US1922323A - Hydraulic installation - Google Patents

Description

Aug. 15, 1933. l A, PFAU 1,922,323

HYDRAULIC INSTALLATION Filed May 18, 1928 @bl d..

Patented Aug. 15, 1933 UNTTED STATES PATENT oFFica Y y1,922,323 HYDRAULIC INSTALLATION 'Arnold Pfau, Milwaukee, Wis., assigner to Allis- Chalmers Manufacturing Company, Milwaukee, Wis., a Corporation of DelawareY Application May 1s, 1928.` serialfNo. 278,886

` claims. (c1. 137-158) This invention relates in general to power installations and it has particular relation to hydroelectric power installations where the hydraulic machine is operative under or against a widely 5, varying head.

Turbines of hydraulic power plants which are subjectto a highly variable head such, for instance, as certain streams or the high Aand low tide of the ocean, suier a considerable loss in the w power developed. This is particularly the case v with very low heads where even a slight change in the head amounts to quite a considerable portion of the full normal head. For instance, if

or 50 revolutions, that is, half of theformer amount, when thehead has dropped t0 1/i 0f the maximum head. -v l If the turbine is directly connected to an alter-v nating current generator, it should always operate at the'samenumber of revolutions, otherwise the number of periods orfrequency of the current would change, and this would render parallel operation with other generators impossible. Therefore, if a turbine were normally designed for 1GO revolutions under 16 meters net head, it would have to develop under 4 meters head, not 50 revolutions, but twice as much, that is, 100 revolutions, in order to produce current of the proper number of periods or frequency. A turbine operating at a speed which is 100 per cent higher than normal, however, shows, such unfavorable hydraulic efc'iencies, thatit becomes unconnnercial tostill use `a` turbine for. such operating conditions. v

The speed of the generator could be' maintained normal by using in steps belt drives or similar devices with proper transmission ratios. This arrangement, however, is impossible where large units are usedland particularly when the turbine and generator are directly coupled, which is the 5ol most favorable mechanical solution.

Thek power developed by the turbine lis even more sensitively affected by a change in the net head; rst, on account of the head itself, second,

on account ofv the discharge capacity. It is well known that f 'QirQr--x/lIw/Hz, Where Q1=quantity of water under thehead H Q2=vquantity of Water under the head I-Iz,v and Y HP1.HP2=H1.'\/1fH2.1/I2-Whr f HPr--power at head H1,. 1

HP2=power at `head H2.

is also subjected toa variation inthe eiciency ofV the turbine, andY this deviates morejfrom the best value as the numberof revolutionsor speed is greater or less than the normal speed. Therefore, if the power or capacity, for in-V stance, under 16 meters net head, is 4000 HP, then it isaccording to the above formulae, only 500 HPunder 4 meters, andthis does not as yetcon-v sider the loss of` power due to reduced elliciency. Now, if the turbine mustmaintain its 100 revolutions, it would have to run twice as fastas isnecessary in order to maintain its normal efficiency. Therefore, the eiciency will dropvto4 such extent vthat nothing `will be left` of the 500 HP. In` othergwords,the'turbine willproduce no power and, therefore,v represents'a `jdead capital investment. 5

cernedwith theprovision of an improved powerV system; for the. economical utilizationv of" aV power v sourcek of relatively widely varying availablehead or'pressure, and it more particularly involves 'the use of a plurality of `power units of such individualdesign as to capacity and normal operating head or pressure under which the units operate, each `atdts predetermined desred'speed,

as to insure operationof thesystem under dif'` ferent headsror pressuresv Yunder conditions of maximum efliciency; And the presenty inven.

tion is further concerned with features of auto.

matic contrelof a system involving a plurality of turbines Vdriving or supplying power toa common load so as to yinsure operation' of. thev load, such asan alternating current generator, vat, a

controlled speed throughout full variation in the;` head independently Vof whether one or more orallof the turbines supply power to theload, Aes- The capacity orpower of the turbine, however,`

. g `so ,y The invention of the present applicationiscon a pecially such operation as is desired to secure economical operation at high overall eiciency of the system. As a further feature, the control of a system, particularly a hydro-electric system, of the character described, as to the necessary changes or operations required to accommodate for the difference in head to which the turbines are subjected, vor other variable characteristic, is rendered automatic in response to an operating condition, such as the change in effective heador pressure on the turbine.

