US1372929A

US1372929A - Condensing-steam-turbine installation

Info

Publication number: US1372929A
Application number: US145709A
Authority: US
Inventors: Baumann Karl; Scanes Arthur Edwin Leigh
Original assignee: British Westinghouse Electric and Manufacturing Co Ltd
Current assignee: Metropolitan Vickers Electrical Co Ltd
Priority date: 1917-01-31
Filing date: 1917-01-31
Publication date: 1921-03-29
Anticipated expiration: 1938-03-29

Description

K. BAUMANN AND A. E. L. SCANES. cowoawsms STEAM TURBINE INSTALLATION.

APPLICATION FILED JAN-31,191]. 1 372 9239 Patent/ed Mar. 29, 192k 3 SHEETS-SHEET 2.

'WITNESSESH 1 WPMINVERQIETQQES Wk mw w K. BAUMANN AND A. E. L. SCANES. CONDENSING STEA'M TURBINE INSTALLATION.

APPLICATION FILED JAN. 31. 1917.

mm wo Patented Mar. 299 1921b 3 SHEETS-SHEET 3.

'IHI I l 'IJIIII" I unirs stares iearsnr CDFFHQEO KARL BAUMANN, 0F URMSTON, AND ARTHUR EDWIN LEIGH SCANES, 0F vASHTOLL ON-MERSEY, ENGLAND, ASSIGNORS' TO THE BRITISH WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, LIMITED, A COMPANY OF GREAT BRITAIIW CONDENSING-STEAM-TURBINE INSTALLATION.

Specification of Letters Patent. Patqgntgd M 29 1 Application filed January 31, 1917. Serial No. 145,709.

T 0 all whom it may concern Be it known that we, KARL BAUMANN, a citizen of the Confederation of Switzerland, and a resident of Urmston, in the county of Lancaster, England, and ARTHUR EDWIN LEIGH SOANES, a subject of the King of Great Britain, and a resident of Ashton-on- Mersey, in thecounty of Chester, England, have invented a new and useful Improvement in or Relating to Condensing-Steam- Turbine Installations, of which the following is a specification.

II condensing steam turbine installations it has already been proposed to divide'up,

the steam flowing from the last row or rows of blades of the turbine to the condenser by means of guide walls, diaphragms or the like located in the exhaust casing of the tur bine, and the present invention relates to condensing steam turbine installations in.

which the exhaust casing of the turbine is provided with such guide walls, diaphragms or the like, and has for its object to provide an improved construction and arrangement of condenser for use with a turbine of the above kind.

In a surface condenser the temperature of the water "flowing through the condenser tubes varies, and as the rate of condensation depends upon the temperature difference be tween the steam and temperature of the water, the cooler portions of the condenser will condense more steam than the hotter portions, with the result that in an installation comprising a turbine and a surface condenser there is a tendency for steam to be drawn by the cooler condensing surface from portions of the exhaust outlet of the turbine other than those portions located immediately above the cooler condensing surface. This tends to increase the length of the path of the steam flowing to the condenser and to increase the pressure drop accordingly. A similar efiect is also observable in condensers of the jet or direct contact type. I v

' In order to obvlate this difliculty, according to the present invention some or all of the turbine through into the condenser itself in such' a manner that the condenser is divided up into a number of compartments each of which will act as a separate condenser.

Stated in another way, the condenser is provlded with partitions or the like adapted to form contlnuations of some or all of the guide walls, diaphragms or the like in the exhaust caslng -of the turbine, which partit1ons divide up the condenser into a plurality of compartments in such a manner that each of sald compartments will act as a separate condense v In order to obtain approximately equal condensation in each compartment of the condenser thus formed the flow of cooling water is preferably so arranged that in the case of a surface condenser the temperature of the water'in the tubes in each'of the compartments is as uniform as possible. This may be accomplished by arranging that the Water willfiow once only through each compartment. Each compartmentwill in this way constitute in effect a single flow condenser, but although in this way the temperature of the water'in each compartment of the condenser is rendered as uniform as possible, the temperature of the water in the sieiferal compartments of the condenser will The invention may be carried into efi'ect v tral cross-sectional view of a condenser con- 1 structed in accordance with this invention and adapted to be used with a turbine havin an exhaust casing of the kind indicated. ig. 2 is a sectional view on line TT-Tli ofFig. 1.

Fig. 23 is a sectional view on line TITTTT of Fig. 1.

