US2277487A - Noncondensing turbine regulating system - Google Patents

Description

March 24, 1942. w LHA N 7 2,277,487

NONCONDENSING TURBINE REGULATING SYSTEM Filed Feb. 10, 1939 2 Sheets-Sheet 1 Drive/1 fmm W turb/nem turbine /2 Inventor: Werner- Guilhauman,

March 24., 1942. W -GU|LHAUMANI $277,487

' NONCONDENSING TURBINE REGULATING SYSTEM Filed Feb. 10, 1939 2 -She ets-Sheet 2 Inventor- Wer-ner', Guilhauman,

Attprney;

- turbances in Patented Mar. 24, 1942 NONCONDENSING T ration of New York URBINE REGULATING YS TEM Werner Guilha'uman, Berlin-Steglitz, Germany,

assignor to General Electric Company, a corpo- Application February 10, 1939, Serial No. 255,742 In Germany February 14, 1938 7 Claims.

. This invention relates to regulating systems for a plurality of non-condensing or back pressure turbines arranged in parallel relationship. Although the invention is not necessarily limited thereto, it is particularly adaptable for use with parallel operating back pressure turbines each having one or more non-regulated extraction stages, the corresponding extraction stages of the various turbines being also connected in parallel.

In certain instances it is desirable to arrange a plurality of non-condensing or back pressure turbines in parallel as regards the flow of elastic fluid therethrough, the generators driven by such turbines being also connected in parallel to common buses. The turbines may be provided with one or more non-regulated intermediate extraction stages, the corresponding stages of the turbines being connected to common conduits for supplying elastic fluid for various industrial uses at a pressure higher than that of the turbine exhaust. The elastic fluid supply to each of the turbines is generally controlled by back pressure regulators responsive to variations in the demand for turbine exhaust fluid. With the usual regulator arrangements, difficulties are experienced in maintaining an even regulation of the turbines due to slight variations in the spring characteristics of the pressure responsive devices, whereby the admission valves of the respective machines are adjusted unequally. With the resulting unbalance of the elastic fluid supply to the different turbines, circulation of elastic fluid may take place from the extraction stage of one turbine through the common connection and into the corresponding extraction stage of another turbine. Such circulation of elastic fluid between the extraction stages of two turbines tends further to disrupt the balance of the elastic fluid exhausted by the various turbines. This results in an undesirable oscillatory regulation of the operating mechanism and causes serious disthe output of the generators.

It is an object of this invention to provide a new and improved regulating system for a plurality of non-condensing extraction turbines connected in parallel.

In accordance with one form of my invention, the admission valve of one of a plurality of parallel operating non-condensing extraction tur bines is regulated in accordance with the back pressure fluctuations, the admission valves of the other turbines being simultaneously and correspondingly adjusted as regards that of the first turbine by automatic means responsive to movements of the admission valve of the first turbine.

In accordance with a further modification of the invention, the admission valveslof parallel operating non-condensing extraction turbines are simultaneously and correspondingly adjusted in response to variations of the back pressure of the turbines by means including an electrical motion transmitting and receiving system interconnecting the operating mechanism of the admission valves.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto taken in connection with the accompanying drawings.

In the drawings, Fig. l is a diagrammatic view of a power plant of the typereferred to illustrating a regulating system according to one modification of the invention, and Figs. 2 and 3 are views illustrating two further modifications of the invention.

Referring to Fig. 1 of the drawings, represent similar non-condensing extraction turbines receiving operating fluid from a suitable source of supply through the connections l3 and i4 and the admission controlling valves l5 and it, respectively. The turbines are adapted to exhaust through connections I! and I8 into a common conduit it which supplies elastic fluid to suitable industrial apparatus, such as a heating system (not shown). The turbines are further provided with a plurality of intermediate extraction stages from which elastic fluid at similar intermediate pressures may be supplied for other industrial purposes, the extraction connections '28 and 2! supplying elastic fluid to the common conduit 22 and the extraction connections 23 and 24 supplying elastic fluid to the common conduit 25. The turbines H! and I 2 are coupled to the generators 26 and 21, respectively, which are adapted to supply electric power to a common bus 21a.

