System aerodynamic injecting a mixture of fuel with air

 

(57) Abstract:

The invention relates to a system aerodynamic injecting a mixture of fuel with air in the combustion chamber of the engine with a gas turbine, which includes a fuel injector with dual flow, providing for issuance of the secondary fuel cone in case of exceeding the engine of a given mode. Primary and secondary swirlers associated with the Venturi tube from the front to flow from the aerodynamic casing mounted on the bottom of the camera. The length of the Venturi and its shape is selected such that the primary fuel cone, extending from the primary fuel circuit, not faced with the wall of the Venturi. This embodiment of the aerodynamic system of injection of the mixture leads to the reduction of emissions from combustion monociclo carbon and unburned hydrocarbons at low rpm. 6 C.p. f-crystals, 2 Il.

The invention relates to a system for injecting a mixture of fuel with air in the combustion chamber of a gas turbine engine or engine that uses a gas turbine.

More specifically, this invention relates to systems aerodynamic injection containing dual fuel portiony fuel circuit in all modes of operation of this engine, and secondary fuel supplied through the secondary fuel circuit after the motor has reached a predetermined operation mode, and aerodynamic casing extending in the direction of flow and containing in its upper stream part of the Venturi tube mounted coaxially relative to the axis of the fuel injector so that the Venturi tube divides the internal flow of air entering through the primary swirl, and the outer air stream flowing through the secondary swirl, and the primary and secondary fuel injected into the internal flow of air in the form of fuel cones.

This aerodynamic dual fuel injector is installed, in particular, on turbojet engines and operates with only one primary fuel until the motor has reached a certain mode, beyond which the secondary fuel begins to Supplement referred to the primary of its consumption.

In the existing fuel injectors of this type of output cones of the two fuel impinges on the inner surface of the wall of the Venturi. This meeting fuel Venturi to skolko part of the fuel, facing the Venturi tube, flows through it, re-injected and re-sprayed at the outlet of this tube in the conditions determined by the aerodynamic characteristics of this output area. These events usually lead to an increase of the opening angle of the fuel cone at the exit of the Venturi;

the second related issue concerns the particle size distribution of the fuel at the exit of the aerodynamic shroud nozzle. This particle size distribution can be violated in relation to its ability to spray that are inherent in the fuel injector.

The increase of the opening angle of the fuel cone when the engine is in idling conditions or at low speed, i.e. in the case when involved only one primary fuel circuit, leads to the release Pisarenko fuel on the walls of the primary zone of the combustion chamber. The cooling device of the walls of the combustion chamber tends to "freeze" reaction of combustion in this zone, which leads to the formation of significant quantities of monociclo carbon (CO) and unburned hydrocarbons (CHx).

The task of the invention is to optimize apicobasal of combustion monociclo carbon and unburned hydrocarbons at low rpm.

The invention achieves its purpose due to the fact that the length used here Venturi, and its shape is adapted to the cone of the fuel flowing from the primary fuel circuit, not faced with the wall of the Venturi.

This design keeps the spray quality nozzle at idling or slow speed, which contributes to combustion stability. In addition, the characteristics inherent in this system of injection of fuel at high speed modes of operation of the engine, do not undergo any significant changes since the cone of fuel issued to the secondary fuel circuit, and so hits in the Venturi specifically in order to obtain a relatively wide fuel cone at maximum gas or the maximum engine speed that allows you to provide the required characteristics of the mixing and homogenization between different fuel injectors.

In accordance with this invention adopted the following preferred features:

- the relationship between the velocity of air flow in the primary and secondary swirlers has a value less than 1.3;
tel adjusted to a value in the range from 60 to 70o;

- the cost of air between the primary swirler and a secondary swirler has a value in the range from 1.1 to 1.2;

- the ratio between the axial length of the expanding portion of the Venturi tube and the diameter of the throat of this Venturi has a value in the range from 0.3 to 0.4.

Other characteristics and advantages of the invention will be better understood from the following description of the example of its practical implementation, where references are given in Appendix figures, among which:

- Fig. 1 is a schematic view in section of the injection system of air and fuel in accordance with the invention, mounted in the bottom part of the combustion chamber;

- Fig. 2 is a graph showing the spatial distribution of the fuel in relation to the distance along the axis of the aerodynamic cover for the case when the functions only one primary fuel circuit, and for the case when the primary fuel circuit operates in conjunction with a secondary fuel circuit.