It is an object of this invention to provide the above described and other related improvements in power systems, and more particularly hydraulic power systems, and their operation, fea-v tures of the invention being apparent from the accompanying description andthe drawing relative thereto, disclosing an embodiment of this' invention, and being more particularly pointed out in the claims herein. u

The illustrative showing of the drawing 1s a diagrammatic showing of. a hydro-electric sys-V nect'ed,`V through a permanent' orzreleasable clutch cennection,to hydraulicturbines 2and 3, of such different design as to secure most eiiicient operation under substantially different heads and preferably capable oi producing substantially the same power when each is subjected to its normal( operating head; "4 Vindicates 'a source of direct currentvoltage for supplying any -required variable degree of excitation of the field of the generator 1. The circuit 6, supplied by the generator 1, is connected through a line switch 7, to an alternating currentfload or distribution system'S. y

The turbines 2 and 3.may be of either the Francis type or open runner or propeller type, and they may be controlled wholly asto the-water admitted thereto andthe power produced thereby may be regulated byv guide-vanes and actuating mechanism therefor of suitable conventional type.-

constant speedunder variable load conditions by 4its individual automatic controlling means, the controlling means for the turbine 2 being indicated.- generally at C2 and asimilar controlling means ,for the turbine 3at C3; As indicated vin the drawing, there '-is present, as shown. schematically, a servo-,motor Miof well Yknown `construction, vsuch `as Vis used for controlling the guide-vane openings'of turbinesn The regulating valve .VV receives ii'uid pressure, as indicated at K,.`and admitssame,laccordinglto the'position oi the. regulating valve'piston V1, either to apassage K1 communicating with the'front side of the regulating piston M1 of` the servo-motor M,

or `to a passage K2 communicating with the rear side of the .regulating piston M1.' The `'desired actuation of'fthe turbine yguide-vanes or other controlling means for'the turbine-'A is transmitted from the regulating piston M1 of the servomotor M` in any suitable well known manner.

`For conveniencafa rod may be provided at the rear side of the pistonV and passing through a sealed -aperture in the rear end wall'of the cylinder, this rod being connected through a lever or crank M2 to theoperating rod 10 for the guidevane actuating mechanism of turbine 2 or the operating rod 11` for the guide-vane actuating mechanism or turbine 3. s

The motion of the regulating piston M1 is transmitted to a'relay R. A speed governor P receives its revolutions'through a drive T from the turbine shaft and transmits the motion oi' the shifting collar or stud of the governor to the floating lever V-P-R. As soon as the regulatf ing'valve piston V1 is raised out Vof its mid position, fluid pressure K reaches the frontI side K1 of the regulating piston M1, moving the latterV until the regulating valve rpiston V1 is brought back to its former mid position. This is attained by the relay R and the floating lever R-P--V in such a way that the motion to the `left of the regulating piston M1 produces an upward -motion of the end R of the floating lever, causing the regulating valve piston V1 to be lowered after it had iirst been raised by the speed governor.

By shifting the hand wheel R2 on the relay rod R1, it is possible to variably determine the controlled speed of Yoperation Vof `each turbine, although for normal operation, the hand wheel occupies a single definite position on theV rod corresponding to that normal speed Nwhich insures the desired frequency of, currentproduced by the generator 1. Likewise, this provision for variably positioning the hand wheel R2v on the rod R1 constitutes a means for shutting olf the supply of water to each turbine, when it is desired to render either turbine inactive. The normally contemplatedoperation ofthe 1 system disclosed herein includes-the operation of the turbine'Z alone-while the head on the storage source is between the values'Hm and Ha, the operation of both turbines 2 and 3 while the availableA head is between the values Ha'and Hb, and the operation of turbine 3 alone while the available head islbetween values 'Hb and Hc, the latter corresponding vto the minimum head that is economically'utilizrable by the turbine 3f The design of the turbine 2 is such that quite efficient operation thereof at the normal operating speed N may be secured -whilev the head occupies any Value between Hm kand Ha; and the design of the turbine 3 is such as to secure quite eflicient operation yfor any values of the head between the-.values H11 and Hc; i' "In the range between the values Ha and Hb,

