US3194021A - Vapor condensing apparatus - Google Patents

Description

July 13, 1965 c. c. PEAKE ETAL VAPOR CONDENSING APPARATUS Filed July 14, 1964 United States Patent O 3,194,5321 VAGR CNEEENSENG APPARATUS Charitas QC. haatte, Media, 13a., and Franklin 5i. Entrants,

Glendora, NJ., assignors to 't/ifestinghouse Electric {Iorporaton, Pittsburgh, Pa., a corporation of Penney/ironia iliiied duly 1d, 1h64, Ser'. No. $552,471 11 Claims. (Si. edu-95) This invention relates to vapor condensing apparatus, more particularly to apparat-us for condensing the exhaust vapor from a vapor motivated turbine power plant, and has for an object to provide improved apparatus of this type and method of operation thereof.

When a vapor condenser is employed to `condense the exhaust vapor `from a plurality of turbines in a closed cycle multi-unit vapor Iturbine power plant, it is often advantageous to divide the condenser into the same number of condensing zones or chambers as the turbines that it serves. Also, for economic reasons the condenser tubes are arranged in a single bundle extending .through all of the chambers. Hence as the coolant liquid flows through the tubes from chamber to chamber, it becomes progressively heated by absorption of heat from the condensing vapor, and the exhaust vapor lin each chamber is subjected to coolant liquid at a different temperature and thus condensed at a different pressure and tempenature.

Condensers of the above type are known as zoned con-densers and attain a lower average condensing pressure and temperature than unzoned or undivided condensers, thereby providing improved thermal eiciency in the vapor cycle ofthe power plant.

Heretofore, in zoned condensers, the condensate from the higher pressure condensing Zones or chambers has Ibeen conducted successively to the lower pressure condensing chambers and allowed to flash into vapor and then cool to the saturation temperature corresponding to the pressure in each of the lower'pressure charnbers. The condensate from all of the chambers was ultimately collected .inthe lowest pressure chamber .and finally withdrawn from this chamber at the correspondingly low saturation temperature prevailing therein.

When Zoned condensing apparatus is employed in a closed cycle power plant having a regenerative feed liquid heating system for preheating the condensate before admission to the vapor generator for vaporization, the feed liquid heaters employ heating vapor extracted from the turbines.

An object of the invention is to prov-ide vapor lcondensing apparatus of the zoned typ-e arranged land operated in such .a manner that the condensate from the lower pressure chambers is introduced to a higher pressure chamber for heating purposes, thereby -to yield condensate from the apparatus at substantially said higher temperature.

Still another object is to provide in `a vapor t-urbine power plant having a regenerative feed liquid heating system, zones condensing apparatus arranged and operated in a manner to yield feed liquid for .the vapor generator at the highest attainable initial temperature.

Briefly, there is provided apparatus for condensing the exhaust vapor from a plurality of, for example, two condensing turbines in .a closed cycle vapor turbine power plant `and divided into an equal plurality of condensing zones or chambers, one for each turbine .associated therewith. The coolant iluid conducting tubes extend through all of the chambers, so that, as 4the tubes absorb heat from the vapor `during the condensation process, the coolant fluid is progressively heated. The attendant saturation or condensation pressures and tempenatures attained in the chambers thereby differ, with the chamber associated with the hotter portion of the tubes having the higher pressure and temperature, and the chamber 3,194,21 Patented .July 13, '1955 ICC as an associated with the colder portion of the tubes having the lower pressure and temperature.

in accordance with the invention, the cooler condensate from the lower pressure and temperature chamber is pumped to at leastV the same pressure as that prevailing in the higher pressure and temperature chamber and then admitted into ythe upper portion of the higher pressure chamber by suitable spraying means. Accordingly, the thus pumped condensate is heated to a higher temperature by the vapor in the higher pressure chamber and then withdrawn with the condensate from the higher pressure chamber and directed through one or more feed liquid heaters before delivery to the vapor genenator.

The feed :liquid heaters employ hot motive vapor extracted from the turbines for heating the feed liquid to the desired vapor generator inlet temperature. Hence, with the invention less extracted vapor is required by the heaters to heat the feed liquid, and more motive vapor is available to generate turbine output power, with an appreciable increase in efficiency in the vapor cycle of the power plant.

