US1141983A - Power-generating system. - Google Patents

Description

G. H. SMOOT.

POWER GENERATING SYSTEM.

1,141,983. APPLICATION FILED APR. II, 1912- PatentedJul-le 8,

2 SHEETS-SHEET I.

Fla. 1- I 3A4! 1 MM.

ATTORNEY C. H; SMOOT.

POWER GENERATING SYSTEM.

APPLICAHON FILED AFJJI, i912 PatentedJmle 8, 131

2 SHEETS--SHEET 2- WITNESSES ATTORNEY character .my invention,

" UNITED STATEE PATENT OFFICE.

CHARLES H. SMOOT, on N W YQRK, N. Y., ASSIGNOR T0 RATEAU, BATTU, sMoo'r COMPANY, or NEW YORK, N. Y., A CORPORATION or NEW YORK.

POWER-GENERATING SYSTEM.

T aZl whom-itmay concern Be it'known that I, CHARLES H. SMOOT, a citizen-of the United States of America, residing in the city, county, and State of New York, have invented a certain new and useful Improvement in Power-Generating System's,=.of which the following is a true and exactd'escription, reference being had to the accompanying drawings, which form a part thereoifi A My-present invention relates to a power generating system in which a steam engine is'isupplied with steam from a source of such that the steam supplied does not vary with the load on the engine, so that the supply of steam furnished by said source may at some periods exceed the amount which the engine requires to carry its then existing load; or may at times be insufiicient to enable the engine to carry its load; or ma exceed at some times and at other times be less thanthat required by the engine.

My invention is primarily intended for use in a power generating system in which a low pressure steam turbine is employed to utilize the exhaust'steam from a high pressure reciprocating engine.

The primary object of my invention is to provide a novel and desirable form of regulating mechanism for a power generating system of the kind referred to.

A more specific-object of my invention is to provide an effective form of regulating mechanism for such a system, having the operating characteristics, functions and advantages hereinafter set forth.

In the preferred mode for carrying out 'as applied to a mixed flow turbine receiving exhaust steam from a high pressure engine, and high pressure steam from a different source when necessary, I connect the turbine betweenthe exhaust out let of the high pressure engine and a condenser, and provide a by-pass about the turbine between said outlet and condenser, and regulate the flow of steam through this bypass by means responsive to the pressure differences created in the connection through which the turbine receives steam from the high pressure engine created by the throttling action of the governing mechanism controlling; the passage of steam through said 'connection. I also utilize the above mentioned means responsive to pressure differences to regulate the supply of high pres- Specification of Letters Patent.

however, and the advantages possessed by it reference should be had to the accompanymg drawings and descriptive matter in Patented June 8, 1915.

Application filed April 11, 1912. Serial No. 690,057.

which I haye illustrated forms of apparatus by which my invention'may be carried out.

Of the drawings, Figure 1 is a diagrammatic representation with parts broken away and in section of one form of power generating system embodying my invention.' Fig. 2" is a View of a portion of the apparatus shown in Fig. 1 showing some of the parts different positions from those occupied by them in Fig. 1. Fig. 3 is a view taken similarly to Fig. 2 showing the parts in still other positions. Fig. 4 is a view taken similarly to Fig. 1 showing a modified form of apparatus embodying my invention. Fig.5 is a View taken similarly to Fig. 4 and showing a modification of the apparatus shown in Fig. 4.

In the drawings and referring first to the construction shown. in Fig. 1, A represents a low pressure steam turbine, B represents a high pressure reciprocating steam engine, C represents the exhaust pipe of the engine B which divides into branches D and E. The branch D runs to the low pressure inlet of turbine A, and the branch E forms a bypass about the turbine A, between the engine B and the condenser F. As shown the branch E opens into the exhaust pipe G running from the turbine A to the condenser F. H represents a high pressure steam supply pipe which may be employed to supply high pressure steam under certain conditions to the turbine A from a boiler I or other source of high pressure steam. Valves 0!, e, and h, are provided to control pipes D, E and H respectively. As shown the valves d and 72. have operating arms connected by the links (1 and h to an actuating lever J.

