US1085123A - Governing mechanism for prime movers and auxiliaries. - Google Patents

Description

R. F. HALLIWBLL.

GOVERNING MECHANISM FOR PRIME MOVERS AND AUXILIARIES.

APPLICATION FILED NOV. 7, 1910.

Patented Jan, 27, 1914.

2 SHEET$SHEET 1.

Witnesses I M Q N. F. HALLIWELL. GOVERNING MECHANISM FOR PRIME MOVERS AND AUXILIARIES.

APPLICATION FILED NOV. 7. 1910 Patented Jan. 27, 1914.

2 SHEETSSHEET 2.

His o ttornes.

mm jfillll) 37 Inventor: Re inald FZHalliweIl,v y

UNITED STATES PATENT OFFICE.

REGINALD FRANCIS HALLIWELL, 0F RUGBY, ENGLAND, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

I GOVERNING MECHANISM FOR PRIME MOVERS AND AUXILIARIES.

Specification of Letters Patent.

Patented Jan. 27, 1914.

Application filed November 7, 1910. Serial No. 591,033.

steam is simultaneously utilized for driving prime movers and for other purposes such as heating and so forth.

In installations where steam of low or medium pressure is required it has hitherto been commonly obtained by reducing the high pressure of steam from a boiler by means of a reducing valve, but this method is obviously wasteful as the energy expended by the steam during its expansion in the reducing valve is lost. Now inorder to utilize the energy which was formerly lost it has been proposed to use the high pressure steam for driving a prime mover and to employ the exhaust steam at a low or medium pressure for. supplying other prime movers or a lower pressure system for operating auxiliary heating or power appliances. An-

other known arrangement consists in stor ing the exhaust steam after it has done work in a prime mover in a steamireceiver or low pressure boiler and then supplying a lower pressure system for operating heating apparatus and other devices from the boiler and through an automatic valve supplying the surplus steam either to another low pressure engine or the low pressure cylinder of a compound engine.

If the amount of steam required for heating and other auxiliary purposes is variable and if the output required from the prime mover is practically constant or varies from time to time in different proportions to the demand for low or medium pressure steam, then theproblem of regulating the admission of'high pressure steam to the prime mover 'and the disposal of the. surplus exhaust steam from the prime mover becomes difticult. A partial solution of the difliculty is obtained when a turbine is employed as the prime mover by providing two or more stages in the turbine and taking the supply for the low or medium pressure system from an intermediate stage and providing means for regulating the amount of steam admitted to the lower pressure stages so that the work done the high and low pressure stages and consequently the amount of steam ad mitted to the turbine can be regulated to suit 'the desired conditions. This method of overcoming'the difiiculty is open to the ob jection that if the variations in conditions are frequent and irregular as is usually the case, constant attention and adjustment is requiredto obtain good results. It is the object of my invention to overcome this difficulty.

Stated broadly my invention consists in providing in a system comprising a cone pound or multi-stage prime mover and an auxiliary low or medium steam pressure system wholly or partially supplied from an intermediate stage of the prime mover, 5 device for automatically regulating the supply of hlgh and low pressure steam simultaneously to the different stages of the prime mover in response to the demand for lower pressure steam for aux liary purposes.

. Stated'another way my invention consists in utilizing the slight variations in pressure in the low or medium pressure auxiliary system or the intermediate stage of a prime mover, so that as this pressure increases less high-pressure steam is admitted to the prime mover and more steam is passed into the lower pressure. stages of the prime mover and vice versa.

I will describe my invention as applied to the case where the low or medium pressure supply of steam for heating or other auxiliary purposes is obtained from an intermediate stage of a multi-stage steam turbine. In this case in carrying out my invention 'I employ high and low pressure valves for the prime mover controlled by a governoroperated lever pivoted to a floatin fulcrum adapted to assume definite positions with slight variations of the pressure .in the in termediate stage of the prime mover.

In the accompanying drawings, Figure 1 is a fragmentary view of a horizontal turbine of the axial flow type to which my in: vention is applied; Fig. 2 is a side view of a heating device utilizing low pressure steam from the turbine and also having means tor supplementing the low pressure supply; Fig. 3 is a detail view in elevation of a turbine having high and low pressure sections arranged in separate casings; Fig. 4 shows my iuVentionappl ed to turbines having separate shafts; and Fig. 5 is a detail view of a means for adjusting the pressure responsive device.

