converter. The converted signal from the output of the signal converter is fed to the input of the comparison element, where it is compared with the calculated value (F _gf ). At the output of the comparison element, a signal ΔF is generated, according to which the setting of the fuel supply unit changes due to a change in the position of the tuning element.

A command to change the setting of the block is given (in manual or automatic mode) until the passage area PC becomes equal to the required value of F _gf (ΔF = 0).

(see RF patent No. 2383001, IPC F01M 15/00. 2010).

As a result of the analysis of the known system, it should be noted that it, like the ones given above, is rather inertial, which does not provide the specified quality of regulation in transient and afterburner operation modes of a gas turbine engine.

Closest to this invention in terms of technical nature and technical result achieved is a control method for a gas turbine engine with FCS, according to which the fuel consumption in the FCS is controlled by the measured air temperature at the inlet of the gas turbine engine, the air pressure behind the compressor, the throttle position and the fuel consumption in the ACS, according to the position The throttle throttle and the pressure drop across the turbine form the specified position of the valves of the critical section of the PC GTE, compare it with the measured position of the valves of the PC and the value of the mismatch between the set and measured value they form a control action on the drive of the PC shutters, and additionally control the amount of mismatch between the set and measured values of the position of the shutters PC, and if the mismatch exceeds the set value determined in advance from the results of the gas turbine test, limit the rate of change in fuel consumption in the FCC.

The system for implementing the method comprises a series-connected sensor block, a master of afterburner GTE operating modes, a first adder, a first electrohydroconverter, an afterburner fuel dispenser, and a second adder input connected to the sensor block. The system also includes a second PC positioner, a second adder, a second electrohydroconverter, a PC actuator hydraulic control spool, connected in series, the second master and the second adder input connected to the sensor unit, the output of the second adder connected to the first master.

In the process of the system operation, according to the temperature measured at the inlet of the gas turbine engine with the sensor block, the air pressure behind the compressor, the throttle position and fuel consumption in the ACS, the first controller generates a predetermined dispenser position, which in the adder is compared with the actual position measured with the sensor block. By the magnitude of the mismatch entering the first electrohydraulic converter, a control action is formed on the dispenser, in accordance with which the fuel consumption in the FCC is regulated.

At the same time, according to the position of the throttle and the pressure drop across the turbine, measured using the sensor block, the second setter generates a predetermined position of the shutters PC.

The signal of the set position of the shutters PC is fed to the second adder, where it is compared with the position measured by the sensor unit and, according to the size of the mismatch between the set and measured values, the second electrohydroconverter controls the shutters of the PC shutters by moving the spool to the corresponding position.

With serviceable elements of the PC control loop (second electro-hydraulic converter, slide valve), the actual position of the PC shutters differs from the set one practically only in dynamic modes, and taking into account that the set position of the PC shutters changes quite smoothly, the size of the mismatch between the set and actual positions in the dynamically debugged system does not exceed the specific value of the tolerance inherent in the gas turbine engine control system. However, in operation there are situations when the amount of mismatch at certain times can exceed this value (for example, during “mashing” of the hydraulic cylinders of the PC drive, at the time of a sharp increase in the required fuel consumption, when the inertia of the fuel pump does not allow an instantaneous increase in the available flow rate, etc. ) In this case, an imbalance arises between the air flow through the gas-air duct (GW) of the gas turbine engine and the fuel consumption in the FCC. To avoid this, the amount of mismatch between the set and actual positions of the PC shutters from the output of the second adder is fed to the first setter, which, when the set value is determined in advance during the gas turbine test, limits the rate of change of afterburner fuel consumption.

(see RF patent No. 2387857, class F02C 9/28, 2010) is the closest analogue for the method and system.

As a result of the analysis of the data of the method and system, it should be noted that they provide a balance between the air flow through the GVT GTE and the fuel consumption in the FCC. However, the known method and system do not take into account the various requirements for the degree of expansion of gases on the turbine at different gas turbine operation modes, they are characterized by insufficient speed, and the deviation of the gas generator (GG) parameters from the FCS established during ignition is counterbalanced by limiting the rate of change in fuel consumption in FCC, and therefore, by increasing the time of afterburner throttle response.

The technical result of the claimed group of inventions is to increase the reliability and safety of a gas turbine engine with the FCC of an aircraft (LA) by reducing the time of afterburner and full acceleration of a gas turbine engine and expanding the area of reliable launch of the FCC, as well as ensuring the operation of a gas turbine engine in a wide range at optimal conditions.

The essence of the claimed group of inventions is illustrated by drawings, which show a diagram of the control system of a gas turbine engine with a FCC.

