US1778921A - Superheat regulator - Google Patents

Description

Patented Oct. 21, l1930 U'NirEDsTATEs PATENT .orFicE EALEH u.-=-sw.inrz, or Bonora, AND svENn 1u....roae;ENsEN,'v or ELIZABETH, NEW JER- snr, '-AssreNons rro THE sUrEnnEA'rEa COMPANY, or NEW Yoan, N. Y.

sUrEE'HEAr REGULATOR,

.Application led July 22,

Our invention relates to'superheat regula-` tors and has for its general object the proVi-.

' sion of novel a' paratus for des'uperheati'ng t in which a and-,reducing t e pressure ofhigh pressure superheated steam in plants where itis sometimes advantageous to utilize high pressure steam at reduced pressure and temperature.

f Amore specific object of the invention is the provision .of apparatus comprising a rewhich willv be subjected in part only 'to the.

pressure of the lowpressure. steam supply and to provide apparatus which will automatically vdeliver steam to a low pressure steam supply line at` uniform temperature.

The nature and more detailed objects of the invention, together with the advantages to be -derived from its use, may best be understood vfrom the following description o f the invention as applied kin a power plant arrangement sueh as is shown and claimed in the application of Wilbur H. Armacost, Se-

rial'No. 207 ,7 03, led July 22nd, 1927, which have chosen by way of illus-7 arrangement we trative example. v

In the accompanying drawings:

Fig. 1 is a diagrammatic illustration of the.

power plant arrangement, and

Fig; 2 is anelevation, artly in section and on an enlarged scale, bod-ying our invention.

v The power plant -illustratedis of the type high pressure power generating unit is joperated'as abase load unit, the exhaust steam from Vwhich .is utilized in a .low

pressureunit, the` latter alsol being supplied with additional low pressure steam from an inde endent source. Under certain load con tions, it' is not possible to operate the highpressure unit at, capacity. These units eated byv o the apparatus ern- 1927. Serial NQ. 207,712.

must, however, be operated'at substantially constant load, and to provide iexibility in the plant, it is oftendesirable to cut the high pressure prime mover Vout of operation. and

continue the high pressure boilers in operation, utilizing the steam therefrom in the low pressure prime movers. l.' The principal difficulty in the above mode of operation lies .in the fact that the total `temperature -of the steam coming from the.

high pressure boilers is above that which can be safely utilized in the low pressureprimel movers, and the present invention provides means 'whereby under such or similar circumstances the high pressure steam can be made use of in apparatus requiring steam at lower pressures andl temperatures than those at which the steam is initially supplied.

Referring lnow to Fig. 1 of the drawings,

the numeral .10' indicates a high pressure. boil- 'er having a steam and water drum 11 and delivering superheated steam to the` high, pressure main 12 through the superh'eater 13. The main 12 isprovided with'two o'take branches 13 and 14, the former having a con- -trol valve 15 located therein and the latter being provided with a control valve 16. The

branch main 13 supplies the high pressure turbine 17 v which exhausts to conduit 18, the Vlatter being provided with a. valve 19 andv delivering to the low pressure steam main 20. Steam controlled by valve 22` is supplied by the low pressure main 20 to the low pressure turbine 2l, k

The branch 14 of the high pressure conduit leads to the reducing valve`23 which delivers A steam at ylow pressure to the regulator, indicated generally at 24. The'regulator 24 is placed in communication throgh'valve 25 with the low pressure side of the power plant. A conduit 26 supplies water to the regulator in the arrangement illustrated.V We hazve shown this conduit as leading from' the water space of the; high pressure drum 11, though this source .of water. supply need not necessarily come from the high pressure drum as willl become ap arent hereinafter. r

Referring tois' shown in detail, it will be seen that the regulator comprises a base rgmber 27 formig.- 2', in which the regulator ing a pair of steamchainbers 28 and 29 separated y'the partition 30. The tops of chambers 28 and`29 are closed by a common tube sheet 31 in which is mounted a plurality of U-sha ed tubes 32 so arranged that one end of eac tube is in communication with. chamber 28 while its other end is in communication -with chamber 29. The tube bundle 32 is enclosed in a housing 33 having a suitable cover plate 34 andl forming a closed chamber 35 which is placed in constant communication with the chamber 28 by means of the conduit 36.