The lever J is connected by a link L to the ball governor M geared to the turbine A. The lever J is formed with a slot J receiving a fixed fulcrum nin K. When the pin Kismidway between ends of the slot J as 4 governing mechanism shown a spring N amount but opposite in direction;

shown in Fig. 2 the movements imparted to the two valvesd and h when the lever J is turned on its pin are practically equal in I As the pin is shifted toward one end or the other of the slot J however, the movement imparted to the two-valves becomes unequal and with pin K at right hand end of the slot J as shownin Fig. 1, the valve h is held in the closed position and is unaffected by the oscillations of the lever J. Similarly when the lever J isshifted asshown in Fig. 3. so that the pin K is at the left hand of the slot J the valve (1 is closed and is unaffected by the oscillations of the lever J. In the connected between a stationary abutment N and the lower end of the link h tends to hold the mechanism in the position in which the "pin K is at the right hand end of the slot J, and the means employed to control the valve 6 serve also to'give the lever J bodily movements to the right under certain conditions as hereinafter described. The

valve e is controlled by a fluid pressure means responsive to the difference between the pressures in the pipe D at the inlet and outlet'sides of the valve 01, and serv'i to open and close-the valve e on a prer "ermined increase and decrease in this pres. re. In the formof apparatus shown in Fi- 1 0 represents a chambered member diviur into two compartments by a diaphragm O. A pipe P connects one of these compartments to the pipe D at theoutlet side of the valve d, while a'pipe Q, connects the second compartment to the pipe D at the inlet sideiof the valved. Springs 0 acting on a stem 0* connected to the diaphragm O tend to move the latter in the same direction as the fluid. pressure admitted to the diaphragm chamber through the pipe P. The stem 0 also carries a pilot valve O" controlling communication between chambers 0 and 0 formed in the member 0. Fluid under pressure, as high pressure steam, is supplied to the chamber 0 by a pipe R and a pipe S connects the chamber 0 to one end of the piston chamber S formed in a'cylinder S. The opposite end of the chamber S is connected by the pipe S to the pipe E at the inlet side of the valve 6. The cylinder S is formed with a second piston chamber S in line with the chamber S Pistons T and T connected to a'common pistonrod or stem T work in piston chambers S and S. A spring T acting between the adjacent end of the cylinder D and a collar T carried at the right hand end of stem T tends to move the latter to the right. The piston chamber S and the piston T form a dash pot device for retarding the movements of the piston T and stem T. S represents a by-pass connecting the opposite ends of the piston chamber S, and S is a valve regulating the flow through thisby-pass and thereby the retarding action of the dash pot. The

valve 6 is provided with an operating arm 6; This arm is connected at its outer end to a'stationary abutment U by a spring U which tends to hold the valve in its closed position. The stem T engages the lever e as the piston T moves to the left hand end of the chamber S and thereby opens the valve 8. Atits opposite end the stemT is extended to engage a thrust block W pivotally connected to the links d and h and thereby force .the lever J into the position shown in Fig. 3, when the piston Tap proaches the right hand end of the piston chamber S With the apparatus described it will be apparent that when the diiference between 'the pressures acting on the opposite sides of the diaphragm O is insufficient to overcome the action of the springs 0 the pressure acting on the left hand side ofthe piston T supplemented by the action'of the spring T tends to move the piston T into the position in which the stem T holds thelever J in the position shown in Fig. 3. Similarly when the pressures acting on the diaphragm 0 result in the opening of the pilot valve 0 the pressure fluid admitted to the right hand end of the'piston chambers S tends to move the, piston T into the position in which the stem T holds'ithe-valve 6 Open. The movement of the piston T to open the valve 6 is opposed, of course, by the actions of the springs U and T and by'the pressure admitted to piston chambers S and 5*.

Under some conditions it may be desirable to dispense with the by-pass E, either tem porarily or permanently. -Thismay be accomplished in effect with the apparatus.

shown Fig. 1 by closing the hand valve X. Vv'ith the hand valveX closed it will be under stood of course, that the valve 6 be comes inctionless and its presence orjabsence then does not atlect the operation of Itmay also be tie-' when less than the full amount of exhaust steam available is required by the turbine.

A to enable the latter to carry its load, valves (i and will each be partly open and a will each exert a throttling action on the steam passing it. the valve 6 will then be that required to ma1n-- The throttling action of tain a pressure at the inlet side of the valve 1. d sufficicnt to cause the necessary amount of steam to pass through the turbine, arid the throttling action of the valve-(l will be suilicient to create a difference in the pressures at its inlet and outlet sides which will maintain the valve 0 in theproper position. Ona decrease in the turbine load the governor will close the Valve d somewhat. This tends to increase the difference in the pressures at the opposite sides of the valve which in turn causes the piston T to move to the left and open the valve 6 still more. This increases the portion of steam passing through pipe E and decreases that passing through the pipe D. The decrease in the amount of steam passing through pipe D tends to decrease the difference in pressures at the opposite sides of valve (1 but an equilibrium is readily established. As the load on the turbine A increases the valve d is moved in the opening direction by the governor, and the valve e is correspondingly closed. When the load on the turbine increases to a certain amount the valve 6 entirely cuts off the steam flow throughpipe E and on a still further increase in the load, the piston T moves to the left far enough so that the stem T engages member V and moves link J to the right thus putting the high pressure valve h under the control of the governor. The turbine A will then receive all the exhaust steam from the engine B and in addition as much high pressure steam as is required to enable the turbine to carry its load. It will be apparent that the lever J will not be forced to the extreme position shown in Fig. 3 in which the valve d is shut tight, except when the supply of low pressure entirely ceases.