The system comprises a first adjuster 1 for generating a setpoint value for the position of the distribution valve, a second adjuster 2 for generating a setpoint value for the position of the PC PC;

Structurally, the controller 4 may be an amplifier.

The system is equipped with a third setter 5 for generating a predetermined value of the degree of expansion of gases on the turbine, the output of which is connected to the first input of the second comparison element 6, the output of the second comparison element 6 is connected with the first input of the controller 7 of the degree of expansion of gases on the turbine.

Structurally, the regulator 7 may be an amplifier.

The outputs of the first master 1, controller 4 and controller 7 are connected to the inputs of the switch 8 of the PC control modes, with the input of which is also connected the first output of the logical unit 9 of the formation of the command to select the control mode PC. As switch 8, a standard multiplexer can be used. The logical unit is made in a known manner, in particular, can be implemented on comparators, logical elements, AND, OR.

The system also contains a third comparison element 10, the first input of which is connected to the output of switch 8, and the output is connected through a series-connected amplifier 11 and an electrohydraulic amplifier (EHU) 12 with a distribution valve 13, which controls the position of the PC PC. To complete the system, a commercially available unit is used as an EHU.

The position of the spool 13 is monitored by a sensor 14 connected to the second input of the third comparison element 10. The spool 13 is hydraulically connected to the hydraulic cylinders 15 that control the critical section of the PC, the position of the working element (rod) of which is monitored by the sensors 16 of the position of the PC center connected to the second input of the first comparison element 3.

GTE is indicated by 18, and the values of its parameters during operation are monitored by sensors conventionally shown in the drawing as block 18. To control the PC area, the following sensors are used: pressure behind the compressor - (P _to ); pressure behind the turbine - (P _t ); rotational speed of a turbocompressor rotor - (n _TC ); air temperature at the inlet of the gas turbine engine - (T _in ), the position of the engine control knob (ORE) (α _ore ). ORE is indicated by 21.

The outputs of the sensors (P _k ) and (P _t ) are connected to the inputs of the divider 19, the output of which is connected to the second input of the second comparison element 6. As a divider 19 in the system, a standard arithmetic device can be used.

The outputs of the sensors n _TC and T _I connected to the inputs of the block 20 calculating the reduced rotational speed of the rotor of the turbocompressor (n _TKpr, ), the output of which is connected to the input of the second setter 2.

The output of the sensor T _I also connected to the input of the third master 5.

The outputs of the sensors n _TK and α _ores are connected to the inputs of the logic unit 9, the second output of which is connected to the input of the master 1.

The system is equipped with standard sensors that are used for their intended purpose.

As the first setpoint, a standard device can be used that produces a constant signal at the output.

As the second and third adjusters, known matrix devices for implementing arbitrary functional dependencies can be used.

The implementation of the blocks, components and assemblies of the system, not given in this application, is known and does not constitute the subject of patent protection.

The control method of a gas turbine engine with a FCC using the above control system is as follows.

The operation of the system during the implementation of the method will be considered in the following modes: gas-turbine engine start-up, gas-turbine engine throttle operation modes, maximum afterburner and afterburner operation modes, gas-turbine engine shutdown.

The launch of a gas turbine engine is carried out by transferring to Ore 21 to a small gas (MG) platform or higher. In this case, the rotor of the shopping mall spins. The values of the position of the ore and the rotational speed of the _{fuel cells by the} corresponding sensors are transmitted to the input of the logical block 9. Block 9 generates a control signal to the input of the switch 8 when the following conditions are met: _ore at the MG site or higher (α _ore = α _RUDmg ) And the rotation speed of the _{fuel cell is} lower than the rotation speed TC in MG mode (n _TC <n _TKmg ). According to this signal, the switch 8 (if it has not been previously translated) is put into a position in which the output of the first master 1 is connected to the first input of the third comparison element 10, the input of which receives a control signal from the second output of the logical unit 9. As a result, it is generated in the master 1 the control signal amplified by the amplifier 11 is transmitted to the ECU 12, which moves the distribution valve 13 to the neutral position.

It should be noted that the control unit 1 generates a predetermined constant value of the position of the distributor spool 13 PC (Lz _{CONST neutral} ), as a result of which the spool is set to the neutral position, which is constant, which allows for minimal fuel leakage through the PC control unit. The predetermined constant value of the position of the distribution valve 13 PC is calculated in a known manner from the parameters of the shutter positioning unit PC.

