RU2372557C1 - Low-pressure atomiser and fuel spraying method - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: low-pressure atomiser consists of annular spraying edges, the housing in which there located is central air swirler, a fuel supplying channel having a screw swirler, and external air swirler is located on the atomiser housing, and swirled HP air supply channel is located around fuel supply channel. At that, external air swirler is of double-tier jet design and has external and internal sloped holes, air swirl stabiliser, as well as annular external and internal spraying edges. Atomiser consists of an additional radial screw swirler installed between the housing and external swirler.

EFFECT: eliminating carbon formation and providing high quality of fuel spraying, reducing power losses.

2 cl, 2 dwg

Description

The invention relates to gas turbine units, and in particular to fuel supply systems.

Known fuel nozzle from the patent of the Russian Federation for invention No. 2107177 dated 07/06/98, which contains a rack with fuel supply holes and a nozzle with a surface for creating a liquid film with a spray edge, as well as internal and external air swirlers in the form of axial concentric channels with open ends and vanes inside, while the surface of the nozzle with a spray edge and the inner surface of the external air swirl are alternately in the circumferential direction at different angles to the axis of the nozzle and formed scheniem envelope around the nozzle axis a plurality of geodesic lines, skew with the axis of the spray nozzle edges at an angle equal to the angle of twist of the fuel film.

The disadvantage of this technical solution is the impossibility of obtaining the necessary fineness of fuel atomization, which will lead to an increase in the propensity of the air-fuel jet to pulsations and a decrease in the zone of stable operation of the combustion chamber.

Closest to the claimed invention is a low-pressure nozzle described in the patent of the Russian Federation No. 2249118, class. F02C 7/22, publ. 03/27/2005. Bull. No. 9, comprising annular spray edges, a housing in which the central air swirl is located, a fuel supply channel having a screw swirl, and an external air swirl is located on the nozzle body, while a high pressure swirl air supply channel is located around the fuel supply channel, moreover, the external air swirl is made of a two-tier jet and has external and internal inclined holes, an air vortex stabilizer, and also annular external and internal spraying other edges.

The method of spraying fuel, carried out by the low-pressure nozzle described above, consists in the fact that when spraying the fuel with the nozzle in the start-up mode, the fuel is introduced through the channel between two swirling air jets, the air being supplied from the inside using a central swirl, and from the outside using a high air swirl pressure, while the resulting air-fuel mixture is sprayed on the annular spraying edges of the low-pressure nozzle and forms a finely dispersed air-fuel mixture with es drops and the resulting mixture is crushed air jets outer swirler configured bunk jet, first at its inner circumferential edge of the spray, and then - on the outside.

The disadvantage of this nozzle, adopted as a prototype, is the possibility of deposit formation on the spraying edges of the nozzle, leading to an increase in the unevenness of the circumferential temperature field, as well as the insufficient fineness of the droplets of atomized fuel.

The technical task of the invention is the elimination of carbon formation, ensuring high quality atomization of fuel, reducing the unevenness of the circumferential temperature field at the outlet of the combustion chamber.

The technical result of the invention is achieved in that in a low-pressure nozzle containing annular spray edges, a housing in which the central air swirl is located, a fuel supply channel having a screw swirl, and an external air swirl is located on the nozzle body, and around the fuel supply channel there is a channel for supplying swirling high-pressure air, while the external air swirl is made of a two-tier jet and has external and internal inclined openings, stable izator air vortex, and outer and inner annular atomizing edge between the body and the outer swirler an additional radial swirler screw. At the same time, the configuration of the additional screw swirler (the area of passage sections, the angle of rotation of the air supply channels) is selected in such a way as to ensure its most efficient operation.

The method of spraying fuel, carried out by a low-pressure nozzle, consists in the fact that when spraying fuel with a nozzle in start-up mode, fuel is introduced through a channel between two swirling air jets, the air being supplied from the inside using a central swirl, and from the outside using a high-pressure swirl, the resulting air-fuel mixture is sprayed on the annular spraying edges of the low-pressure nozzle and forms a finely dispersed air-fuel mixture, and drops the learned mixture is crushed by air jets of an external swirl made by a two-tier jet, first on its inner annular spray edge, and then on the outside, in addition, air is fed to the spray edges of the additional screw swirl, thereby preventing carbon formation and reducing the unevenness of the ambient temperature field in the main the combustion chamber, while the radial supply of a swirling air stream further increases its circulation and provides a smaller crusher droplets of fuel, improving the process of preliminary preparation of the air-fuel mixture.

Figure 1 presents a General view of the low-pressure nozzle (longitudinal section).