Fig. 4 is a view taken on the line l[V-TV of Fig.1. 4 Fig, 5 is a developed view of the extrac-. tion chamber of the condenser shown in Figs. 1, 2, and? Fig. 6 is a plan view of another form of condenser constructed in accordance with this invention and adapted to be used with a turbine ,having an exhaust casing of the kind shown for example in Figs. 1 and 2,

Fig. 7 is a longitudinalsectional View of the condenser shown in Fig. 6 and Fig. 8 a

cross section on the line VIIIVIII of Fig. 6.

Fig. 9 is a sectional view taken on the line IX IX of Fig. 8.

In the installation shown in Figs. 1 to the turbine is of the kind described in the specification of Patent No. 105,933 of 1916,

the steam being exhausted from a plurality of rows of moving blades, as hereshown from four rows of moving blades, and the exhaust casing for the turbine is of the kind having segregating partitions or diaphragms. The

uide 22 for directing the steam flowing from the antepenultimate row of moving blades is extended until it reaches the side wall 23 of the exhaust casing 1 of the turbine, the longitudinal partition wall 7 of the condenser'2 making joint with the extended guide 22 at the exhaust outlet of the turbine. In addition the exhaust casing of the turbine is provided with a central vertical web. 24 which extends from a point closely adjacent to that portion of each of the rows of moving blades from which the steam is exhausted. to the inclosing casing of the turbine exhaust. At the exhaust outlet the vertical web 24 makes joint with the transverse partition wall 3 of the condenser.

The condenser is thus divided into four separate compartments A, B, C, D, of which compartments A and B receive and condense the steam flowing from the last and penultimate rows of moving blades of the turbine while compartments C and D receive and condense the steam flowing from the two preceding rows of moving blades.

Further, by reason of the vertical web 24:

compartments A and B and compartments C and D each respectively receive and condense the steam'flowing from one half only of said rows of movin blades. Each of the compartments A, B, 5, D, is provided with an atmospheric relief valve so that the plant may be run non-condensing if desired, the relief valves for compartments A, B and C being indicated respectively at 29, 29 and 29" it being understood that a similar valve (not shown) is provided for compartment D.

A developed view of the condensate extraction chamber 9 is shown in Fig. 5, from V which it will be seen that the level of the water in the varlous compartments of the condensate extraction chamber 9 varies in accordance with the vacuum obtaining in each of said compartments. The water in said chamber however forms a seal so that a single extraction pump may be connected to the outlet 10.

In those cases in which condensers constructed in accordance with this invention are used in conjunction with turbines, the steam from which is exhausted from a plurality of rows of moving blades, such as is the case in the construction hereinabove described with reference to Figs. 1 to 5, it is preferred to arrange that the steam leaving the row or rows of blades nearest the high pressure end of the turbine passes into the compartment or compartments of the con denser in which the lower vacua exists.

A further improvement'consists in heating the condensate in-the steam space of that compartment of the condenser operating at the highest temperature to a temperature approximately equal to the temperature of the steam entering" that compartment. This can be accomplished either by placing a surface heater in the steam space of the compartment operating at the highest temperature through which heater the condensate is passed, or by injecting the con densate into the steam space of said compartment, in which case the condensate will be heated up by direct contact with the steam therein.

The invention may also be carried out in such a way that the vacuum in each com.- partmentof the condenser is maintained approximately the same. This is accomplished by so constructing the condenser that the area of the condensing surface in each compartment is varied in accordance with the temperature of the cooling water passing therethrough. the compartment supplied with the coldest water having the smallest condensing surface, while the compartment adjacent to the water outlet will have the largest condensing surface. In other words.

the condensing surface in each compartment is so proportioned that the weight of steam condensed per unit area of surface is approximately inversely proportional to the difference in temperature of the steam and the temperature of the water.

With the construction above described and illustrated it will be readily understood that the steam flowing from the last rows of moving blades is divided by the walls 24 and the diaphragm 22 in the exhaust casing of the turbine-into four separate volumes each of which volumes passes into a separate com partment of the condenser. The-vacuum obtaining in the four compartments of the condenser will vary, being highest in that compartment through which the condensing reaaoae water first flows and lowest in that compartment through which the condensing water last flows before passing away through the water outlet 14. The partition walls 3 and 7 extending downward into the extraction chamber 9 enablea water seal to be formed by the condensate in this chamber to com"- pensate for the varying vacua obtaining so that a single extraction pump only may be used. The air and non-condensable gases may be extracted from the several compartments of the condenser by providing an air pump for each compartment or by means of a multiple stage air pump, or in any other way found suitable. ably, however, the condenser is so constructed that the vapors and non-condensable gases are discharged from that compartment of the condenser operating at the highest temperature into the compartment having the next lower temperature. and thence through the remaining compartments of successively decreasing temperatures until the compartment having the lowest temperature is reached from which the vapors and noncondensable gases are extracted by a single pump or other air extracting device;

