US2603453A

US2603453A - Cooling means for turbines

Info

Publication number: US2603453A
Application number: US696287A
Authority: US
Inventors: Ferdinand P Sollinger
Original assignee: Curtiss Wright Corp
Current assignee: Curtiss Wright Corp
Priority date: 1946-09-11
Filing date: 1946-09-11
Publication date: 1952-07-15
Anticipated expiration: 1969-07-15

Description

July 15, 1952 F. P. SOLLINGER COOLING MEANS FOR TURBINES 3 Sheets-Sheet 1 Filed Sept. 11, 1946 N TOR INVE FERDINAND F SDLLINEER.

AT T CIRNEY IIIIIJA IIIII n 0 n m 3 m m? n w w "4 m July 1952 F. P. SOLLINGER coouuc MEANS FOR TURBINES 3 Sheets-Sheet .2

Filed Sept. 11, 1946 R. NEER.

L N W R m m Patented July 15, 1952 COOLING MEANS FOR TURBINES Ferdinand P. Sollinger, Paterson, N. assignor to Curtiss -Wright 7 of Delaware Corporation, a corporation Application September 11, 1946, S'erial'No. 696,287

I This invention relates to turbines and is particularly directed to the construction of the turbine'rotor .to provide for the flow of a cooling fluid in heat exchange relation therewith.

- A conventional form of turbine rotor comprises a rotor :disc portion having a cylindrical outer rimfrom which the turbineblades project radially, these blades beingsubjected to the heat of the hot working fluid of the turbine. Turbines, particularlygasturbines, are designed for operation at extremely high temperatures of the working' fluid for maximum turbine efficiency. If the high temperature of the turbine workingzzfluidis transmitted to the disc and hub ofithe turbine rotor, thesafe operating stress of .theiturbine rotor is materially reduced. Accordingly, one of the problemsencountered in the design and operation ofga turbine is the provision of means foradequatelycooling the turbine rotor. 1 v

An object of 'thisinventionis; the provision of novel means. permitting the flow of cooling air in heat exchange relation with the rim of the turbine wheel. Specifically, the invention comprises a pair of shelf-like spaced flanges projecting from a turbine blade shank, these flanges cooperatingwith similar flanges on the shanks of the adjacent turbine blades to provide passagesbetween the shanks of each blade communicating with opposite ends of the turbine rotor. In addition, means are provided for circulating cooling air through these passages to cool the the shank of the turbine blades thereby reducing the amountof heat conducted tothe web ofthe turbine rotor. The radially outerflange of said spaced flanges cooperates with the cor responding flanges on the adjacent blades to form a continuous cylindrical surface forming the radially inner boundary of the turbine working fluid,,the working portions of the turbine blades. projecting radially outwardly from this surface. J

A further object of this invention is the provisionof anovel flange construction on each blade of ,a, multi-stage turbine. rotor whereby the flanges on the blades of one stage cooperate with the flanges on the blades of the adjacent stage to provide a continuous cylindrical surface forming the radially inner boundary oi the turbine working fluid. A still further object of this invention comprises a turbine blade flange construction on a multi-stage turbine rotor whereby the flanges on the blades of each stage cooperate with the flanges on the blades of an adjacent stage to provide passages establishing communi- 7 Claims. v (01. 25a-39.15)

2 cation between the remote ends of the multistage rotor through which a cooling fluid may flow. 7

Other objects of this invention will become .apparent upon reading the annexed detailed along lines 2-2, 33, 4-4 and 5-5 respectively of Figure 1;

Figures 6 and 7 are perspective views of the firststage turbine blades looking in downstream and upstream directions respectively;

-Eig ure 8' is a perspective view of the second stage turbine blades as viewed in an upstream direction;

Figure 9 is a side view partly in section of a modified turbine blade; and

Figures 10, 11 and 12 are sectional views taken along lines Ill-l0, H-ll and l2l2 respectively of Figure 9.