In practice the mechanism 1s so ad usted that the difference between the pressures at the opposite sides of the valve d due to its throttling action are small, say a pound or so. The back pressure imposed on the engine B never exceeds that required to enable the turbine to carry its load more than by this small pressure difference due to the throttling action of the valve (Z. The use of the present invention thus makes it possible to pass all of the exhaust steam from the engine B to the condensing apparatus, and enables the engine B to receive the benefit of practically all the vacuum available, and avoids loss of energy due to excessive throttling by the low pressure governor valve (1.

The regulating apparatus shown in Fig. 1 with the by-pass E dispensed with possesses advantages under certain conditions over the means for regulating mixed flow turbines heretofore employed. In such case the adjustment of the governor mechanism will still be responsive to the differences in pressure created at the opposite sides of the valve (Z by the throttling action of the latter. In consequence the admission of high pressure steam to the low pressure turbine through the conduit H is controlled by pressure valves which aradependent on the load prevailing on the turbine. For instance, assume apparatus in which at full load steam must be supplied to the low pressure turbine when the pressure of the low pressure steam in conduit C falls to a given value, say 15 pounds absolute. Under such conditions it has heretofore been the practice to provide means for supplying the low pressure turbine with high pressure steam whenever the pressure of the low pressure steam fell to this minimum valve of 15 pounds, even though the amount of low pressure steam available might be ample to enable the low pressure turbine to carry the reduced load then imposed upon it. With the apparatus disclosed herein, however, the admission of high pressure steam is independent of'the extent to which the pressure of the steam supplied by conduit C may fall, and the high pressure steam will be admitted only when the load imposed on the low pressure turbine is such that it cannot be carried by the low pressure steam available. With the present invention therefore, the pressure in conduit C; 6., the back pressure on engine B is not restricted to the minimum value at which high pressure steam must be supplied to the low pressure turbine to-enable it to carry its full load.

It will be apparent, of course, to those skilled in the art that theuse of the differential pressure controlled pilot valve 0 is not essential to enable me to obtain the general results sought. These results may be obtained for instance, with the apparatus shown in Fig. l wherein the piston chamber S in the cylinder member SA in which the piston T works has its opposite ends connected by pipes S and S to the pipe D at the opposite sides of the valve d. The use of the diaphragm controlled pilot valve 0 possesses the important advantage how ever, of enabling the powerful forces to be imposed on the piston T, thus insuring its rapid and positive action. The dash pot retarding mechanism for the piston T shown in Fig. 1 while desirable, is not essential in all cases, and is omitted in Fig. 4.

While I consider it advantageous in most cases to provide an auxiliary high pressure steam supply connection to the turbine A, my invention contemplates the use of the differential pressure controlled by-pass Without any high pressure steam supply and when a source of high pressure steam is provided its regulation may be independent of the governor controlling the low pressure steam supply. For instance, as shown in Fig. 5, the flow through the high pressure supply pipe H may be controlled by a throttle valve ha. which may be adjusted by hand to entirely out off the supply of high pressure steam or to pass any desired quantity. In Fig-5 the lever JA replacing the lever J in Figs. 1 andt can turn but not slide relatively to the fulcrum pin KA, and the piston stem T does not act on the governor mechanism.

Under some ccaiditions it may he ilesirahle 5 to limitthe vacuum or niininnim pressure maintained in the power generating system. This may readily be accomplished by limit ing the minimum pressure acting against the under side of the diaphragm (l in the regulating apparatus of Fig. 1 or in the left hand end of the cylinder SA of Figs. 4 and 5. For this purpose I may employ the valve Z shown in Figs. 1 and 4. The casing of this valve is connected to the pipe P or to the pipe S as the case may be, and

is formed with a port Z opening to the atmosphere and controlled by the inwardly opening valve member Z A spring Z", the tension of which may be adjusted as desired tends to hold the valve member Z against its seat. It will be apparent that on a decrease of the pressure in the pipe P or S, the valve Z will open and admit atmospheric air thereto to prevent any further reduca tion in pressure therein. The effect of the air thus admitted on the operation of regulating apparatus is analogous to an increase in the pressure on the outlet side of the valve d, or to a decrease in the differential between the pressures on the two sides of the valve d. The small hand valve P in the pipe P and S in the pipe S may be set to restrict the flow of the air into the pipe D so that the amount of air which thus leaks into the turbine A will ordinarily be so small as to have no material effect on the operation of the system as a whole.

ZA represents a hand valve for cutting the valve Z out of operation.

