DE2807369A1 - BURNING DEVICE, IN PARTICULAR FOR GAS TURBINE ENGINES - Google Patents

Description

PATBN

Dipl. Ing. E.

PHILIPPINE -WEIiSEB - STHASSE 14

8900 ATJGSBUKG

ΤΕΜΒΕΌΪΓ 516475

533 202 patol d

M. 613

Augsburg, February 20, 1978

The Secretary of State for Defense in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland, Whitehall, London SWl, England

Combustion equipment, in particular for gas turbine engines

The invention relates to a combustion device, in particular for gas turbine engines, with a combustion chamber and one disposed at the upstream end thereof Fuel injector.

Smoke in the exhaust gas of a gas turbine engine is a disadvantage that is common to known gas turbines in general

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by accepting a certain loss of engine performance is avoided. It is known that soot is formed during the combustion of rich fuel mixtures, and that smoke formation is reduced by increasing the proportion of primary air flowing into the combustion chamber can be. The engine performance can, however, for example by lowering the stability limits the combustion, are adversely affected.

The invention is based on the object of a burning device to improve the type mentioned so that smoke emission through improved fuel-air mixing is avoided or largely reduced in the primary combustion zone.

This object is achieved according to the invention by the arrangement specified in the characterizing part of the main claim solved.

The arrangement according to the invention has the advantage that the fuel i "passes through the air inlet openings incoming air is drawn in, so that a good fuel-air mixture is created. The one from the fuel injector The generated fuel jets may contain fuel mist and / or fuel vapor.

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The combustion chamber can be cylindrical or ring-shaped. The rows of air intakes can run radially in a straight line or, if the fuel jets are given a twist, arcuate. the In this case, fuel jets are forced to follow the curvature of the rows of air inlet openings.

According to a preferred embodiment of the invention the air inlet openings are circular and have one in each row as the distance from the fuel injector increases progressively larger diameter to ensure a uniform entrainment of the fuel from the fuel injector through the air.

Some embodiments of the invention are described below with reference to the accompanying drawings described in more detail. It shows:

Pig. I made a longitudinal section through a focal

device according to the invention,

Fig. 2 shows a cross section through the in

Figure 1 shows the burning device along the line A-A in Figure 1,

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Pig. 3 an axial half section through a

further embodiment of the invention,

FIG. 4 shows a cross section of the line shown in FIG

arrangement shown along the line B-B in Figure 3, and

Fig. 5 is a section through a still

Another embodiment of the invention.

The combustion device shown in FIG. 1 has an essentially tubular combustion chamber 8 with an approximately cylindrical part 5 which ends downstream in a convergent nozzle J and merges into a conical part 4 upstream. The cylindrical part 5 has two circumferential slots 6, which are arranged at a mutual axial spacing, for introducing cooling air.

In the wall of the conical upstream part 4 of the Combustion chambers are eight with mutual circumferential distances arranged axial or radial rows of three circular primary air inlet openings 3 each formed, as from Figure 2 clearly emerges. The diameters of the inlet openings 3 increase progressively in the downstream direction to.

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Furthermore, the combustion device has a fuel injector 2, which is fed via a fuel feed line 1 communicates with a fuel tank (not shown).

The fuel injector 2 has eight injection nozzles arranged at mutual circumferential distances, the respective fuel mist jets (indicated by the dashed lines in the drawings) longitudinally the spaces between adjacent rows of inlet ports 3 generate.

In operation four de η those generated by the fuel injector Fuel jets carried away by primary air jets, which flow into the combustion chamber through the inlet openings 3 on both sides of each fuel jet, so that a combustible fuel-air mixture arises.

The embodiment shown in Figure 3 has a annular combustion chamber 8, the central part 5 has concentric cylindrical walls, the downstream merge into an annular nozzle 7 and, on the upstream side, into a part 3 diverging downstream. The middle part 5 has two in its walls in the circumferential direction

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extending secondary air inlet slots 6. Of the upstream combustion chamber part 3, in which a likewise annular fuel injector 3 is arranged is with a number of with mutual circumferential intervals arranged rows of three circular primary air inlet openings 3, as from Figure 4 can be seen in more detail. The diameters of these inlet openings increase in a downstream direction Direction progressively to. The fuel injector 11 has a number of radially inner and radially outer Injection nozzles, which are arranged so that they jets of fuel mist (again by dashed Lines indicated) along the spaces between adjacent rows of inlet openings 3, which are directed towards or away from the combustion chamber axis.

