JPS59115401A - Cooled blade of gas turbine - Google Patents

Abstract

PURPOSE:To remove cooling fluid without mixing it with main flow gas, by a method wherein a cylindrical injection tube, which extends radially and is coupled to a cooling passage in a blade body, is mounted to the forward end of a cooled blade. CONSTITUTION:A cylindrical injection tube 20, extending radially, is mounted to the forward end of a cooled blade 23. Cooling fluid, fed to a cooling fluid feed port 11 formed in the base part of the blade 23, passes through cooling passages 12 from the interior of a platform 19, and is guided in a gap 22 inside the forward end to be ejected outside the blade through the injection tube 20. The ejected cooling fluid is collected in a collector 15 mounted in the peripheral direction of a turbine casing 18. This enables the cooling fluid to be removed without mixing it with main flow gas.

Description

Detailed Description of the Invention [Technical field to which the invention pertains] The present invention relates to a gas turbine cooling blade that is cooled by a cooling medium, in which the cooling medium is collected in a casing part to eliminate mixing with mainstream gas, and to improve the gas turbine cooling blade. The present invention relates to a gas turbine cooling blade that improves the thermal efficiency of a turbine device.

[Prior art and its problems]

As is well known, gas turbines have many advantages over reciprocating engines, such as being smaller, lighter, and more powerful.

Taking such a gas turbine, for example, an isobaric combustion type, as shown in FIG. A compressor J and a power turbine generator are respectively configured between the casing 1 and the combustor 5 with high pressure air compressed by the compressor 3.
The internal pressure is increased, fuel is injected and combusted in this state, and the ultra-flat high temperature gas generated by this combustion is guided to the power turbine 4 and expanded, thereby obtaining rotational power for the shaft 2. ing. In the case shown in the figure, the compressor 3 is an axial flow type in which guide vanes 6 and rotary vanes 7 are arranged in the axial direction. It is constructed by alternately arranging fixed stator vanes 9 in the axial direction.

By the way, in order to improve the efficiency of the above-mentioned gas turbine, it is said that increasing the gas temperature at the inlet of the power turbine is the most effective means. However, the permissible temperature of the metal material constituting the water turbine 4 is generally about so, and the gas temperature cannot be increased beyond this. Therefore, in order to raise the gas temperature above the above value, it is necessary to efficiently cool the members constituting the power turbine east, especially the blades.

Conventionally, various means for cooling blades have been considered, and these can be broadly classified into air cooling methods and liquid cooling methods. Both systems have multiple refrigerant passages under the surface of the blade,
Air and cooling liquid are allowed to flow through this passage.

However, with air cooling systems, when trying to raise the gas temperature, the amount of air required increases significantly, the attached equipment also increases in capacity, and when the gas temperature exceeds a certain value, the overall There was a problem that efficiency decreased.

In those that employ a frozen liquid cooling system, the coolant after cooling is spouted out from the tips and trailing edges of the blades, making it extremely difficult to recover the coolant. FIG. 2 shows a conventionally used recovery device. In the recovery device 15 attached to the casing 18, the air flows into the recovery device body 17 through the recovery hole 14 provided at a position facing the tip of the cooling blade. There have been methods for taking the coolant out of the casing 18 through the coolant outlet 16, but these methods do not allow almost all of the coolant to be recovered. Therefore, the cooling liquid that cannot be recovered flows as a mixture with the mainstream gas 10, causing a decrease in the temperature of the mainstream gas and a decrease in thermal efficiency. In addition, there was a problem in that the turbulence of the wake wake increased due to the ejection from the trailing edge of the blade, and the characteristics of the blade cascade deteriorated.

In recent years, the development of highly efficient turbine equipment has been progressing.
As the mainstream gas temperature tends to rise more and more, there is a strong desire for gas turbine cooling blades with excellent thermal efficiency and blade row characteristics.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to improve the thermal efficiency and blade cascade characteristics of turbine blades exposed to high-temperature gas, and in particular to improve the cooling fluid passing inside the blades. An object of the present invention is to provide a gas turbine cooling blade that does not mix with mainstream gas.

