Stationary blade for gas turbine

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a stationary blade of a gas turbine applied to thermal power generation and the like.

【0002】

[Conventional technology]

FIGS. 2 and 3 are explanatory views of hollow blades of a conventional gas turbine used for thermal power generation and the like. In the figure, this stationary blade is manufactured by precision casting in which the blade profile 1 is integrated with the inner shroud 2 and the outer shroud (not shown). A sheet metal insert 4 having a large number of holes 3 is inserted into the hollow portion A in the stationary blade, and cooling air is supplied from the top of the insert 4 to the inside through an outer shroud by a compressor. It is supposed to be done. The insert 4 may be divided into two front and rear parts.

【0003】

The cooling air supplied to the inside of the insert 4 flows out from the hole 3 to the hollow portion A in the stationary blade and collides with the inner wall of the profile 1 to perform impingement cooling. Then, a part of this air flows out from the hole 5 provided in the wing profile 1 along the outer surface of the wing profile 1 to perform film cooling, and the remaining air flows through the slit 6 at the trailing edge of the wing. After convection cooling of the trailing edge of the wing, it flows out from the trailing edge and joins the combustion gas. In order to promote this convection cooling, pin fins 7 may be provided on the trailing edge of the wing. In addition, a hole 8 may be provided at the leading edge of the wing, and cooling air flows out from this hole 8 to perform shower head cooling.

【0004】

[Problems to be Solved by the Invention]

As described above, in the stationary blade of a conventional gas turbine, the cooling air supplied to the inside of the insert 4 flows out from the hole 3 to the hollow portion A in the stationary blade, collides with the inner wall of the profile 1, and impinges. This impingement cooling simply causes the cooling air flowing out of the hole 3 of the insert 4 to collide with the smooth inner surface of the wing profile 1 and wing the hollow part A between the insert 4 and the wing profile 1. It just flows to the trailing edge side. Therefore, the efficiency of impingement cooling is low, and a large amount of cooling air is required to keep the metal temperature of the stationary blade within the permissible range as the temperature of the gas turbine rises, which lowers the thermal efficiency of the gas turbine. ing.

【0005】

[Means for solving problems]

The purpose of the stationary blade of the gas turbine according to the present invention is to solve the above-mentioned problems. The inside is hollow, an insert is inserted into the hollow portion, and the insert is flown out to the hollow portion through a hole for impingement cooling provided in the insert. In the stationary blade of a gas turbine to which the cooling gas is supplied from the outside, a semicircular rectangular fin having a cross section extending in a direction crossing the flow of the cooling gas flowing to the wake side is provided on the inner wall of the hollow portion. It is characterized by a configuration in which the insert is provided so as to face a hole for cooling the impingement.

【0006】

【0007】

[Action]

That is, in the stationary blade of the gas turbine according to the present invention, the cooling gas flows to the wake side on the inner wall of the hollow portion of the stationary blade of the gas turbine in which the inside is hollow and the cooling gas is supplied from the outside to the hollow portion. A semi-circular rectangular fin extending in the direction across the gas flow is projected, and the heat transfer area on the inner wall of the hollow portion increases by the amount corresponding to the surface area of the fin, and the cooling gas flowing through the hollow portion increases. The flow is disturbed by the fins, a vortex is generated on the wake side of the fins, and the heat transfer coefficient is increased, so that the efficiency of impingement cooling in the hollow portion is improved.

【0008】

Moreover, as described above, in the present invention, the semicircular rectangular shape-shaped fin provided on the inner wall of the hollow portion extending in the direction crossing the flow of the cooling gas flowing to the wake side is provided for impingement cooling on the insert. Since the heat transfer area on the inner wall of the hollow part increases by the amount corresponding to the surface area of the fin, the flow of the cooling gas flowing through the hollow part is greatly disturbed by the fin and the fin is greatly disturbed. A strong vortex is generated on the wake side and the heat transfer coefficient becomes very high, so that the efficiency of impingement cooling in the hollow portion is extremely improved.