- Chamber 29 is placd in communicationv with the -low pressure side o'f the plant through valve 25 and conduit 37, the latter having placed therein a thermostatic element 38 which controlsthe valve 39 located in conduit 26 connecting the chamber 35 with the 'drum 1-1. Adjacent to the upper end of chamlber 35, a ball oat 40 is provided'which'controls, through the connection 41, a stop valve placed in conduit between valve 39 and drum 11. The ball ioat 40 is housed in a casing forming a chamber 43, the latter being in communication with the chamber 35 through connections 44 and 445.

Chamber 35 is preferably provided with a suitable safety valve 46 and chamber 28 is also provided with a suitable relief valve 47."

The operation of the power plant illustrated is as follows: When the lant. is operating' under a load greater than that which can be supplied by either the high or low pressure units alone, steam generated in the igh ressure boiler 10 passes through tur- Ibine 1 from which it is exhausted to the low pressure side of the plant in communication with the low pressure main 20 (the latter beingsupplied with low pressure steam fromboilers not shown) and this low 'pressure steam is utilized to operate turbine 21. With the plant operating in this manner, valves 16 andd25 are closedand the regulator 24 is not use When the load on the plant drops to`a pointwhere this combined output of turbines 17 and 21 isgrea'ter than required, the former is cut out of service, but as the regulation of the load on boiler 10 is much more diificult than on thellow pressure boilers, this boiler is kept running under its normal load and the steam therefrom isutilized in the low pressure turbine, the total amount of low pressure steam being reduced by cutting one or more of the low pressure boilers out of service. vWhen the plant is operated in, this manner, valves 15 and 19 are closed, thereby cuttinig of the turbine 17. Valves 16 and 25 are opened and vsteam delivered from the boiler 10 passes through lthe reducing valve 23 and is delivered at low pressure to the chamber `28. From the' latter it passes through the tubes 32- to thechamber 29 and from the latter through the connection 37 l and valve ,25 to the low pressure turbine 21. 'lhe vsteam assing through the tubes 32 is desuperheate by givin up a. portion of its heat to water'sup lie .to the chamber 35 through the conduit 26, and the amount of desuperheating whichv takes place obviously varies in' accordance with the amount of water in chamber 35.

As the highest rate of heat transfer mayV be obtained from the evaporation of water,

,it is highly desirable that the water supplied to chamber 35 be at a temperature at or near thatY at which it will evaporate, 'and for this reason I refer to connect the conduit 26 with the rum 11 althou h other sources of heated water, such as the" oiler feed line in case a preheater is used, may be utilized.

Steam formedin chamber 35 by the' va oration of water therein is conducte liy means of the conduit 36 to the chamber 2,8,

where it mingles with the superheated steam at 'reduced pressure andv passes through the tubes 32, reducing to some extent-the amount of desuperheating which must be accompli'shed in these tubes. The water level'in chamber 35 is maintainedv at the rope;` height to give the final temperature esired to the steam leaving the re ulator by the reg- .ulation of the valve 39, w ich is responsive to the thermostatic element 38 subject to the influence of the steam passing from thel reguator. y

The ioat 40 is provided to operate the 'emergency shutoff valve 42 in case the valve 39 fails to function properly, thus preventing the water in chamber 35 rising and passingover through conduit 36 into the/steam chamber 28, from which it would be carried into the low pressure mains with serious re,-

sults to the low pressureturbines.

