JPS6082724A - Gas turbine combustor - Google Patents

Abstract

PURPOSE:To prevent a self ignition and a back fire producing a low NOx, and get a small-sized and light weight premixer by a method wherein a premixer having at least two panels and a plurality of cylinders passing through the panels are arranged upstream of a combustor and at the same time ports are arranged at the circumferential surfaces of the cylinders. CONSTITUTION:Air compressed and heated to a higher temperature enters a cylinder 14 and is mixed with fuel fed from the ports 18. The air enters a combustion area through a step 17 and is burned. The fuel fed into the cylinder 14 forms a thin film D at the inner surface of the cylinder 14 and flows downward, is peeled off by the step 17 and then is mixed with the air flow. A panel 13 is exposed to the combustion gas to generate a high temperature. The cooling air flows as indicated by Q to cool the wall surface of the panel 13 resulting in that the panel 13 may not be burnt down. Since a space for the cooling air is present, the space for fuel may not be over-heated and over-heating and pyrolysis of the fuel are not occurred.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention 1 relates to an improvement in an obstructor for a gas turbine, and more particularly to a combustor for a gas turbine provided with a premixing device to improve the mixing of fuel and air.

In gas turbine combustors, premix combustion systems are being researched to reduce NOx emissions.

However, when adopting the premixing method, there was a drawback that spontaneous combustion was more likely to occur unless the premixing time was shortened.

Furthermore, flashback from the combustion region to the upstream side remains a major problem.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above drawbacks and provide a gas turbine combustor having a small and lightweight premixer.

This will be explained in detail below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the present invention.

A gas turbine combustor 1 has a casing 2 and a liner 3. A liner 3 is arranged within the casing 2. A compressor outlet guide vane 4 is provided at the upstream end of the casing 2, and a turbine nozzle 5 is provided at the downstream end. The turbine nozzle 5 directs combustion gas to the rotor blades 6 of the turbine.

A combustion chamber 7 is formed inside the liner 3, and a premixer 8 of the present invention is provided on the upstream side.

A fuel supply port 9 is provided on the outside of the casing 2 and supplies fuel to the premixer 8 . A dilution air inlet 1o is provided on the downstream side of the liner 3. In addition, the air supply port 9
It is provided as necessary, as described below.

In the gas turbine combustor 1 described above, when the air introduced from the guide vanes 4 passes through the premixer 8, fuel is premixed therein, and the air is combusted in the combustion chamber 7. Then, it mixes with the dilution air introduced from the inlet 10, passes through the turbine nozzle 5, and rotates the rotor blades 6.

Next, one embodiment of the structure of the premixer 8 will be described.

FIG. 2 is a sectional view showing one embodiment of the premixer 8.
The figure is an enlarged view of section A in FIG. 2.

The three panels 11.12 that the premixer 8 partitions into the liner
．． 13, and a cylindrical body 14 passing through three panels 11 and 12°13. The number of cylinders 14 can be freely selected.

A space 15 and a second space 167 are divided, the first space 15 on the upstream side is supplied with fuel, and the second space 16 on the downstream side is supplied with air for cooling the downstream panel 13 and the fuel. will be introduced.

The upstream side of the cylindrical body 14 is expanded into a trumpet shape to reduce the resistance to air introduction, and the downstream end is provided with a step 17 that protrudes inward. A plurality of vents 18 are provided at positions facing one space 15, and a plurality of air outlets [ ] 19 are provided in the panel 13.

The functions of the premixer constructed as described above are as follows.

The compressed, high-temperature air enters the cylinder 14 as indicated by arrow P. Then, the fuel and air introduced from the vent [8 form a mixture V, which enters the combustion region through step 17 and is combusted.

The fuel introduced into the cylinder 14 forms a thin film on the inner surface of the cylinder 14 and flows downstream, but is separated by the step-F and mixed into the air flow.

4- The panel 13 is exposed to combustion gas and becomes high in temperature, but since the cooling air flows like Q and cools the wall surface of the panel 13, the panel 13 will be burnt out and the cooling air will Since there is a space, there is no fear that the fuel space will be overheated, and there will be no overheating or thermal decomposition of the fuel.The above is one example, and the present invention is not limited to the above example.

For example, the spaces to which fuel is supplied may be provided in two or more multiplexes.

Further, the space provided can be omitted if necessary.

The effects of the present invention described above are listed below.

Since the premixer has a small flow direction dimension, the residence time of the fuel is short and there is no risk of self-ignition. Furthermore, the overall length of the combustor can be shortened.

Even if a backfire occurs inside the cylinder, there is no flame-holding part inside the cylinder, so the flashback will not continue and will only end temporarily.

Since the internal volume of the cylinder is small, the cooling effect is high and sparks are less likely to occur.

The premixer has multiple barrels so that the fuel is evenly distributed across the front of the panel. Therefore, combustion becomes uniform, temperature distribution becomes uniform, and N
Ox reduction, HC reduction IC will be useful.

Either liquid or gas can be used as the fuel, and even in the case of liquid, the fuel can be sufficiently atomized into droplets.

If fuel is supplied from a plurality of locations and cylinders are grouped for each fuel supply means, the amount of fuel can be changed considerably.

By flowing the cooling air, overheating of the fuel and thermal decomposition of the fuel are prevented, and thermal damage to the panel is also prevented.

In addition to the above embodiments, the premixer may have a structure shown in FIGS. 4(a), 4(b), and 4(c).

That is, it is also possible to form the panel 20 with a V-shaped cross section as shown in FIG. 4(a)K, and to shift the combustion area in the axial direction. This prevents vibrational combustion.

The ones shown in (b) and (c) also shift the combustion area in the entire axial direction, and the one in (b) has two panels 21.2 inside and outside.
2 is provided, and the one in (c) is provided with a convex multi-stage panel 23.

It is clear from the gist that the embodiment shown in FIG. 4 above is also included in the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention IM, FIG. 2 is a schematic sectional view of the premixer shown in FIG. 1, FIG. 3 is an enlarged view of section A in FIG. 2, and FIG. ), (b), and (c) are schematic sectional views showing other embodiments of the present invention. Gas turbine combustor, 2: casing, 3: sheath, 7: combustion chamber, 8: premixer, 11, 12, 13: panel, 14: cylindrical body. 15th 2g 35th! I

Claims (1)

[Claims] In a combustor in which a gas is provided in a casing, air and fuel are introduced from upstream of the liner and burned in a combustion chamber in the liner, and the combustion gas rotates a turbine rotor blade, the upstream side of the combustion chamber. a premixer having at least two panels and a plurality of cylinders passing through the two panels, introducing fuel between the two panels, and introducing the fuel into the cylinders. A gas turbine combustor characterized in that a vent is provided on the circumferential surface of a cylindrical body in order to