The low-pressure nozzle consists of a housing 1 with a supply of external 2 high-pressure air placed on it into a channel 3, twisting the air flow by a high-pressure air screw swirler 4, and an annular spray edge 5 is located at the outlet of the channel 3. Also, a fuel supply 6 to the channel is located on the housing 1 7 fuel swirl with a screw swirl 8 located in it, an annular spray edge 9 is located at the outlet of channel 7. A sealing cylinder 10 is installed inside the housing 1, separating the swirl and feed channel 3 High pressure air and the fuel channel 7. The sealing cylinder 10 is fixed in the housing 1 by means of an axial guide 11 containing a central air swirler 12 and a swirling air supply channel 13 with an edge 14 coaxially disposed with spray edges 9 and 5. The external swirl 15 is made of a two-tier jet, in which there are inner and outer inclined holes 16 and 17, respectively, between their exits there is a spray edge 18, and the stabilizer 19 of the air vortex and the annular outer spray edge 20 are located outside uzhnyh inclined holes 17. Between the housing 1 and the outer swirler 15 is disposed outside air supply channel 21. The channel 21 has an additional screw 22 swirl air flowing out of the compressor at all operating conditions of GTE.

Description of the low-pressure nozzle.

Through the central swirl 12 of air in the process of spinning the engine along the channel 13, swirling air is supplied to the edge 14. When reaching certain engine speeds through the fuel supply 6 and the fuel swirl channel 7, fuel is supplied through the screw swirl 8 to the annular spray edge 9, at the same time (in case of difficult starting conditions), by supplying 2 high-pressure external air and air flow swirl channel 3 through the screw swirl 4, high pressure air is supplied to the spray edge 5. In this case, the fuel is between two swirling air streams formed by the central swirler 12 and the high-pressure air screw swirl 4, crushing on the two spray edges 5 and 9. The air supplied through the central swirl 12 opens and stabilizes the fuel-air torch, providing it to the internal 18 and the outer 20 annular spray edges of the outer swirler 15, made of a two-tier jet. Getting on these last ones, blown by air jets from the outer and inner inclined holes 16 and 17 of the outer swirl 15, droplets of the air-fuel mixture are additionally crushed, forming a finely dispersed mixture. The air and fuel in the nozzle swirl in the swirls in one direction. The stabilizer 19 of the air vortex is used to stabilize the geometric stability of the fuel-air torch. Channel 21 through an additional screw swirl 22 is supplied with air due to the compressor, blowing the edges 14 and 9, to prevent carbon formation on them. In this case, finer crushing of the droplets of the air-fuel mixture also occurs.

When starting the engine on the ground, depending on the starting conditions, two nozzle operating modes can be used: the first is the start without high pressure air supply, the second is the start when the high pressure spray air and air are fed through the central channel and the channels of the radial air swirl . The launch option using high pressure air is only necessary under very difficult launch conditions: high launch altitude and low air temperature. The chamber is launched without high-pressure air supply in autorotation mode and at normal atmospheric air pressure.

The claimed invention allows to increase the circulation of the gas stream and to provide finer crushing of the droplets of the air-fuel mixture, to improve the quality of the preliminary preparation of the air-fuel mixture, to reduce the unevenness of the circumferential field in the main combustion chamber by preventing carbon formation on the end surfaces of the edges spraying fuel.

Claims (2)

1. A low-pressure nozzle containing annular spray edges, a housing in which the central air swirl is located, a fuel supply channel having a screw swirl, and an external air swirl is located on the nozzle body, and a high-pressure swirl air supply channel is located around the fuel supply channel while the external air swirl is made of two-tier jet and has external and internal inclined holes, the stabilizer of the air vortex, as well as annular external and internal nnie the spray edge, characterized in that the screw comprises an additional radial swirler mounted between the body and the outer swirler. 2. The method of atomization of fuel, carried out by a low-pressure nozzle, which consists in supplying fuel and pumping air through a central swirler and an external swirler, supplying fuel between two swirling air flows formed by a central swirler and a channel for supplying swirling high-pressure air, and arriving at the annular spraying edges of the nozzle air and fuel flows form a finely dispersed air-fuel mixture, while the drops of the resulting mixture are crushed by air jets an external swirl made by a two-tier jet, first on its inner annular spray edge, and then on the outer one, characterized in that air is supplied to the spray edges of the additional screw swirl, thereby preventing carbon formation and reducing the unevenness of the ambient temperature field in the main combustion chamber, Moreover, the radial inlet of the swirling air stream further increases its circulation and provides finer crushing of fuel droplets, improving the percentage Ess preliminary preparation of the air-fuel mixture.

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