One such construction in which this arrangement is carried into effect is illustrated in Figs. 6 to 9 of the drawings. a The condenser is here, as in the construction shown in Fi s. 1 to 5, provided with partition walls 3 an 7 dividing the condenser into four separate compartments which, for convenience, will be referred to in the description of these figures by the letters A, B, C, D. Portions of each of the compartments are divided of? by plates to form air cooling spaces and also a communication channel between adjoining compartments through which the vapors and non-condensable gases maypass from one compartment to the next in the manner described above. The plateincompartment D is shown at 15, in compartment 0 at 16, in compartment B at 17 and incompartment A at 18. None of the plates 15 to 18 extend the full length of the compartment so that vapors and'non-condensable gases may pass from each of the compartments proper into the passages formed between said plates and the shell of the condenser or the partition wall 7, as the case may be. As will be seen.

from Figs. 9 and 7 apertures are also provided in the partition wall 3 and in the lefthand end of the partition wall 7 through which the vapors and gases flowing from one compartment to the next may pass. The circulating water last flows through compartment D, which compartment therefore operates at the highest temperature and the flow of the vapor and gases from this compartment through compartments C, B and A in succession, in conjunction with the vapor and gases from other compartments, is indicated by the arrows in Figs. 6 and 9.

Prefeh

Additional plates

19 and 20 in compartment A form a pocket which leads to the air outlet 21 to which the air pump or other air extracting device is connected in the usual way.. The passages above referred to, through which the air and vapors are discharged from one compartment into the next succeeding compartment, should, as shown, be relatively small so that a minimum amount of steam will be passed from one compartment to another through such passages. i

For the sake of clearness no discharge outlet for the condensate from the several compartments of the condenser shown in Figs. 6 to 9 has been indicated. Each of such compartments may have a separate discharge outlet which may conveniently be connected together by siphon legs to compensate for the different vacua obtaining in said compartments and allow of a single condenser extraction pump being used, or said condensate discharge outlets may be of the form shown in Figs. 1 and 2. If it is desired to adapt the plant so that it may be run noncondensing if necessary, an atmospheric relief valve should be provided for each 00m partment into which the condenser is divided, as shown in Figs. 1 and 3.

While we have illustrated our invention as embodied ina turbine utilizing a plurality parting from the spirit and scope of the invention as set forth by the appended claims.

-What we claim as our invention is:

1. In combination with an axial flow steam turbine having a stageor section provided with means for dividing the steam flowing therethrough into annular portions, a condenser having a plurality of separate condensing compartments each arranged to receive the steam of one or more of said annular portions.

2. The combination with an axial flow steam turbine having a stage or section provided with blading structures so arranged as to seggregate the steam into separate concentric annular portions, a condenser having a plurality of separate condensing compartments' each receiving the steam of one or more of said portions.

3'. In combination with an axial flow steam turbine having a stage or section provided with blades constructed in multiple tiers, a condenser provided with a plurality of separate condensing compartments each of which is arranged to receive the steam from one or more of said tiers.

4. In combination with a steam turbine having a stage or section provided with means for seggregating the steam flowing therethrough into separate portions, a con denser provided with separate condensing compartments each arranged to receive one 7 or more of said separate portions, said condenser being so constructed that the condensing water flows once only through each of said compartments.

5. In combination with a steam turbine having a stage or section provided with means for seggregating the steam flowing therethrough into separate portions, a condenser provided with separate condensing compartments of diflerent area each arranged to receive one or more of said separate portions.

6. In combination with an axial flow steam turbine having a stage or section provided with means for seggregating steam flowing therethrough into separate portions and an exhaust casing divided into separate compartments through which one or more of such separate portions flow, a condenser having separate condensing compartments each communicating with one of the compartments of said exhaust casing; said condensing compartments being arranged to act as separate condensers.

In testimony whereof we have hereunto subscrlbed our names this second day of January 1917.

KARL BAUMANN.

,ARTHUR EDWIN LEIGH SCANES.

Witnesses:

F. NIXON,

W. MORRIS. e