Fuel nozzle body

Abstract

A fuel nozzle body having a rearward end and a front end with an outer tube which extends from the rearward end to the front end and has radial openings for a first fuel in the region of the front end, and an inner tube which is arranged concentrically to the outer tube and which opens in the region of the front end into a nozzle head, which has additional openings for a second fuel, wherein, in the region of the front end, the inner tube is guided in the outer tube by two fits which are arranged axially between the radial openings and the additional openings, and wherein the first fit closest to the radial openings is configured as a circumferential web around the inner tube, and wherein the second fit is configured with at least one interruption on the perimeter.

Claims

1. A fuel nozzle body comprising: a rearward end and a forward end, comprising an outer tube, which extends from the rearward end to the forward end and has radial openings for a first fuel in a region of the forward end, and an inner tube, which is arranged concentrically with respect to the outer tube and which opens in the region of the forward end into a nozzle head, which has additional openings for a second fuel, wherein, in the region of the forward end, the inner tube is guided in the outer tube by two fits, which are arranged axially between the radial openings and the additional openings, wherein a first fit of the two fits comprises a leakage seal between a first surface feature of the inner tube and a first surface feature on the outer tube encircling the first surface feature of the inner tube, wherein a second fit of the two fits comprises a second surface feature of the inner tube and a second surface feature on the outer tube encircling the second surface feature of the inner tube, wherein the second surface feature of the inner tube comprises at least one interruption, and wherein the first fit is closer to the radial openings than the second fit.

2. The fuel nozzle body as claimed in claim 1, wherein the first fit comprises a first gap between the first surface feature of the inner tube and the first surface feature on the outer tube, wherein the second fit comprises a second gap between the second surface feature of the inner tube and the second surface feature on the outer tube, and wherein the second gap is narrower than the first gap.

3. The fuel nozzle body as claimed in claim 1, wherein at least one of the second surface feature of the inner tube and the second surface feature on the outer tube of the second fit is chrome-plated.

4. The fuel nozzle body as claimed in claim 1, wherein at least one of the second surface feature of the inner tube and the second surface feature on the outer tube of the second fit is hardened.

5. The fuel nozzle body as claimed in claim 1, wherein the nozzle head is detachably connected to the inner tube.

6. The fuel nozzle body as claimed in claim 1, wherein the inner tube projects from the outer tube in the region of the forward end, and an encircling web is arranged on that part of the inner tube which projects from the outer tube.

7. The fuel nozzle body as claimed in claim 1, wherein the inner tube further comprises an encircling web disposed between the second fit and the additional openings, wherein the fuel nozzle body further comprises a sleeve comprising a sleeve first end which is detachable connected the forward end of the outer tube and a sleeve second end that comprises a radially inward-oriented flange that engages the inner tube between the encircling web and the additional openings.

8. The fuel nozzle body as claimed in claim 7, wherein the sleeve tapers radially inward toward the sleeve second end.

9. The fuel nozzle body as claimed in claim 1, wherein the inner tube is an oil line.

10. The fuel nozzle body as claimed in claim 1, wherein an annular channel formed between the inner and the outer tube is a gas line.

11. A burner comprising: the fuel nozzle body as claimed in claim 1.

12. A gas turbine comprising: a compressor, a turbine, and a combustion chamber having at least one burner as claimed in claim 11.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features, characteristics and advantages of the present invention will become apparent from the following description of illustrative embodiments with reference to the attached figures.

(2) FIG. 1 shows the schematic diagram of a gas turbine,

(3) FIG. 2 shows the view of a jet burner,

(4) FIG. 3 shows a fuel nozzle body with oil and gas injection in accordance with the prior art without a thermal compensation function,

(5) FIG. 4 shows a fuel nozzle body with oil and gas injection according to the invention with a thermal compensation function,

(6) FIG. 5 shows an inner tube in the region of the forward end in perspective view,

(7) FIG. 6 shows an inner tube in the region of the forward end in section,

(8) FIG. 7 shows an outer tube in the region of the forward end in section,

(9) FIG. 8 shows the forward end of the fuel nozzle body in perspective view,

(10) FIG. 9 shows the forward end of the fuel nozzle body in section, and

(11) FIG. 10 shows the forward end of the fuel nozzle body with retention sleeve.

DETAILED DESCRIPTION OF INVENTION

(12) FIG. 1 shows a gas turbine 31 schematically. This comprises a compressor section 32, a combustion chamber section 33 and a turbine section 34 as well as a combustion chamber 27 having at least one burner 23 in the region of the combustion chamber section 33. A burner 23 of this kind is described in greater detail in FIG. 2. The burner 23 has a fuel nozzle body 1, which is described in greater detail in FIGS. 3 to 10.

(13) During the operation of the gas turbine 31, air is drawn in through an air inlet of the compressor section 32 and is compressed there. The compressed air is fed to the combustion chambers 27, which are arranged in the combustion chamber section 33. A gaseous or liquid fuel, e.g. gas or oil, is also injected into the combustion chambers 27 via burners 23 or fuel nozzles. Here, fuel nozzle bodies comprise fuel nozzles/openings for liquid and gaseous fuels. The air/fuel mixture which forms is ignited and burned in the combustion chambers 27. The hot combustion exhaust gases flow from the combustion chamber section 33 into the turbine section 34, where they expand and cool down.