Figure 5 shows a section of a burning device, which is basically similar to the burner device shown in FIG is. In the case of the combustion device shown in FIG. 5, the upstream part 4 is the combustion chamber however rounded and the likewise annular fuel injector 26 is T-shaped in cross section. Of the Fuel injector has a baffle 25 which serves to pass through a series of slots 19 in the

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Deflect the air flowing in from the combustion chamber so that it passes over the inner wall in the area close to the fuel injector of the rounded upstream chamber end part flows. The fuel injector also has a Shank part 20, in which a series of bores is formed, through which fuel to a corresponding one Series of injection nozzles 23 and 24, which are arranged so that they fuel jets along of the spaces between the rows 3 of air inlet openings.

In operation, air flows in through slots 19 and is off baffle 25 of the fuel injector deflected away from the line Y-Y over the inner wall surface of the upstream rounded chamber end part 4. In the deflected air stream 3 fuel from the nozzles is between the adjacent rows of inlet openings and 24 introduced, which is entrained by the air jets flowing in through the inlet openings, so that a A fuel-air mixture that is capable of burning well is created.

Various advantageous modifications are also conceivable in the constructions just described. For example can be another secondary air inlet slot running in the circumferential direction at or near the

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Transition between the upstream Kamnierteil and be arranged in the middle part of the chamber in order to provide additional cooling or to suppress undesired recirculations to effect.

According to a further modification, the rows of primary air inlet openings can be extended along the side walls of the combustion chamber to the division by sector to maintain the fuel-containing flow.

Furthermore, a deflection device of the type shown in FIG The basic type shown also in the embodiment according to FIGS. 3 and 4 in oblique radial-axial Find direction along the fuel jet direction application.

When using thicker combustion chamber walls, the reveals of the primary air inlet openings can be designed to converge in the direction of flow, and it can large air flow velocities apply to an entry angle deviating from the more usual right-angled direction through the inlet openings entering air to achieve better control of the mixture formation and also the combustion

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by controlling the recirculation and the mixing ratio in the critical area of the air / fuel mixture formation near the fuel injection points to support.

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Claims (7)

Claims Qj Combustion device, in particular for gas turbine engines, with a combustion chamber and a fuel injector arranged at its upstream end, characterized in that rows of air inlet openings (3) for the entry of primary air are formed at the upstream combustion chamber end (4) and that the fuel injector (2; 13 ; 20) injects the fuel in the form of fuel jets each running along the spaces between adjacent rows of air inlet openings. 2. Burning device according to claim 1, characterized in that the air inlet openings (3) in each row downstream direction a progressively increasing Have size. 3. Burning device according to claim 1 or 2, characterized in that the rows of air inlet openings (3) with mutual circumferential distances like a wreath around the Chamber axis are arranged around. 4. Burning device according to one of claims 1 to 3, characterized in that the combustion chamber (4, 5) and the 8U9834 / 0834 ORKSiNAL INSPECTED Fuel injectors (11, 13) are annular. 5. Burning device according to claim 4, characterized in that the fuel injector (H ₃ 13) each between the rows of inlet openings (3) located injection nozzles (13), some of which jet fuel in the direction of the Karnmerachse and a other part of the nozzles generates fuel jets in the direction away from the chamber axis. 6. Burning device according to claim 5, characterized by that the nozzles (13) are each arranged in pairs in radial alignment with one another. 7. Burning device according to one of claims 4 to 6, characterized in that the fuel injector (20) an air deflector (25) for deflecting through has at least one further air inlet (19) for incoming air and that the nozzles (23, 24) are arranged so that they inject the fuel jets into the deflected air stream. 809834/0834