The above and .the objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

FiGURE 1 is a schematic diagram of a closed cycle vapor turbine power plant system of the regenerative feed liquid heating type with vapor condensing apparatus in accordance with the invention; and

FIG. 2 is a vertical elevational View, partly in section, of a portion of the power plant system shown in FIG. 1 and illustrating van embodiment or" the condensing apparatus.

`Referring .to the drawings in detail, in FIGURE 1 Vthere is sho-wn schematically, a closed cycle vapor .tuubine power plant system, generally designated 1t), 4of the regenerative feed liquid heating type and having vapor condensing apparatus, generally indicated 12, in accordance with lthe invention.

The invention may be employed in conjunction with a turbine power plant system employing 'any condens-able vapor, for example, steam, ammonia, etc. Henceforth the terms steam and water will be employed for simplicity and facility of understanding.

The power plant 11i, as illustrated, is provided with an HP (high pressure) steam turbine unit 13, an IP (intermediate pressure) steam turbine unit 14 and a plurality of (three in this instance) LP (low pressure) steam turbine units 15, 16 and `17. The turbine units 13, 14, 15, 16 and 17 4are connected in tandem to each other by suitable shaft couplings 18, so that the total power output of the turbines is taken olf at the output shaft 19 of .the LP unit 17 and, by 'a suitable coupling Ztl, the power output shaft 19 is employed to drive a suitable single load, for example, an electrical generator Z1.

Hot motive steam to motivate the units 13 to 17, inclusive, is provided by a suitable steam generator 23 connected to the HlB unit 13 by a suitable steam supply conduit 2d. Accordingly, the steam generated by the steam generator E3 is directed through the steam supply conduit Z4 to the HP unit 13 and after expansion therein it is directed by a suitable conduit Z5 to the IP unit 14. After expansion in the 1P unit 14, the steam is directed to the three LP units 15, 16 and 17 by conduit structure 25 having parallel branches Z7, ZS and 29, respectively connected to the LP units 15, 16, and a.

The LP units 15, 16 and 17 are substantially of the same size and type and, as illustrated, may be of the well known central admission, double opposed flow type. Accordingly, with reference to the LP unit 15, for example, the stearn is admitted thereto at the center by the `conduit .27' and thence divides, with one half of the steam owing to the right for expansion through Vthe right half expansion portion a and the remaining half being directed toward the left and expanded through the left-hand expansion portion 15b and is exhausted therefrom in two streams, as

indicated by the' arrows 3f) and 31. The remainingl two LP units 16 and 17 are arranged and operated in the same manner as the LP unit 15 and need described. Y

After the steam is exhausted from the LP units 15,16

re-vaporization, thereby completing the Vclosed loop or Cycle.

The feed water heaters 34, 35 and 36 are of the regenerative heat exchanging type (well known in the art) andV are employed to preheat the condensate flowing therethrough by way of the conduit 37. These heaters may be substantially identical in structure. Accordingly, only the yfeed water heater 34 will be'described in detail. i

The feed water heater 34- comprises a shell V'structure' 38 defining a compartment 39 and within the compartment 39 there is provided a suitable heatexchanger tube structureitl.V Steam is extracted from the units 15, 16 and 17, after partial expansion therein,'by three pairs of conduits 41 and directed 'to the compartment 39v of the feed water heater 34 by a common conduit 42. Accordf ingly, as the Afeed water is directed through the heat exchanger tube structure 40, it is initially heated to a degree' by heat exchangeditherewith and the resulting condensate formed by the steam admitted thereto is returned to the feed water conduit structure37 at a point upstream of the heater 34 by suitable conduit structure 45.

In asimilar manner, the feed water heater 35 is effective to heat the feed Water flowinggtherethrough to an additional and higher degree, by steamV extracted from theV IP unit 14Vand directed thereto by a suitable conduit 46, and the last or highest feed water heater 36 is effective to further heat thetcondensate flowing therethroughY to the f final or terminal value before admission to'the steam generator 23, by employment of stream extracted from not be further Y Referring nowv more particularly to FIG. 2, wherein the LP units 15, 16 and 17 are shown in more detail and illustrating the condensing apparatus 12 in accordance with the invention, it will be seen that the condensing apparatus 12 is employed in conjunction with all of the LP units 15, 16 and 17. The condensing apparatus 12 includes a suitable shell structure 50 coextensive with the exhaust outlets Y51, 52 and 53 of the , LP units 15, 16 and 17, respectively. Within the shell structure 50 there are provided partitions 54 and 55 which together with the shell structure 56 divide the latter into zones or l Ychambers 56, 57 and 58, each of which is substantially the HP unit V13 Vand directed thereto by suitable conduit structure 47.

