US2737366A

US2737366A - Gas turbine

Info

Publication number: US2737366A
Application number: US222980A
Authority: US
Inventors: Ledinegg Max
Original assignee: Simmering Graz Pauker AG
Current assignee: Simmering Graz Pauker AG
Priority date: 1950-05-02
Filing date: 1951-04-26
Publication date: 1956-03-06
Anticipated expiration: 1973-03-06

Description

United 1 States GAS TURBINE Max Ledinegg, Vienna, Austria, assignor of one-half to Simmering-Graz-Pauker Aktiengesellschaft fur Maschinen-, Kesselund Waggonbau, Vienna, Austria, a company of Austria Application April 26, 1951, Serial No. 222,980

Claims priority, application Austria May 2, 1950 2 Claims. (Cl. 253-3945) This invention relates to means for cooling the blades in gas turbines, in particular at operating temperatures exceeding 700 deg. C. The blades are cooled by an evaporating liquid, such as water, which is circulated within the blade by centrifugal force through thin bores. In the construction suggested the steam formed in the blade is condensed in a cooler, which is made in one piece with the blade.

The invention essentially consists in that each blade has associated with it a radiator of its own, in which the condensation of the steam formed in the blade takes place. The cooler is situatedinside the rotor and is swept over by air, to which the heat absorbed by the blade is delivered.

In Figs. 1 to 7 of the accompanying drawings an embodiment of the subject of the invention is shown by way of example.

Fig. l is a longitudinal sectional view taken through one half of a turbine, with runner wheel and guide wheel.

Fig. 2 shows on a larger scale the construction of the first two blades with coolers, shortly called blade coolers.

Fig. 3 illustrates in a sector-shaped fragment the structure of Fig. 2 taken in a plane normal to the plane of Fig. 2 and comprising blades. In this figure the blade coolers are not shown in section.

Fig. 4 shows the same view as Fig. 3 but with the blades and coolers removed.

Figs. 5, 6, 7 are three sectional views of a blade cooler, taken along the lines 5-5, 66, and 77 respectively, of Fig. 2.

In Fig. 1, 1 is the casing of the turbine and 2 the rotor. The hot gases enter at 3, the waste gases are collected and conducted away at 4. The casing has fitted in it the guide blades 5.

The rotor 2 has runner wheel disks 6, which are either shrunk on or integral with the rotor. The disks 6 have oblong radial openings 7 (see also Fig. 4). The several disks 6 are formed with grooves 21 (Fig. 2), and the blade coolers having flanges which fit in grooves 21.

The air, which is delivered by the compressor of the gas turbine plant and the pressure of which approximately equals that of the combustion gas at 3, flows through the rotor body. The entrance takes place at 8 in the direction of the arrow, the escape takes place at 9. The size of the openings 7 is such as to permit of the escape of the air without appreciable pressure loss. During its passage through the rotor, the air sweeps over the coolers 10 so that the steam within the cooler is condensed. Centrifugal force urges the condensate immediately back into the appertaining blade, where it evaporates again. In this manner each blade with its cooler forms a closed cycle, which is inserted and mounted independently of the rest of the blades, just as in a conventional, uncooled turbine.

On an enlarged scale, Fig. 2 shows for the first two blades from the left the cooler 10 and the runner blade 11 integral therewith. Each blade has several tiny bores ice 12 and a somewhat larger bore 13, which bores communicate with each other through a duct 14. The cooling water flows through 13 from the inside outwardly, and through 14 enters the ducts 12, where it partially evaporates and flows inwardly under the action of the centrifugal force prevailing as a result of the great difference in density. In the cavity 15 of each blade, the centrifugal force leads to the formation of a liquid level 16. The steam generated enters the cooler body 10, which may be provided with gills and in which the condensation of the steam takes place. In order to protect the runner wheels 6 from contact with the hot combustion gases, each blade has a flange 17, which has also bores 19 forming part of the internal closed cooling path described below in connection with Fig. 5. The cooling air flows through between the cooler gills in the direction of the arrow 22.

Fig. 3 shows in elevation several blades lying one beside the other and having cooling gills 18 arranged on the cooler bodies. A runner blade disk 6 (Fig. 4) lies behind each of the planes formed by the coolers and extending at right angles to the axis of the turbine. The cooling air flows through the openings 7.

In Fig. 5 (section 5-5 of Fig. 2) the cooling bores 12, 13 of the blade 11 are shown. This drawing also shows the construction of the flange 17 and the system of bores 19 provided there. The bores 19 have the substantially U-shaped configuration shown in Fig. 5, communicate at one end with the elongated bores 12, and communicate at their opposite'end with the hollow space in the elongated projection 10 of each blade. Fig. 6 shows the cross sectional shape of cavity 15 and a pair of opposed flanges of cooler 10. Fig. 7 shows the cooler itself with the gills 18.

As compared with the previous constructions, the embodiments described achieve an effective cooling of the blade exposed to the hot gas, the heat carried off by the cooler being transferred to the combustion air. In this manner the heat carried off by the cooler is fully retained in the process so that the cooling involves no loss of heat. Moreover, each blade cooler is completely closed in itself and can be fitted and removed separately. This feature enhances the safety of operation of the turbine as a whole. The supply and discharge of the air, at 8 and 9, respectively (Fig. l), are elfected by means of guide wheels 20 passed on the shaft and provided with guide blades.

What I claim is:

1. In a turbine, in combination, a rotor formed with a hollow space therein; a plurality of blades mounted on said rotor, having extensions located in said hollow space thereof so as to be cooled by a cooling medium therein, and being formed with a plurality of elongated bores located in the interior thereof and communicating with each other so that a cooling medium in said bores cools said blades; and a plurality of flanges located against the outer surface of said rotor, being respectively fixed to said blades and being formed with passages communicating with said bores, so that said flanges present a cooled surface to the gases passing through the blades of the turbine, said flanges being located closely adjacent to each other and substantially covering said outer surface of said rotor, the periphery of each flange abutting axially and circumferentially the perpiheries of the neighboring flanges.

2. In a turbine, in combination, a rotor formed with a hollow space therein; a plurality of blades mounted on said rotor, having extensions located in said hollow space thereof so as to be cooled by a cooling medium therein, and being formed with a plurality of elongated bores located in the interior thereof and communicating with each other so that a cooling medium in said bores cools said blades; and a plurality of flanges located against the I said blades and beingfdr'rfi'd'wim passages communicating "tjtliler a xially eind cii uf'riferen tiglly, and substantially dov- With said bores, so 'thavsaid' flanges 'present a "cooledsur- UNITED STATES PATENTS face to the gases passing through the blades of the turbine, 2440O69 Bloomberg 1948 said flanges being rectanglilanin shape, abutting each FOREIGN PATENTS 229,933 Switzerland-"1. Feb. 16, 1944 enng sa1d outer surface of sand rotor. 381 851 Great Britain Oct 13 1932 610,737 Great'Britin Oct. 20, 1948 10 895,583 France Apr. 3, 1944