US1573781A

US1573781A - Governing mechanism for turbines

Info

Publication number: US1573781A
Application number: US674523A
Authority: US
Inventors: Kieser Walter
Original assignee: AEG AG
Current assignee: AEG AG
Priority date: 1923-11-13
Filing date: 1923-11-13
Publication date: 1926-02-16
Anticipated expiration: 1943-02-16

Description

Feb. 16 1926. 1,573,781

W. KIESER GOVERNING MECHANISM FOR TURBI'NES Filed Nov. 13, 19'25 Lwento: Walter Kieser, by MM2 f/f. His Attorney.

To all iti/wm t may con-cern:

Patented lFeb. 16, 1926. Y

' UNITED STATES PATENT oFFlcE.

, WALTER xIEsER, 0E CHARLOTTENEURG, GERMANY, AssIGNoR, BY MEsNE ASSIGN-` MENTs, To ALLGEMEINE ELEKTRIGITATS MANY, A CORPORATION or GERMANY.

GOVERNING MECHANISM YEGR TURBINEs.

Applicatirm filed November 13, 192,3. SerialNo. 674,523.

Be it vknown that I, WALTER KIEsER, a citizen of Switzerland, residing at Charlottenburg, Germany, have invented certain new and useful Improvements in Governing Mechanisms for Turbines, of which the following is a specification.

AThe present invention relates to governing mechanisms for turbine installations inv which a pair of Aturbines is arranged to drive a common load, such as an electric generator for example, and in addition to independently lsupply steam for heating and cooking purposes. In such installations the requirements on the governing mechanism are unusually exacting as will vbe appreciated from the fact that the load on the generator may vary as well as the amounts of steam 'extracted from the turbines and that these variations may take place simultaneously and in the same or different directions.

The object of my invention is .to yprovide a simple, reliable governing mechanism for installations of the general character above referred to. For a consideration vof what I believe to be novel and my invention, jattention is directedfto the accompanying description and the claims yappended thereto.

In the attached drawing is illustrated `more or less diagrammatically one of the embodiments of my invention. A

l1 indicates a multistage turbine of suitable construction arranged to operate as a con` densing and extraction unit. The extraction pressure may be approximately that of' the atmosphere or above it as desired. For simplicity it will be referred to as the main turbine.v 2 indicates the steam supply pipe, 3 the admission valve therefor, 4 the Aextraction conduit, y5 the overflow valve regulating the supply of steam from the extraction stage to the lower pressure stages,

and 6 the exhaust conduit which may be, and r I ing the other as may be required to preserve secondary` turbine.

the lpoint of consumption; Both turbines have their rotors mounted on the same shaft 11 and through it drive the rotorl ofthe electric generator 12. The generator is designed to bedriven at constant or approximately constant speed as is usually the case. The regulating. valves 3, 5 and 9 are operated by Huid motors of ordinary construction, each comprising a cylinder 13 and piston 14, the latter being connected to the valve to beV operated.` '1 each piston are controlled by al pilot valve 15 of usual construction.' Each pilot valve stem is 4also connectedto the, piston rod of its motor as by alever ,15a which forms a follow-up device to prevent'overtravel of the moto`r. The mechanism for controlling the actions of the main regulating valveslwill nowv be described. 16 indicates a Vcentrifugalspeed governor driven by any suitable meansfrom the main shaft 11 y whereby its effective action varies with changes'of speedof the shaft.- The movable collar of the governor is pivotally attached to a lever 17 through the medium of a fulcrum or pivot, 28.1' AThe left-hand end of this leveris provided vwith a pivot 29 which is connected by a system of linksk andlevers to the pilot valves of the motors which vactuate the controlling valves ofthe mainy turbine 1. To the lever 18 of theproper' speed of the shaft 11. It is tobe noted that the load variations of the generator betweenV certain rather wide limits are taken care of by varying the amount of steam flowing through the main turbine,

and that when the load is decreased below the lower of 'said limits furthergoverning is accomplished by varying the amount of steam iowing through the yauxiliary or he movements of GESELLSCHAFT, OEBERLTN, ,GER-Y i' The right-hand end of governor lever 17 is pivotally attached to the rod 2l which forms a part otl the governing mechanism of the back pressure or secondary turbine. 22 indicates a pressure regulator of the same character as regulator 19 and its action is responsive to the extraction or exhaust pressure in the conduit 10. s

In order that a single speed governor may control both turbines, an elastic coupling 23 is provided in one of the systems oit links and levers. As illustrated it is associated with the secondary turbine 7 and is located in the rod 2l between the pressure regulator and the mechanism controlled thereby. It comprises a member 24 connected to the movable part or piston of the regulator 22, and abutment 25 on the rod 2l and a coiled compression spring 2G between the member and abutment. Under normal conditions the tension of the spring is such that it and its associated parts move with the rod 2l and piston of the regulator 22 a unit, but under other conditions the spring 26 yields to permit the speed governor to control the valve 9 as will appear later.