In Fig. 1 schematically shows an injection system 1 mixture of fuel with air in the combustion chamber 2 of the engine with a gas turbine used apriantono two annular shirts />in Fig. 1 is not shown/, spaced from each other in the radial direction with respect to the axis of this turbojet engine and connected in the front by the flow of part of the bottom of the annular combustion chamber 3.

This is the bottom of the chamber 3 contains a number of holes 4, evenly distributed circumferentially around the axis of this turbojet engine. In each of these holes 4 set the injection device 1 mixture of fuel with air in accordance with the invention. Gaseous products of combustion flow stream into the combustion chamber 2 and nourish or operate then a high-pressure turbine, which results in rotational movement high-pressure compressor, located on the stream above the bottom of the combustion chamber 3. This high pressure air compressor feeds air injection device toplivootdachey a mixture of 1 and two annular space located in the radial direction, respectively, inside and outside of the combustion chamber 2.

The air enters the combustion chamber 2 through the injection device 1 and is actively involved in the evaporation of the fuel and its combustion in the primary zone of the combustion chamber, while the air circulating outside on the igenia for to cool the combustion products are passed to a high-pressure turbine.

The annular baffle or reflector 10 is installed in the hole 4 with the inner sleeve 11. This deflector or reflector 10 is located in the combustion chamber 2 in parallel to the bottom 3 of the combustion chamber and is cooled in the result of a collision with streams of air passing through the through hole 12 in the bottom of the camera 3.

Inside the sleeve 11 is mounted aerodynamic casing 20, which has a wall 21 extending in the direction of flow in a continuation of the cylindrical wall 22 that is located coaxially relative to the axis 23 of the hole 4. The wall 21 has many holes 24 of the introduction of air into the combustion chamber.

Cylindrical wall 22 comprises a Venturi tube 30 with the axis 23, and the inner loop 31 of this Venturi has a converging shape, blending smoothly into divergent. Venturi tube restricts the flow of air coming from the primary swirler 32 and a secondary swirler 33.

Referred to the primary swirler 32 radial type is located on the stream before the Venturi tube 30 and provides the internal flow within the Venturi.

Venturi tube 30 includes at its front downstream end of the radial flange 34 that separates the primary swirler 32 and a secondary swirler 33.

The primary swirler 32 is rigidly connected at its front stream side with fastener 40, which has an annular groove 41, the open side of the axis 23 of the hole 4. In this annular groove 41 is mounted a sleeve 42 of the mounting end of the injector spraying fuel 43 fuel nozzle dual fuel circuit. Mentioned sleeve 42 has a possibility of some movement in the annular groove 41 in the radial direction in order to allow adjustment of the jet fuel depending on thermal conditions, the effect of which is exposed to this fuel injector and the parts mounted on the bottom 3 of the combustion chamber.

Consider here the fuel injector has a primary fuel circuit 50, which provides delivery of the primary fuel 51 in the form of the fuel cone forming an angle with the axis 23 during all modes of engine operation, and a secondary fuel circuit 52, which provides for the issuing of fuel 53 in the form of fuel or in case of exceeding a specified fuel consumption.

In accordance with the invention the shape and geometrical dimensions of the Venturi 30 and the position of the end of the fuel injector and the corners and fuel cones 53, 51 are calculated so that the fuel cone 53 secondary fuel is always a hit in the inner wall 31 of the Venturi 30 and the fuel cone 51 of the primary fuel never been faced with this inner wall 31 of the Venturi 30.

The opening angle of the primary fuel cone 51 is relatively small, however, it must exceed a certain minimum angle necessary to ensure satisfactory conditions run this engine depending on position of the ignition system.

The proposed design of the fuel injector provides the spatial distribution of fuel at the exit of the aerodynamic casing 30 and the primary zone of the combustion chamber, are very different for the two above-mentioned modes of operation of this fuel injector.

In Fig. 2 solid line presents the curve C1, showing the spatial distribution of fuel as a function of distance X from the aerodynamic casing 20 along the axis 23 in the case where the functioning of the spatial distribution of the fuel as a function of distance X from the aerodynamic casing 20 along the axis 23 for the case, when the primary fuel circuit 50 and the secondary fuel circuit 52 operate simultaneously and jointly issuing fuel.