The turbine i0 is provided with a speed governor 3B which in any well-known manner is adapted to effect the closing of the admission valve 15 upon the occurrence of a predetermined excess speed condition. As illustrated diagrammatically in the drawing, the governor 30 is connected by the link 31 to the fulcrumed lever 32, the other end of which lever is linked with the left end of the floating lever 33. A point intermediate the ends of the lever 33 is connected by link 3 with the floating lever 35 connecting the stems of the pilot valve 36 and the hydraulic valve operating motor 31. The turbine I2 is prom and l2v vided similarly with a speed governor 38 which is adapted to effect the closing of the admission valve I6 through the pilot valve 39 and the hydraulic valve operating motor 40 upon the occurrence of a predetermined excess speed condition of that machine.

In accordance with my invention, the admission valves I and lb of the non-condensing turbines are simultaneously and correspondingly regulated in accordance with any predetermined variable operating condition of the power plant such as the condition of the elastic fluid pressure in the exhaust conduit l9. As indicated in the drawings, a suitable pressure responsive device 4| communicating by means of the connection 42 with the conduit I9 is adapted to control the energizing circuit of the reversible valve regulating motor 43. The pressure responsive device 4| is arranged for actuating a pivoted contact making arm 44 which in one position engages With an adjacent contact 45 for completing an electrical circuit extending from the positive side 46 of a suitable direct current source of supply (not shown) to the Winding 41, through the armature of the motor 43 and to the negative side 48 of the source of supply. In the other position, the arm 44 engages with the contact 49 completing the circuit for the reversing winding 5|] of the motor 43. A cam disk 5| driven by the motor 43 is adapted to be engaged by the roller 52 provided on the right end of the floating lever 53 of the turbine valve operating mechanism, the roller 52 being held against the cam 5| by means of a suitably arranged spring 54. Movement of the cam disk 5|, in response to the energization of the motor 43, is transmitted to a similar cam disk 55 associated with the operating mechanism of the admission valve |5 of turbine II]. For this purpose, an electrical motion transmitting device 55, of a well-known form, is coupled to the motor 43 and adapted to be driven thereby, the impulses from the device 55 being transmitted through connections 51 to the receiving device 58 which is arranged for driving the cam disk 55. The cam disk 55 is engaged by the roller 59 provided on the right end of the floating lever 33 of the turbine valve operating mechanism, the roller 59 being held against the cam 55 by means of a suitably arranged spring 60. Suitable alternating current excitation is supplied to the devices 53 and 58 through the connections BI and 52, respectively. While in the drawings I have indicated the motor 43, the device 56 and the cam 5| as being mounted upon a common shaft, it is obvious that any suitable speed reduction gearing may be provided between the various elements as may be necessary. A connection similar to that used between the device 56 and the cam 5| may be used between the device 58 and the cam 55 so that movements of the cam 5| will be accompanied by substantially identical and corresponding movements of the cam 55.

In the operation of the system described a decrease in elastic fluid pressure in the conduit l9 results in the collapse of the pressure responsive device 4| moving the arm 44 into contacting relationship with the contact 45 thereby effecting the energization of the winding 41 of the motor 43. The motor 43 will rotate the cam disk 5| lowering the right end of the lever 53 and through the pilot valve 39 and motor 49 effect an opening movement of the valve It. Through the operation of the devices 56 and 53, the cam disk 55 will be moved simultaneously with disk 5| and by a like amount so that the admission valves of the two turbines will open to increase uniformly the supply of elastic fluid to the two turbines thereby building up the pressure within the conduit |9 to the desired value. Upon this condition obtain ing, the pressure responsive device 4| will be expanded breaking the circuit of the motor 43 and arresting further opening movement of the turbine admission valves. Conversely, assuming a decrease in the demand for elastic fluid from the conduit l9 causing the pressure therein to increase, the pressure responsive device 4| Will act to close an energizing circuit for the reversing winding 50 of the motor 43 thereby driving the cam disks 5| and 55 in the reverse direction causing a corresponding closing movement of the turbine admission valves I5 and I6. Upon the recurrence of the predetermined normal condition of pressure in the conduit IS, the motor 43 will be deenergized and further movement of the turbine admission valves arrested.

