RU2468257C2 - Gas turbine engine control method - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention can be used in electronic hydro mechanical automatic control systems (ACS) of gas turbine engines (GTE). The essence of the invention consists in the fact that in addition, in all GTE operating modes - from idle to maximum - air pressure is measured after GTE compressor, relative change and relative speed of air pressure change after compressor is calculated, relative pressure change is compared to the first pre-set value determined for each type of GTE experimentally, and relative speed is compared to the second pre-set value determined for each type of GTE experimentally; if relative pressure change is more than the first pre-set value and relative speed is more than the second pre-set value, SURGING signal is shaped, supplied to the display in the crew cabin and elimination of surging is started; besides, in addition to fuel trip there opened are air bypass valves from behind intermediate stages of GTE compressor and from behind GTE compressor, and ignition unit is activated for the pre-set period of time determined by means of calculations and experiments; if, as a result, relative pressure change becomes less than the first pre-set value, and relative speed becomes less than the second pre-set value, SURGING signal is cancelled and GTE control is performed in compliance with normal control programmes; at that, the programme restricting the fuel consumption to GTE combustion chamber is reduced by the pre-set value for the pre-set period of time, the values of which are determined by means of calculations and experiments.

EFFECT: higher GTE operating reliability owing to performing the actions allowing to take GTE compressor from surging without repeated surging.

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Description

The invention relates to the field of gas turbine engine building and can be used in electronic hydromechanical systems (ACS) for automatic control of gas turbine engines (GTE).

There is a known method of controlling a gas turbine engine, which consists in the fact that a signal from a surge signaling device disables the gas turbine engine, I. Keba “Flight operation of helicopter gas turbine engines”, Moscow, “Transport”, 1976, p. 33-35.

The disadvantage of this method is its low efficiency and the inability to use helicopters and aircraft included in the composition of single-engine power plants.

Closest to the present invention, the technical essence is a method of controlling a gas turbine engine, which means that on a running engine, using a surge signaling device, the start of compressor surge is determined, to stop the surge, a stop valve (KO) is turned on and the fuel supply to the combustion chamber (KS) of the gas turbine engine is stopped for a predetermined time, depending on the characteristics of the gas turbine engine, after this time has passed, the fuel supply system is turned off and the fuel supply to the gas turbine engine is resumed, Cherkasov B. A., “Automation and regulation of the WFD”, M., “Mechanical Engineering”, 1988, p. 111- 112.

The disadvantage of this method is the following. The cessation of fuel supply to the COP usually provides the output of the engine compressor from surging. But the process of restoring gas dynamic stability (GDU) reserves of a compressor is highly dependent on the individual characteristics of a gas turbine engine. This is especially true of modern gas turbine engines (PS-90A, PS-90A1, PS-90A2), the gas generators of which are "squeezed" in the sense of gas-turbine engine reserves to ensure the economic performance of the engine.

This leads to the fact that, for modern gas turbine engines, the proposed method of restoring fuel consumption (after a predetermined time - in the same volume) can aggravate the condition of the engine - if the engine has not yet surged by the time the predetermined time expires, or cause a second surge - if, by the time the predetermined time has elapsed, the engine has not yet gained the required supply of the GDU.

This reduces the reliability of the engine and may lead to the need to turn it off. This reduces the reliability of the gas turbine engine and the safety of the aircraft (LA).

The aim of the invention is to improve the quality of work of self-propelled guns in terms of protecting a gas turbine engine from surging and, as a result, improving the reliability of a gas turbine engine and the safety of aircraft.

This goal is achieved by the fact that in the method of control of the gas turbine engine, which consists in the fact that the CT is switched on and the fuel supply to the gas turbine engine is stopped for a predetermined time, depending on the characteristics of the gas turbine engine, to stop the flow of fuel and stop the flow fuel in the gas turbine engine, additionally at all gas-turbine engine operating modes from “small gas” to maximum, the air pressure is measured behind the gas-turbine compressor, the relative change and the relative rate of change of air pressure per with a pressor, the relative pressure change is compared with the first predetermined value determined experimentally for each type of gas turbine engine, and the relative speed is compared with the second predetermined value determined for each gas-turbine engine type experimentally, if the relative pressure change is greater than the first predetermined value, and the relative speed is greater the second in advance of the set value, the signal "Surge" is generated, give it to the indicator in the cockpit and begin to eliminate surging, and in addition to the cutoff in Liva, open the air bypass valves because of the intermediate stages of the gas turbine compressor and because of the gas turbine compressor and turn on the ignition unit for a predetermined time determined by calculation and experimental means, if after that the relative pressure change is less than the first predetermined value, and the relative speed less than the second predetermined value, remove the signal "surge" and carry out the control of the gas turbine engine in accordance with standard control programs, while the program limits the fuel consumption in the compressor station underestimate on predetermined value at a predetermined time in advance, whose values are determined by computational and experimental.

The figure shows a diagram of a device that implements the inventive method.

The device contains series-connected sensor unit 1 (DB), electronic controller 2 (RED), dosing unit 3 (DG), stop valve 4 (KO), and DG 3 is connected to BD 1, and KO 4 is connected to RED 2, command unit 5 (KA), the input of which is connected to RED 2, and the output to the unit 6 of the executive valves (AIC).

RED 2 is an on-board computer system, which includes input / output devices and a computer that contains the processor part, a constant, operational and reprogrammable memory area.

The device operates as follows.

The pilot controlling the gas turbine engine using the engine control lever (ORE is not shown in the drawing), the position of which is measured with the help of DB 1, sets the gas turbine engine operation mode: start, low gas, nominal mode, maximum mode.

