JPS62203903A - Blade for gas turbine - Google Patents

Abstract

PURPOSE:To enable cooling to be carried out sufficiently over all range of the outer surface of a blade with a small quantity of cooling, air, by providing a cooling air supply port for the tip end portion of a turbine blade and a cooling air supply port for a tempering air duct individually for differentiating cooling air passages. CONSTITUTION:The housing 1 of a blade has an internal cavity, and a hollow insert 2 and an insert 3 being similar to the configuration of the housing are inserted into the housing 1 from the outside thereof. The insert 2 is located in the tip end portion of the housing 1, so that cooling air introduced from a cooling air supply port 10 into the insert 2 flows from holes 5 formed on the insert 2 to one shroud 4 through a turbulence cavity 6. Also, cooling air introduced from a cooling air supply port 11 into the insert 3 flows to a tempering air duct 8 through an opening between the inserts 2 and 3 so as to blow off from the rear end edge of the blade. The tempering air duct 8 is formed between protrusions 7 and 7 which are arranged on the inner wall of the housing 1 so as to extend in the chord direction, and separated from the turbulence cavity 6 by a partition plate 9.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to gas turbine blades.

[Technical background of the invention and its problems]

In recent years, in order to improve the performance of gas turbines, the gas temperature has increased, and the blades are increasingly exposed to high temperatures. Under certain conditions, when the blades of a gas turbine have a relatively small amount of cooling air and the temperature on the outside of the blades is exposed to high temperatures, Achieving even and sufficient cooling is difficult.

Additionally, a large amount of cooling air was required to keep the temperature of the blades below an allowable value. If the flow rate of cooling air is large,
Although the ability to lower the temperature of the blades is improved, on the other hand, the average gas temperature decreases due to an increase in the amount of cooling air that warms the mainstream gas, which may cause problems such as lowering the output efficiency of the gas turbine. be.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and even when the temperature outside the blade is high, it can be smoothly maintained with a considerable amount of cooling air.
In the range C, the object is to provide a gas turbine blade that can achieve almost uniform and sufficient cooling.

[Summary of the invention]

It has a jacket and an insert, the insert touching chord-like protrusions on the inner wall of the jacket, and between the protrusions forming a cold-air duct for the gas turbine blade. This is a gas turbine blade in which a cooling air supply port at the sales tip and a cooling air supply port to the cold air duct are provided separately to provide separate cooling channels.

〔Effect of the invention〕

That is, the gas turbine blade according to the present invention (ζ) has a cooling air supply port to the tip and a cooling air 1 to the cold air duct.
By providing separate dust supply ports and separate cooling channels, compared to the case where the supply ports are common, more cooling air can flow to the tips of the blades, which are relatively hot on the outer surface, and
By providing a cooling air supply port to the cold air duct, more cooling air can flow than the cold air duct TC,
As a result, the outer surface of the blade can be sufficiently cooled with a relatively small amount of cooling air. Further, by providing laminar cooling air holes in the tip of the jacket and the side wall of the jacket, it becomes possible to achieve even more sufficient cooling with a small amount of cooling air.

On the other hand, there is also the effect that the cooling air flowing through the tip can be used to cool the sheroud.

[Implementation sequence of the invention]

Examples of the present invention will be described below. In Figure 1,
FIG. 2 shows a cross-sectional view of the internal structure of the blade of the present invention, and a cross-sectional view is shown in FIG. A jacket 1, which has the stable shape and mechanical strength required for the blade, surrounds an internal cavity, in which a hollow insert 2 and an insert 3 having the same shape as the jacket are located. It is introduced from the outside and is firmly connected to the shroud 4 on the underside. In addition, a hollow insert 2 is installed at the tip of the outer cover 1, and cooling air passes through the insert 2 from the supply port to the insert 2.
The air flows through a hole 5 drilled in the shroud 4 through a turbulence chamber 6. The insert 3, which still has substantially the same shape as the jacket, contacts the chordwise extending protrusions 7 present on the inner wall of the jacket 1, forming cold air ducts 8 between the protrusions 7. The cooling air flowing inside from the supply port of the insert 3 is transferred to the hollow insert 2 installed at the tip.
and flows through the gap of the insert 3 to the cold air duct 8,
The cold air passes through the duct flow path and blows out from the trailing edge of the blade. Note that the turbulence chamber 6 and the cold air duct 8 are separated by a partition plate 9.
The end has been made by In order to achieve uniform or sufficient cooling in all areas of the blade, the cooling air supply port 1° to the tip and the cooling air supply port 11 to the cold air duct are provided separately, and the cooling channels are separated. By making the Ic- It's h. As a result, a relatively small amount of cooling air is sufficient to cool the entire area of the blade outer surface. Further, by providing laminar cooling air holes in the tip of the jacket and the side wall of the jacket, it is possible to achieve even more sufficient cooling with a small amount of cooling air. On the other hand, the cooling air flowing through the tip can also be used to cool the sheroud.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the blade according to the present invention, and FIG.
The figure is a cross-sectional view of the embodiment shown in FIG. 1, and FIG. 3 is a perspective view showing the conventional structure. 1... Outer covering, 2... Insertion body, 3... Insertion body. 4... Sheroud, 5... Hole, 6... Turbulence chamber. 7...Protrusion part, 8...Cold air duct, 9...Partition plate. 10, 11...Cooling air supply port. Agent Patent Attorney Nori Chika Yudo Kikuo Takehana

Claims (4)

[Claims] (1) having a jacket and at least one insert abutting chord-like protrusions on an inner wall of the jacket, and having a cold air duct between the protrusions; is formed, a perforation is provided at the tip of the insert, and the blade of the gas turbine cools the inner surface of the tip of the jacket through a turbulence chamber between the jacket and the insert. A gas turbine blade characterized in that a cooling air supply port to the tip and a cooling air supply port to the cold air duct are provided separately, and the cooling flow paths are different. (2) The gas turbine blade according to claim (1), characterized in that a partition plate is provided between the turbulence chamber and the cold air duct. (3) The gas turbine blade according to claim (1), characterized in that a layered cooling air hole communicating with the cold air duct is bored in the side wall surface of the outer jacket. (4) The gas turbine blade according to claim (1), wherein a layered cooling air is provided at the tip of the outer jacket.