Referring first to Figure 1 to 8, a two-stage turbine rotor indicatedat It! comprises a pair of rotor members l2 and I4, each drivably con nected to a shaft; [6. The radially outer portions of the discs of the rotor members 12 and I4 are secured together by bolts 18 projecting through the rotor members and suitable bosses formed thereon. Blades 20 are welded to the outer rim ofthe turbine rotor "member l2 as indicated at 22 and blades 24 are welded to the outer rim of the turbine rotor member [4 as indicated at 26. As illustrated in Figures 2 and 3 there is one blade '24 for each blade 20. The blades 20 comprise the first stage of the turbine rotor and the blades24 comprise the second stage of the turbine rotor. Instead of welding the blades tothe turbinerotor, they may be secured thereto by any othersuitable means. Fixed blades 28 project radially inwardly between the first stage blades 20 and the second stage blades 24 from the turbine housing structure 29. i

The turbine motive fluid is suitably directed into the blades 20 from a combustion chamber 3] by an annular nozzle construction 30 having fixed blades32. After leaving the first stage blades 20,'the turbine motive fluid is directed by the fixed blades 28 into the second stage blades 24... From the second stage blades, the turbine motive fluid discharges into the exhaust duct '34. The relative'disposition of the rotary blades20 and 24 and stationary blades 28' is best seen'in Figure .2. This fl'gure also discloses. by suitable 3 arrows, the approximate direction of the entrance and exit velocity of the working fluid relative to the

blades

28 and 24 respectively and the direction of rotation of these blades.

Each blade 28 is provided with a flange or shelf-like construction 36 having a substantially rhomboid shape. The shank of each blade 28 is provided with a second flange or shelf-like construction 36 radially spaced from said first flange and also having a substantially rhomboid shape. Each flange 36 terminates adjacent to the corresponding flanges of the adjacent blades 28 to form a substantially continuous outer cylindrical surface from which the working pottion of the blades 28 project. Similarly, each flange 38 terminates in substantially abutting relation with the corresponding flanges of the I adjacent blades 28 whereby the

flanges

36 and 36 provide passages 48 between the shanks of adjacent blades.

Each blade 24 is also provided with a pair of shelf-

like flanges

42 and 44 having a spacing similar to the spacing of the

flanges

36 and 38. Each

flange

42 and 44 terminates adjacent to V the corresponding flanges of the adjacent blades 24. Thus, the flanges 42 form a substantially continuous cylindrical surface from which the working portions of the blades 24 project. In

. addition, the flanges 42 of the second stage blades 24 form a smooth continuation of the flanges 36 of the first stage blades 28. As illustrated; the

flanges

36 and 42 abut approximately midway of the fixed blades 28. In this way, the flanges 36 and form a substantially continuous inner boundary for the turbine working fluid from one end to the other of the multi-stage turbine rotor I8. Similarly, the flanges 44 terminate adjacent the corresponding flanges of the adjacent blades 24 whereby the flanges 42 and 44'provide passages 46 between the shanks of the blades 24. 'Also,- the flanges 44 of the second stage blades 24 form a continuation of the flanges 38 of the first stage blades 28 so as to aline the passages 48 and 46 thereby providingcontinuous closedpassages 48, 46 through the multi-stage rotor 18: The passages 48, '46 extend between the shanks of the

rotor blades

28 and 24 from one end of the multi-stagerotor 18 to the other and each of these passages is completely closed by the tur bine blade flanges and the adjacent blade shanks. Also, there is one such passage 48, 46 on each side of each pair of

turbine rotor'blades

28 and 24. i

The passages 48, 46 permit the flow of cooling air therethrough, thereby cooling the turbine rotor blade shanks and reducing the heat conducted to the web of theturbine rotor. To facilitate the flow of' air through the passages 48, 46, the upstream end of the turbine rotor member i2 is provided with a centrifugal im peller communicating'with the passages 48, 46. For this purpose, a shroud 46 is secured to the rotor by the bolts l8 and conventional centrifugal blower or impeller blades 58 are formed rigid therewith. As illustrated, these blades 58 and the shroud 48 extend radially outwardly to the entrance of the passages 48, 46.

ing air is forced through the blade shank passages 48, 46 by the'iinpeller 58 and from these passages the cooling air discharges into the ex- With this arrangement, during turbine operation, cool- 4

flanges

36 and 38 that this portion of the blade shank has substantially the same general outline as the radially inner end of the working portion of the blades 28. With this construction, the centrifugal forces acting on the working portions of the blades 20 are transmitted radially inwardly to the turbine rotor 12 without inducing bending, stresses in the

flanges

36 and 36. That'is, the shank 'of' the blades 28 between the

flanges

36 and 38 is formed so as not to undercut any substantial portion of the inner end of the working portion of the blades 28. In this way, substantially each point on the blades 28 has a radially straight metallic connection through the shank of each blade with the rim on the'turbine rotor I2. Accordingly, the

flanges

36 and 38 do not transmit the centrifugal forces acting on the working portions of the blands 28 to the blade shanks and to the turbine rotor. As best seen in Figures 3 and 7, the shank of each blade 28 is extended downstream between its spaced

flanges

36 and 38 by a web construction 51 hollowed out on its inner side to reduce its weight. As illustrated, each blade 28 also has recessed

portions

52 and 54 radially inward of the flanges 38 for decreasing the Weight of the blades. 'The

recess portions

52 and 54 for the blades 28 also do not undercut the working portions of these blades.