' In the drawing 1 indicates the shaft and 2 the outer shell of the turbine between which two parts are located suitable-packings 3 and 4. The shell 2 is provided with three flanged openings 5, 6 and 7 and also with rows of stationary buckets 8 and 9. These buckets cooperate with two or more rows of buckets carried by turbine wheels 10 and 11 which in the present case are located in the high agd low pressure stages respectively of the turbine. Between these stages are suitable diaphragms l2 and 13, and the shell 2 and diaphragm 13 are provided with nozzles 14 and 15, respectively, for the pars sage of the motive fluid. The shell is provided with a passage 16 at the exhaust side of the low pressure stage communicating with the condenser or atmosphere as the case may be. The valve casing 17 is suitably secured to the'turbine shell and contains a.

piston valve 18 operating to control the supply of high-pressure steam which enters at 19 and passes through the duct 20 to the inlet nozzle or nozzles 14. The casing 17 is provided with a cover 21 and a stufling box 22 in theusual way. A steam chest 23 is also secured to the turbine shell so as to communicate with the opening 6 and this seat the valve dis casing is provided with an outlet 24 connected with the heating system which is to be supplied with steam at a low or medium pressure. The casing 23 is also provided with an extension 25 in which a movable abutment such as a piston 26 ..secured to a rod 27 passing through a cover 28 of the extension is located. Between the cover 28 and the piston 26 is arranged a spring 29 which will be hereinafter referred to. The casing 23 communicateswith another casing 30 which forms a chamber 31 communicating through the inlet 7 with the lower stage of the turbine. Within the casing 30 is an extension 32 'liavin valve seats adapted to 33 and 34 carried by a rod 35 which passes through the cover of the casing 30.

The rods connecting with the high pressure valve 18, the piston 26 and the low pressure valve 33 and 34, are all connected to a lever 38 in the manner hereinafter described. This lever 38 is secured at one extremity to a rod which carries a piston 40 operating within-a relay cylinder 41 to which motive fluid is admitted, through'ducts 42 and 43 so as to act on oneside or the other of the piston 40,.by means of a pilot valve 44. The cylinder of the pilot valveis provided with a fluid inlet 45 and outlets 46. The piston rod 39 and the rodof the pilot valve 44 are connected with a floating lever 47 of the type commonly used in hydraulic valve gears; this lever being connected in the'usual way with the turbine speed governor 48.

Referring now to the pivoted lever 38 which carries the high and low pressure valves regulating the supply of high and low pressure fluid to the primary and low pres sure stages of the/turbine, this lever is fulcrumed at 49 in the forked end of the rod 27. The position of this rod and its actuating piston 26 is determined by the pressure in the intermediate stage of the turbine. The spring 29 operates to move the piston so as to balance the pressures on both sides there of. If the pressure in the intermediate-stage increases the piston 26 is raised and with itthe fulcrum 49 of the lever 38 and consequently the high pressure valve 18 and the low pressure valve 33, 34 are also raised. It should be pointed out here that the pressure in the intermediate stage of the turbine is the same as the pressure in the auxiliary or heating system. The lever 38 is also operated by means of the piston 40 in the relay cylinder that in turn is controlled by-the pilot valve 44 which admits fluid through the inlet 45 or exhausts fluid through the outlets 46 under the influence of the governor 48, the latter being connected in any convenient manner to the turbine. The connection is such' that as the speed rises, the

tel-mediate space to which the out'let24 is connected, and assuming the parts to be in the positions shown in the drawing, then, if

the pressure beneath the piston 26 increases,

the fulcrum 49 is raised and the highpressure valve 18 s also raised so as to redui';

' the supply of high pressure steam, wherei.-

the low pressure valve 33, 34 which is also raised admits more fluid to the low pressure nozzle 1:7. This limitation of the supply of high pressure steam to the first stage of the turbine and the increase in amount of steam supplied to the low pressure stage reduce the pressure beneath the piston 26 until a state of equilibrium is again reached. The

arrangement of the parts is such that the normal governing of the turbine and the pressure of the steam supplied to the auxiliary system are effected without interfering with each other. It will be understood that the. amount of steam passing to the condenser will be reduced when the piston 26 descends and at the same time theamount of steam admitted to the turbine will be in creased so that the pressure in the space between the high and low pressure stages will be increased. Conversely if the pressure in the intermediate space becomes too high the piston 26 will rise and the'high pressure valve will tend to close and the low pressure valve will tend to open and the pressure between the stages will be decreased.

no change in speed takes place. This difl'er-' ential action of the regulators has the very decided advantage that it acts very quickly to reestablish the proper operating conditions after a change Has taken place.

By the improved governing and valve gear hereinbefore described the necessary adjustments are automatically made by the governor and a; practically constant pressure maintained in' the auxiliary low or medium pressure system by the turbine governor so long as there is sufficient load on the turbine to utilize the energy obtained in expanding the required amount of steam from the. higher to the lowerpressure of the auxiliary system. -Under extreme conditions the turbine governor might not be able to control satisfactorily the supply of steam to the auxiliary system and consequently under these conditions I employ a reducing valve in the system so as to obtain a low pressure supply inthe usual manner.