In this manner, the supply of operating fluid to the various turbines may be so controlled that with fluctuations in the demand connected to the conduit l9, the demand will be met equally by the exhaust from the various turbines. The pressure of the corresponding extraction stages will also be maintained equal so that no circulation from one turbine to the other will take place through the extraction connections. An equal distribution of load will therefore also be maintained between the generators driven by the turbines.

While I have shown and described the regulating system in connection with a power plant installation comprising two turbines, it is obvious that it is equally applicable for use in connection with any greater number of turbines since the electrical motion transmitter 55 may be coupled for driving additional follow-up devices associated with such other turbines.

In Fig. 2 of the drawings, I have illustrated a second modification of the invention in which similar elements are given the same reference characters as are used in connection with Fig. 1. In this modification, the admission valve 6 of the turbine I2 is regulated in accordance with the variations of pressure obtaining within the common exhaust conduit l9 by means of a back pressure regulator indicated at 65. This regulator may be of any well-known form and is illustrated diagrammatically as comprising a casing 66 having a flexible diaphragm 61 arranged therein. The chamber above the diaphragm is in communication with the conduit l9 by means of the connection 68 while movements of the diaphragm in response to pressure variations are transmitted by the stem 69 through the fulcrumed lever 10 and link 1| to the left end of the floating lever 12. The stem 69 is biased in the upward direction by a suitably arranged spring 13. The operating mechanism for the admission valve l5 of the turbine I 0 includes a cam disk 14 adapted to be engaged by the roller 15 of the floating lever 16, the roller 15 being maintained in engagement with the cam 14 by means of a suitably arranged spring 11. The cam disk 14 is adapted to be driven by a reversible motor 18 in accordance with a difierential indication of the relative conditions of adjustment of the admission valves 5 and IS. The motor 18 is provided with oppositely wound field windings 19 and which are connected in parallel and continuously energized from the source of direct current indicated by the connections'9I and 82. The winding I9 has a variable resistance 83 connected in series therewith, the sliding contact arm 84 being adapted for adjustment by the valve stem I8 through a loose connection 85 therewith. A variable resistance 86 in series with the motor winding. 80 is provided with a sliding contact arm 01 which is adapted to be adjusted by the valve stem I5 through the loose connection 88 therewith.

The operation of this modification of the invention may be described as follows. Assume first, that the system is in equilibrium and that the pressure obtaining within the common exhaust conduit I 9 is at the normal value. During such condition, the motor I8 is stationary due to the fact that the oppositely wound field windings I9 and 80 are substantially equally energized since equal portions of the variable resistances 83 and 85 are inserted in the series circuits of each winding. Now assume that the demand for elastic fluid from the common exhaust conduit I9 has increased causing a decrease in the pressure therein which results in a corresponding upward movement of the diaphragm 01 of the pressure regulator 65. By the upward movement of the stem 69 under the force of the biasing spring I3, the floating lever I2 will be given a rotational movement in the counterclockwise direction. Through the operation of the pilot valve 99 and the hydraulic motor 49, which is well understood, the admission valve IE will be moved to a predetermined open position. The sliding arm 84 will be shifted so as to insert a greater portion of the resistance 83 in series with the field winding I9 thereby increasing the relative energization of the winding 89. The motor I8 will thereby be rotated in a corresponding direction driving the cam disk I I in such a manner as to shift the floating lever I6 in a clockwise direction which in turn causes, through the pilot valve 36 and the hydraulic motor 31, an opening movement of the admission valve I5. It will be noted that the opening movement of the admission valve I5 is accompanied by a clockwise rotation of the sliding arm 81 correspondingly increasing the portion of the resistance in the series circuit of the winding 89. It is obvious that the motor I will continue to operate and accordingly effect the opening of the admission valve I only until the valve I5 is positioned substantially identically as compared with the admission valve I9 of the turbine I2 as indicated by'the balancing of the resistances 86 and 83 and accordingly the energization of the windings 99 and I9, re-

spectively.