The shank of each blade 24 is formed. gen= erally similar to the shank of the blades 28. That is, the shank of each-blade 24 radially inward of its working portion and between its

flanges

42 and 44 follows the general outline of the inner end of the working portion of the blade 24. The shank of each blade 24 is extended upstream between its

flanges

42 and 44 by a web construction 55 similar to the web 5| of the blades 28. In addition, as illustrated the shank extension 5| of each blade 28 abuts the corresponding extension 55 of a blade 24. whereby said shank extensions separate each passage 48, 46 from its corresponding adjacent passages.

The cooling air leaving the passages 48, 46 discharges into an annular diffuser passage 56. This annular difiuserrpassag'e is provided with diffuser vanes 58 to reduce'the rotationalvelocity of the; cooling air as it leaves turbine rotor 48, 46 thereby straightening out this flow before it discharges into the exhaust duct 34. Also,- the eflective cross sectional areaof the discharge end of the diffuser passage 56' is designed so that the cooling air discharges into the exhaust duct 34 with substantially the same-velocity as the ad jacent velocity of the turbine exhaust fluid inthe duct 34.

With the aforedescribed' construction, the. spaced shelf-like flanges on the shanks of the fixed blades 28. In ges andturbine rotor ous passage-walls from urb'ine motive fluid e rotor. os'e a two-stage turymwardiy of the space him rotor, the invention is not so limited but may of stages of, rotating blades.

1 Figures 9 to, 12 disclose a modified blade construction for a single stage turbine, each blade 60 being secured to the rim of a turbine rotor 62, for example, by welding, as indicated at 64, or by any other suitable construction. Each blade 60 has a pair of radially spaced

flanges

66 and 68 which terminate adjacent. to corresponding flanges of the adjacent bladegBfl. Thearrangement is such thatthe facing walls of the

flanges

66 and 68, and the adjacent blade shanksform the walls of passages extending through the turbine rotor between the shanks of the blade 60. With this construction, a suitable cooling fluid can be caused to, ,flow through these passages between the shanks of the turbine blades, e. g. by means of a blower as illustrated in Figure l.

The passages between the shanks of the turbine blades may be made quite irregular by providingribs or baiiies In, H and 12 on one side of the blade shank and. abutting ribs or baffles '14, 15 and 16 on the adjacent blade shank. Except for baffle 12, these baffies only extend radially part way across the passages between the blade shanks so that the cooling fluid, in flowing through these passages, must follow the irregular paths around the baiiles as indicated in Figure 9, thereby insuring intimate contact of the cooling fluid with the shanks of the blades 60. Obviously, if desired, similar baffies may be provided in the structure of Figures 1-8.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications. I

I claim as my invention:

1. A turbine comprising a multi-stage turbine rotor having a first and a second stage of turbine blades secured thereto about its periphery, the blades of each stage being circumferentially spaced about said periphery and being axially spaced from the blades of the other stage, fixed turbine blades disposed between said first and second stage turbine rotor blades, and a shelf-like flange projecting laterally from the shanks of each of said turbine rotor blades, each said flange extending circumferentially into substantially abutting relation with the adjacent blades of its stage of turbine rotor blades and extending in a generally axial direction into substantially abutting relation with the flanges of said other stage of turbine rotor blades to form the inner boundary of the turbine motive fluid path between said blades and to form passages inwardly thereof between the shanks of adjacent circumferentially spaced turbine rotor blades'for the flow of a cooling medium through said passages.