Although I have described one specific method ofcarrying out my invention I wish it to be distinctly understood that. I do not desire to be limited thereto. Instead of using a multi-stage' prime mover having high and low pressure stages. within the same casing I may employ a prime mover in which the high and low pressure stages are not in the same casing, or I may employ independent prime movers so long as the shafts thereof are coupled either by mechanical or electrical means so that their speeds bear a definite relation to each other. In short my invention comprises an arrangement of parts in which the high and low pressure valves are controlled by a governor-operated lever the fulcrum of which is adjusted by slight variations in pressure in an intermediate stage of a prime mover in such a manner that this pressure increases less high pressure steam is admitted to the turbine and more steam is passed into the low pressure stage andvice versa.

In Fig. 2 is shown a heating device 50 that receives steam from the conduit- 24 by the pipe 51. carried oil by the pipe 52; 53 and 5% indicate pipes for conveying fluid to and. from the heating device. 51 indicates a pipe carrying live steam to supplement the supply of The exhaust from said. device is steam from the turbine. In the pipe is an automatic pressure reducing valve 51" In F ig. 3 is shown a turbine fitted with my improved governing mechanism and comprising a high pressure portion contained in a casing 55 and a low pressure portion contained in a. casing 56, both of said casings beingmounted on the same bed plate 57. The exhaustfrom the low pressure portion is discharged into the condenser 58 or other exhaust receiver.

In Fig. 4: are shown independent turbines- 59 and 60, the steam passing from one to the other through conduits-and valve means dcscribed in connection with Fig. 1. Each turbine drives its own three phase electric generator 61 and the said generators are connected in parallel to the bus bars 62. The turbine shafts are independent in this case but are caused to rotate synchronously by reason of the parallel connected generators.

In Fig. 5 is shown the pressure regulator comprising .the piston 26 located within the .sing 25, the latter being open to a region of intermediate steam pressure in the turbine. The opposing spring 29 is situated between collars 63 and 6s and its ten-' sion can be adjusted by the screw carried by the frame 66. This may be taken as a typical representation of any suitable means for adjusting the tension of the spring and hence of a device for varying the opposition to out-ward movement of the piston 26.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. In a system comprising a compound or multi-stage prime mover and'an auxiliary. low or medium steam pressure system receiving steam from an intermediate stage or region of the prime mover, the combination of valve means for regulating the sup- 1 ply of high and low pressure steam to different stages of the prime mover, a device responsive to the demand for lower pressure steam for the auxiliary system, a connection between both of said valve means and said device which acts to vary at least one of said supplies and load responsive means acting on said connection to vary said supplies.

2. In a system comprisirga compound or multi-sta'ge prime mover and an auxiliary low or mediumsteam pressure system receiving steam from an intermediate stage or region of the prime mover, the combination of valve means for controlling the admission of steam to the in tial stages 0 t e 'and its control.

turbine and its flow from said intermediate stage cr'region to a subsequent stage or stages, and a device responsive to variations in pressure in the-low or medium pressure auxiliary system or in the intermediate stage of the prime mover which device acts on said-valve means to cause it to admit less high pressure steam to the prime mover as this pressure increases and to pass more steam into the lower pressure stages of the prime mover and vice versa.

3. Ina system comprising a compound or multirstage prime mover and an auxiliary low or medium steam pressure system receiving steam from an intermediate stage of said prime mover, the combinatipn of high and low pressure valves for the prime mover, a governor-operated lever controlling carrying a fulcrum for said lever between said valves, a relay for moving said lever, and a speed governor controlling said relay.

5. A turbine having a rotor, a casing, a high pressure inlet and an exhaust outlet, in combination with a conduit cormected to the turbine using at a oint of intermediate pressure for withdrawing motive fluid therefrom, a valve means for regulating the admission of 'mot-ive fluid-to the turbine, a governor for controlling the action of the valve-means, and aregulator responsive to said intermediate pressure for moving the valve means independently of the governor 6. A turbine having a rotor, acasing, a high pressure inlet and an exhaust outlet, in combination with a conduit connected to and withdrawing steam from the turbine casing at a point of intermediate pressure, a valve means for regulating the admission of steam to the' turbine, a speed responsive device that primarily controls the valve means, and a means adapted to move the valve means independently of the action of the speed responsive device and which is responsive to the pressure of the steam leaving the turbine through said conduit.

TIA-turbine having a rotor, 'a casing, an inlet and an exhaust outlet, in combinationwith a valve means in said inlet, a. motor, a controller therefor, an actuator moved by the -.i0tor for opening and closing theyalve, a speed governor for actuating the motor controller, means for withdrawing steam from a region of the casing located intermediate said inlet and outlet, and 'a device responsive to the pressure in said region that exerts a variable force on the actuator to modify the action of the motor on the valve means.

