RU222836U1 - SMALL SIZE GAS TURBINE ENGINE WITH FUEL LUBRICATED BEARINGS - Google Patents

Abstract

The utility model relates to the field of aircraft engine building, in particular to small-sized gas turbine engines with a bearing lubrication and cooling system.

The technical problem, the solution of which is provided by using the proposed utility model, is the possibility of further use of fuel used for lubrication and cooling of bearings of a small gas turbine engine.

The technical result that the proposed utility model is aimed at achieving is the creation of a gas turbine engine that uses fuel as lubrication and cooling of bearings, by simplifying the engine lubrication system with subsequent afterburning of the fuel in the afterburner, which will increase engine thrust, increase its efficiency and increase aircraft flight speed.

A small gas turbine engine with fuel-lubricated bearings contains a compressor, a turbine and a combustion chamber. The compressor and turbine have a common rotor shaft, supported by a front support with a bearing and a rear support with a bearing, while the supports have fuel supply channels. The combustion chamber is located between the compressor and the turbine and contains a rotating nozzle. The engine also contains an afterburner installed behind the rotor shaft and the rotating nozzle, while the rotor shaft is hollow, with holes for fuel removal from the front and rear supports to the rotating nozzle.

Description

The utility model relates to the field of aircraft engine building, in particular to small-sized gas turbine engines with a bearing lubrication and cooling system.

The engine is known, presented in the RF patent No. 2295047 for the invention “Gas Turbine Engine” (authors: Sergeev V.B., Kuzmenko M.L., Markin A.K.; patent holder: OJSC Scientific and Production Association “Saturn”; priority date 05/23/2005), which contains a compressor, a turbine, a first support with a bearing located between the compressor and the turbine, a combustion chamber installed around this support, a second support with a bearing located in front of the compressor or behind the turbine, a rotor shaft mounted on two supports , a fuel supply line to the first support and a fuel outlet channel from it into the combustion chamber. The engine is also equipped with a fuel supply line to the second support and a channel for removing fuel from this support, while in its cavity there is a fuel collector made in the form of a cup mounted on a shaft around the support, inside of which the main fuel intake is installed, the entrance of which is located near the wall of the cup, with In this case, the fuel intake is connected through the fuel outlet channel to the combustion chamber.

The disadvantage of this gas turbine engine is the difficulty of ensuring the supply of fuel from the rear support (low pressure area behind the turbine) into the combustion chamber (high pressure area). To ensure fuel pumping, an additional device (pump) will be required, which increases the weight of the engine and complicates the design.

A known system for lubrication and cooling of rotor bearings of a gas turbine engine with an air-fuel mixture is disclosed:

in the article “Prospective scheme for lubrication and cooling of bearings of a short-life gas turbine engine with an air-fuel mixture” (authors: V.N. Klimov, N.I. Klimov; Omsk State Technical University, JSC “Omsk Engine Design Bureau” (Omsk), 2017;

in the article “Features of testing the air-fuel lubrication system of a gas turbine engine” (authors: V.N. Klimov, D.Ya. Dudiev, V.Ya. Sigailo, N.I. Klimov; branch of PJSC "UEC-SATURN-OMKB" ( Omsk), 2018;

in the article “Study of the performance of the lubrication and cooling system of rotor bearings of a gas turbine engine with an air-fuel mixture” (authors: V.N. Klimov, D.Ya. Dudiev, V.Ya. Sigailo, N.I. Klimov, Yu.K. Mashkov ; branch of PJSC "UEC - Saturn" - Omsk Engine Design Bureau, Omsk State Technical University (Omsk), 2019;

in RF patent No. 2597322 for the invention “Small-sized gas turbine engine” (authors: Kostogryz V.G., Dudyev D.Ya., Sigailo V.Ya., Gelmedov A.Sh., Klimov N.I., Kosholap Yu.G. , Bugaev S.I., Klimov V.N., Likhodid P.V., Lavrik A.S., Novikov M.V., Valitova Z.R., Romanov A.V.; patent holder: OJSC "Omsk Motor-Building Design Plant" Bureau"; priority date 04/28/2015), adopted as a prototype.

In the described design, a small-sized gas turbine engine contains a compressor, a turbine, and a combustion chamber. The turbocharger rotor is supported by a front compressor bearing and a rear turbine bearing. The fuel system includes a container with a fuel-oil mixture and a line for supplying the fuel-oil mixture to the combustion chamber. The lubrication and cooling system for bearings consists of a line for extracting air from the compressor, a line for supplying the fuel-oil mixture, a mixer, a line for supplying the working fluid to the bearings, and a line for removing the spent working fluid from the bearings. The air bleed line from the compressor is made in the form of an annular manifold, covering the middle part of the compressor housing above the impeller. The ring manifold is connected to a mixer, which ensures mixing of the fuel-oil mixture with air (creating a working fluid). The flow part of the compressor is connected to the annular manifold by holes in the compressor housing, which are made in the form of a plurality of grooves evenly spaced around the circumference, the grooves being inclined to the engine axis in the direction of rotation of the impeller at an angle coinciding with the direction of air flow at the point where air is taken from the compressor. In this case, the mixer is made in the form of a tee, has an input channel for supplying the fuel-oil mixture, an input channel for supplying air, a mixing cavity and an output channel for supplying the working fluid to the rotor bearings, while the bearings in the rotor supports are installed with a preload provided by a spring located in the turbine support , and the line for removing the working fluid from the bearings is made in the form of two lines: the line for removing the working fluid from the front bearing into the cavity in front of the compressor rotor and the line for removing the working fluid from the rear bearing into the central channel of the jet nozzle.