【0009】

[Example]

FIG. 1 is an explanatory view of a hollow blade of a gas turbine according to an embodiment of the present invention. In the figure, the hollow vane of the gas turbine according to the present embodiment is a hollow vane of a gas turbine used for thermal power generation and the like, and the blade profile 1 is an inner shroud like the hollow vane of the conventional gas turbine in FIG. Manufactured by precision casting integrally with the outer shroud (not shown in 2). A sheet metal insert 4 having a large number of holes 3 is inserted into the hollow portion A in the stationary blade so that cooling air is supplied from the top to the inside through the outer shroud by a compressor. It has become. The insert 4 may be provided separately in the front and rear.

【0010】

The cooling air supplied to the inside of the insert 4 flows out from the hole 3 to the hollow portion A in the main vane and collides with the inner wall of the blade profile 1 to perform impingement cooling. Then, a part of this air flows out from the hole 5 provided in the wing profile 1 along the outer surface of the wing profile 1 to perform film cooling, and the remaining air flows through the slit 6 at the trailing edge of the wing. After convection cooling of the trailing edge of the wing, it flows out from the trailing edge and joins the combustion gas. In order to promote this convection cooling, pin fins 7 may be provided on the trailing edge of the wing. Further, a hole 8 may be provided at the leading edge of the wing, and cooling air flows out from the hole 8 to perform shower head cooling.

【0011】

However, simply the cooling air flowing out of the hole 3 of the insert 4 collides with the smooth inner surface of the wing profile 1 and flows through the hollow chamber A between the insert 4 and the inner wall of the wing profile 1 toward the trailing edge side. Due to the low efficiency of ment cooling, in the hollow blade of this gas turbine, fin 9 confronts hole 3 for impingement cooling of insert 4 on the inner wall of blade profile 1 as shown in Fig. 1. The fin 9 is integrally formed with the hollow vane 1 as a semi-circular rectangular fin having a cross section extending in a direction crossing the flow of cooling air flowing to the wake side, and the inner wall of the wing profile 1 is formed by this fin 9. The flow of cooling air along is disturbed and curved in the direction of the arrow, generating a vortex on the wake side of Fin 9.

【0012】

Since the fin 9 is integrally formed with the wing profile 1 on the inner wall of the wing profile 1 in this way, the heat transfer area on the inner wall of the wing profile 1 increases by the surface integral of the fin 9, and the hollow inside the wing. The cooling air flowing through the part A to the trailing edge side is disturbed by the fin 9, and a vortex is generated on the trailing side of the fin 9 to increase the heat transfer coefficient. Improves the efficiency of impingement cooling in wing profile 1. In particular, since the fin 9 is projected so as to face the hole 3 for impingement cooling, the flow of cooling air is greatly disturbed by the fin 9, and a strong vortex is generated on the wake side of the fin 9. , The heat transfer coefficient becomes extremely high. As a result, the reliability of the hollow blade of the gas turbine is increased, the amount of cooling air is reduced, and the thermal efficiency of the gas turbine is improved.

【0013】

[Effect of the invention]

The gas turbine vane according to the present invention is configured as described above, and the efficiency of impingement cooling in the hollow portion is improved, so that the amount of cooling air is reduced and the thermal efficiency of the gas turbine is improved.

[Simple explanation of drawings]

[Figure 1]

FIG. 1 (a) is a cross-sectional view of a main part of a hollow vane of a gas turbine according to an embodiment of the present invention, and FIG. 1 (b) is a view taken along the line bb in FIG.

[Figure 2]

FIG. 2 (a) is a partially broken perspective view of a hollow blade of a conventional gas turbine, and FIG. 2 (b) is a cross-sectional view.

[Fig. 3]

FIG. 3 (a) is a cross-sectional view of the main part, and FIG. 3 (b) is a view taken along the line bb in FIG. 3 (a).

[Explanation of symbols]

1 wing profile 2 inner shroud 3 holes 4 insert 5 holes 6 slit 7 pin fin 8 holes 9 Fin