8. An elastic fluid turbine havin" an inlct and an outlet, in combination with a high pressure valve means, an intermediate pressure valve means, mechanism mechanically uniting said valve means, a. conduit that withdraws steam from the turbine at a .--=int between said valve means, and a device responsive to pressure changes of the st earn withdrawn by thecouduit for moving said valve means.

9. An elastic tluid turbine having an inlet aud an outlet, in combination with a o-nduit for withdrawing motive fluid from the turbine at an intermediate pressure. a pair ofvalves one on the high and the other on the low pressure-side of said conduit, and an actuator that is common lo and move; both bf said valves.

10. An elastic fluid turbine having a n inlet and an outlet, in combination with a conduit for withdrawing motive lluid from the turbine at an intermediate pressure, .a pair of valves one on the high and the other on the low pressure side .of said conduit. an actuator thatis common to and moves both of said valves, and a device sensitive to the pressure of the fluid flowing through the .conduit for modifying the action of the actuator on said valves.

11. An elastic fluid turbine having an inlet and an outlet, in comb'natiou with a conduit for withdrawing motive fluid from the turbine at an intermediate pressure. a pair of valves one on the high and the other on the low pressure side of said conduit, :1 governor controlled lever that. actuares both valves, and a pressure responsive device for changingth position of the fulcrum of the lever;

12. An elastic fluid turbine having an in let and an outlet, in combination with a conduit for withdrawing motive fluid from the turbine at an intermediate ire-sure. a regislater on the high pressure sine of the duit, a regulator on the low are side of said eonduit, and a means condition of the motive flui in the resi n of the conduitwhich acts dili'ereutinllv on said regulatois. m- 1 13. A turbine having fluid (list-limping and directing devices, a rotor, a casi q steam inlet leading from a region of Ella: rag ing in advance of said devices amt where the steam pressure is subject to \ZH'EQE'HQHS. and an outlet, in combination with a valve controlling the passage of steam through the inlet to said devices, a speed governor fo controlling the action of the valve, and a device responsive to the pressure existing in said region for modifying the effective aetion of the governor on the valve.

14. A steam turbine having an inlet and an outlet, in eomhinatioh with a eondnitfor Withdrawing steam iron: an inlimillediiilin stage or region of the turbine valve means for regulating the admissionoi steam to the turbine, a lever connected t the valve means, a fulcrum for the lever, a pre ire responsive device for moving fulcrum as the pressure of the steam \vitluliaivn varios, and a speed responsive deviha eon aeeted to the lever.

15. A steam turbine ha ir; an inlet and an outlet, in combination 0 iii a, eondnit. for withdrawing stoan': from an intro mediate stage or re a: of the turbine, valve means for regular 'ie ail/vii: "vain to the turbine, valve means a: i sing the flow of steam from said intern iate stage or region to a an aqnert s! stages, a speed responsive device for tontrtdling both valve means, and a (luv t ire to the pressure in said interimyliate eta-153s which also eonlr 'ils at hast ne of said means,

16. A steam ti hine navin inlet, and anontle'l, in eomlrralion with a a withdrawing strain iron" an intermediate stage or region of the turbine, valve means for regniating the, min ion ol' strain to the turbine, valve nn-a admin; the lion of steam fr m said inlernnaliat stage or region to :1 nhsr nvni. riiilll: or surges, means for Sili'inllnnrinnlv wning and rinsing the admission val e means and the stage valve means, and a ileviee PSi/Ulm 'r; to the pressure in said inte mediate sin also controlling; the stage v mew l7. clbillll turbine having: 5' inlet and an outlet, in eomhinunon with a .iinit for r i or l'cil'a'f li tor hit for Withdrawing steam from an intermediate stage or region of the turbine. valve means for regulating the admission of steam to the turbine, valve means for regulating the llOW of steam from said intermediate stage or region to 1L subsequent stage or region. a speed responsive device, a device responsive to the pressure in said intermediate stage or region, and means connecting; the two valve means and the speed and pressure responsive devices.

18. A steam turbine having an inlet and an outlet, in combination with a conduit for withdrawing steam from an intern'iediate stage or region of the turbine, valve means for regulating the admission of steam to the turbine, valve means for regulating the low of steam from said intermediate stage or region to a subsequent stage or region. and a device responsive to the pressure of the steam withdrawn from'said stage or region for controlling the two valve means.

19. A turbine having a rotor, a easing, an inlet leading from a region of the casing where the steam pressure is subject to variations, and an exhaust outlet, in combination nith a valve means in said inlet, a motora eontroller therefor, an actuator moved by the motor for opening and closing the valve, :1 speed governor for aetnatiing, the motor vontroller, and a device responsive to the pressure in said region that exerts a variable have on the aetnator to modify the artion of the motor on the valve means in win s whereof I have hereunto set my hand this filth day of October, llllO.

RltlllhAhl) l llANClS liiililil WE lili.

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