both turbines 2 and 3 operate at reduced efficiency and hence reduced output; `but,nevertheless,v thel Vtwo turbines together are capable of producing a required average amount of power corresponding to atleast the normal output of .either of the turbines under its normal or most efficient' operating head, Through this provision, a vsubstantial amount of power can be eX- tracted at Aa relatively high general or average eiiciency` from a source of supply whose head is subject to variation over a relatively wide range, and this resultl may be secured with a relatively small capital investment.

Where the variation in head occurs relatively often or at a relatively rapid-rata'it may be de'- may be secured through the use of control ap- 150 paratus `of the character illustrated which includes the provision of a float 12 in the head water of the turbine and a float 13 in the tail water of the turbine, with flexible cords or chains connected to each of these floats and suitably guided and passing over pulleys fixed to jack shafts 14, 15, respectively, of aV mechanicaldifferential, the iloats 12 and 13 being balanced by suitable weights16 and 17, respectively, connected to the other end of the flexible cords attached to the oats. The mechanical differential gear including the jack shafts 14 and 15, has as its differentially driven element a gear 18 which actuates a geared segment 19 connected to an indicating needle 21 which moves overa scale to give an exact indication of the difference in level between the floats 12 and 13, and hence, the net effective head on the turbine or turbines The indicating needle 21 is mounted so as to move over and in engagement with contacts 23 and 24. The contact 23 is so disposed relative to the path of movement of the needle 21 that, while the needle is in engagement with the contact 23, the head on the storage source is between the values Hm and Hb; and the contact 24 motor 29 for forward and reverse operation, de-

pending upon Whether the switch is in its upper closed position, as indicated in the drawing, or in its lower closed position. When the needle 21 is in engagement with the contact 24, a circuit is closed through the energizing winding 31 of Aa reversing switch 32 having bridging portions 34 and 35 serving to establish the operating circuit of an electric motor 36 for forward `or reverse operation, depending upon Whether the switch is in its upper or lower closed position, the switch being indicated in the drawing as being in its lower closed position.

It will be noted that during a certain part of the travel of the needle 21, corresponding fto an' available head on the storage source ofa value between Hs and Hb, engagement is made by the needle 21 with both of the contacts 23 and 24, under which circumstances the energizing Windings of both reversing switches 26 and 31 are closed' and the reversing switches occupyl their upper closed positions. A

Each of the motors 29 and 36 has its shaft provided with a pinion 52, the Asame being engageable with a gear 53 attached tothe adjusting wheel R2 on the relay rod R1 of the controlling means C2 and C3, respectively. In the motor circuit through the switch 26 in its upper position, is located a switch 56 biased to closed positionand operable to open position by an electro-magnet .having an energizing Winding 57; and in the motor circuit closed through the switch 26 in its lower position, there is disposed a switch 58 biased to closed position and operable to open position by an electro-magnet having an energizing I winding 59. The circuit of the energizing wind- Y ing 57 is completed through a switchl; and the circuit through the energizing winding 59 is completed through'a switch 63. A o

A portion of the adjusting wheel Rg is provided with a projection Yor ilange 67 adapted, through thereciprocation of the wheel or'nut on the relay rod R1,` to actuate the switches 61 and 63 Vto closed position, these switches being assumed to be biased toA open position. However, this operating means may include aloose connection or portion between the element 67 :and the several switches, .which insures positive operation of these switches to both open and closed position; and these switches 6l and 63 may be of the snapoperated type. The preferable means for con-- necting the end of the lever V-P-R to the adjusting wheel R2 includes a sleeve 68 held between flanges -on the rotatable adjusting wheel proper, this sleeve `being held against rotationk in any suitable manner and having the end of the lever connected lto this non-rotatable sleeve. o The switch-actuating projection 67 is preferably mounted on the sleeve 68.

