RU2550224C1 - Gas turbine engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: in gas-turbine engine air cavities of shaft and bearing supports are connected with the high and low air pressure ring manifolds designed with a possibility of switching of air selection from the high air pressure manifold to the low air pressure manifold. The low air pressure manifold at the inlet is connected with the flow-through part of the gas-turbine engine downstream the third stage of the low pressure compressor. The high air pressure manifold at the inlet is connected with the flow-through part of the gas-turbine engine downstream the third stage of the high pressure compressor. Between the high air pressure manifold and air cavities of bearing support and the shaft the air-air heat exchanger placed in the channel of external circuit of the gas-turbine engine is installed.

EFFECT: invention improves reliability of the gas-turbine engine by decrease of air temperature passing from the high pressure manifold for cooling of shafts of the gas-turbine engine and for pressurisation of air cavities of bearing supports.

4 dwg

Description

The invention relates to gas turbine engines and can be used in the aviation industry.

A gas turbine engine is known in which the air cavities of the shaft and bearing bearings are connected to the compressor using radial air cavities (patent RU No. 2124644, F02C 7/06, publ. 10.01.1999).

A disadvantage of the known design is its low reliability due to the possible leakage of oil from the oil cavities of the bearing supports at reduced operating modes of the gas turbine engine.

Closest to the claimed one is a gas turbine engine in which the air cavities of the shafts and bearings are connected to the annular collectors of high and low air pressure with the ability to switch the air selection from the high air pressure manifold to the low air pressure manifold (patent RU No. 2323263, IPC F02C 7 / 06, 7/047, publ. 05/10/2008).

A disadvantage of the known design adopted as a prototype is its low reliability due to the increased temperature of the air taken from the high pressure manifold, which can lead to coking of the oil and overheating of the bearings in the bearings, which can lead to breakdown of the gas turbine engine.

The technical result of the claimed invention is to increase the reliability of a gas turbine engine by reducing the temperature of the air coming from the high pressure manifold to cool the shafts of the gas turbine engine and to pressurize the air cavities of the bearing supports.

The specified technical result is achieved by the fact that in a gas turbine engine, the air cavities of the shafts and bearings in which are connected to the annular collectors of high and low air pressure, configured to switch the air selection from the collector of high air pressure to the manifold, the low air pressure manifold at the inlet connected to the flowing part of the gas turbine engine behind the third stage of the low-pressure compressor, and the collector of high air pressure on During the running part connected to the gas turbine engine of the third stage of the high pressure compressor, and between the collector and the increased air pressure air cavities of bearings and shafts mounted air-to-air heat exchanger disposed in the channel of the outer contour of the turbine engine.

The connection of the manifold of reduced air pressure at the inlet with the flowing part of the gas turbine engine behind the third stage of the low-pressure compressor allows for reliable cooling of the fan shafts and low-pressure turbines, as well as the bearing bearings of the fan, high-pressure compressor, high-pressure turbine and low-pressure turbine, in the main operating modes of the gas-turbine engine pressure to exclude leakage of oil from the oil cavities of the bearings' bearings due to the boosting of the labyrinth seals of bearings by excessive air pressure. This embodiment of the structural parts of the gas turbine engine allows you to get an air stream that is optimal in the combination of temperature and pressure for cooling and pressurization of the shafts and bearings.

The connection of the manifold of increased air pressure at the inlet with the flowing part of the gas turbine engine behind the third stage of the high-pressure compressor makes it possible to ensure that the labyrinth seals of bearings are pressurized with excess air pressure at reduced engine operating conditions, when the low-pressure compressor rotor mounted on the fan impeller has low revolutions and, accordingly, low pressure at the outlet of the third stage of the low pressure compressor.

The presence of an air-air heat exchanger between the collector of high air pressure and the air cavities of the shafts and bearing bearings allows to reduce the air temperature at lower engine operating modes at the entrance to the air cavities of the bearings and shafts, which increases the reliability of the gas turbine engine.

The placement of the air-air heat exchanger in the channel of the outer circuit of the gas turbine engine provides cooling of the heat exchanger by the air of the channel of the external circuit, which allows increasing the draft and improving the efficiency of the gas turbine engine by reducing the temperature of the air in the channel of the external circuit obtained by cooling the heat exchanger, as well as reducing the negative impact of selection “Expensive” air due to the third stage of the high pressure compressor.

Figure 1 shows a longitudinal section of a gas turbine engine.