The analysis of the graphs shown in Fig. 2, it can be seen that the zone 60 where the fuel density is maximum, are removed from the aerodynamic casing 20 in the case, when together are the primary and secondary fuel through this fuel injector.

Shape optimization of aerodynamic casing 20 and Venturi 30 was performed using two-dimensional and/or three-dimensional aerodynamic calculations and associated account for various phenomena of dwuhfaznosti fuel, such as crushing fuel, secondary sputtering on the surface of the Venturi 30, the phenomenon of evaporation of fuel.

Primary fuel circuit 50 used fuel injector is determined by a purely mechanical way, i.e. so that the fuel injected in this primary circuit 50, crushed under the pressure of injection of fuel.

The fuel supplied through the primary fuel circuit 50, are not faced with the surface of the Venturi 30 and does not interact with the fuel cone 53 secondary fuel circuit that allows the technology in this field, and to shift the zone of recirculation air, which underlies the stability of the combustion chamber.

The air which nourishes the aerodynamic casing 20 has the dynamics of output, heavily dependent on the Venturi 30. Here we are talking about the ratio of speeds between the inner air stream and an outer stream of air, the adjustment of each of the swirler air and the distance at which two air flow merge together that determines the position of the recirculation zone at the exit of the aerodynamic shroud. Fuel, in particular its smallest droplets enclosed in these zones of air are drawn in such a way that provides a stable flame, regardless of the speed of the flow of air around the aforementioned aerodynamic shroud. The determination of the trajectories of the droplets of fuel is carried out using two-dimensional aerodynamic calculation taking into account dwuhfaznosti.

In accordance with this invention adopted the following preferred features:

- the ratio of velocity of air flow in the primary 32 and secondary swirler 33 has a value less than 1.3;

- the primary swirler 32 is adjusted to a value in the range from 55oup to 65o60oup to 70ofor example, a value of 70o;

- the cost of air through the primary swirler 32 and through the secondary swirler 33 has a value in the range from 1.1 to 1.2 and is, for example, 1,13;

- the ratio of the axial length L of the expanding portion of the Venturi 30 to the diameter D of the throat of this Venturi tube 30 has a value in the range from 0.3 to 0.4 and is, in particular, 1,3.

1. System aerodynamic injecting a mixture of fuel with air in the combustion chamber (2) engine that uses a gas turbine, and this system includes a fuel injector (43) with dual flow, designed for injection of the first fuel (51), issued by the primary fuel circuit (50) in all operation modes of the engine, and the second fuel consumption (53), issued by the secondary fuel circuit (52) in case of exceeding some pre-defined mode of operation of this engine, and aerodynamic casing (20), extending in the direction of flow and containing in its front downstream side of the Venturi tube (30), which are located coaxially relative to the axis (23) of the fuel injector (43), and the Venturi tube (30) separates the internal air flow generated by the escape of fuel (51) and the second fuel consumption (53) injected into the internal flow of air in the form of fuel cones, characterized in that the length of the Venturi and its shape is selected such that the fuel cone (51) coming from the primary fuel circuit (50), not faced with the wall of the Venturi tube (30).

2. The system under item 1, characterized in that the ratio of velocity of air flow in the primary (32) and secondary (33) the swirler has a value less than 1.3.

3. The system under item 1 or 2, characterized in that the primary (32) and secondary (33) of the swirler is a radial.

4. The system under item 3, characterized in that the primary swirl (32) is adjusted to a value of 55 to 65o.

5. The system under item 3 or 4, characterized in that the secondary swirl (33) is adjusted to a value of 60 - 70o.

6. System according to any one of paragraphs.1 to 5, characterized in that the ratio of costs of air through the primary swirl (32) and through the secondary swirl (33) has a value of 1.1 - 1.2.

7. System according to any one of paragraphs.1 - 6, characterized in that the ratio of the axial length of the expanding portion of the Venturi tube (30) to the diameter D of the neck of the Venturi tube (30) has a value of 0.3 - 0.4.

 

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Drain system // 2244142

FIELD: mechanical engineering; gas-turbine engines.