When the ore is moved above the MG site, the TC rotation frequency increases and the gas turbine engine reaches throttle operation modes. According to the measurements of the sensors (n _TC and α _ORE ), in accordance with the conditions “ORE above the MG site and below the MAKS platform” (maximum GTE operating mode) AND “TC speed is higher than the TC speed in the MG mode and lower than the TC speed in the mode MAX ”(α _RUDmg = α _RUD <α _RUDmax AND n _TKmg = n _TK <n _TKmax ), the logic unit 9 generates a command to switch switch 8 to the position at which the output of controller 4 is connected to the input of the third comparison element 10. In these modes, GC PC positioning program to maintain the required area riticheskogo PC section depending on the relative frequency of rotation of the low pressure compressor rotor. In parallel, the value from the sensors (n _TC , T _I ) is supplied to the input of block 20, in which the reduced value of the parameter (n _TKpr ) is _calculated according to the dependence:

Block 20 can be implemented on a matrix device for implementing arbitrary functional dependencies.

The value obtained in block 20 (n _TKpr ) is supplied to the input of the setter 2, in which the program of the set position of the SC PC is formed according to the dependence of the SC _pos = f (n _TKpr ). The preset value of the position of the PC GC is supplied to the first input of the first comparison element 3, the second input of which receives the position of the PC GC 15 measured by the sensor 16.

On the comparison element 3 compares the set value of the position of the HZ PC from the output of the setter 2 with the actual value of the position of the HZ 15 PC. The output of the comparison element 3 is the value of the mismatch, which is fed to the input of the controller 4. In accordance with the size of the mismatch, the controller 4 proportionally generates the set value of the position of the spool 13, which is fed to the first input of the third element of the comparison 10, where it is compared with the current position of the spool the control signal obtained as a result of the comparison, amplified by the amplifier 11, is supplied to the EHU 12, which moves the distribution valve 13 to a predetermined position, respectively In the proper way, it manages the HZ 15 PC.

When the ore is moved from the throttle mode area to the MAKS platform, the rotational speed of the fuel cell reaches its maximum value and the gas turbine engine reaches its maximum operating mode. When the ore is moved above the MAX site, the afterburner of the combustion chamber (FCC) is ignited and the gas turbine engine enters the afterburner operation mode.

Logic unit 9 analyzes the readings of the sensors (n _TK and α _ORE ) and, in accordance with the conditions "ORE at the MAX site or higher" AND "the rotation speed of the _{fuel cell} is equal to the frequency of rotation of the _{fuel cell} in the MAX mode" (α _ORE = α _RUDmax And n _TK = n _TKmax ), gives a control signal to switch 8, according to which switch 8 is switched to a position in which the output of controller 7 is connected to the first input of the third comparison element 10.

The third setter 5 for the measured parameter T _I forms a predetermined value of the degree of expansion of gases on the turbine. In this case, the dependence π _T = f (T _in ) is used.

For 18 sensors the measured pressure values P _k and P _m divider 19 generates a current value of the expansion ratio of the turbine gases, as the ratio of P _{to T} to P. The comparison element 6 compares the set value and the actual value π _t , and according to the magnitude of the error obtained as a result of the comparison, the regulator 7 proportionally generates the set value of the position of the distribution valve 13.

Thus, at these operating modes, a predetermined pressure ratio in the selected engine sections is maintained (for example, the ratio of pressure behind the TC to pressure behind the turbine is the degree of expansion of gases on the turbine).

When the ore is moved below the MAKS site, the TC rotation frequency decreases and the turbine engine switches to throttle operation modes.

According to the measurements of the sensors (n _TK and α _ores ), under the conditions α _RUDmg = α _RUD <α _RUDmax AND n _TKmg = n _tk <n _TKmax ), block 9 generates a command to switch switch 8. Switch 8 is switched to the position at which the output of controller 4 is connected to the input of the third comparison element 10. In these modes, the PC PC positioning program is again run to maintain the required critical section area PC depending on the reduced rotor speed of the low-pressure compressor.

When the ore is moved below the MG site, the engine is stopped, while the TC speed drops below the TC speed in the MG mode.

In the shutdown mode of the gas turbine engine when the ore conditions are below the MG site and the TC speed is lower than the TC speed in the MG mode (α _ORE <α _RUDmg And n _TC <n _TKmg ), logic unit 9 sends a command to the _control unit 1 to change the set position of the spool ( Lz _{CONST neutral} ) to the position at which the PC opening flow rate (Lz _{CONST-opening} ) is supplied to the power HZ 15. The logic unit 9 also switches the switch 8 to the position where the switch 1 is connected to the first input of the comparison element 10. During the run-off of the rotors of the fuel cell, the fuel pump continues to operate and the HZ 15 shift the PC to the full opening position. After stopping the gas turbine engine, this position is maintained until its next launch. An open nozzle on a stopped gas turbine engine facilitates inspection of the FCC during maintenance of a gas turbine engine.