In the circuit of the motor 36 when closed through the switch 32 in its upper position, there is provided a switch 71 biased to closed position and actuatable to open position,'as indicated, by an .electro-magnet 'having an energizing winding 72; and in the motor circuit closed through the switch 32k in its lower position, there is provided a switch 73 vbiased to closed position, as indicated, and actuatable to open position vby an electro v magnet having an energizing winding 74. The circuit of the energizing windings 72 and 74 are closed by switches 61 and 62, respectively, both biased to open position and moved to closed positheillustrative disclosure, the turbine 2V is operative to drive the generator 1, the turbine 3 at this time beinginoperative, having been reni dered `so through the actuation of the guide-vanas or other Vinlet regulating device to closed position by its controlling means c3, the hand when R2 of'which is moved to its lowest position bythe electric motor 36. This operating condition continues while the available head on the storage source remains above the'valueHa, corresponding to the lower limit at which a substantial load can be efficiently supplied by lthe generator 1 when driven by the turbine 2 alone. On reaching the head value corresponding to Ha, the needle 21, while maintaining engagement with the contact23, now 'also makes engagement with the contact 24. KVThrough this latter engagement, wherein itcompletes the energizing circuit of the las winding 31, the reversing switch 32 is actuated to i its upperclosed position; With the switch V32in tion of the 4controlling means Caas includes mov ing'the adjusting nut or hand wheel Raupwardly upon the relay rod R1, toga position wherein it actuates the switch 61 to closed position, thus causing opening of the switch 71 and stoppage of the motor 36, this position oi the hand wheel R2 .corresponding to that setting of vthe, end R of the lever V-P-R which corresponds. with the normal speedfof operation or the turbine and genera-tor l. With this condition existing, the turbine 3 assumes a portionof the load and thus assists in .driving the generator 1..' At this time, each of the turbines 2, 3 continues to' supply a proportionate share of the variable load, the turbines being controlled by their individual speed regulating mechanism. Y

If the available head on the storage source continues to drop to a value corresponding to Hb, the indicating needle at this time breaks engagenient with the contact 23, thus deenergizing. the winding l and .permitting reversing switch .25 to drop to its lower closed position wherein the operating circuit or the Yrnotor 29 is closed to produce operation of the latter ina reverse direction. The eil'ect oithis operation on the controlling means Czofthe turbine 2 is to shift the adjustable hand wheel R2 downwardly upon its .relay rod R1 to a position corresponding to an inactive condition of the turbine 2 wherein the guide-varies or other inlet controlling means Aare closed. As the adjustable hand wheel R2 reaches Aits vlower limiting position corresponding to a rendering of the turbine 2 inactive, the limit switch 63 operatively associated with the hand wheel R2 is moved to closed position wherein it energizes the winding 59 causing opening of the switch 58 in the motor circuit and consequent stoppage vof the saine. y

Under these conditions, the turbine 3 is .alone eiective to drive the generator 1;.and this condition exists while the available head on the storage source remains above the value Hc. As has been described hereinabove the turbine. 3 isde-V signed and operative to drive the generator l at normal .operating speed under an averageiavai.-

able head between the values Trib and Hs, to theref by produce power at maximum efficiency. It is presumed the value. Hc is predeterminedjat such a value as will produce reasonably Veiiicient operation of the turbine 3. When .the available head drops below such aV lower 'limiting value, the

sure disconnection of the generator iro'rnthelive circuit.

