RU2435973C1 - Method of fuel flow control at start of gas turbine engine - 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). In addition, during start-up of GTE there compared is the measured rotor rotation frequency of engine to the pre-set idle rotation frequency set point; when engine rotation frequency reaches the idle set point, there blocked is further increase in the specified engine rotor rotation frequency by the pre-set time required for engine warm-up; the second manifold is connected to batched fuel supply path through hydraulic resistance equal as to flow test to 15-20% of total hydraulic resistance of injectors of the first manifold; when the engine warm-up time elapses, the second manifold is directly connected to batched fuel supply path and blocking of the specified engine rotor rotation frequency is released.

EFFECT: reducing the weight and cost of ACS, improving its reliability and GTE reliability and aircraft safety.

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Description

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

A known method of controlling fuel consumption at the start of a gas turbine engine is that a constant fuel consumption is supplied to the combustion chamber (CS) of the engine — the ignition rate, determined for each engine type by calculation and experimental means (Cherkasov B.A. “Automation and regulation of the WFD” . M.: "Engineering", 1965, S. 324-328).

The disadvantage of this method is its low efficiency in terms of providing the required reserves of gas-dynamic stability (GDU) of the compressor and, as a result, the inability to use modern gas-turbine engines, namely turbojet engines with a high bypass ratio (TRD), such as PS engines -90A and PS-90A2.

Closest to this invention in technical essence is a method of controlling fuel consumption at the start of a gas turbine engine, which consists in measuring engine parameters, air flow parameters at the engine inlet and the position of the engine control lever (ORE), in accordance with the measured parameters and the position of the throttle according to a predetermined dependence, the required fuel consumption in the engine CS is determined, the fuel is supplied to the combustion chamber (CS) manifolds, and the fuel distribution between the collectors is carried out using fuel distribution unit (APT) (Razdolin M.V., Surnov D.N. “Aggregates of the WFD.” M.: “Mashinostroenie”, 1973, p. 232-235, 352).

The disadvantage of this method is the following.

APT is a rather complex hydromechanical device with real failure rate, real weight and real cost.

So, for example, the price of the RT-2000 unit used to distribute fuel to the collectors of the KV of the TV3-117SBM1 engine, which is part of the power plant of the An-140 aircraft, is 16% of the cost of the hydromechanical part of the self-propelled guns and 8.5% of the total cost of self-propelled guns .

As a result, the presence of APT in the ACS reduces the reliability of the ACS, increases the weight and cost of the ACS and, as a result, reduces the reliability of the engine and the safety of the aircraft.

The aim of the invention is to increase the reliability of a gas turbine engine and the safety of an aircraft.

This goal is achieved by the fact that in the method of controlling fuel consumption at the start of a gas turbine engine, which consists in measuring engine parameters, air flow parameters at the engine inlet and the throttle position, the required flow rate is determined in accordance with the measured parameters and the throttle position from a predetermined dependence fuel in the compressor station and the metered fuel is brought to the first collector of the compressor station; in addition, during the start-up of the gas turbine engine, the measured rotor speed of the engine is compared with the predetermined speed setting “small gas”, when the engine reaches the “small gas” settings, they block a further increase in the set engine rotor speed by the predetermined time required for the engine to warm up, the second collector is connected to the dosed fuel supply path through a hydraulic resistance equal to 15 -20% of the total hydraulic resistance of the nozzles of the first collector, after the time of warming up the engine, connect the second collector to the dosed fuel supply path directly unlocks predetermined rotor speed.

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

The device contains a series-connected block 1 of sensors (DB) of engine and air parameters at the engine inlet, an electronic controller 2 (ER) of engine operation modes, a block of electrohydraulic converters (EGP) 3, a fuel dispenser 4, a switch 5, a hydraulic resistance 6, a dispenser 4 through a sensor 7 position is connected to the database 1, the controlled input of the switch 5 is connected to the control output of the ER 2.

The device operates as follows.

According to the parameters measured with the help of DB 1, in ER 2 it forms, according to a predetermined dependence, the required fuel consumption in the engine CS

Where

GT ass - fuel consumption required

Twh., Pvh. - temperature and air pressure at the engine inlet;

α ores - position of the ore;

nк, nв - rotational speed of the compressor and engine fan;

Tg is the temperature of the gases behind the turbine of the turbocharger of the engine;

Pk - air pressure behind the engine compressor.

Depending on the required fuel consumption of ER 2, using the flow characteristic of the first dispenser 4, which is recorded in the non-volatile memory of the ER 2 during the engine acceptance tests, determines the set position of the dispenser 4, compares the actual position of the dispenser 4 with the sensor 7 and DB 1, and It controls fuel consumption by changing the position of the dispenser 4 using the EGP 3.

Metered fuel is supplied to the first collector of the COP (not shown).

Additionally, in the process of starting a gas turbine engine in ER 2, the rotor speed of the engine rotor measured using DB 1 is compared with the predetermined setpoint for the “small gas” rotational speed, which is stored in the non-volatile memory of ER 2 during the engine acceptance tests (for the PS-90A2 engine, for example, this setting is 7900 rpm).

When the engine speed reaches the “small gas” settings in ER 2, a further increase in the set rotational speed of the engine rotor is blocked by a predetermined time required for warming up the engine (for a “cold” PS-90A2 engine, for example, this time is 300 s).

At the command of ER 2, using switch 5, a second collector (not shown) is connected to the dosed fuel supply path behind the dispenser 4 via a hydraulic resistance 6.

The resistance value is chosen equal to the spill 15-20% of the total hydraulic resistance of the nozzles of the first collector.

After the engine warm-up time has elapsed, by command from the ER 2, using the switch 5, the second collector is connected to the dosed fuel supply path behind the dispenser 4 directly. At the same time, in ER 2, the lock of the set rotational speed of the engine rotor is removed, providing the possibility of transferring the gas turbine engine to operating modes (nominal, take-off, etc.).

Thus, it provides a reduction in the weight and cost of self-propelled guns, increasing the reliability of the self-propelled guns and, as a result, increasing the reliability of the engine and the safety of the aircraft.

Claims (1)

The method of controlling fuel consumption at the start of a gas turbine engine (GTE), which consists in measuring engine parameters, air flow parameters at the engine inlet and the position of the engine control lever (ORE), in accordance with the measured parameters and the position of the ORE according to a predetermined relationship, determine the required total fuel consumption in the combustion chamber (KS) and the metered fuel is fed to the first collector of the KS, characterized in that, in addition to the process of starting the gas turbine engine, the measured frequency in Connecting the engine rotor with a predetermined setpoint speed of "small gas", when the engine speed reaches the set point of "small gas" block a further increase in the set rotational speed of the engine rotor by the predetermined time required for warming up the engine, connect the second manifold to the dosed fuel supply path through hydraulic resistance equal to 15-20% of the total hydraulic resistance of the nozzles of the first collector after pouring, after the engine warm-up time has passed the second collector to the dosed fuel supply path directly and remove the lock of the set rotational speed of the engine rotor.

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