The operation of the governing mechanism is as follows: For changes in load on the generator the speed governor 16 opens or closes the valves il and 5 as required to maintain the desired speed, the lever i7 moving about its pivoted connection with the rod 2l. A variation in the amount of steam taken from the extraction conduit l causes the pressure regulator 19 to modify the action or" the governor on the valves. Thisis done through the lever 18 turning on the pivot 27 in a manner to increase the opening of one valve and decrease that et the other. The pressure regulator 22 is sensitive to variations in the amount et steam flowing through the secondary turbine and controls the valve 9. Under normal conditions the regulator 22 in causing a decrease ot steam admitted to the secondary turbine by the valve 9,also acts on the governor lever 17 turning it on pivot 28 in such a. manner as to open the valves 3 and 5 so that the speed of the set as a whole will be maintained. 1When the load decreases below that requiring the two turbines to drive it, the eovernor first closes the valves 8 and 5 and then begins to close the valve 9, this being permitted by the elastic coupling in 'the rod 2l. In other words the governor 'through the lever 17 and pivot 29 exerts suthcient pressure to compress the spring 26 in the elastic coupling 23 thereby permitting the rod 2l to move in a direction to cause a decrease of the opening of valve 9. From the foregoing it will be seen that the pressure regulator 22 in addition to directly controlling the secondary turbine also performs the function of dividing the load between said turbines. Also that under certain conditions the speed governor assumes control of the secondary turbine to the exclusion ot' the regulator,

In accordance with the provisions o 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 may be carried out by other means.

lVhat I claim as new and desire to secure by Letters latent otl the United' States, is,-

l. In combination, a main turbine, an auxiliary turbine operating on the extraction plan, said turbines being arranged to drive a common load, admission valves for the turbines, a speed governor which successively controls said admission valves, anda regulator responsive to a condition ot' the fluid extracted trom the auxiliary turbine which normally controls its admission valve, and which also modifies the action of thegovernor on the admission valve of the main turbine in such manner as to cause said valve to move in the opposite sense to the valve of the auxiliary turbine.

2. In combination, main and auxiliary turbines both operating on the extraction plan and arranged to drive a common load, admission valves for the turbines, speed governor which normally controls the admission valve oi' the main turbine, a regulator sensitive to the pressure of the Vluid extracted from the auxiliary turbine which normally controls its admission valve, a regulator sensitive to the extraction pressure ot the main turbine, said regulators acting on the speed governor in such manner as to cause it to vary the admission olf fluid to the main turbine between predetermined load variations and to cause it to assume control ot' the admission of tiuid to the auxiliary turbine for loads below said limit.

3. In combination, a main turbine, an auxiliary turbine operating on the extraction plan, said turbines driving a common load, admis. ion valves for the turbines, a regulator responsive to the extraction pressure ot the auxiliary turbine, mechanism controlled by the regulator which includes an elastic coupling for normally actuating the admission valve of the auxiliary turbine, a speed governor which normally controls the operation of the admission valve of the main turbine, and means connecting the governor to said mechanism in such manner that under conditions of decreasing load the governor lirst shuts oil' motive fluid to the main turbine and thereafter acts in opposition to the pressure regulator to decrease the admission of fluid to the auxiliary turbine. Ll. In combination, a main elastic fluid turbine and an auxiliary back pressure turllO bine connected with a common l0ad,.elasticv connection between the pressure regulator and the admission valve of the vauxiliary prime mover, a lever in the connection between the pressure regulator and the admission valve of the main turbine, said lever L being pivotally connected at one end with the rod and having a fulcrum between its ends whereby said valve is moved by the pressure regulator in an opposite sense to that of the auxiliary turbine through the intermediary of said lever, and a `,speed governor operatively connected with vthe fulcrum of said lever.

5. In combination, a main elastic Huid turbine and an auxiliary back pressure tur-1 bine connected with a common load, elastic fluid admission valves for said' turbines, a pressure regulator responsive to the extraction pressure ofthe auxiliaryturbine, a rod operatively connected with theV admission valve of the `auxiliary turbine and with the pressure regulator, an elastic coupling in said rod, a speed governor, a governor lever therefor pivotally connected with the rod at a point between the elastic coupling and the point of connection `with the admission valve of the auxiliary turbine, and means operatively connecting the lever with the admission valve of the main turbine.

6. In4 combination, a main elastic fluid turbine, an auxiliary back pressure turbine, said turbines being connected with a common load, admission` valve mechanisms for said turbines, a speed governor operatively connected with the valve mechanism `of the main turbine to control the same, a pressure responsive device operated by the back pressure of the auxiliary turbine operatively connected with the admission valve thereof to control said valve, means providing anV andV control the a auxiliary turbine under certain operating admission valve of the main turbine, and an elastic coupling means in saidy connection which permits thejs eed governor to move ission valve of the conditions.

7 In combination, a main and an auxiliary elastic fluid turbine, both being of the extraction type and being arranged yto drive a vcommon load, elastic fluid admission valves for the turbines, a pressure regula-V tor responsive to the extraction pressure of the auxiliary turbine operatively connected with the admission Vvalve thereof, a speed..

governor, a governor lever therefor opera.- tively connected with the pressure regulator, an overiiow valve for the main tur. bine, a pressure regulator responsive to the lextraction pressure of the main turbine, a

lever connected therewith, a fulcrum for the lever connected with the governor lever, and means operatively connecting the overflow and admission valves of the Vmain turbine with said lever in spaced relation to and Vo loppositesides of the fulcrum.

S. In combination, a main and an auxiliary elastic fluid turbine, both being of the extraction type and being arranged to drive a commonzload, elastic fluid admission valves for said turbines, a pressure regulator responsivey to the extraction-pressure of the auxiliary turbine operatively connected with the admission valve thereof, an elastic coupling means in said connection adjacent the regulator, a speed governor,"a governor lever thereof operatively connected with the pressure regulator, said connection including the elastic coupling means, an overflow valvefor the main turbine, a pressure regulator responsive to the extraction pressure of the main turbine, a lever connected therewith, a. fulcrum for thelever connected with the governor lever, and means operatively connecting the overflow Y and admission. valves of the main turbine with said leverv in spaced relation to and on opposite sides of said fulcrum. In witness whereof, I have hereunto set my hand this 19th day of October, 1923.

' WALTER 'KIESE-R,