RU2435972C1 - Control method of fuel flow to multi-manifold combustion chamber 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). Essence of invention is that additional fuel distribution between manifolds is performed by means of batchers the number of which corresponds to the number of fuel manifolds of CC (combustion chamber); at that, depending on the required fuel flow to the first fuel manifold of CC, the specified position of the first batcher is determined; actual position of the first batcher is measured and fuel flow is controlled to the first manifold by changing the position of the first batcher, and maintenance of fuel pressure drop on the first batcher is provided owing to changing the fuel pump capacity; the inlets of the rest batchers are hydraulically connected to the inlet of the first batcher; the specified position of the rest batchers is determined on the basis of the required fuel flow to the appropriate fuel manifold of CC; actual position of the rest batchers is measured and fuel flow is controlled by means of changing the position of the rest batchers; at that, the specified position of the rest batchers is corrected depending on hydraulic resistance in fuel supply path after the first batcher and hydraulic resistance in fuel supply path after the corresponding batcher.

EFFECT: improving ACS operating quality and GTE reliability and aircraft safety owing to introducing the recording algorithm of actual characteristics of fuel supply path to CC.

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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 in the combustion chamber (CS) of a gas turbine engine, which consists in supplying a constant fuel consumption to the engine CS — ignition flow, determined for each engine type by calculation and experimental means (B. Cherkasov, “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 in a two-manifold compressor unit 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 position ORE according to a predetermined dependence determine the required total fuel consumption in the engine KS, depending on the required total fuel consumption in the KS determine the preset dosage position RA, measure the actual position of the dispenser and control fuel consumption by changing the position of the dispenser and maintaining the differential pressure of the fuel on the dispenser by changing the performance of the fuel pump, and the fuel distribution between the collectors is carried out using the fuel distribution unit (APT) (M.V. Razdolin Surnov D.N. “Aggregates of the WFD”, Moscow, “Mechanical Engineering”, 1973, p. 232-235, 352).

The disadvantage of this method is that it is practically not applicable for the COP with the number of collectors more than two. This is because the range of operation of any dispenser is limited in fuel consumption through the dispenser, while APT is practically unsuitable for controlling fuel consumption through the collector.

In addition, the presence of differential pressure maintenance valves (KPDD) on each dispenser with an increase in the number of dispensers reduces the reliability of the ACS and, as a result, reduces the reliability of the engine and the safety of the aircraft.

The decrease in reliability is due to the following factors.

The efficiency factor itself is a rather complex hydromechanical device with a real failure rate. An increase in the number of efficiency factors will lead to an increase in the total failure rate of the device, and therefore, to a decrease in its mean time between failures, i.e. decrease in reliability. In addition, the failure of the KPDD can lead to an uncontrolled change in fuel consumption through the dispenser, and therefore in the gas turbine engine, which reduces the reliability of the engine and the safety of the aircraft. An increase in the number of HPAIs increases the likelihood of this event.

It should also be noted that each KPDD is inherently a regulator of the fuel pump (VT) flow rate. The presence of several control actions on one regulatory object reduces the stability of the VT operation and can lead to the loss of its operability, which also 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 in a multi-collector CS 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 throttle in a predetermined relationship determines the required total fuel consumption in the engine CS, in addition, the distribution of fuel between the collectors is carried out using dispensers, the number of which corresponds to the number of fuel collectors KS, while depending on the required fuel consumption in the first fuel collector KS determine the predetermined position of the first dispenser, measure the actual position of the first dispenser and control the fuel consumption in the first collector by changing the position of the first dispenser and maintaining the differential pressure of the fuel at the first the metering unit by changing the performance of the fuel pump, the inputs of the remaining metering units are hydraulically connected to the input of the first metering unit, the specified position e of the remaining dispensers is determined based on the required fuel consumption in the corresponding fuel collector KS, the actual position of the remaining dispensers is measured and fuel consumption is controlled by changing the position of the remaining dispensers, while the set position of the remaining dispensers is adjusted depending on the hydraulic resistance in the fuel supply path after the first dispenser and hydraulic resistance in the fuel supply path after the corresponding dispenser.