It will be apparent that ras the available head on the storage source again-rises through yeral values Hc, Hb and Hs reverse operations occur,

as will be apparent :irornthe description lhereinabove, inap. order which lirst renders the tilrbine 3 operative to drive generator l, .then renders the turbine 2 operative to. assist the turbine .3 as the head reaches the value Ht, and, `as .the head reaches the value lja, causes theturbine .3 to be rendered inactive, the turbine 2 alone continuing to furnish the power requiredior the operation of the generator l. k

With the above described arrangement yofl the hydraulic and yelectrical features of the installation whichpermits transferring the'load or power requiredfor operating the generator from one to .the other. of. the turbines' which are of such individualdesign and capacity as to efficiently supply iherequired power throughout the total variation in head, the amountoij water used perv horsepower ldeveloped is reduced,v and` the. available water is economically and eiiiciently used; and the capital investment vinvolved in the, installation is made to pay anV increased return. Y l f .While the hydro-.electric unit described above iindsgreat utility when connected with a distribution system whoseirequency is definitely establishediby means .other than thisparticular unit, nevertheless, it finds considerable utility when it is the only power unit connected to or establ-ish- Y efficient operation under different heads, a power translating unit operatively connectible turbines to be driven thereby, regulating means operatively associated with saidI turbines for causing either one alone or both oi'y said turbines'to effectively drive said power translatingunit, land means automatically'. responsive vto the energy available at the turbineinlet-"for controlling said regulating means. n

2.*In combination, a power unit comprising a plural-ity oi iiuid driven prime movers subject to operation under widelyv varying' fluid heads, a power translating device arranged tof be driven by either of ysaid prime movers,V and` governing means'including instrumentalities responsive toA the available'luid head on saidl prime inoversior insuring operation of said translating device by one or lthe-other of said primeinovers. 5

3. vIn a power system, a plurality of hydraulic turbines, a machine arranged to be driven thereby, means :for regulating the admission of water to saidI turbines, speed Vresponsive governinghmeans iorcontrolling the speed of said turbines to insure operation'thereof' at one predetermined speed under normal running conditions,` and `ineansresponsive to the effective head on said turbines. for adjusting,saidgoverning means to'V cause thev latter toin'sure controlled operation of said driven machine by one ortheother of said turbines alone depending upon the value or" lsaid effective head.

4. In a poweri system, aplurality of hydraulic turbines; apower translating unitl arranged to be ldriventhereby, means for regulating the yadmission of water .to said turbines, speedresponsive governing means iorcontrolling the `speed or' said turbines toiinsure operation thereof at apredetermined speed'under normal'running conditions, and means'responsive to the eiective head on said'turbines for adjusting saidL governing means-to cause the latter-to :insure'controlled operation of rsaid power translating unit byone or the --other ofsaid turbines alone or both of said turbines. i vi .Y

5. A hydraulic Vpower installa-tion;comprising a plurality of hydraulic turbines'designed for most eicient operation under different heads and subjectv to a variable available supply of Water, a

vas

power translating unit arranged to be driven by either one of said turbines, controlling means for said turbines operative to maintain a predetermined characteristic of the power output of said translating unit under conditions of variable load thereon, and means automatically responsive to a characteristic of the available head on said turbines for providing for eifective operation of said translating unit by either one of said turbines alone.

6. A power installation comprising a plurality of hydraulic turbines designed for most efiicient operation under Widely different heads and subject to a variable available supply of water, a power translating unit arranged to be driven by either or both of said turbines, and means responsive to a characteristic of the available supply of water for determining which of said turbines is in effective power supplying relation to said translating device, whereby the eniciency of operation of said installation is sustained to an increased degree in spite of operation of said turbines under variable heads.

7. In combination, a power unit comprising a plurality of hydraulic turbines subject to operation from a storage source of widely varying head, a power translating device arranged to be driven by said turbines, and governing means ly varying head, a powertranslating unit arrangedr to be driven by said turbines, means for regulating the admission of water to said turbines speed responsive governing means for controlling the speed of said turbines to insure operation there-- of at a predetermined speed under variable load conditions, and means responsive to the effective head on said turbines for adjusting said governing means to cause the latter to insure the effective operation of said power translating unit by one or the other of lsaid turbines alone or both'turbines together determined by the available head of saidV storage source.