The disadvantages of this engine are excessive weight and size characteristics and high cooling air temperature. The presence of a system (line) for extracting air from the compressor and a system (cavity) for mixing fuel and air leads to coking of the fuel and oil in the flow part of the engine. The presence of a turbine lubrication and cooling system due to the discharge of the fuel-oil-air mixture at the compressor inlet leads to an increase in the thermal load on the bearings due to the mixing of fuel and oil with hot air.

The technical problem, the solution of which is provided by using the proposed utility model, is the possibility of further use of fuel used for lubrication and cooling of bearings of a small gas turbine engine.

In known solutions, this problem is solved either by creating a system for preparing and using fuel, which increases the mass and complicates the design, or by dumping fuel into the engine output nozzle, which worsens fuel efficiency.

The technical result that the proposed utility model is aimed at achieving is the creation of a gas turbine engine that uses fuel as lubrication and cooling of bearings, by simplifying the engine lubrication system with subsequent afterburning of the fuel in the afterburner, which will increase engine thrust, increase its efficiency and increase aircraft flight speed.

To achieve the specified technical result, a small-sized gas turbine engine with bearings lubricated with fuel contains a compressor, a turbine and a combustion chamber. The compressor and turbine have a common rotor shaft, supported by a front support with a bearing and a rear support with a bearing, while the supports have fuel supply channels. The combustion chamber is located between the compressor and the turbine and contains a rotating nozzle. The engine also contains an afterburner installed behind the rotor shaft and the rotating nozzle, while the rotor shaft is made hollow with holes for fuel removal from the front and rear supports to the rotating nozzle.

The utility model is illustrated by the attached engine drawings:

figure 1 - General view of a small-sized gas turbine engine with bearings lubricated with fuel;

figure 2 - View A of figure 1;

figure 3 - View B of figure 1;

figure 4 - View B of figure 1.

The claimed utility model contains:

1 - compressor;

2 - turbine;

3 - combustion chamber;

4 - front support;

5 - bearing;

6 - fuel supply channel;

7 - rear support;

8 - bearing;

9 - fuel supply channel;

10 - rotor shaft;

11 - holes for fuel drainage from the front support;

12 - holes for fuel drainage from the rear support;

13 - rotating nozzle;

14 - afterburner.

The proposed design of a small-sized aviation gas turbine engine contains (figure 1) a compressor 1, a turbine 2, a combustion chamber 3, an afterburner 14. The compressor 1 and the turbine 2 have a common rotor shaft 10, supported by a front support 4 with a bearing 5 (figure 2) and a rear support 7 with bearing 8 (figure 3). The combustion chamber 3 is located between the compressor 1 and the turbine 2 and contains a rotating nozzle 13 (figure 4). The front support 4 and the rear support 7 have fuel supply channels 6 (figure 2) and 9 (figure 3), respectively. The rotor shaft 10 is hollow and has holes for fuel drainage from the front support 11 (figure 2) and holes for fuel drainage from the rear support 12 (figure 3) to the rotating nozzle 13 (figure 4). The afterburner 14 is installed behind the rotor shaft 10 and the rotating nozzle 13.

The gas turbine engine operates as follows:

The air compressed by the compressor 1 enters the combustion chamber 3, in which fuel combustion occurs, then the hot gas enters the turbine 2, rotating the rotor shaft 10. The rotor shaft 10 rotates in bearings 5 and 8, fixed, respectively, in the front support 4 and the rear support 7. Additional fuel enters the fuel supply channels 6 and 9 for lubrication and cooling of bearings 5 and 8, respectively, after which, through the fuel outlet holes from the front support 11 and rear support 12, it enters the rotor shaft 10. Along the rotor shaft 10, the fuel enters the rotating nozzle 13, which sprays it. The atomized fuel enters the afterburner 14, where it mixes with the gas leaving turbine 2 and burns, creating additional thrust for the engine.

For small-sized short-life engines, the mass of the engine is of particular importance, therefore the possibility of eliminating the oil lubrication system for bearing units is being considered. In this case, the injection and discharge pumps, filters, valves, oil tank, oil itself, pipelines, etc. are removed.

Alternatively, a basic fuel (eg kerosene) can be used to lubricate the bearings. This creates the problem of using fuel that has cooled, lubricated the bearings and can no longer be burned in the main combustion chamber.

Therefore, it is proposed to burn this fuel in the afterburner 14, located behind the turbine of the engine 2. The fuel supply to the afterburner 14 is supposed to be carried out along the hollow shaft of the rotor 10, and the fuel is sprayed using a rotating nozzle 13 mounted on the rotor shaft 10 and ensuring good atomization quality with a small mass.

Since cooling and lubrication can take up to 30% of the total fuel consumption, this will increase the temperature and speed of the gases leaving the engine nozzle, which means increasing its thrust, increasing the speed of the aircraft and fuel efficiency.

The use of a rotating nozzle to supply fuel to the main combustion chamber has been tested on numerous Russian and foreign engines (for example, the Marbore 2 engine). At the same time, afterburners usually use a fuel supply system from special jet fuel injectors integrated into a manifold (for example, an AL-31 engine).

Claims (1)

Small-sized gas turbine engine with bearings lubricated by fuel, containing a compressor, turbine and combustion chamber; the compressor and turbine have a common rotor shaft, supported by a front support with a bearing and a rear support with a bearing; in this case, the supports have fuel supply channels; the combustion chamber is located between the compressor and the turbine and contains a rotating nozzle, characterized in that it contains an afterburner chamber installed behind the rotor shaft and the rotating nozzle; in this case, the rotor shaft is made hollow, with holes for fuel removal from the front and rear supports to the rotating nozzle.