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 the engine operating modes, a block of electrohydraulic converters (EHP) 3. to the output of block 3 are connected the controlled inputs of the first fuel dispenser 4 and other dispensers 5 (one for each fuel collector KS), each dispenser 4 and 5 is connected to the OBD 1 through its position sensor 6, the “consumable” inputs of the dispensers 4 and 5 are connected to the “consumable” output of the fuel pump (VT) 7, “consumable” entry and exit first of the first dispenser 4 are hydraulically connected to the KPPD 8, the control output of the KPPD 8 is connected to the controlled input of the VT 7.

The device operates as follows.

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

Where

GT ass - required total fuel consumption,

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.

Next, ER 2 distributes the required total fuel consumption between the fuel collectors (not shown), the number and flow characteristics of which are recorded in the non-volatile memory of ER 2 during the acceptance test (PSI) of the engine.

Depending on the required fuel consumption in the first fuel collector KS ER 2 using the flow characteristics of the first dispenser 4, which is recorded in the non-volatile memory of the ER 2 in the process of acceptance tests of the engine, determines the set position of the first dispenser 4, compares with the measured using the sensor 6 and the database 1 by the actual position of the first dispenser 4 and controls the fuel consumption in the first collector, changing using the EGP 3 the position of the first dispenser 4. Maintaining the differential pressure of the fuel on the first dispenser 4 It is provided with the help of KPDD 8 due to a change in the performance of VT 7.

At the same time, ER 2 determines the preset position of the remaining dispensers 5, based on the required fuel consumption in the corresponding fuel collector KS and the flow characteristics of the corresponding dispenser 5. Consumption characteristics of all dispensers 5 are recorded in the non-volatile memory of ER 2 in the process of engine PSI.

Next, using sensors 6 and DB 1, ER 2 measures the actual position of the remaining dispensers 5 and controls fuel consumption by changing using EGP 3 the positions of the remaining dispensers 5.

Moreover, in the control process, the preset position of the remaining dispensers 5 is adjusted depending on the hydraulic resistance in the fuel supply path after the first dispenser 4 and the hydraulic resistance in the fuel supply path after the corresponding dispenser 5.

Because The "consumable" inputs of the remaining dispensers 5 are hydraulically connected to the "consumable" input of the first dispenser 4, the corrective effect on the i-dispenser is calculated based on the following considerations.

As you know (see, for example, Moth R. "Hydropneumoautomatics", M., "Mechanical Engineering", 1975, p.236-237), for any dispenser, you can apply the dependence of the "balance of costs":

Where

Fek.i - the area of the conditional flow area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the i-th fuel supply path to the compressor station,

Fd.i - the flow area of the i-th dispenser,

Fкi is the nominal bore area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the fuel supply pipes to the i-th fuel collector and the hydraulic resistance of the nozzles of the i-th fuel collector themselves.

Since the constructively “expendable" inputs of all the dispensers 4 and 5 are hydraulically connected, then at the input of any i-th fuel supply path to the compressor station there will be pressure created by the ТН 7 (Рн), and the gas pressure in the compressor station (Р г кс) will be at the output. Given this, you can accept:

Where

Gt.i - fuel consumption through the i-th dispenser to the i-th collector,

Gt.1 - fuel consumption through the first dispenser to the first collector,

K1 is the coefficient of the ratio of fuel consumption through the i-th dispenser to the i-th collector and through the first dispenser to the first collector,

Fek.i - the area of the conditional flow area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the i-th fuel supply path to the compressor station,

Fekv.1 - the area of the conditional bore, the hydraulic resistance of which corresponds to the total hydraulic resistance of the fuel supply path to the compressor station through the first dispenser and the first collector.