The invention has been' desgrkibed 'as applied in a vspecific form of powerplant desi in order to illustrate the several speci c advantageslwhich use'of the invention `makes available. It willxbe apparent, however, to those skilled in the art that the invention is susceptible 'to use in many other arrangements, Ain some of which all of the advantages hereinbefore pointed out may be .availed of and in others of which some of -the advantages inherent in the invention may be availed of to the exclusion of others. From the foregoing it will be understood that theinvention is not limited to the speciic arrangement shown byway of example, but embraces Iall such variations as may fall within the scope of the appended claims.v We claim:

l. In apparatus of the class described, a highv pressure superheated steam conduit, a-

low pressure team conduit, a steam connection between said conduits comprising a pressure reducing valve and a superheat regulator located in series in the connection, said regulator-,comprising a plurality of f tion with one of said first named conduits,-

whereby said chamber is maintained under a pressure at least aslhigh as the pressure in the low pressurerconduit.

2. In apparatus of the class described, a high pressure superheated steam conduit, a low pressure steam conduit, a steam connectionbetween said co duits comprisin a pressure reduci-ngI va e and a super eat regulatorlocated in said connection, said regulator comprising inlet andoutlet chambers, a plurality of tubular elements connectingsaid chambers, a casing forming a closed chamber around said elements, lmeans for -supplying water to said chamber, means for maintaining the water level in said chamber below a predetermined level, whereby .a steamspace is maintained in the upper portion of the chamber, and a conduit connect- 4ing said steam space with one of said first named conduits whereby the water in said casing is maintained under a pressure at least as high as the pressure in the low pressure conduit.

3. In apparatus of the class described, a high pressure superheated stea conduit, a low pressure steam conduit, a nnection be tween said conduits comprising a pressure reducingvalve and a superheat regulator located in series in' said connection, said regu-l `lator comprising a plurality of tubular elements forming part ofv the connection, a cas'- ing forming a closed chamber around said` elements, means for supplying heated water under pressure to said chamber, means for controlling the water level in,said'chamber to provide a steam spacein the upper portion thereof, and a conduit for conveying from said chamber steam generated therein, the discharge end of said conduit being connected to a steam space under pressure, whereby the water in said casing is maintained under1 pressure 'and the steam, generated therein is rendered available for useful work. y

4. In a power fplant, a high pressure superheated steam supply line, a low pressure steam supply line, al conduit' connecting the high pressure and low'pressure lines, a pressure reducing valve and a superheat regulator cf thetypew erein steam is desuperheated by evaporating water out of contact therewith locat-l V ed in series i-n sai-d conduit, a conduit for sup-.

plying water to said regulator, and a conduit for cnveylng steam generated by the evaporation of water insaid regulator to a point in communication with one of said steam.

" lines.

5. In apower plant, ahigh` pressure super- -heated steam supply line, a low pressure.

tor of the type wherein steam is desuperheated by evaporating water out of contact therewith located in series in said. conduit, a con-l duit for supplying heated waterunder pressure to said regulator, and a conduit for' conveying steam generated by the evaporation of water in said regulator to a point in communication with one of said steam lines.

` 6. In a power plant, a high pressuresuperheated steam supply line, a low pressure steam supply line, a'conduit connecting'dthe high pressure and low pressure lines, a pressure reducing valve and a supgeihcat regulator of the type wherein steam is desuperheated by evaporating water out of contact ther with located in series in said conduit, a conduit for supplying water to said regulator, and means pressure and low pressure lines, a presfor conducting steam generated by the evaporation of water in said regulatorto a zone of pressure from which said steam is taken to do useful work, whereby the water is maintained under pressure in said regulator and the steam generatedl therein is usefully emrployed. f