SUBSTANCE: system is designed for utilization of fuel leaks in drain systems of gas-turbine engines. Proposed system contains drain tank divided into upper and lower spaces by spring-loaded flexible partition. Upper space is connected through check valve and drain valve with nozzle manifolds, through other check valve, with atmosphere, and through third check valve, with fuel pump input. Lower space is connected with high-pressure source through pressure selector. Fuel-air medium sensor is installed under check valve communicating with atmosphere. Selector is made in form of electromagnetic valve with spool device. Check valve connected with fuel pump is located lower than minimum permissible fuel level in tank, level being set by program. Such design of drain system precludes getting of air to fuel pump input and meets ecological requirements as to effective combustion of fuel owing to return of fuel from drain tank into fuel tank at steady state operating conditions of engine.

EFFECT: provision of pollution-free engine.

1 dwg

FIELD: mechanical engineering; engines.

SUBSTANCE: invention is designed for draining fuel leaks from manifold and returning fuel into engine fuel system. Proposed device contain drain tank connected with drain fuel source, ejector with working nozzle, outlet and receiving chamber, drain tank shutoff valve, float installed in drain tank and connected with shutoff valve. Constant pressure valve connected with ejector outlet is installed at inlet of ejector working nozzle. Throttling needle with spring and piston is installed in working nozzle of ejector. One space of piston being connected with drain space and the other, with ejector outlet.

EFFECT: prevention of cavitation in ejector and getting of air into fuel system.

1 dwg

FIELD: mechanical engineering.

SUBSTANCE: invention relates to devices and methods of combustion of fuel-air mixture in air-jet engines, small-size gas-turbine engines and gas-turbine plants. Proposed low-pressure nozzle contains annular atomizing edges, body accommodating central air swirler, channel to feed fuel with auger swirler, and outer air swirler arranged on nozzle body. Channel to supply swirled high-pressure air is arranged around fuel feed channel. Two-tier jet outer air swirler is provided with outer and inner inclined holes, air vortex stabilizer and annular outer and inner atomizing edges. Method of fuel atomizing by low-pressure nozzle comes to delivery of fuel and pressure feeding of air through central swirler and outer swirler. Fuel is fed between two swirler air flows formed by central swirler and channel to supply swirler high-pressure air. Flows of air and fuel getting to annular atomizing edges of nozzle form finely dispersed fuel air-mixture. Drops of mixture are atomized by air jets of outer swirler first on its inner annular atomizing edge, and then on outer edge. Said peculiarities of proposed invention increase payload capacity of aircraft, reduce exhaust of harmful substances.

EFFECT: reduced energy losses and expenses.

3 cl, 1 dwg

FIELD: rocketry and aeronautical engineering; fuel systems of flying vehicles.

SUBSTANCE: device proposed for realization of this method includes fuel tanks connected in succession by means of pipe lines; sequence of fuel utilization is estimated by intensity of heating of fuel contained in them.

EFFECT: reduction of temperature at engine plant inlet.

3 cl, 1 dwg

FIELD: metered delivery of fluid medium from supply source to users.

SUBSTANCE: proposed meter includes metering valve sliding in body at working stroke C; this valve has inlet hole for receiving fluid medium from supply source and outlet for discharge of fluid medium to user. Meter is provided with passage for fluid medium for performing washing motion of fluid medium over contact surfaces of valve and body. Passage is formed by helical groove at width L and screw pitch P. Besides that injector is proposed which is fitted with this meter.

EFFECT: avoidance of accumulation of contaminants during flow of fluid medium through meter.

3 cl, 3 dwg

FIELD: mechanical engineering; turbomachines.

SUBSTANCE: proposed fuel injection system contains high-pressure pump for delivering fuel at high pressure from fuel tank, fuel nozzles arranged in combustion chamber of turbomachine and metering device located between said high-pressure pump and fuel nozzles to control rate of fuel getting into fuel nozzles from high-pressure pump. Metering device contains delivery valve operated in accordance with two delivery levels by metering valve to which fuel is delivered from said high-pressure pump. Electrically controlled shutoff valve is provided additionally to cut off fuel delivery to said fuel nozzles.

EFFECT: possibility of limiting heating of fuel and setting optimum dimensions of system components.

5 cl, 2 dwg

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