US3441040A - Valve gear locking and emergency closing system - Google Patents

Valve gear locking and emergency closing system Download PDF

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Publication number
US3441040A
US3441040A US617321A US3441040DA US3441040A US 3441040 A US3441040 A US 3441040A US 617321 A US617321 A US 617321A US 3441040D A US3441040D A US 3441040DA US 3441040 A US3441040 A US 3441040A
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US
United States
Prior art keywords
valve
hydraulic
line
fluid
valves
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US617321A
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English (en)
Inventor
Russell A Gray
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Application granted granted Critical
Publication of US3441040A publication Critical patent/US3441040A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
    • F01D21/20—Checking operation of shut-down devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D17/00—Regulating or controlling by varying flow
    • F01D17/10—Final actuators
    • F01D17/12—Final actuators arranged in stator parts
    • F01D17/14—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits
    • F01D17/141—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of shiftable members or valves obturating part of the flow path
    • F01D17/145—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of shiftable members or valves obturating part of the flow path by means of valves, e.g. for steam turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/003—Systems with load-holding valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/31523—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member
    • F15B2211/31529—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member having a single pressure source and a single output member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves

Definitions

  • This invention relates generally to valve operators and, more particularly, to hydraulic valve actuating systems having a dual control to provide for improved reliability.
  • control valves having aprovision for locking the same open and out of service. While out of service, maintenance or other operations may be performed on the valves or on their control systems. While such a control valve or set of valves and their associated controls are rendered inactive in this manner, it is also desirable that the turbine overspeed mechanism still be capable of closing the valves in the event of an emergency overspeed.
  • the present invention provides a means to lock the turbine control valves open so that maintenance may be performed while at the same time a backup hydraulic circuit enables the valves to close as a response to any overspeed condition.
  • valve operator 2 having a piston 3 and piston rod 4 movable therein.
  • Piston rod 4 is operatively connected by mechanical means to the stem of a steam control valve (not shown).
  • valve operator 2 and its associated turbine control valve are but one of a plurality of control valves in a set. In the uppermost position of rod 4, the steam valve is in its fully open position, and at the lowermost position of rod 4, the associated steam valve is closed.
  • a second hydraulic circuit parallel to the first, includes a solenoid-operated four-way valve 22 which also communicates with the source of hydraulic pressure 8 through line 80.
  • Solenoid valve 22 is connected to a drain line 24, a hydraulic pressure line 26 leading to one end of cylinder 2, and a hydraulic pressure line 28 to one side of a dump valve 30.
  • Dump valve 30 in turn communicates with one end of cylinder 2 through hydraulic line 32 and with a drain through line 34.
  • Hydraulic line 26 includes a oneway check valve which permits hydraulic fluid to flow only in the direction toward the cylinder 2.
  • Line 26 also includes a relief valve 42.
  • Dump valve 30 includes a seating member 36 which is biased by a spring 38 in a direction such as to close communication between hydraulic line 32 and drain line 34.
  • Seating member 36 is also effectively a piston which is biased in the closing direction by pressure from line 28.
  • valves 16, 18 and 20 and valves in supply line 8 are open, and system hydraulic pressure is supplied to the servovalve 6 and therethrough to the valve operating cylinder 2.
  • hydraulic fluid is directed through the solenoid operated four-way valve 22 to the dump valve 30, keeping it in a closed position.
  • hydraulic line 26 is vented to the drain 24, with check valve 40 preventing escape of hydraulic fluid through line 26.
  • the valve operating cylinder 2 is controlled by servovalve 6, and hydraulic fluid is prevented from escaping through the secondary or parallel hydraulic circuit by means of check valve 40 and dump valve 30 being kept closed.
  • valves 16 and 18 and check valve 40 as well as dump valve 30 and piston seals on piston 3 are all of the zero leakage type.
  • elements of the primary hydraulic circuit as, for example, the servovalve 6, now being out of service, can be removed for service or adjustment, etc. by appropriate closing of other incidental valves not shown.
  • solenoid valve 22 If, in this locked condition, there is an overspeed of the associated turbine, an overspeed signal to the solenoid valve 22 operates the valve so that hydraulic fluid from source line 8 and line is directed through line 26 and check valve 40 to drive the piston 3 downward to close the steam valves.
  • solenoid valve 22 connects hydraulic line 28 to the drain line 24 so that the seating member 36 in dump valve 30 is permitted to shift, opening the dump valve 30 and draining the hydraulic line 32 through drain line 34.
  • this parallel or secondary hydraulic system functions to close the steam valves when they are in a locked position with reference to the primary hydraulic system.
  • the parallel or secondary hydraulic circuit works in exactly the same way to close the steam valves by means of hydraulic valve operator 2.
  • the flow pattern is slightly different in that, when the overspeed signal trips the solenoid, the pressurized fluid from the solenoid valve 22 and from line 26 forces the piston downward to close the valves, and in addition some of the fluid is forced through line back toward the servovalve which is in a drain position with respect to line 10.
  • the restricted flow through the servovalve 6 from line 10 to drain line 14, because of the orificing within the valve 6, and the relatively larger area of solenoid valve 22, is such that the net result is still a pressure buildup on top of the piston 3 to drive the piston downward to close the steam valves. That is to say, that the drain through servovalve 6 and line 14 is a relatively low volume drain, while the draining through hydraulic line 32 and dump valve 30 is a relatively high volume drain with a resultant net pressure increase on the top side of piston 3 and a decrease on the bottom side of piston 3, with a consequent downward stroke and closing of the valves.
  • a reciprocating fluid motor having a first expansible chamber to provide a first output stroke and a second expansible chamber to provide a second output stroke
  • said fluid motor being operatively connected to a first independent fluid control circuit and a second parallel independent fluid control circuit
  • said first circuit including a servovalve communicating with a source of fluid pressure and with said first expansible chamber controlling fluid flow thereto,
  • said second circuit including a secondary valve communica-ting with said source of fluid pressure and with said first expansible chamber
  • said secondary valve being normally closed between said fluid pressure source and said first expansible chamber, and being responsive to a selected signal to open and permit fluid flow from said fluid pressure source to said first expansible chamber.
  • said signal being responsive to an overspeed condition of said turbine.
  • a valve operating system including a double acting hydraulic cylinder operatively connected to a valve stem
  • said first circuit including a servovalve communicating with said fluid reservoir and with each end of said hydraulic cylinder controlling the same and an isolation valve in each line between said hydraulic cylinder and said servovalve,
  • said second circuit including a four way valve communicating with said fluid reservoir, a check valve and a dump valve, said check valve disposed to permit passage of hydraulic fluid from said four way valve to one end of said hydraulic cylinder,
  • said dump valve disposed to receive fluid flow from the opposite end of said hydraulic cylinder
  • said dump valve further disposed in communication with said four way valve and biased closed by fluid pressure therefore
  • said four way valve being responsive to a signal to shift position venting the biasing pressure to said dump valve and directing pressure through said check valve to said cylinder.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Control Of Turbines (AREA)
US617321A 1967-02-20 1967-02-20 Valve gear locking and emergency closing system Expired - Lifetime US3441040A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US61732167A 1967-02-20 1967-02-20

