JPH0230409B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a combustor of a gas turbine.
More specifically, the present invention relates to a gas turbine combustor equipped with a premixing device to improve mixing of liquid fuel and air.

(Prior Art) A premix combustion method is being researched in gas turbine combustors to reduce NOx emissions.

In this premixing method, liquid fuel and air are mixed in advance and then introduced into the combustion chamber. This allows the length of the flame to be reduced compared to the conventional combustion method in which liquid fuel is injected into the combustion chamber. This is to shorten the length of the combustion chamber, thereby avoiding the occurrence of localized hot spots in the temperature distribution of combustion gas inside the combustion chamber.

(Problems to be Solved by the Invention) However, when adopting the premixing method, there was a drawback that spontaneous combustion was likely to occur unless the premixing time was shortened.

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

An object of the present invention is to improve the above-mentioned drawbacks and provide a gas turbine combustor having a small and lightweight premixer.

(Means for Solving the Problems) The present invention is characterized by the following configuration.

That is, in a gas turbine combustor in which a liner is provided in a casing, air and fuel are introduced from upstream of the liner and burned in a combustion chamber within the liner, and the turbine rotor blades are rotated by the combustion gas, the combustion chamber is at least three panels are provided on the upstream side, the three panels form a first space on the upstream side and a second space on the downstream side, and a plurality of panels penetrating the three panels are provided. A cylindrical body is provided, a hole is provided on the circumferential surface of the cylindrical body through which the fuel introduced into the first space is introduced into the cylindrical body, and a step for separating the fuel flowing along the circumferential surface of the cylindrical body is provided. An air outlet is provided at the downstream end of the cylindrical body and blows out the cooling air introduced into the second space into the combustion chamber.

(Example) This will be explained in detail below using figures.

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 combustor 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,
Fuel is supplied to the premixer 8. A dilution air inlet 10 is provided downstream of the liner 3. Note that the air supply port 9A is provided as necessary, as will be described later.

In the gas turbine combustor 1 described above, air introduced from the guide vanes 4 is premixed with fuel when it passes through the premixer 8, and is combusted within the combustion chamber 7. and,
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, and FIG. 3 is an enlarged view of A in FIG.

Three panels 1 with premixer 8 partitioning inside the liner
1, 12, 13 and three panels 11, 12, 1
3 and a cylindrical body 14 passing through the cylinder. Cylindrical body 14
The number may be freely adopted.

Three panels 11, 12, and 13 partition a space 15 in FIG. 1 and a second space 16, and the first space 15 on the upstream side is supplied with fuel, and the second space on the downstream side is Cooling air for cooling the downstream panel 13 and the fuel is introduced into the space 16.

The upstream side of the cylindrical body 14 is flared to reduce resistance to air introduction, and the downstream end is provided with a step 17 that protrudes inward. Further, a plurality of vents 18 are provided on the circumferential surface of the cylindrical body 14 at positions facing the first space 15, and a plurality of air outlets 19 are provided in the panel 13.

The operation of the premixer according to the present invention constructed as described above is as follows.

The compressed, high-temperature air enters the cylinder 14 as indicated by arrow P. Then, the fuel introduced from the port 18 and the air become mixed, and the process proceeds to step 17.
It enters the combustion area through and burns.

The fuel introduced into the cylinder 14 forms a thin film-like membrane D on the inner surface of the cylinder 14 and flows downstream, but is separated in step 17 and mixed into the air flow. .

Although the panel 13 is exposed to the combustion gas and becomes hot, the cooling air flows like Q and cools the wall surface of the panel 13, so that the panel 13 will not be burnt out. Furthermore, since there is a cooling air space adjacent to the space where the fuel flows, there is no risk of the fuel space being overheated, and there is no overheating or thermal decomposition of the fuel.

Note that the above is one example, and the present invention is not limited to the above example.

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

In addition to the above embodiment, the premixer is also shown in Fig. 4A,
The structures shown in (b) and (c) may also be used.

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

The ones shown in (b) and (c) also shift the combustion area in the axial direction, and the one shown in (b) has two panels 21 inside and outside,
22, and the one shown 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.

(Effects of the Invention) The effects of the present invention described above are enumerated as follows.

Due to the small flow direction dimensions of the premixer, 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 flashback were to occur inside the cylinder, there is a flame-holding part inside the cylinder, so the flashback would not continue and would end up being a temporary flashback.

Since the internal capacity of the cylinder is small, the cooling effect is high and backfire is 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 and temperature distribution becomes uniform, which is useful for reducing NOx and HC.

Fuel droplets can be sufficiently atomized.

By supplying fuel from multiple locations and grouping cylinders for each fuel supply means, the amount of fuel can be varied.

Since the cooling air is caused to flow, overheating of the fuel and thermal decomposition of the fuel are prevented, and thermal damage to the panel is also prevented.

Since the step is provided at the downstream end of the cylinder, separation of the fuel and mixing with the air is improved.

The step also has the effect of preventing flashback.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention, 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. 1: Gas turbine combustor, 2: Casing,
3: liner, 7: combustion chamber, 8: premixer, 11,
12, 13: Panel, 14: Cylindrical body, 15: First space, 16: Second space, 17: Step, 1
9: Air outlet.

Claims (1)

[Claims] 1 In a gas turbine combustor in which a liner is provided in a casing, air and liquid fuel are introduced from upstream of the liner and burned in a fuel chamber in the liner, and the turbine rotor blades are rotated by the combustion gas, the combustion chamber is at least three panels are provided on the upstream side, the three panels form a first space on the upstream side and a second space on the downstream side, and a plurality of panels penetrating the three panels are provided. A cylindrical body is provided, a hole is provided on the circumferential surface of the cylindrical body through which the fuel introduced into the first space is introduced into the cylindrical body, and a step for separating the fuel flowing along the circumferential surface of the cylindrical body is provided. A gas turbine combustor, characterized in that an air outlet is provided at the downstream end of the cylindrical body and blows out the cooling air introduced into the second space into the combustion chamber.