About Lovejoy Controls Corporation

Transcription

1 Turbine Control Systems with Electric and SAFECLOZE Actuators p1 About Lovejoy Controls Corporation LCC is an independent, privately owned manufacturer of turbine controls and instruments located in Waukesha, Wisconsin. Primary LCC products of it's 2 15,000 ft manufacturing facility are modern digital governor systems, steam valve actuator retrofit packages, redundant overspeed trip systems for fossil power, nuclear power, and naval military markets. LCC also provides engineering support and turn key services for a wide range of rotating equipment repair and diagnostic evaluation. LCC has been in continuous business since Contact Info: Address Lovejoy Controls Corporation 1301 Sentry Drive, Waukesha, WI Phone Fax Web sales@lovejoycontrols.com Information Bulletin No.

2 Turbine Control Systems with Electric and SAFECLOZE Actuators p2 Turbine Control System Retrofits with Electric and SafeCloze Actuators Issue July 2007

3 Turbine Control Systems with Electric and SAFECLOZE Actuators p3 INDEX Section Topic Page 1.0 Governor Products Overview Series Series TEG Dedicated Operator Control Stations DCS Interface Control Electric Actuators as Valve Operators Stand Alone Electric Actuator Applications LCC SAFECLOZE Fail Safe Actuators Application Recommendations Governor Recommendations Electric Actuator Recommendations Other LCC Products 25

4 Turbine Control Systems with Electric and SAFECLOZE Actuators p4 1.0 Governor Products Overview NOTE: The use of LCC turbine governors with LCC valve operating systems is not mandated. Units with recent digital governor upgrades can be retrofit with LCC electric or hybrid actuator packages operating from third party systems. LCC desires it's clients to benefit from available technology improvements but does not believe that wholesale equipment changes are always necessary. If you have a recent vintage and successfully operating GE Mark V or VI, ABB P14, Woodward 505, Wood Group, ICS Triplex, InvenSys 310, Alstom Microgovernor or P320, or other solid digital system. LCC can provide a clean adaptation to electric actuator control. LCC manufactures three platforms of steam turbine governors for turbine controls upgrades. The platforms features are overlapping and in many applications two systems will fit with particular options and preferences best guiding the selection. The LCC Series 2 is the most economical solution where the standard capabilities meet the control requirements. The LCC 200 Series is more versatile, employing a modular architecture with fully redundant networked LCCNET Modules, each proven in hundreds of unit operating years to date. 200 Series Governors can control any steam turbine on earth in simplex, duplex, or 2-of-3 redundant configurations. The LCC TEG-5 Series is a compact, integrated digital governor and electric actuator servo drive for nuclear safety related turbine applications such as Auxiliary Feedwater, RICSI, HPSI. All of LCC's governor platforms meet speed loop closure criteria for the most demanding of turbine control applications.

5 Turbine Control Systems with Electric and SAFECLOZE Actuators p5 1.1 Series 2 Series 2 is a very compact, single 19"-rack fit package (10" height) that includes required electronics to operate most small turbines. One complete rack-mount case includes: # Simplex Turbine Governor # Operator Control Station Port # DCS Information/Control Port # Electric/Hybrid Actuator Position Demand Network (ValveNet) # Redundant Power Supplies with Auctioning & Monitoring Series 2 Front Panel View Series 2 Rear Panel View

6 Turbine Control Systems with Electric and SAFECLOZE Actuators p6 Series 2 may operate multiple governor and throttle valve turbines and is compatible with all operator control station and DCS control options. Series 2 may install in an existing plant control cabinet or LCC may provide a floor or wall mount enclosure. Series 2 operates on redundant (2) magnetic speed probes usually located in proximity to an existing turbine speed wheel or turning gear. Series 2 Block Diagram

7 Turbine Control Systems with Electric and SAFECLOZE Actuators p Series The basis of the 200 Series platform is the dual LCCNET communications network which distributes control tasks between independent control and information units termed LCCNET Modules. By selective inclusion of specific LCCNET Modules a system is built to exacting feature requirements with the desired level of redundant backup. 200 Series Photos 200 Series Graphics

