Turbine Governing system



Key Points
Ø  Governing- Regulation of Turbine Speed under No Load and Varying Load
Ø  Others Works: CV Actuation/ Initial Run-up & Synchronization/ Load Variation to meet Grid Freq
Ø  500 MW KWU: Throttle Governed Machine
Ø  2 Governors , EHC and HG connected in Parallel: Only One at a time through Hyd Minimum slection
Ø  CVs Open according to Secondary oil Pressure
Ø  Between 100 MW  to 525 MW , Load variation done by HPCV throttling
Hydraulic Governor
Ø  Only one control Loop: Speed controller
Ø  Machine Speed: measured & Indicated by Primary Oil Pressure
Ø  Range of Speed Control : 2800-3210 rpm
Ø  Speed Regulation Range( Droop) of HG= 7%
Ø  HG acts as a Back-up to EHG
Ø  HG Cannot be isolated Mechanically
Ø  HG is the Primary Governor of KWU turbine
Electro-Hydraulic Governor
Ø  EHG has 3 control loops for speed, Load, Pressure
Ø  EHG enhance Turbine life by TSE
Ø  Faster Response and Precise Frequency control
Ø  Actual Speed Measured by Hall Probes
Ø  Range of speed Control : 0-3210 rpm
Ø  Speed Regulation( Droop) can be changed from 2.5% to 8% in step of 0.5% on Load, Usual setting: 5%
Ø  EHG Can be mechanically isolated by closing secondary oil from local
RTS:
Ø  Running condition: De-energized(Drain : closed), Tripping condition: Energized( Drain : Open)
Ø  Running: Control Oil àTo Trip Gear
Ø  Tripped Condition: Control Oil Path Locked & Trip oil from Trip Gear àDrained through Drain Port
Ø  02 in Nos in Series
Turbine Trip Gear
Ø  Main Protection Mechanism | 02 in Nos
Ø  Control OilàRTSàControl OilàTrip Gear spoolà Spool MovementàTrip Oil (from top) & Aux Trip Oil ( From Bottom)
Ø  Aux Trip Oil Keeps Spool in Lifted Position
Ø  Aux Trip Oil is connected to hydraulic Safety Devices: Over-speed, Low Vacuum & Thrust Bearing Trip Devices
SLLD
Ø  Resets Turbine after Tripping
Ø  Opens : SVs and Release CVs for Opening
Ø  AT 0% starting Device:
Bellows compressed ( CVs Closed)
Aux start up Oil Resets Trip Devices
Start up oil Resets SVs ( ESVs & IVs)
Ø  Raising starting Device:
Start-up Oil & aux start-up Oil circuits drained
ESV Opens at 42% and IVs open at 56%
Speeder Gear
Ø  Bellow + Spring
Ø  Bellow compression controlled by
Starting Device Position
Speeder Gear Position ( alerts Spring Tension)
Primary Oil Pressure
Ø  Draining /closing of oil drains happens through Aux FUP connected through link with speeder Gear

Test Valves
Ø  HP/IP SVs receive Trip Oil Through their Test valves
Ø  Port Opening for start-up oil and Trip Oil
Ø  Resets SVs after Turbine Tripping
Ø  Test valve can be operated with Handwheel
Working of Governing system
Control OilàStarting DeviceàAux Start-Up oil àTrip GearàHydraulic Protection Devices
                                                   àStart-Up oil àTrip GearàESVs
                                                                (Speeder Gear linked with Starting Device)
Trip Oil àAux FUP(movement according to SG)àAux secondary Oil à Input to Hydraulic Converter
Control Oil + Aux Sec OilàHydraulic converterà(trip oil àFUPs)àHP/IP Secondary oil to CVs


Comments

  1. Woodmac IndustriesFebruary 23, 2022 at 10:15 PM

    Manufacturer of Hydraulic Cold Press Machine - 50 Ton Hydraulic Cold Press Machine, 100 Ton Hydraulic Plywood Cold Press Machine offered by Woodmac Industries , Amritsar, Gujarat. We are largest Manufacturers and Exporters of Hydraulic cold press and laminate plywood cold press machine at Woodmac, Umaboy, Umiboy Ahmedabad, Gujarat, India.

    ReplyDelete

Post a Comment

Popular posts from this blog

HP & LP Bypass Operation and Protection

Image
HP & LP Bypass Operation and Protection Purpose Boiler operation independent of the turbine Minimum steam flow through SH & RH tubes during start-ups, low load operation & sudden unloading of unit Utilized or building up of steam parameters Avoiding the boiler trip on Reheat protection No steam flow through Boiler steam tubes will lead to starvation & thereby overheating and lead to premature failure of tubes  The capacity of HPLP bypass is 60% of full load turbine steam flow  Reheat Protection: RH protection (delay=10 sec) will act if TURBINE HP V/V & HPBP CLOSED [ either turbine HP stop v/v or HP CV in both HP line closed ] & [ both HP BP <2%]             OR TURBINE IP V/V & LP BP closed [ Either IP stop v/v or IP CV v/v in both IP line closed ] & [ Either LP BP stop v/v or LP BP C/V in both LP line is closed] OR   Generator ckt bkr open & [both HP BP closed OR both L...
Read more

Generator Air Tightness Test

Generator Air Tightness Test Period Of Test= 24 Hrs without a Break Air Pressure Drop (Allowed in 24 Hrs) : <=0.15 ksc Air Test Pressure = 3.5 ksc All LLDs Drain Closed. Ensure Seal Oil system in Operation Seal Oil DP >1.5 ksc AS Seal Oil Pr>4.5 ksc, start H2S Seal Oil system H2 Cooler Isolated PW in Winding is in filled condition, Winding Isolated. PW also kept Isolated. PW Tank at Atmospheric Pressure Ensure availability of  Instrument air and Bleed Out moisture from it by keeping it open till  Connect flexible air hose with the gas plant through the coupling and ensure no air leakage is there  The filling is to be done by opening the valves in the normal H2 filling line where as the valve from H2 rack side will remain closed. Once the air filling is commenced the test record data sheet   The air valve is to be opened full. While pressurising the LLD / Seal oil DP / Seal oil parameters are to be recorded as per the enclosed sheet. The...
Read more