In Fig. 3 is illustrated a third modification of the invention in which similar elements are given the same reference characters as are used in connection with Figs. 1 and 2. In this modification, the admission valve l9 of the turbine I2 is regulated in accordance with the variations of pressure obtaining within the common exhaust conduit I9 by means of a pressure responsive device similar to that shown in Fig. 1. As indicated in the drawings, a suitable pressure responsive device 99 communicating with the conduit I9 by means of the connection 9| is adapted to control the energizating circuit of the reversible pilot valve adjusting motor 92. The pressure responsive device 99 is arranged for actuating a pivoted contact making arm 93 which in one position engages with an adjacent contact 94 for completing an electrical circuit extending from the positive side 95 of a suitable direct current source of supply to the motor field winding 96, the connection 91, the armature of the motor 92 to the negative side 99 of the source of supply. In the other position of adjustment, the arm 93 engages with the contact 99 to complete the circuit for the reversing winding I00 of the motor 92. The motor 92 is arranged for adjusting, through suitable gearing I 0|, the compound pilot valve I93. The pilot valve I03 is of a well-known form comprising an outer casing I04 having a suitably ported cylindrical sleeve or bushing I05 slidably arranged therein. A stem I06 is provided with a pair of spaced apart valve heads which are slidably arranged within the sleeve I05. The pilot valve is adapted to control the passage of operating fluid to and from the turbine admission valve operating motor I91 in a well-known manner either by adjustment of the pilot valve heads on the stem I by the speed governor 38 or by actuation of the sleeve I through the gearing I9I by the motor 92. The admission valve I5 of the elastic fluid turbine I9 is adapted to be regulated by means of the pilot valve I08, similar to pilot valve I93, and a hydraulic motor I09. Means are provided for insuring simultaneous and corresponding adjustment of the admission valve I5 with respect to valve I6 upon the energization of the motor 92. For this purpose there is provided an electrical motion transmitting device H9 which is driven by the motor 92 and connected by the leads III to the electrical motion receiving device II2, the latter device being arranged for adjusting the sleeve of the pilot valve I 98 through suitable gearing I I3. The devices H0 and H2 may be. energized from a suitable source of alternating current through the connections IM and H5, respectively.

The operation of this modification of the invention may be described as follows. Assume first that the turbines are operating in a condition of equilibrium each supplying its proper portion of exhaust fluid to the common conduit I9. Upon an increase in the demand for elastic fluid, the pressure within the conduit I9 will decrease causing the collapse cf the pressure responsive device 99. The contact making arm 93 will be moved into engagement with the contact 99 thereby completing the energization circuit for the motor winding 99. The motor 92 will thereupon be driven in a corresponding direction and through gearing IIBI effecting an upward movement of the pilot valve sleeve I95 and a consequent opening movement of the admission valve I9 of the turbine IE. Motion of the motor 92 will be transmitted through the devices H0 and H2, the gearing I It to the pilot valve I98 effecting a corresponding opening movement of the admission valve I5 of turbine I0. Upon the establishment of normal pressure within the common conduit I9, the motor 92 will be deenergized arresting further movement of the admission valves I5 and I5. Conversely, upon a predetermined abnormal increase of pressure in the common conduit I9 the direction of the motor 92 will be reversed effecting a corresponding closing movement of the turbine admission valves I5 and I9 to decrease somewhat the supply of elastic fluid to the exhaust conduit.

Having described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiments thereof, I desire to have it understood that the apparatus shown is only illustrative and that invention may be carried out by other means.