8 Turbine Control Systems with Electric and SAFECLOZE Actuators p8 A short list of LCCNET Modules includes: # Governors...! Fossil BFPT Once-Thru Boiler Specific! Fossil BFPT Drum Boiler Specific! Nuclear BWR RFPT Specific! Nuclear PWR SGFPT Specific! Generation Main Unit, Governor Valves Only Specific! Generation Main Unit, Governor & Interceptor Specific! Generation Main Unit, Governor & Extraction Specific # Valve Controllers...! All Electric Actuators! Hybrid Electric Actuators! EHC # Data Interfaces...! Plant Computer! Remote Dispatch (AGC)! Operator Control Station MMI! DCS Links! Analog Signal! Digital Logic... and Many More. Because of the distributed, modular design, LCC's 200-Series may also incorporate additional instrumentation functions of: # Turbine Supervisory Instruments # Torsional Vibration Monitor # Custom Instrumentation Monitoring

9 Turbine Control Systems with Electric and SAFECLOZE Actuators p9 1.3 TEG Electronic Governor, Electric Actuator Solution The LCC TEG-5 provides full turbine control to Tech Spec parameters without the use or need of the troublesome Terry turbine lube oil system. Redundant 115 VAC feeds power the governor/servo drive and remote operator station. The Digital Governor, Servo Drive, Power Supplies, and all communications electronics is packaged in a single stainless steel enclosure Parallel Application The TEG-5 was designed on the same platform as LCC's Steam Generator Feedpump Turbine Governor system for large naval vessels. This production guarantees long term support and renewal parts availability missing in "warm over commercial" qualifications and adds the advantage of military specification testing of EMI/RFI, shock, and vibration far beyond typical governor standards. Sharing the same Bill of Materials and differing only in application firmware, the units have been qualified to: MIL-STD-461 E: MIL-S MIL-S-901D EMI/RFI Source & Susceptibility Vibration, Environmental & Internally Excited Shock Test, High Impact Electric Actuator Direct Valve Stem Drive For PWR Auxiliary FPTs the actuator is mounted on a spool piece which bolts to the governor valve bonnet flange, providing direct valve actuation which eliminates linkages and valve stem side loads. Direct operation results in superb valve positioning and governor control.

10 Turbine Control Systems with Electric and SAFECLOZE Actuators p NOT Vapor Ware... In Current Production Over the years several vendors, including the current Terry Turbine ownership, have advertised systems "in development" or "proposed solutions". The TEG-5 is in current production and available for immediate orders subject to EQ Specification Fail-In-Place Actuator with Manual Drive In the event that all drive power is lost, the actuator retains sufficient back wind resistance to maintain its last operated position. Further, the de-powered actuator may be manually positioned by an external handle or drill driver or wrench Remote Operator Station Replaces HICs A fully digital Remote Operator Station mounts in a 1/4-DIN cut out providing operator command inputs for both operation and surveillance testing. Communications between the station and governor is accomplished via existing analog two-conductor cable with an RS-485 link.

11 Turbine Control Systems with Electric and SAFECLOZE Actuators p Fully Configurable to Plant Operations The existing turbine control methods can be exactly duplicated in the TEG-5, requiring no changes to operating and/or surveillance procedures. The end result is a control system transparent to operators and familiar in control procedures Design and Manufacturing Quality Assurance The full design and manufacturing of the TEG-5 was performed under Lovejoy Controls Corporation's Quality Management System, conforming to 10-CFR 50 Appendix B and successfully passing two audits to NUPIC standards in Complete software controls, component traceability, and defect reporting procedures are in use.

12 Turbine Control Systems with Electric and SAFECLOZE Actuators p Fully Integrated Governor and Servo Drive The TEG-5 single electronics enclosure holds all turbine-local electronics, including both the Digital Governor and the AC Servo Drive which operates the Electric Actuator. The combination of these control elements in a single EMI/RFI contained stainless steel enclosure eliminates costly field packaging of loose electronic components as offered by competitive systems Site Specific Parameters Entry with Laptop PC Specific turbine speed ranges, start up ramp speeds, governor parameters and servo drive parameters may be entered using a laptop PC. Settings are held in nonvolatile memory. Record files are created to maintain setup history.