7 In apparatus of theclass described, a .high pressure steam inlet conduit, a low pressure steam delivery conduit, a pressure reducmg valve located 1n said inlet condult, a

superheat regulator located between said reducing valve and' said delivery conduit, said regulator comprising inlet and. outlet Ichambers, a,plurality of tubular elements connecting said chambers, a casing forming a closed chamber around said elements, means for supplying heated water to said chamber, and

means responsive to the temperature of the` steam in one of said conduits for maintaining a water level in said last namedphamber below the top thereof.-

v 8.-,I-n apparatus of the classv described, a

highpressure steam inlet conduit, a low .pres- `sure steam delivery conduit, a pressure reducingvalve located in said inlet conduit, a superheat regulator located between said reducing valve and said delivery conduit, said regulator comprising inlet and loutlet chambers, a plurality of tubular elements connecting said chambers, a casing forming a closed .chamber around said elements, means supplying heated water to said chamber, and

means lresponsive to the/temperature of steam v passing through said delivery conduit for maiptaining a water level in saidlast'named chamber below the top thereof.l

9; In v.apparatus of the class described, a

high pressure steam inlet conduit, a' low pres sure, steam delivery conduit, la pressure `reducing valve located in said inletconduit, a

superheatregulator located between said reduci'ng valve and saiddelivery conduit, said regulator comprising inlet and "outlet chambers, a'plrality of tubular elements connectfor ing said chambers, a .casing forming a closed chamber around sai'd elements, means for supplying heated water to said chamber, means responsiveto the temperature ofA the steamin one ofs'a'id conduits for contrdlling the water level in 'said chamber and a conduit connecting said last named chamber above the 'water level therein with said inlet chamber. f j

10. In apparatus of the class described, a. high'pressui'e'fsteam inlet conduit, a-low pres# sure steam delivery conduit, a pressure re" ducing valve located in said inlet conduit, a superheat regulator locatedv between said .re-

Y ducing valve andsaid delivery conduit, saidregulatorfcomprising inlet and outlet chambers a pluralityof tubular elements connecting said chambers, a casing forming a closed chamber around said elements,me'ans for supplying heated water to said chamber, means responsive to the temperature of steam passing through said delivery conduit for controlling the water level in said chamber, and a conduit connecting said last-named cham- 14. In a power plant, a high .desuperheate'd by evaporatingfondelvering steam generatedb ,the eva generated by the evaporation of water withln said regulator' to the steam inlet en of said regulator.

` RALP M. SWARTZ. vSV END M. lJORGrENSEN.

bei' above'the water level therein with said inlet! chamber.

11. A -superheat .regulator comprisingY means forming an `inlet chamber and an outlet chamber, a plurality of tubular elements connecting said cham ers, a casing forming a closed vchamber around said elements, means for admitting water to said last named chamber, means responsive to the temperature of steam 'leavingl the 'regulator for controlling the water level-in said last named chamber, a'nd a conduit connecting said last named chamberabove the water 'level therein with said inlet chamber. 12; A superheat regulator comprising meansforming anginlet chamber and an outT let'v chamber, a plurality of tubular elements connecting said chambers,v a'casing forming 5 a closed chamber around said elements, a conduit supplyingwater to said last named z chamber, a thermostatically controlled valve 'loctedinfsaid conduit, said valve being re;

,sponsive to the, temperature of steam leaving the-"regulator, aastop valve-in said conduit, 44iioahcontrolled means for closing said last namdvalve. when the water level inl said 4;, lastaxminedchamber reaches a redetermined he1ght,and"a conduit connectmg a point inysaid iast .named chamber above said predeteriniarheight with said inlet chamber. :4' 13. In a power plant, a high pressure 'superhdatedfsteain-"supply, a low pressure steam "supply,I mn's, for reducing the pressure and tempe'ilture af-steam passing 4from said high pllsghllippl'y tosaid low pressure supply,

said-comprs1ng a pressure reducing @at regulator of the type wherein steam is de'superleated' by evaporating .water out of contact' therewith, said regulator receiving nidireducing'valve. and deliver.- mgitfto said'lw pressure supply, andmeans galve'receivinghigh pressure steam, a super-

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