One control loop does not meet the requirements for regulating the PC GTD in all operating modes.

At the start of the gas turbine engine, it is necessary to ensure minimal leakage through the GC PC positioning unit and unload the fuel pump and turbocharger shaft; to do this, position the control valve in the neutral position all the time during start-up.

To ensure the required quality of PC control, minimize the influence of perturbations exerted on the GG parameters when changing the degree of gas turbine engine acceleration, ensure the gas-dynamic stability reserves of the compressor and obtain the specified gas-turbine thrust, it is advisable to use a control loop for the degree of gas expansion on the turbine. However, the use of this circuit in the throttle operation modes of a gas turbine engine at subcritical pressure drops on a PC does not provide the required control accuracy. Therefore, in throttle operation modes, it is necessary to use a circuit to maintain a given area of the PC.

For the convenience of technical maintenance of a gas turbine engine (for example, inspection of an afterburner), a fully open nozzle on a stopped gas turbine engine is required. To fulfill this requirement, a spool positioning loop is used to a predetermined position.

Thus, the control of the gas turbine engine with the FCC is carried out according to one of the three control loops; an individual control program is set on each of the loops, which is adjusted according to a specific group of sensors, the readings of which are most important for operation in this particular mode. This allows you to significantly simplify the process of managing the operation of a gas turbine engine and at the same time make it more efficient.

Claims (2)

1. A method of controlling a gas turbine engine with an afterburner, which consists in the fact that during operation of the engine, sensors measure engine performance, compare them with the set values and control the position of the spool valve controlling the hydraulic cylinders that control the position of the shutters of the critical section of the jet nozzle engine, characterized in that when starting the engine, the distributor valve is moved to the neutral position, in throttle mode the engine operation determines the reduced rotor speed of the turbocompressor and the position of the hydraulic cylinder of the jet nozzle and according to the results of comparing these signals, a control signal is obtained, according to which the position of the distribution valve is maintained to maintain a given area of the jet nozzle at maximum afterburner and afterburner modes according to the measured pressure values in two given sections of the engine form the current value of the pressure ratio in these sections, which is compared with the set m value and the largest error resulting from the comparison is formed setpoint position distribution spool and the motor when stopping distribution spool is moved into position for complete disclosure of the nozzle. 2. A control system for a gas turbine engine with a boost combustion chamber, comprising a control unit, a comparison element, a position regulator for the hydraulic cylinders of the jet nozzle, serially connected electro-hydraulic converter and a distribution valve for controlling the hydraulic cylinders of the jet nozzle with a position sensor for the cylinder of the jet nozzle and sensors of motor parameters: rotational speed of the turbocompressor rotor, temperature at the inlet to the engine, pressure in two sections of the engine and a position sensor engine control knobs, characterized in that the system is equipped with a position sensor for the distribution nozzle of the jet nozzle, a second and third adjuster, a second and third comparison elements, an amplifier, a logic unit, a switch, a divider, a pressure ratio regulator in two engine sections, a unit for calculating the reduced speed rotor of a turbocompressor, the first and second inputs of which are connected with temperature sensors at the inlet to the engine and rotational speed of the rotor of the turbocompressor, respectively, and the output is connected to the first master, the output of which is connected to the first input of the first comparison element, the second input of which is connected to the position sensor of the hydraulic cylinder of the jet nozzle, and the output is with the position regulator of the hydraulic cylinders of the jet nozzle, the input of the second master is connected to the temperature sensor at the engine inlet, and the output connected to the first input of the second comparison element, the second input of which is connected to the output of the divider, and the output is connected to the input of the pressure ratio regulator in two sections of the engine, with the input of the third setter the second output of the logical unit is knitted, while the outputs of the third setter, the position regulator of the hydraulic cylinders of the jet nozzle, the pressure ratio regulator in two sections of the engine and the first output of the logical unit are connected to the inputs of the switch, the output of which is connected to the first input of the third comparison element, the second input of which is connected to the position sensor of the distribution valve, and the output is through an amplifier with a servo-connected electro-amplifier and a distribution valve controlling the position hydraulic cylinders of the jet nozzle, while the inputs of the logical unit are connected to the sensors of the position of the engine control lever and the rotor speed of the turbocompressor, and the inputs of the divider are connected to pressure sensors in two given engine sections.

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