Publications (1)

Publication Number Publication Date
US3441040A true US3441040A (en) 1969-04-29

Family

ID=24473168

Family Applications (1)

Application Number Title Priority Date Filing Date
US617321A Expired - Lifetime US3441040A (en) 1967-02-20 1967-02-20 Valve gear locking and emergency closing system

Country Status (4)

Country Link
US (1) US3441040A (de)
CH (1) CH471314A (de)
DE (1) DE1601847A1 (de)
GB (1) GB1184503A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4082115A (en) * 1976-08-16 1978-04-04 General Electric Company Valve operator
US4437809A (en) 1981-12-31 1984-03-20 General Electric Company Turning gear interlock
CN108104883A (zh) * 2017-12-13 2018-06-01 中国船舶重工集团公司第七0四研究所 小型液压安保装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2998017A (en) * 1960-03-28 1961-08-29 Gen Electric Emergency governor exerciser
US3342194A (en) * 1965-05-12 1967-09-19 Gen Electric Emergency governor exerciser system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2998017A (en) * 1960-03-28 1961-08-29 Gen Electric Emergency governor exerciser
US3342194A (en) * 1965-05-12 1967-09-19 Gen Electric Emergency governor exerciser system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4082115A (en) * 1976-08-16 1978-04-04 General Electric Company Valve operator
US4437809A (en) 1981-12-31 1984-03-20 General Electric Company Turning gear interlock
CN108104883A (zh) * 2017-12-13 2018-06-01 中国船舶重工集团公司第七0四研究所 小型液压安保装置
CN108104883B (zh) * 2017-12-13 2020-05-05 中国船舶重工集团公司第七0四研究所 小型液压安保装置

Also Published As

Publication number Publication date
CH471314A (de) 1969-04-15
DE1601847A1 (de) 1971-01-21
GB1184503A (en) 1970-03-18

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