The condensate forming in they feed water heater 36 is directedV to Vthe compartment of the upstream feed water heater 35 by suitable conduit structure 43 for refiashing intonsteam, thereby to impart additional heat to the feed water flowing therethrough. The condensate resulting therefrom is directed to theV upstream feed water heater 34 by a suitable conduit 49 for further feed water heating and then joins the condensate in the feed water heater 34. The condensate connecting arrangement o f.

from the units 13 to 17, inclusive, they divert someof the steam from the turbine units that would otherwise be employed'to'motivate the turbines and thereby provide y y `'water' heaters maybe extracted from the units 13 to 17 at anylocation inthe expansion range and more or less` feed water heaters may be employed than the three shown and described above, as well known in the art.

pressure tightl with respect to the other, although the partition 55 is provided with an opening 59 disposed at the lower end thereof and normally covered by a Water level ,existing therein, as more fully to be explained subsequent hereto. Y

VTlere'is further provided a plurality or bundle of elongated tubes 66 coextensive with the shell 50 and extending thr'ogh the partitions 55 and 54 and serving, byk heat exchange, to condense the exhaust vapor from the LP unit 15 as indicated bythe Varrows 3@ and 31 and from the LP units 16 and 17, as indicated by the arrows 30a, 31a and 3%, 31h, respectively.

Externally lof the shell structure 50 there is provided an inlet water box 61 rand an outlet water box 62. Water or other coolant fluid is admitted to the inlet water box 61 by a suitable conduit 63, then directed through the tubes and finally discharged from the outlet water box 62 toa suitable discharge conduit 64; Since the tubes 60 are maintained in a cool state by the water ilow therethrough, they are effective to condense the exhaust vaporsY admitted into the chambersV 58, 57 and 56 in a well known manner, and the resulting condensate formed in each chamber drops Vto the bottom thereof as a rain andV collects to aflevel shown at 65, It will be noted thattthe condensate level 65 in chamber 57 is above the opening 59. yHence, no vapor'can escape through the outlet 59 from the4 chamber 57 'tothe chamber 58, in normal operation. Y, The lowery portion of chamber 58 is provided with a condensate discharge outletY 67 connectedv to a suitable water pump 68 and discharge from the pump 68 is directed through a suitable conduit 69 to a suitable spray manifold70 disposed in the upper portion of the chamber 56. The manifold 76 is provided with a plurality of apertures 71 effective to direct the water downwardly in a fine spray in commingling relation vwith thenexhaust vapor admitted into ythe chamber 56 bythe LP unit 15, thereby promoting intimate heat exchange relationship between the two.

T he resulting condensate in chamber 56 is withdrawn therefrom through a suitable discharge outlet .73 disposed at the bottom of the shell structure 50 and communicating with a water pump 74, the outlet of which is connected to the conduit 37 (previously described). Further, the returning condensate from the feed water heaters in conduit 45 is admitted to the outlet 67 ahead of the pump 68, thereby to rejoin the Vcondensate in the feed water conduit 37, v

If desired, the water level 65 in thechamber 58 may be controlled by a suitable valve 75 controlled by a float structure 76 arranged to reducethe flow through the valve 75 when thecliquid level falls below a preselected height,

VFor'lfacility of comprehension, in FIG. l steam flow is denoted by the dotted arrows, condensate (and feed water is Ydenoted by thesolid arrows, and the coolant water is denoted by the` arrows with tails.