Figure 2 shows the element I in figure 1 in an enlarged view.

Figure 3 shows an element II in figure 1 in an enlarged view.

In Fig.4 - element III in Fig.1 in an enlarged view.

The gas turbine engine 1 includes a fan 2, a low pressure compressor 3, a high pressure compressor 4, a combustion chamber 5, a high pressure turbine 6 and a low pressure turbine 7. The rotor 8 of the low pressure compressor 3 is mounted on the impeller 9 of the fan 2, which, in turn, is installed in the ball bearing 11 of the front support 12 of the fan 2 using the shaft 10. The rotor 13 of the high pressure compressor 4 is installed in the ball bearing 15 of the support 16 of the compressor 4 4 high pressure, and the rotor 17 of the high pressure turbine 6 is installed in the roller bearing 18 of the support 19 of the high pressure turbine 6. The rotor 20 of the low pressure turbine 7 by the rear shank 21 of the shaft 22 of the low pressure turbine 7 is installed in the roller bearing 23 of the support 24 of the low pressure turbine 7. The air stream 25 from the fan 2 enters the channel 26 of the external circuit, from which through the nozzle 27 of the external circuit is discharged into the atmosphere.

The air cavities 28 of the bearing bearings 12, 16, 19, 24 and the shafts 10, 22 are connected to the annular collectors 29 and 30, respectively, of reduced and increased air pressure, with the possibility of switching the air sampling from the collector 30 of the increased air pressure to the collector 29 of the reduced air pressure. The collector 29 of reduced air pressure at its inlet is connected to the flowing part 31 of the gas turbine engine 1 behind the third stage 32 of the low pressure compressor 3. The manifold 30 high pressure at its inlet is connected to the flow part 33 of the gas turbine engine 1 behind the third stage 34 of the compressor 4 high pressure. Between the manifold 30 of the increased air pressure and the air cavities 28 of the bearing bearings 12, 16, 19, 24 and the shafts 10, 22, an air-air heat exchanger 35 is installed located in the channel 26 of the outer circuit of the gas turbine engine 1.

In the main operating modes of the gas turbine engine 1, the cooling air entering the low pressure manifold 29 from the flow part 31 behind the third stage 32 of the low pressure compressor 3, through the air sampling switch 36 is supplied through the channels 37 to pressurize the air cavities 28 of the supports 12, 16, 19 , 24 and for cooling the shafts 10 and 22, ensuring reliable operation of engine 1. At reduced and transient modes of operation of the gas turbine engine 1, the air sampling switch 36 connects the channels 37 to the high pressure manifold 30 air connected at the inlet to the flowing part 33 of the gas turbine engine 1 behind the third stage 34 of the high-pressure compressor 4, thereby preventing the entry of oil from the oil cavities 38, into the air cavities 28 of the supports 12, 16, 19, 24 and further into the gas-air duct 39 The high pressure air stream 40 taken from the manifold 30 has an excess temperature, and an air-air heat exchanger 35 is installed in the outer circuit channel 26 between the collector 30 and the air sampling mechanism 36, in which the air stream 40 and the pressure is cooled to the desired temperature of air stream 25, the channel 26 of the outer contour. This leads to the heating of the air flow 25 of the outer circuit and to increase the thrust of the gas turbine engine 1 by increasing the speed of the outflow of air from the nozzle 27 of the outer circuit. Next, the cooled stream 40 of high pressure air through channels 37 is supplied to cool the shafts 10 and 12, as well as to pressurize the air cavities 28 of the supports 12, 16, 19 and 24.

The use of air due to the third stage of the low-pressure compressor 3 for cooling the shafts 10 and 22, as well as for boosting and cooling bearings 12, 16, 19 and 24, allows to improve the efficiency of the gas turbine engine 1 in the main modes of operation, as it uses the least “expensive »Cooling air.

Claims (1)

A gas turbine engine, the air cavities of the shafts and bearings in which are connected to the annular collectors of high and low air pressure, configured to switch the air from the collector of high pressure to the collector of low air pressure, characterized in that the collector of low air pressure at the inlet is connected to the flow part of the gas turbine engine behind the third stage of the low-pressure compressor, and the manifold of increased air pressure at the inlet is connected to the flow part a gas turbine engine behind the third stage of a high pressure compressor, and an air-air heat exchanger installed in the channel of the external circuit of the gas turbine is installed between the high pressure air manifold and the air cavities of the bearing bearings and shafts.

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