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

1. A pair of elastic fluid non-condensing turbines, each of said turbines having a non-regulated extraction connection for supplying elastic fluid at substantially equal pressures to a common conduit, admission valves for said turbines, means including pilot valves for adjusting said admission valves, reversible motor means geared to the pilot valve of the first of said turbines and a pressure responsive device associated with the motor means for regulating the admission valve of the first turbine in response to variations in the back pressure of said turbine, an electrical motion transmitting device coupled to said motor means, and means including an impulse receiving device connected to said transmitting device and geared to the pilot valve of the second of said turbines for controlling the admission valve of the second turbine to maintain substantially constant the ratio of elastic fluid admitted to said second turbine and to said first turbine.

2. In combination, a plurality of non-condensing turbines, admission valves for controlling the supply of elastic fluid to each of said turbines, a common conduit for receiving the exhaust from said turbines, cam means for adjusting the admission valves of said turbines, a reversible motor for actuating the cam means associated with the admission valve of one of said turbines, means for controlling said motor in response to variations in elastic fluid pressure in said exhaust conduit, an electrical motion transmitting device driven by said motor, an electrical motion receiving device for driving the cam means associated with each of the other turbine admission valves for effecting simultaneous and corresponding adjustments of said other admission valves.

3. A plurality of elastic fluid non-condensing turbines, each of said turbines having a plurality of non-regulated extraction stages, the corresponding extraction stages of the plurality of turbines being connected in parallel, admission valves for controlling the supply of elastic fluid to each of said turbines, a common conduit for receiving the exhaust from said turbines, means responsive to predetermined variations in pressure in said common conduit for effecting the adjustment of the admission valve of one of said turbines, and means automatically operable in response to the adjustment of said one turbine admission valve for simultaneously and correspondingly adjusting the admission valves of the remainder of said plurality of turbines.

4. The combination of a plurality of non-condensing turbines, an exhaust conduit connecting the exhaust ends of the turbines in parallel, an extraction conduit connected to an intermediate stage of each turbine, each turbine having an admission valve and a governing mechanism for the valve, means for actuating the mechanism of a first turbine in response to variations of an operating condition of such turbine, and means for automatically adjusting the valves of the other turbines upon adjustment of the valve of the first turbine in order to maintain uniform flow through the extraction stages and thereby to prevent backflow of fluid from one extraction stage to another.

5. The combination of a plurality of non-condensing turbines, an exhaust conduit connecting the exhaust ends of the turbines in parallel, an extraction conduit connected to a high pressure intermediate stage of each turbine, another extraction conduit connected to a low pressure intermediate stage of each turbine, each turbine having an admission valve and a mechanism including a speed governor for controlling the valve, means including a pressure-responsive device connected to the exhaust conduit for controlling the Valve of a first turbine, and electrical motio-ntransmitting means between the regulating mechanisms to effect uniform load distribu tion among the turbines and thereby to prevent backflow of fluid from one of the extraction conduits to one of the intermediate stages.

6. The combination of elastic fluid turbines having exhaust conduits connected in parallel and intermediate extraction conduits connected in parallel, a valve for each turbine, and a load distributing system for controlling the valves to prevent backflow of fluid from the extraction conduit to an intermediate stage, said system comprising a governing mechanism for each turbine, means including a reversible motor and a pressure-responsive device connected to the exhaust conduit for adjusting the governing mechanism of one turbine and electrical motion-transmitting means between the governing mechanism of the different turbines to effect uniform setting of all mechanisms in response to movement of one mechanism.

7. A governing system for controlling a plurality of turbines and for uniformly distributing load changes among them comprising a plurality of separate speed governing mechanisms each including a hydraulic motor for moving a turbine valve, a pilot valve with a valve head and a bushing for controlling the motor and a speed governor for controlling the pilot valve head, a gearing for moving the bushing, electric motor means interconnecting the gearings to effect movement of one gearing in response to movement of the other, a reversible motor for moving one of the gearings, and a pressure responsive device for connection to one of such turbines for controlling the reversible motor.

WERNER GUILHAUMAN.

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