Y In operation, the exhaust steam from theLP units 15,

16 and 17 is directed into the associated condenser chambers 56, 57 and 55 for condensation therein by heat exchange with the tubes 6% extending through the heat exchanger structure. Accordingly, the water flowing in the tubes 60 becomes progressively hotter from left to right, as when viewed as illustrated in FIG. 2, by absorption of the heat from the condensing vapor and, in view of this phenomenon, the condensate in chamber 5S is formed at a lov-Jer temperature and pressure value than in chamber 57 Where the tube portions tib are somewhat Warmer than the tube portions 60a in the chamber S8. Accordingly, the ambient in chamber 57 is stabilized at a condensing pressure and temperature that is higher than that in chamber 58 and, similarly, the chamber 56 is maintained at a still higher condensing pressure and temperature by the tube portions dus than the preceding two chambers 57 and 5S. Hence, the condensate forming in chamber 5d is warmer than the condensate forming in chamber 57, and similarly, the condensate forming in chamber 57 is Warmer than the condensate formed in chamber 5S. Because of the pressure differential between chambers 57 and 5S, the condensate forming in chamber 57 flows into the chamber through the opening 5@ with resulting re-boiling and release of some heat to chamber 5S because of the temperature difference. The condensate in chamber 5S, together with the condensate flowing thereinto from chamber S7, is Withdrawn through the outlet 67 and pressurized by the pump 68, and then sprayed into the chamber 5e by the spray manifold 70. Since the water sprayed into the upper portion of the chamber 55 by the manifold 76 is at a lower temperature than the condensation temperature prevailing therein, as the Water spray drops to the bottom of the chamber V56, it absorbs heat therefrom. The mixture is subsequently withdrawn through the outlet 73 by the pump 74 and directed to the feed Water heaters by the conduit 37.

lt will now be seen that all of the condensate formed in the condensing apparatus 12 is Withdrawn therefrom at substantially the same temperature. Further, since the condensate from the lower temperature chambers 57 and 5S is admitted into the highest temperature chamber 55 for further heating before directing to the feed water heaters, all of the condensate is Withdrawn from the condensing structure 12 at the highest prevailing temperature.

Since the condensate is directed to the feed Water heaters at a higher value than heretofore, less extraction of steam from the turbine units is required than heretofore to heat the feed water in the feed water heating system to the temperature desired before admission to the steam generator 23. Accordingly, more of the motive steam may be gainfully employed in the turbine units to produce power at the output shaft 19.

The condenser apparatus 12 has been shown and described as a unitary structure, however, as illustrated schematically in FIG. 1, the three condensing chambers Se, 57 and SS may be provided by separate and distinct shell structure and, similarly, the tube structure o@ need not be unitary, but may be divided into three intercom nected groups to provide the tube portions oda, etlb and 69C.

it will now be seen that the invention provides condensing apparatus of highly improved form and an improved method of operating condensing apparatus employed in conjunction with a closed cycle vapor turbine power plant system having a regenerative feed liquid heating system for preheating the condensate before admission to the steam generator.

1t will further be seen that with the arrangement shown there is provide a condensing vapor turbine power plant operable at higher thermal efficiency than heretofore by condensing structure that is economical to manufacture and simple to employ.

fir

Although in the embodiment shown, threeV double- dow LP units 15, 16 and 17 of the condensing type have been shown, it Will be understood that more or less condensing turbine units may be employed and that they need not be of the double-flow type.

Although only one embodiment of the invention has been shown, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modications Without departing from the spirit thereof.

What is `claimed is:

1. The method of operating a vapor turbine power plant having at Xleast two ycondensing turbines exhausting to vapor condensing apparatus at different pressures and temperatures,

said condensing apparatus having :a first pressure and temperature condensing zone communicating wit-h one turbine and a second and higher pressure and temperature condensing zone communicating with the other turbine; comprising pumping the condensate from the first condensing zone to said second zone, and

spraying the thus pumped condensate into said second Zone for reheating.

2. The method recited in claim 1 and further including mixing the reheated .condensate With the condensate in the secon-d Zone t-o provide feed liquid for a vapor generator, and

directing the resulting feed liquid to said vapor generator for evaporation into vapor for motivating the turbines.

3. The method recited in ciaim 1, and further including directing cool-ant iiuid irst through .the fir-st condensing zone and then through the second .condensing Zone, thereby to maintain the difference in pressure :and temperature between the condensing Zones.

fi. The method of operating a vapor turbine power plant having at least three condensing turbines exhausting to vapor condensing apparatus,

:said condensing :apparatus having first, second and third condensing Zones, eac-h communicating with an associated one of said turbines; comprising maintaining :said tirst, second and third condensing zones at successively higher rst, secc-nd and third pressures ,and temperatures,

directing the condensate from said second Zone to said first Zone into mixing relation with the condensate in said first zone,

pumping the resuiting condensate mixture from said :first Zone `to said third Zone, and

spraying the thus pumped condens-ate into said third Zone for reheating S. The method recited in claim d, 'and further comprising directing Ithe condensate from the third zone through at least :one regenerative heater to further heat the condensate, and

then directing the condensate as feed water to a vapor generator for evapora-tion into vapor `for motivating the turbines.

`6. The method recited in claim 4, and further comprising :directing coolant fluid successively through the first,

second :and third condensing zones, thereby maintaining the first, second and third pressures and temperatures therein.