The position of the throttle throttle is transmitted from DB 1 to RED 2. RED 2 in accordance with the throttle position according to the signals of the sensors of the air flow parameters at the engine inlet and the parameters of the gas generator obtained from DB 1 according to known dependencies (see, for example, the book by I. Keb . “Flight operation of helicopter gas turbine engines”, Moscow, “Transport”, 1976, pp. 117-135) calculates the required fuel consumption in the gas turbine engine and the preset position of the mechanized gas turbine engine mechanization elements (air bypass valves due to intermediate stages - ZPV KND - not shown in the figure, air bypass valves and compressor - CPV KVD - the figure is not shown, the inlet guide vane apparatus - BHA - not shown in the figure). The fuel consumption in the compressor station is controlled by the RED 2 commands with the help of DG 3 and KO 4. During normal operation, the gas turbine engine KO 4 is in the “Open” position. The position of the mechanization of the gas turbine compressor is controlled by the commands of RED 2 with the help of KA 5 and AIK 6. In addition, RED 2 can issue control commands to the “Surge” indicator in the cockpit and the ignition unit (A3) - not shown in the drawing.

Additionally, at all modes of operation of the gas turbine engine from “small gas” (for the PD-14 engine developed by Aviadvigatel OJSC, Perm, this is 5000 rpm in terms of high-speed rotor speed n _ind ) to the maximum (n _ind = 14000 rpm ) in RED 2 using DB 1 measure the air pressure behind the compressor of the gas turbine engine and calculate the relative change in air pressure behind the compressor and the relative rate of change of air pressure behind the compressor, compare the relative change in pressure with the first predetermined value determined for each type of gas turbine engine exp experimentally, and the relative speed with a second predetermined value determined experimentally for each type of gas turbine engine:

Where

- размах пульсационной составляющей давления воздуха;

- the range of the pulsating component of the air pressure;

- максимальное давление за каждый цикл колебаний давления при вознкиновении помпажных явлений в компрессоре ГТД;

- the maximum pressure for each cycle of pressure fluctuations during the occurrence of surge phenomena in the gas turbine compressor;

A is the first predetermined value (for PD-14, this value varies in the range from 0.4 to 0.55 depending on the particular engine, the value of A is specified and entered into the non-volatile memory of RED 2 during the final test of the gas turbine engine);

Where

- величина изменения давления за время Δτ;

- the magnitude of the pressure change over time Δτ;

- величина давления в момент перед началом изменения давления в интервале времени Δτ;

- pressure value at the moment before the beginning of the pressure change in the time interval Δτ;

Δτ is the time interval (for PD-14 this value is 0.01 s);

B - the second predetermined value (for PD-14, this value is 7).

If the relative change in pressure is greater than the first predetermined value, and the relative speed is greater than the second predetermined value, at the output of the RED 2 form the commands according to which

- light up the “Surge” indicator in the cockpit;

- turn on the CO (transfer it to the “Closed” position) and stop the fuel supply to the gas turbine engine for a predetermined time (for PD-14 this time is 0.3 s);

- using KA 6 and AIK 7 open the air bypass valves due to the intermediate stages of the gas turbine compressor (ZPV KND) and because of the gas turbine compressor (KPV KVD);

- turn on the ignition unit АЗ for a predetermined time (for PD-14 this time is 10 s).

If after this the relative change in pressure has become less than the first predetermined value, and the relative speed has been less than the second predetermined value, the signal "Surge" is removed and, according to the commands of the RED 2, with the help of DG 3, KA 5, AIK 6, they control the gas turbine in accordance with control programs, moreover, the fuel consumption limitation program in a gas turbine engine underestimates a predetermined value in advance by a predetermined time, the values of which are determined by calculation and experimental means (for PD-14, for example,

where Gt is the given fuel consumption in the compressor station;

- величина давления воздуха за компрессором;

- value of air pressure behind the compressor;

n _{vd pr} - the rotational speed of the high pressure rotor, given by the air temperature at the engine inlet, is underestimated by 10% for a period of 4 s).

Thus, the quality of the self-propelled guns is improved in terms of protecting the gas turbine engine against surge: actions are taken to remove the compressor from the surge without the risk of re-surge, leading to the need to turn off the engine. This increases the reliability of the gas turbine engine and the safety of the aircraft.

Claims (1)

The method of controlling a gas turbine engine, which means that on a running engine to eliminate surging, turn on a stop valve (KO) and stop the fuel supply to the combustion chamber (KS) of the gas turbine engine for a predetermined time, depending on the characteristics of the gas turbine engine, after that time, the KO is turned off and restarted fuel supply to the compressor station of the gas turbine engine, characterized in that, in addition to all gas turbine engine operation modes from “small gas” to maximum, the air pressure is measured behind the gas turbine compressor, the relative change and the relative rate of pressure change are calculated air behind the compressor, the relative pressure change is compared with the first predetermined value determined experimentally for each type of gas turbine engine, and the relative speed is compared with the second predetermined value determined experimentally for each type of gas turbine engine if the relative pressure change is greater than the first predetermined value, and the relative speed - more than the second predetermined value, generate the signal "Surge", give it to the indicator in the cockpit and begin to eliminate surging, moreover but the air bypass valves are opened to the fuel cut-off due to the intermediate stages of the gas turbine compressor and because of the gas-turbine compressor and turn on the ignition unit for a predetermined time determined by calculation and experimental means, if after that the relative pressure change is less than the first predetermined value, and the relative speed is less than the second predetermined value, the signal "Surge" is removed and the gas turbine engine is controlled in accordance with standard control programs, while the flow restriction program the fuel in the gas turbine engine underestimate the predetermined value by the predetermined time, the values of which are determined by calculation and experimental means.

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