From (3) we can calculate

Where

Fek.i - the area of the conditional flow area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the i-th fuel supply path to the compressor station,

K1 is the coefficient of the ratio of fuel consumption through the i-th dispenser to the i-th collector and through the first dispenser to the first collector,

Fekv.1 - the area of the conditional bore, the hydraulic resistance of which corresponds to the total hydraulic resistance of the fuel supply path to the compressor station through the first dispenser and the first collector.

Using dependence (1), it is possible to calculate the area of the passage section of the i-th dispenser Fдi:

Where

Fd.i - the flow area of the i-th dispenser,

Fek.i - the area of the conditional flow area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the i-th fuel supply path to the compressor station,

Fкi is the nominal bore area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the fuel supply pipes to the i-th fuel collector and the hydraulic resistance of the nozzles of the i-th fuel collector themselves.

Substituting the data of expression (4) in (5), it is possible to calculate the area of the required passage section of the i-th metering device Fдi taking into account the hydraulic resistance in the fuel supply path after the first metering device and the hydraulic resistance in the fuel supply path after the i-th meter.

The calculation of Fdi is performed by ER 2 using the predetermined values stored in the non-volatile memory of ER 2 and the values calculated from the measured parameters according to the following relationship:

Where

Fd.i is the required flow area of the i-th dispenser,

Fкi is the nominal bore area, the hydraulic resistance of which corresponds to the total hydraulic resistance of the fuel supply pipes to the i-th fuel collector and the hydraulic resistance of the injectors of the i-th fuel collector themselves (it is stored in the memory of ER 2 in the process of engine PSI).

K1 is the coefficient of the ratio of fuel consumption through the i-th dispenser to the i-th collector and through the first dispenser to the first collector (calculated in ER 2 from the measured values of the positions of the i-th dispenser and the first dispenser),

Fekv.1 - the area of the conditional bore, the hydraulic resistance of which corresponds to the total hydraulic resistance of the fuel supply path to the compressor station through the first dispenser and the first collector (it is stored in the memory of ER 2 in the process of engine PSI).

Next, ER 2 using the pouring characteristics of the i-th dispenser stored in its non-volatile memory after entering the engine in the PSI process determines the required position of the i-th dispenser:

Where

Xdi required - the required position of the i-th dispenser,

Fd.i is the required flow area of the i-th dispenser.

After that, ER 2 calculates the correction value of the set position of the i-th dispenser:

Where

Δ Хдi - the correction value of the set position of the i-th dispenser,

Xdi required - the required position of the i-th dispenser,

Хдi - the position of the i-th dispenser measured with sensor 6.

The value Δ Xdi is used by ER 2 to correct the set position of the i-th dispenser.

Where

Xdi ass. correspondent - adjusted set position of the i-th dispenser,

Xdi ass. - the specified position of the i-th dispenser, calculated by ER 2 using the flow characteristics of the i-th dispenser from the required fuel consumption through the i-th collector,

Δ Хдi - correction value of the set position of the i-th dispenser.

Claims (1)

A method of controlling fuel consumption in a multi-collector compressor unit 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 ore, the required total flow rate is determined from a predetermined dependence fuel in the engine KS, characterized in that in addition the distribution of fuel between the collectors is carried out using dispensers, the number of which corresponds to the number of fuel to collectors KS, while depending on the required fuel consumption in the first fuel collector KS determine the set position of the first dispenser, measure the actual position of the first dispenser and control the fuel consumption in the first collector by changing the position of the first dispenser, and maintaining the differential pressure of the fuel on the first dispenser provide due to changes in the performance of the fuel pump, the inputs of the remaining dispensers are hydraulically connected to the input of the first dispenser, the specified position of the stop lnogo dispensers are determined based on the required fuel consumption in the corresponding fuel collector KS, the actual position of the remaining dispensers is measured and fuel consumption is controlled by changing the position of the remaining dispensers, while the set position of the remaining dispensers is adjusted depending on the hydraulic resistance in the fuel supply path after the first meter and hydraulic resistance in the fuel supply path after the corresponding meter.

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