7. A vapor turbine power plant, comprising at least two condensing turbines,

vapor condensing apparatus,

said condensing apparatus having a first condensing chamber .communicating with one of said turbines and a second condensing chamber communicating with the other `of said turbines,

means disposed in said iirst and second chambers for condensing the exhaust vapo-rs fromsaid turbines at.

different pressures Vand tempenatures', Y Y means for pressurizingV the condensatel fromthe lower pressure and temperature chamber, :and means forspraying the lthus pressurized condensate into the'hi-gher pressure and' temperature chamberv for re'heating purposes. Y v v i8. The structure recited in `elaim 7, Yand further comprising j :a steam generator for providing motive vapor to the turbines,

:a ynegenerative heating system having a heater for heat-Y ing feed liquid to'said steam generator, and means for directing the condensate from the higher pressure and temperature chamber .toy said heater as feed liquid. j 9. Oondensing apparatus for' a condensing multi-unitV Y vaporturbine power plant, Ycomprising shell structure defining at least two vapor condensing chambers, K

a bundle of coolant conducting tubes extending through said condensing chambers and delini-ng `a singlecoolant pass, Y Y

means for directing coolant liquid through said tubes,

so lthat vapor in one of said chambers is condensed at a ylower pressure `and ytemperature than in the'y other of said chambers, means for pumping the condensate from said one chamber to the other chamber, means in said other chamber for spnaying the thus pumped condensate into the upper portion `thereof,Y thereby to promote the :absorption of heat by said condensate spray, and

means for withdrawing the combined condensate from said other chamber. V16. Condensing .apparatus for a condensing multi-unit vapor turbine power plant, comprising shell structure defining y'at least three juxtaposed vapor condensing chambers, Y 'Y a bundle of tubes ior conducting coolant ui'd throughl said chambers in a, single pass, Y,

inlet and out-let .means fior'directlng coolant liquid to land from said tubes, respectively, whereby yvapor, is

. condensed at successively higher pressures 4andftemper'atures in each of saidV chambers, with the chamber adjacent said inlet means being maintained `at a lower pressure andrtemperatune than the next adjacent chamber4 and the chamber adjacent said outlet` means vbeing maintained at arhigher pressune and ftemperature than said next adjacent chamber, means for directingr theY condensate from the next adjacent chamber, toft-he chamber adjacent .said inlet, means for pumping the condensate from the chamber Vadjaccn-t said inlet to the chamber adjacent said out- -let,"' M

means for :admitting the thuspumpedy condensate in' Ifinely divided form into theV cham'beradjacent said outlet toY promote .absorption of heat thereby, and

means for 'withdrawing the combined condensate fromV the chamber adjacent said outlet for steam generation purposes. l 11. A vapor turbine power plant, comprising :a rst yturbine unit,

at least two condensing turbineu-nits, said Vfirst unit operating at .a higher pressure than said condensingunits,

1 vapor condensing apparatus,

from the lower pressure and temperature chamber toV the higher pressure and temperature chamber,

means forv spraying the thus pressurized condensate into'the higher pressure and temperature chamber for reheating purposes,` Y

ia .steam generator forV providing motive vapor toY said' turbines,

.a regeneratlve heating systemv having Ia :heater for heat ing feed liquid to said steam generator,

' Ymeans Vfor ydirecting the. condensate from theV higher pressure and temperature chamber to said heater as feed liquid, and

means for extracting a yportion .of the motive vapor from one of said turbines and Idirecting it to said j j heater.

No references cited.

Claims (1)

1. THE METHOD OF OPERATING A VAPOR TURBINE POWER PLANT HAVING AT LEAST TWO CONDENSING TURBINES EXHAUSTING TO VAPOR CONDENSING APPARATUS AT DIFFERENT PRESSURES AND TEMPERATURES, SAID CONDENSING APPARATUS HAVING A FIRST PRESSURE AND TEMPERATURE CONDENSING ZONE COMMUNICATING WITH ONE TURBINE AND A SECOND AND HIGHER PRESSURE AND TEMPERATURE CONDENSING ZONE COMMUNICATING WITH THE OTHER TURBINE; COMPRISING PUMPING THE CONDENSATE FROM THE FIRST CONDENSING ZONE TO SAID SECOND ZONE, AND SPRAYING THE THUS PUMPED CONDENSATE INTO SAID SECOND ZONE FOR REHEATING.

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