13 Turbine Control Systems with Electric and SAFECLOZE Actuators p Diagnostic Condition Monitoring Computer Link A Condition Monitoring output serial link is available for connection to a plant instrumentation monitoring computer. Data includes the electric actuator current draw which provides a good tracking indication of valve stem friction and actuator motor health LCC's Extensive Electric Actuator Installation Experience LCC has more steam turbine governor valve control experience with servo controlled electric actuators than any other manufacturer worldwide. LCC has successful retrofits in operation on generation turbines, feedwater pump turbines, and hydro turbine applications.

14 Turbine Control Systems with Electric and SAFECLOZE Actuators p Dedicated Operator Control Stations For many turbine control retrofits, a dedicated operator control station (OCS) is required for either primary operator input or as a backup to DCS control. Usually the available space on bench boards or control room panels is very restricted. For these reasons LCC offers a compact (1/2-DIN size) OCS which requires only a 3 1/2" x 7" panel cut out yet provides full operator control and display features for both the Series 2 and 200 Series systems. Operator Control Station Front View LCC's OCS design features a 4 x 3 switch panel matrix of tactile, back lighted switches combined with an LCD viewing screen for data presentations. LCC also offers color graphics touch screens and LED-based hard panel displays when these MMI styles are preferred.

15 Turbine Control Systems with Electric and SAFECLOZE Actuators p DCS Interface Control With the popularity of distributed control and "soft" control rooms of the Distributed Control System (DCS) it is advantageous to bring as many plant systems within the "loop" as possible. While the DCS offers the benefit of centralized operator interaction and combined systems condition monitoring, the process control loop closure times of most DCS exceed 0.15 second (150 milliseconds) and do not meet the performance standard for turbine speed control. NOTE: The speed loop closure time for the LCC Series 2 and the 200 Series governor platforms is less than 35 milliseconds, as is the value for most dedicated governor systems. Although some DCS are too slow to perform the full governor function, the DCS's workstations can still be used to provide operator control input and data display. A straight forward ModBus RTU serial link between the systems provides the data gateway. LCC supports DCS workstation interfacing by supplying suggested control screen formats and data set protocol. In applications where the DCS meets loop closure criteria, LCC can support software and hardware development to bring the turbine governor control functions into the DCS.

16 Turbine Control Systems with Electric and SAFECLOZE Actuators p Electric Actuators as Valve Operators There are several steam turbine valve types, each with specific actuator performance and emergency shut down (trip) requirements. No single actuator design is acceptable for all steam turbine valve types. Electric Actuators use direct drive AC motors operating roller screw assemblies to produce linear motion. By "direct drive" we mean that each incremental rotation of the motor results in a corresponding motion of the shaft at a ratio established by the roller screw lead or pitch. The direct drive action enables unprecedented control accuracy and solves the most difficult of valve positioning tasks. Electric Actuator Direct Drive Roller Screw While the direct drive contributes greatly to control response, precision, and repeatability it also presents a dilemma when applied to valve positioning requiring rapid fail-safe closure (trip) action. By definition the Fail-Safe Condition of a direct drive electric actuator is the elimination of all power feed. By design specification of return spring force and actuator screw thread the actuator can be designed to slowly open, retain position, or slowly close upon power feed loss. By itself, however, the actuator cannot provide a rapid fail safe closing action. LCC's SAFECLOZE actuator designs add fail safe closure capability to electric actuator control.

17 Turbine Control Systems with Electric and SAFECLOZE Actuators p Stand Alone Electric Actuator Applications For many turbine valve control applications the valve operator need not have a rapid fail safe closing (trip) action. For these, the valve positioning system can be managed by a stand-alone electric actuator. These applications include both fulcrum operated single and multiple valves and individual steam line governor valves. The following figures illustrate stand-alone electric actuator use where a fail safe trip capability is not needed. Electric actuator operating a nuclear Main Feedwater Pump Turbine governor rack.

18 Turbine Control Systems with Electric and SAFECLOZE Actuators p18 Electric actuator operating a generation turbine governor valve rack.