[Summary of the invention]

The present invention relates to a cast turbine cooling blade of a liquid-cooled turbine that is exposed to high-temperature and high-pressure gas, in which a plurality of cooling liquids are provided inside the blade body near the surface to cool the blade. The cooling liquid passes through a cooling channel, is guided to a gap at the tip of the blade, and is further jetted out to the outside of the blade by a cylindrical jet tube provided at the tip of the blade. On the other hand, the coolant recovery device attached to the casing on the outer periphery of the turbine blade is provided in a manner that encompasses the above-mentioned jet pipe, so that the coolant jetted out from the jet pipe is not mixed with the mainstream gas. It is characterized by the fact that it can be recovered.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG.

Here, the cooling liquid supplied to the cooling liquid supply port 11 attached to the root of the blade goes from inside the blade platform 19 to the tip of the blade, and passes through a plurality of cooling channels 12 provided inside near the blade surface. and is guided to the air gap 22 inside the blade tip. Further, the coolant collected in the gap 22 is jetted out of the blade from a cylindrical jet pipe 20 provided at the tip of the blade.

On the other hand, the coolant recovery device 15 attached in the circumferential direction of the turbine casing 18 has an inner gap 17, and the tip of the jet pipe 20 attached to the tip of the cooling blade reaches the inner gap 17, Most of the coolant spouted from the spout pipe 20 is recovered in the recovery device 15, and can be further taken out to the outside of the casing through the coolant outlet 16.21.

〔Effect of the invention〕

Therefore, in conventional blades, as shown in Fig. 2, the cooling liquid is injected directly into the mainstream gas from the pores 13 at the tip and trailing edge of the blade, which lowers the temperature of the mainstream gas and causes a decrease in thermal efficiency. By adopting the method described above, it is now possible to easily take out the cooling fluid without mixing it with the mainstream gas, and it is therefore possible to provide cooling blades for gas turbines with good thermal efficiency. became.

[Other Embodiments of the Invention J The number of jet pipes used in the blade according to the present invention is not necessarily limited to one, and even if a plurality of jet pipes are provided depending on the difference in the internal cooling structure of the blade, it will not be partially recessed. Father, in the above explanation, we are looking for an integrated type of coolant recovery device, but as shown in Figure 4, it is 15', 15
``The recovery device may be separated into two parts and installed independently to simplify the installation method.

Further, as shown in FIG.
Bend the tip of the jet pipe 2 in the direction opposite to the direction of blade rotation.
Alternatively, a method may be adopted in which the tip of the blade is formed into a jet nozzle 24 in the form of a nozzle 24 to jet the coolant, thereby obtaining a reaction force and contributing to the rotation of the blade.

Note that arrow A in the figure indicates the blade rotation direction, and 23 is a rotor blade of the gas turbine.

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view of the gas turbine;
The figure is a structural diagram of a conventionally used liquid-cooled turbine blade.
The figure is a cross-sectional view showing a gas turbine cooling blade according to the present invention, FIG. 4 is a cross-sectional view showing another embodiment of a cooling liquid recovery device used in the present invention, and FIG. 5 is a cross-sectional view showing a cooling liquid collector used in the present invention. FIG. 3 is a perspective view showing another embodiment of the ejection pipe of FIG. 15...Recovery device, 20...Ejection pipe, 22...Gap, 23...Motor blade of gas turbine. Agent Patent attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2 P Figure 8 1? Figure 4 1? / Figure 5

Claims (2)

[Claims] (1) Cooling medium is supplied from the root of the blade, passes through multiple cooling channels provided inside the blade body near the surface, and is jetted out from the tip and trailing edge of the blade for cooling. In the gas turbine cooling blade, a gap connected to the cooling flow path is provided inside the cooling blade tip, and the blade tip is provided with at least one or more cylindrical ejection pipe in the radial direction of the blade. A gas turbine cooling blade characterized by: (2) The cylindrical ejection pipe has a length that reaches the inside of the cooling medium recovery device installed in the circumferential direction of the casing above the cooling blade.
The gas turbine cooling blade described in .