(14) FIG. 2 shows, schematically and by way of example, a burner 23, in particular a jet burner, in section with a nozzle support 35. The nozzle support 35 comprises a hot side 37, which faces a combustion zone 36 during operation, and an opposite cold side 38, which faces away from the combustion zone 36, wherein premixing tubes 30 in the nozzle support 35 extend from the cold side 38 to the hot side 37, i.e. parallel to the main axis 39 of the burner 23, each having an inlet 28 facing a premixing section on the cold side 38 and an outlet 40 on the hot side 37.

(15) The premixing tubes 30 serve as jet nozzles, which, in the current example, are arranged on two circles and at the inlets 28 of which fuel nozzle bodies 1 are arranged. During operation, a fuel 6, 10 and compressor air 29 flow through the jet nozzles, i.e. the premixing tubes 30, and enter the combustion chamber 27, delimited by a shell 41, as a fuel/air mixture at the outlets 40 of the jet nozzles.

(16) FIG. 3 shows, schematically and by way of example, a fuel nozzle body 42 with oil and gas injection in accordance with the prior art. The fuel nozzle body 42 has a rearward end 2 for feeding fuel to the fuel nozzle body 42 and a forward end 3 having openings 5, 9 assigned to different fuels. In particular, the fuel nozzle body 42 comprises an outer tube 4, which extends from the rearward end 2 to the forward end 3 and has radial openings 5 for a first fuel 6 in the region of the forward end 3, and an inner tube 7, which is arranged concentrically with respect to the outer tube 4 and which opens in the region of the forward end 3 into a nozzle head 8, which has additional openings 9 for a second fuel 10. The fuel nozzle body 42 is arranged at the inlet 28 of a premixing section. During operation, compressed air 29 flows past the fuel nozzle body 42 into a premixing tube 30. In the gas mode, gaseous fuel 6 is passed through the annular channel 21 formed by the inner 7 and the outer tube 4 and is injected into the air stream 29 surrounding the fuel nozzle body 42 via the radial openings 5. In the oil mode, oil is fed into the surrounding air stream 29 via the inner tube 7 and the nozzle head 8 having the additional openings 9 for injecting oil 10. The annular channel 21 thus acts as a gas line 22, and the inner tube 7 acts as an oil line 20.

(17) FIG. 4 shows a fuel nozzle body 1 according to the invention having a thermal compensation function, which is characterized in that, in the region of the forward end 3, the inner tube 7 is guided in the outer tube 4 by two fits 11, 12, which are arranged axially between the radial openings 5 and the additional openings 9.

(18) FIGS. 5 and 6 show the inner tube 7 in the region of the forward end 3 in a perspective view and in section. It shows the first fit 11, the second fit 12 and an encircling web 15. FIG. 7 shows the mating part, the outer tube 4 with the radial openings 5 for the first fuel 6.

(19) FIGS. 8 and 9 show the forward end 3 of the fuel nozzle body 1 in a perspective view and in section.

(20) FIG. 8 essentially shows the outer tube 4, a web 15 of the inner tube 7 and the nozzle head 8 with the additional openings 9 for the additional fuel 10.

(21) FIG. 9 shows that the nozzle head 8 is detachably connected to the inner tube 7, being screwed to it in the example shown (see screwed joint 24). The gap seal 14 of the first fit 11 is embodied in such a way that there is a minimal controlled leakage during operation. In particular, there should be less than 5% leakage via the first fit 11, based on the total injection zone. The second fit 12 is designed in such a way that it ensures a closer fit in all load cases than the first fit 11, also referred to as a leakage fit, and hence no contact arises between the first fit 11 and the inside of the outer tube 4, with the result that the leakage is defined by means of the first fit 11. In particular, the second fit 12 is more closely toleranced than the first fit 11. To make this work, fit 12 must not make contact with the entire circumference as an encircling web 13, like fit 11. For this reason, the second fit 12 is embodied in a star shape (not visible in the sectional drawing in FIG. 9 but visible in the embodiment in FIG. 10).

(22) FIG. 9 furthermore shows that the inner tube 7 projects from the outer tube 4 in the region of the forward end 3. The encircling web 15 arranged on the part of the inner tube 7 which projects from the outer tube 4 can also be seen in FIG. 8. This web 15 can be used as an abutment for the nozzle head 8. FIG. 9 shows the expansion distance 25 between the forward end of the outer tube 4 and the web 15.

(23) FIG. 10 shows an alternative use for the web 15. In this case, a sleeve 16 is detachably connected, e.g. screwed, at its first end 17 to the forward end 3 of the outer tube 4. At its second end 18, the sleeve 16 engages behind the encircling web 15 of the inner tube 7 by means of a radially inward-oriented flange 19. The sleeve 16 is intended to prevent loss of the inner tube 7. FIG. 10 furthermore shows that the sleeve 16 is embodied in a manner optimized in terms of flow and tapers toward the forward end 3.