19 Turbine Control Systems with Electric and SAFECLOZE Actuators p LCC SAFECLOZE Fail Safe Actuators For valves requiring trip action LCC's (Patent Pending) SAFECLOZE actuator system adds high speed fail-safe controlled valve closure in the form of an hydraulic position-latching cylinder physically mounted in series with the electric actuator and having slightly greater stroke capability. The SAFECLOZE valve actuator position is enabled by a self-contained hydraulics reset cylinder which places the electric actuator in steam valve control position. If this pressure is removed, as occurs in a trip event, the electric actuator is re-located to a steam valve closed position independent of the immediate roller screw action or relative stroke retraction. For reset of a tripped SAFECLOZE valve the electric actuator is first automatically fully extended (valve closed direction), then the hydraulic cylinder is retracted to the reset position, with the reset pressure maintaining the full cylinder retraction. The steam valve can then be operated by the electric actuator position servo over the entire valve stroke range, yet be ready to immediately trip to the closed position if necessary without electric actuator interaction. The small self-contained hydraulics consists of a motor operated gear pump which pressurizes the reset cylinder when the trip solenoid valves are seated in the reset position. Check valves maintain the reset cylinder pressure resulting in very low SAFECLOZE motor/pump operating duty and very long service life. Two typical LCC SAFECLOZE actuator applications are bonnet flange mounted individual valve actuation and fulcrum lift bar rack actuation. Each application is illustrated in the following figures.

20 Turbine Control Systems with Electric and SAFECLOZE Actuators p20 SAFECLOZE operating single valve internal view

21 Turbine Control Systems with Electric and SAFECLOZE Actuators p21 SAFECLOZE operating fulcrum lift rack, internal detail view.

22 Turbine Control Systems with Electric and SAFECLOZE Actuators p Application Recommendations 3.1 Governor Recommendations APPLICATION DCS GOVERNOR CODE DESIGN DIGITAL GOVERNOR ADAPTATION LCC 200-SERIES GOVERNOR LCC SERIES-2 GOVERNOR LCC TEG-5 GOVERNOR STEAM TURBINES GENERATION < 5 CONTROL VALVES YES YES USA, CANADA USA, CANADA, EUROPE NO GENERATION, >4 CONTROL VALVES YES YES USA, CANADA NO NO MAIN FEED PUMP TURBINE DRIVE YES YES USA, CANADA USA, CANADA, EUROPE NO AUXILIARY FEEDPUMP TURBINE DRIVE NO NO NO NO YES RICSI NO NO NO NO YES HPSI NO NO NO NO YES HYDRO TURBINES WICKET GATE YES YES NO YES NO KAPLAN YES YES NO YES NO

23 Turbine Control Systems with Electric and SAFECLOZE Actuators p Electric Valve Actuator Recommendations The valve application table provides LCC's recommendations for retrofit actuator types for the most common steam turbine valve applications. For special applications contact LCC. Turbine Type Valve Type Fail Safe? Closing Test? Modulation Recommend Fossil and Nuclear Main Feed Pump Drive Turbine Small Generation Turbine Stop Yes Yes No Hydraulic Cylinder with Valve Test Control Governor No No Yes Stand-Alone Electric Actuator Throttle Yes Yes Yes SAFECLOZE with Valve Test Governor No No Yes Stand-Alone Electric Actuator Mid Size Generation Turbine Stop Yes Yes No Hydraulic Cylinder with Valve Test Control Throttle Yes Yes Yes SAFECLOZE with Valve Test Governor No No Yes Stand-Alone Electric Actuator Extraction Yes No Yes SAFECLOZE

24 Turbine Control Systems with Electric and SAFECLOZE Actuators p24 Turbine Type Valve Type Fail Safe? Closing Test? Modulation Recommend Large Generation Main Stop Yes Yes No Hydraulic Cylinder with Valve Test Reheat Stop Yes Yes No Hydraulic Cylinder with Valve Test Governor Yes No Yes SAFECLOZE Interceptor Yes No Yes SAFECLOZE Extraction Yes No Yes SAFECLOZE

25 Turbine Control Systems with Electric and SAFECLOZE Actuators p Other LCC Products LCC also manufactures and offers for sale: # Full Turbine Supervisory Instruments, including:? Tuned Vibration Monitors (solve proximity probe problems)? Thrust Position Monitors? Sensor Alarm Monitors (RTD, thermocouple, analog)? Condenser Humidity Monitors? Torsional Vibration Monitors? Stress Corrosion Monitors # Small and Micro Hydro Turbine Control:? Governors? Synchroscopes? Reverse Power Protection # Naval and Marine:? Turbine Governors? Valve Control Systems