US1720709A - Compound-turbine arrangement - Google Patents

Description

INVENTOR R.C.A| len CCPQUMM ATTORNEY R.' C. ALLEN COMPOUND TURBINE ARRANGEMENT Filed April 19 1927 July 16; 1929.

"WITNESSES Patented July 16, 1929.

i Qumran sra ROBERT C. ALLEN, OF SWARTHMORE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 8c MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA..

COMPOUND-TURBINE ARRANGEMENT.

Application filed April l19,

My invention relates to an elastic fluid turbine arrangement, particularly to the arrangement of an elastic fluid turbine of large capacity and using high initial pressure, and

it hasfor its object to provide a practical, e`fficientand economical arrangement of the elements thereof. .l

Another object is to provide an arrange# ment'having'g; sufiicient low pressure bla-ding 10 to completely expand the large quantities of elastic fluid.

In order to obtain greater eliicicncies it has become the practice in turbine engineering to increase the capacity of the turbines and also f to increase the initial pressure of the motive fluid ladmitted'to the turbine. This fluid is then expanded to-a high vacuum in order to extract alll the available power. As the volume of the'iluid becomes tremendous at the lower pressures, the problem is presented of providing sufficient low pressure blading to coinple'telyextract all the available power. v In accordance with my invention, I provide a high pressure turbine element, an intermediate pressure turbine eleinent and a low pressure turbine element. The motive fluid is admitted at high initial pressure to the high pressure element; and, upon being discharged therefrom,l it is admitted to the intermediate pressure element. .In t-he intern'iediate pressure element,.theflow of` motive fluid is divided, a portion 'thereof being passedin one direction through vblading which expands it completely to a vacuum, and the remaining portion thereof being passed in the'opposite .direction but only partly expanded therein. The latter portion is discharged from the intermediate elemente-nd passed to the vlow pressure'turbine element in which it again divides and flows in opposite directions to vacuum. Y Y .y

Referring to the drawing for illustration of one embodiment ofmy invention:

A. The single figure shows an arrangement of turbine elements in accordance with my invention.

Referring to the drawing indetail, I show a high pressure turbine element 10, an intermediate pressure-turbine element 11 and a low pressure turbineelement 12, each turbine element being provided With a lseparate casln. The highpressureelement 10 is coupled toand drives an electrical generator 13, while 1927. Serial No. 185,008.

the intermediate pressure and the loW pres-- sure elements are coupled in tandem and drive another electrical generator 14.

The high pressure turbine element l0 consists of a casing 15 and a rotor 16 carried by a shaft 17. High pressure steam is supplied from a conduit 18 and admitted to the turbine by any suitable control means such as a valve 19, which may be governor operated. The steam admitted to the turbine is expanded through blading carried by the casing and the rotor, and discharged through the outlet passage 20.

The intermediate pressure turbine element 11 includes a casing 21 and a rotor 22 mounted on a shaft 23, rotating in suitable bearings. The casing and the rotor carry `cooperating rows of blades of any suitable-design. The turbine element l1 is of the double-How type comprising tivo flow sections 24 and 25. 'The casing is provided with an inlet passagev 26 disposed intermediate the sections 24 and 25, and communicating With said sections. A conduit provides communication between the outlet passage 2O of the high pressure element and the inlet passage 26 of the intermediate pressure element. A reheater 30 is preferably interposed in the conduit 2O for reheating the steam transmitted to the turbine element 11.

Communicating with the exhaust end of .the section 24 are two vertical condensers-27 for receiving the motive fluid flowing therethrough. The blading in section 24v is designed to completely expandthe motive fluid flowing therethrough from the pressure at which it isreceived therein completely to a vacuum, for example, of about 29 inches. The

section 24 is further designed to receive approximately one-third of the motive fluid re* `ceived from the high pressure turbine element.

The section 25 includes bla-ding which is .designed to only partly expand the remain- 'er'aby also of the double-flow type and comprises a casing S0 and a rototl carried by admi `tijd to said' clement, or one-third of the"V original fiow from the high pressure element. Each section is designed to coi'npletely expand its portion of thc fluidrfto'afvacuum of, for example, 29 inches. The outer ends of the'fsect-ions 31 and 32 are'providcd with outlet: connections '35 andj lpcommunicating with the condensers 372and38 respectively.

"A coupling provided for connecting the shaft 17 of the' high pressure element directly tothe shaft ll of' the generator' 13; The

' shafts' Q- and 62" of the intern'iediate pressure Cil and low pressure lclen'ients respectively yare directly connected by the coupling ft2, and the latter shaft is directly connected to the shaft 43 of the generator'lfi by a coupling 44.

It is apparent, of course, that the vgenerators are merely given as an exan'iple of driven machine; and that the turbine elements may be'used'todrive any'type or types of drivenmaehine.- Also', the 'coupling of the intermediate vpressure 'and the lowl pressure elements in tand'cnrisfonly -one'desirableg though not essential, 'arranfgcinent The operationvoff-the' turbine arrangement is as follows: Steam 'or other motive fluid is supplied to the high -pressiire|` element v1() at a pressure of, for example.l 500 pounds 'per square incli,'tlie admission being controlled in any suitable manncrlby a valve 19." The high pressure turbine element extracts power from the steam flowing therethrough, reducing` the pressure thereof, for example, to 40 pounds' per square incln'gauge.