2. In combination, a multi-stage turbine rotor having a first and a second stage of turbine blades secured thereto about its periphery, the blades of each stage being circumferentially spaced about said periphery and being axially spaced from the blades of the other stage, fixed turbine blades disposed between said first and second stage turbine rotor blades, a shelf-like flange projecting laterally from the shanks of each of said turbine rotor blades, each said flange extending circumferentially into substantially abutting relation with the adjacent blades of its stage of turbine rotor blades andextendingin a generally axial direction into substantially abutting relation with the flanges of said other stage of turbine rotor blades to form the inner boundary of the turbine motive fluid path between said blades, said flanges being arranged to form passages inwardly thereof between the shanks of adjacent circumferentially spaced turbine rotor blades, and means for causing a cooling medium to flow, through said passages. l

1 3'. In combination, a multi-stage turbine rotor having a first and a second stage of turbine blades secured thereto about its periphery, the blades of each stage being circumferentially spaced about said periphery and being axially spaced from the blades of the other stage, fixed turbine blades disflanges being arranged to form passages inwardly thereof between the shanks of adjacent circumferentially spaced turbine rotor blades, meanslfor causing a cooling medium to flow through said blade shank passages, passage means establishing communication between said blade shank passages and said exhaust duct, said passage means having side walls inclined to the rotor axis to at least partially straighten out the w of the cooling medium before said medium discharges into said exhaust duct. '1 l 4. A- turbine comprisingga multi-stage turbine rotor having a first and a second stage of turbine blades secured thereto aboutits periphery, the blades of each stage being circumferentially spaced about said periphery and being axially spaced from the blades of the other stage, fixed turbine blades disposed between said first and second stage turbine blades, a pair of radially spaced flanges projecting laterally from the shank of each of said turbine rotor blades, each pair of said flanges projecting circumferentially into substantially abutting relation with the corresponding flanges of the adjacent turbine rotor blades of its stage and projecting generally axially into substantially abutting relation with the corresponding flanges of the turbine rotor blades of the other stage, said flanges and the shanks of said turbine rotor blades forming the walls of passages through said multi-stage rotor between the shanks of adjacent circumferentially spaced turbine rotor blades for the flow of a cooling medium through said passages.

5. A turbine comprising a multi-stage turbine rotor having a first and a second stage of turbine generally axially into substantially abutting re- 'to the other between the shanks of adjacent cir-- cumferentially spaced turbine rotor blades for the flow of a cooling medium through said passages.

6. A turbine comprising a multi-stage turbine rotor having afirst and a second stage of turbine blades secured thereto about its periphery, the

blades of each stage being circumferentially spaced about said periphery and being axially spaced from the blades of the other stage, fixed turbine blades disposed between said first and second'stage turbine blades, a pair of radially spaced flanges projecting laterally fromthe shank of each of said turbine rotor blades, each pair of said flanges projecting circumferentially into substantially abutting relation with the corresponding flanges of the adjacent turbine rotor bladeslof its stage, said pairsof flanges and the blade shank portions therebetween projecting generally axially into substantially abutting relation with the shanks and corresponding flanges of the turbine rotor blades of the other stage, said flanges and the shanks of said turbine rotor blades forming the walls of individual passages extending through said multi-stage rotor from one end to the other between the shanks of adjacent circumferentially spaced turbine rotor 8 turbine blades disposed between said first and second stage turbine blades, 9, pair or radially spaced flanges projecting laterally from the shank of each of said turbine rotor blades, each pair of said flanges projecting circumferentially into substantially abutting relation with the corresponding flanges of the adjacent turbine rotor blades, the shank of each turbine rotor blade be- 1 tween its said flanges being formed so as not to undercut any substantial portion of the working portion of its blade for the flow of a cooling medium through said passages.

'7. A turbine comprising a multi-stage turbine rotor having a first and a secondstage of turbine blades secured thereto about its periphery, the blades of each stage being circumferentially spaced about said periphery and being axially spaced from-the blades of the other stage, fixed blades of its stage, said pairs of flanges and the blade shank portions 'therebetween projecting generally axially into substantially abutting relation with the shanks and corresponding flanges of the turbine rotor blades of the other stage, said flanges and the shanks of said turbine rotor blades forming the walls of individual passages extending through said multi-stage' rotor from one end to the other between the shanks of adjacent circumferentially spaced turbine rotor blades, the portion of the shank of each turbine rotor blade between its said flanges radially inwardly of the working portion of its blade havinga profile generally the same as the profile'of the radially inner end of said working portion for the now of a cooling medium through said passages.

FERDINAND P. SOLLINGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,061,648 Westinghouse May 13, 1913 1,544,318 Hodgkinson June 30, 192% 1,708,402 Schilling Apr. 9, 1929 2,213,940 Jendrassik 1 Sept. 3, 19% 2,243,467 Jendrassik May 27, 1941 2,401,826 Halford June 11, 1946 2,407,531 Birmann Sept. 10, 1946 FOREIGN PATENTS Number Country Date- 665,762 Germany Oct. 3, 1938