While in. accordance with the provisions of the statutes I have illustrated and described the best forms of my invention now known to me it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention, and that under some conditions certain features of my invention may he used with advantage without a corresponding use of other fea 5o tures.

Having now described my invention, what I claim is new and desire to secure by Letters Patent is:

1. In a power generating system, the combination with an engine, of regulating means therefor comprising a valve regulating the passage of steam to the engine, means responsi i: to the speed of the engine for adjusting said valve and means responsive to the difference in pressures at the opposite sides of said valve due to its throttling action for i...odiiying the action of said regulating means.

2. A power generatimf system comprising in combination, an engine, a valve regulating the passage of steam to the engine, means responsive to the speed of the engine for adjusting said valve and means responsive to the difi'ei'ence in pressures at the opposite sides of said valve due to its throttling action for modifying the Speed regulating elfcct of said valve. I

3. A power generating system comprising in combination, an engine, a throttle valve controlling the passage of steam to the engine, means responsive to the speed of the engine for adjusting said throttle valve and means responsive to the difference in pressures at the opposite sides 0t said valve due to its throttling action for modifying the pressure of the steam entering said valve.

4. In a power generating system the combination with a plurality of engines receiving steam 'pom a plurality of sources at different pressures, of a throttling valve responsive to the speed of one of said engines for controlling the passage of steam to one of said engines from one of said sources, and means, responsive to the differential in pressaire at opposite sides of said valve due to its throttling action, for controlling the supply of steam from another of said sources.

A power generating system comprising in combination, two engines receiving steam in series, a valve controlling the passage of steam from one engine to the other, means responsive to the speed of the engine receiving steam through said valve for adjusting the latter, a bypass about said second engine for steam passing through the first engine,

a valve controlling said by-pass and means for adjusting said valve in response to the differences in pressure at the opposite sides of the first mentioned valve due to the throttling action of the latter.

6. In combination, a source of low pres sure steam, an engine receiving steam from said source, condensing apparatus into which said engine exhausts, a by-p'as's about said engine connecting said source to said condensing apparatus, a valve regulating the passage of steam from said source to said engine, a speed. governor controllin said valve, a second valve regulating the j ow of steam through said by-pass, and operating means therefor responsive to the difference in the pressures at the opposite sides of the first mentioned valve for opening and closing said second valve as said pressure difference increases and decreases.

7. In combinatioma steam engine, a conduit connecting said engine to a source of low pressure steam, a second conduit connecting said engine to a second source of steam, a valve in each conduit, condensing apparatus into which said engine exhausts,

a lay-pass about said engine connecting said low pressure source of steam to said condensing apparatus, governing mechanism connected to said valves and responsive to the speed of said engine and means responsive to the diii'erences in pressure in the loW pressure conduit at the opposite sides of the valve therein, for adjusting said governing mechanism to open and close the valve in said second conduit.

S. in combination, a steam engine, a conduit connecting said engine to a source of low pressure steam, a second *onduit connecting said engine to a second source of steam; a valve in each conduit, @ndensing apparatus into which said engine exhausts, a bypass about said engine connecting said low pressure source of steam to said condensing apparatus, governing mechanism connected to said valves and responsive to the speed of said engine, means responsive to the difierences in pressure in the low pres sure conduit at the opposite sides of the valve therein, for adjusting said governing mechanism to open and close the valve in said second conduit and a valve in said by pass controlled by said means and opening and closing as said difl'erence increases and decreases.

9. In a power generating system, the combination With an engine, of regulating means therefor, comprising a valve regulating the passage ofsteam to the engine, means responsive to the speed of the engine for adjusting said valve, means responsive to the differences in pressure vat the opposite sides of said valve due to its throttling action for modifying the action of said regulating means, said last mentioned means comprising a differential pressure irotor, adapted to admit atmospheric air to one the pressure chambers of said motor one predetermined drop in the pressure of said steam.

10. In a power generating system, the com hination with an engine, of regulating means therefor, comprising a valve regulating the passage of steam to the engine, means re sponsive to the speed of the engine for ad justing said valve, means responsive to the differences in pressure at the opposite sides of said valve due to its throttling action for modifying the action of said regulating means, and means responsive to the pressure of said steam for modifying the action of the last mentioned means on a predetermined reduction in the pressure of said steam.

11. In a power generating system, the combination with an engine and a steam supply conduit connected thereto, of regulating means comprising a valve regulating the passage of steam to the engine through said conduit, means responsive to speed of the enginefor adjusting said valve, means responsive to the ditferences in pressure at the opposite sides of said valve due to its throttling action for modifying the action i. said regulating means, and a pressure relief valve connected to said conduit on the supply side of said throttle valve.

CHARLES H. SMOOT.

Wi tnesses I L. BATTER, C. S. BROOKS.

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