This motive fluid is then conducted througl'i they conduit 20 t-o theinlet 26 of the 'intermediate pressure element' where it is divided, onef-tliirdl passing through the section Qtandlbeing completely expanded-therein."The remaining two-'thirds-lows through the section 25 and is partly expanded 4to yan intermediate pressure, for example, 8 pounds per square inclngauge. It vis then passed to the inletl 33 of the low pressure element.

Iii-the low pressure element the-steam is again' divided and flows in 'eq'ual portions -to the sections 31 and 32,' each section receiving one-third ofthe'stcam discharged by the high pressure element. Eac'hflow vpressure section completely 'expands the motive fluid flowing therethrough and communicates with one -pair of the condenser-s 37, 38, which receives 'the expanded motivefhud and condenses the same. i

From the-'above description it will be seen that I have provided a turbine arrangement wherein motive fluid'is expanded from a very high pressure and 1n which there are three low pressure ends and condensers for etliciently and completely expanding the motive '-'While I-"have shown my' lnvention in one l form, it--will be obvious to those skilled in the `art that it is not so limited, but is susceptible j of varioi'i's `changes and modifications', withoutI departing from the spirit thereof, and Irdesire, therefore, that only such limitations shall be placed thereupon as are imposed by the prorart or as are specifically set forth in the appended claims.

`1.'[n a compound-turbine arrangement, a high-pressure l turbine element having inlet and outlet openings, la A'divided flow intermediate pressure turbine element having an inlet' opening communicating with the outlet opening of the high-pressure element, said intermediate element including a section Vfor expandinga portion of the'motivefluid received through said inletopening tovacuum and another section -for partially expanding anotherportion thereof, a discharge opening communicating with the second-mentioned section,l and a divided flow low-pressure clement having an inlet opening communicating with the discharge opening of the intermediate pressure 4turbineclement, saidv lowpessure turbine element completely expanding all-the motive'fiuid admitted thereto to vacuum. "f

2. Ina compound turbine, the combination of a high-pressure element, a double flow intermediate pressure element comprising two sections both receiving motive fluid from the high-pressureelement, the section receiving the flow in one direction completely expanding the motive fluid flowing therethrough to vacuum and the section receiving 'the'low .in the' other direction partially expanding the-motive 4fluid flowing therethrough, and a double ow'low-pressure turbine element receiving motive fluid from the last-mentioned section :of-'the intermediate pressure element and completely expanding said `fluid to vacuum. 1

- 3;'In a compoundlturbine, the combination of a turbine element comprising two sections receiving-motive fluid at the-same pressure, fone section completely expanding the motive -fluid flow-'ing therethrough to vacuum and the other section partially expanding the motive fluid 'iowing therethrough, and a second turbine element receiving the motive fluid discharged frein the last-mentioned section and completely expanding said motive fluid to vacuum. i i

'4. In a compound turbine arrangement, the combination of a high-pressure turbine lelement partially expanding the motive fluid 'iowing therethrough, a driven machine coupled 'directly to said high-pressureelement, a double flow intermediate pressure turbine element comprising two flow sections each lll) receiving motive fluid discharged from the high-pressure element, one section completely expanding motive fluid `flowing therethrough to a vacuum and the other flow section partly expanding the motive fluid flowing therethrough, a condenser communicating with the lirstunentioned section, a double flow low-pressure element receiving the motive fluid discharged from the last-mentioned section nand completely expanding said motive fluid to vacuum, a condenser communieating with each flow section of the lowpressure turbine element, said intermediate pressure and low-pressure elements being directlycoupled to each other, .and a second driven machine directly coupled to one of the last-mentioned turbine elements.

5. In a compound-turbine arrangement, a high-pressure turbine element having inlet and outlet openings, a double flow intermedi` ate pressure turbine element having an inlet opening connnunicating with the outlet flowing in one direction to vacuum and an other section for partially expanding the y portion flowing in the other direction, a discharge opening communicating with the second-mentioned section, and a low-pressure element having an inlet opening communieating with the discharge. opening of the intermediate pressure tllrbine element.

6. In a compound turbine, the combination of' a double flow turbine element comprising two sections receiving motive fluid at the same pressure and through which motive fluid flows in opposite directions, one section completely expanding the motive fluid floW` ing therethrough to vacuum and 'the other section partially expanding the motive fluid flowing therethrough, and a second turbine element receiving the motive fluid discharged from the last-mentioned section and completely expanding said motive fluid to vacuum.

7. In a co1npound-turl ine arrangement, the combination of a high-pressure turbine element, an intermediate-pressure turbine element comprising two sections each receiving motive fluid from the high-preSSure element, one of said sections completely expanding motive fluid flowing therethrough to a vacuum and another of said sections partially expanding the motive fluid flowing theretln'ough, and a low-pressure turbine elemel'lt receiving partially expanded motive fluid :from said last-mentioned section and completely expanding the same.

In testimony whereof, l have hereunto subscribed my name this eleventh day of Jllpril, 1927.

ROBERT C. ALLEN.

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