9. A power installation, comprising a plurality of hydraulic turbines subject to operation under a widely varying range of head thereon, a mal chine arranged to be driven by one or the other Y head to which said turbines are subjected.

10. Apower installation for operation under conditions of widely varying head, comprising a plurality of hydraulic machines each designed for most efficient operation under a head different from that' for which the other is designed.A a power translating unit arranged to be driven by either of said hydraulic machines, a power system connected to said power translating unit a characteristic of whose operation is established by means other than said power translating unit, and instrumentalities automatically controlled in response to the available head to which said hydraulic machines are subjected for insuring under certain conditions the transfer of energy between said power system and said power translating unit with only that one of said hydraulic machines in effective operation which operates with the greater efficiency under the head available at the time.

11. The method of operating a power installation comprising a plurality of prime movers operable from a source of fluid energy of variable available energy supply and each designed for most efficient operation under different conditions from the other as to available energy supply at said source and arranged to drive a common load, which comprises utilizing as the effective source of power for said load that one of said prime movers which is designed for more efficient operation under the condition of available energy supply existing at the particular time, and changing from one to another of said prime movers for the effective source of power for said load as the said condition of available energy supply varies.

12. Method of operating a hydraulic power installation comprising a plurality of hydraulic turbines operable from a fluid supply under variable head and each turbine designed for most efficient operation under a head value different from the other turbine and said turbines being arranged to supply energy` to a common load,

which comprises utilizing as the effective source Y of energy for said load that one of said turbines whose most efficient operating head more closely approximates the head available for the turbines, and changing from one to another of said turbines as the effective source of energy for said coinmon load as the head on said iiuid supply approaches the most efficient operating heads of the several turbines.

13. In a hydraulic power installation, the combination of a plurality of hydraulic turbines subject to operation under varying values of available head, means for converting the energy of said turbines and supplying said energy to a common load, and controlling means forsaid turbines responsive to the available head thereon for insuring that the turbine capable of operation with greater efficiency at a particular value of availr able head supplies under such value of head a greater proportion of its full load than the other turbine.

14. In a power installation, the combination of a plurality of iiuid-operated prime movers subject to operationunder varying values of inlet pressure, means for transmitting the energy of both of said prime movers to a common load, and controlling means for said prime movers responsive to the available supply of energy for said prime movers for insuring operation of one or the otherV or both of said prime movers depending upon the value of said inlet pressure.

15. In a power installation, the combination of a plurality of fluid-operated prime movers each designed for most efficient operation under a different degree of inlet pressure from the other and subject to operation from a source of fluid energy of variable available pressure, and controlling means for said prime movers lincluding means responsive to the available-pressure of said energy source and operative under certain pressure y ARNOLD PFAU' CERTFICATE 0F CORRECTION.

Parent No. 1,922,323. August i5, 1933.

ARNOLD PFAU.

it is hereby ertified that errm ppears in ille printed specification of the @have numbered pateri requiring orrerzticm as follows: Page 4, line 1121, claim 2, aier "movers" insert "aione"; page 5, ine 37, claim 8, aiter "urbins" inser a crm-rma; and that rire said Leiers Parent should be read with these correciins iaereiii rmr the same may conform to the recrd of the case in the Patent ffice.

Signed and saaled this 26th day of Sepember, A. 1 1933.

M. Hopkins (Seal) Acting Commissioner oi Patents.

CERTlFlCATE 0F CORRECTION.

Parent No. 1,922,323. August 15, 1933.

ARNOLD PFAU.

lt is hereby certified that error appears in the printed specification oi the above numbered paten requiring correction as follows: Page 4, line 21, claim 2, after "movers" insert "alone"; page 5, line 37, claim 8, after "turbines" insert a comme.; and that me said Leters Parent should be read with these correcions merrain filmt the same may oonorm to the record of the case in the Patent Office.

Signed aard sealed this 26th day of September, A. D. 19.33.

. M. Hopkins (Seal) Acting Commissioner of .Pertanto

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