TOPICS BEING COVERED 1. BRIEF INTRODUCTION OF BASIC PRINCIPLES OF STEAM TURBINE 1.1 IMPULSE TURBINE 1.2 REACTION TURBINE 2. MODE OF STEAM ADMISSION 2.1 NOZZLE CONTROL MACHINE 2.2 THROTTLE CONTROL MACHINE 2.3 SLIDING PRESSURE OPERATION MODE 2.4 MODIFIED SLIDING PRESSURE OPERATION MODE 3. ARRANGEMENT OF STEAM/WATER CYCLE 3.1 210 MW 3.2 250 MW3.3500MW4. IMPROVEMENTS IN CYCLE EFFICIENCY 5. SCOPE FOR FURTHER IMPROVEMENTS (O&M PRACTICES)6. IMPROVEMENT IN EXISTING TURBINES

BASIC PRINCIPLES OF STEAM TURBINE

CONVERSION OF HEAT ENERGY INTO KINETIC ENERGYDEPENDS UPON THE DYNAMIC ACTION OF THE STEAMDROP IN PRESSURE OF STEAM THROUGH SOME PASSAGE RESULTING TO INCREASE IN VELOCITYCHANGE IN DIRECTION OF MOTION GIVES RISE TO A CHANGE OF MOMENTUM OR FORCETHIS IS DRIVING FORCE OF THE PRIMEMOVER

IMPULSE TURBINEMaximum steam velocity( Impulse) is created at the inlet of moving bladeWhich means high Kinetic EnergyThis energy is utilised for rotation of moving bladeSteam Velocity can be maximised by having maximum pressure drop in the Nozzles.Hence in 100% Impulse steam Turbine, whole pressure drop will be in stationary blades or nozzlesTo sustain high velocity impulse stage should be very robust in construction.

REACTION TURBINEReaction is created due to action of change of direction of steam through bucket.This thrust or reaction causes the driving forceThis requires whole pressure drop in moving blade100% Impulse or Reaction stage is purely a theoretical assumption not practically feasible

PRACTICAL SCENARIOFOLLOWING COMBINATIONS FEASIBLENOZZLE CONTROL MACHINE WITH FIRST IMPULSE STAGE AS CURTIS WHEEL, REGULATING STAGE & SUBSEQUENT STAGES WITH VARYING DEGREE OF REACTIONTHROTTLE CONTROL MACHINE WITH ALL STAGES HAVING VARYING DEGEE OF REACTION AROUND 50%

MODE OF STEAM ADMISSION NOZZLE CONTROL MACHINE THROTTLE CONTROL MACHINE SLIDING PRESSURE OPERATION MODE MODIFIED SLIDING PRESSURE OPERATION MODE

NOZZLE CONTROL MACHINE

SALIENT FEATURES AREIMPULSE TURBINE WITH DIAPHRAGMS, LINEAR NOZZLE SEGMENTS IN THE PERIPHERYPRESSURE DROP IN THE NOZZLESSEQUENTIAL VALVE OPENINGPARTIAL ARC ADMISSIONLOWER THROTTLING LOSS AT PART LOADSPERFORMANCE NOT VERY POOR AT PART LOAD TURBINES IDEAL FOR PEAK LOAD OPERATION

THROTTLE CONTROL MACHINEFEATURES IN COMPARISON AREIMPULSE TURBINE WITH DIAPHRAGMS, LINEAR NOZZLE SEGMENTS IN THE PERIPHERYPRESSURE DROP IN THE NOZZLESSEQUENTIAL VALVE OPENINGPARTIAL ARC ADMISSIONLOWER THROTTLING LOSS AT PART LOADSPERFORMANCE NOT VERY POOR AT PART LOAD TURBINES IDEAL FOR PEAK LOAD OPERATIONREACTION TURBINE NO NOZZLE SEGMENTSNO PRESSURE DROPSIMULTANEOUS VALVE OPENINGFULL ARC ADMISSIONHIGHER THROTTLING LOSS AT PART LOADSPERFORMANCE POOR AT PART LOAD TURBINES IDEAL FOR BASE LOAD OPERATION

STEAM TURBINE CHARACTERISTIC CURVE

Nozzle Control Machine

Throttle Controlled MachineNOZZLE CONTROL MACHINE

SLIDING PRESSURE OPERATION MODE

IN THROTTLE CONTROL MACHINEADMISSION VALVES FULLY OPEN AT ALL LOADSBOILER PRESSURE TO BE MATCHED WITH FIRST STAGE HENCE STEAM PRESSURE SLIDES WITH RESPECT TO LOADMINIMUM THROTTLING LOSS

SLIDING PRESSURE OPERATIONPROBLEMS NO SPINNING RESERVECANNOT MEET THE GRID DEMAND OF SUDDEN LOAD INCREASECOMPLEX BOILER CONTROLNO LOAD CONTROL ON TURBINE GOVERNINGTURBINE CONTROL INEFFECTIVE

MODIFIED SLIDING PRESSURE OPERATION MODE

SOME THROTTLING RESERVE ( 10 TO 20% ) MAINTAINEDADMISSION VALVES NOT FULLY OPEN BUT SLIGHTLY CLOSEDMAIN CONTROL STILL WITH BOILERCONSTANT THROTTLING LOSS AT ALL THE LOADSPERFORMANCE SLIGHTLY POOR

210 MW LWZ DESIGN200/210 MW KWU DESIGN250 MW KWU DESIGN500 MW KWU DESIGN

CROSS SECTIONAL ARRANGEMENT

CROSS SECTIONAL ARRANGEMENT OF NEW DESIGN OF 210 MWSINGLE FLOW IPT HP TURBINE LP TURBINE

IMPROVEMENT IN TG PERFORMANCE POSSIBLE THROUGH INCREASE IN TURBINE CYLINDER INTERNAL EFFICIENCY ENHANCING TERMINAL PARAMETERS OPTIMISATION OF REGENERATIVE FEEDHEATING CYCLE IMPROVED O & M PRACTICES

IMPROVEMENT IN STEAM TURBINE PERFORMANCEPOSSIBLE BY1. IMPROVED BLADE PROFILE2. OPTIMISED FLOWPATH3. IMPROVEMENT IN SHAFT SEALING SYSTEM4. REDUCTION IN PRESSURE DROPS5. REDUCED FRICTION LOSSES 6. OPTIMISATION OF INLET & EXHAUST SECTION7. OPTIMISED EXHAUST LOSS

WHY TO OPT FOR NEW DESIGN ? MORE EFFICIENT STEAM TURBINE SIGNIFICANT REDUCTION IN POLLUTION ENVIRONMENT FRIENDLY ADVANTAGE OF BETTER HEATRATE FOR THE ENTIRE LIFE TECHNO-ECONOMICAL COST EFFECTIVE & QUICKLY RECOVERABLE COMPACT DESIGN EASE IN ERECTION & OVERHAULING REDUCTION IN OVERHAULING DOWN TIME

MAJOR DEVELOPMENTS IN 210 MW SETSVARIANT A-- T2 PROFILE BLADING-- SMALLER INLET VALVES-- A1 EXTRACTION BEFORE LAST STAGE-- WELL PROVEN & RELIABLEEARLIER SETS ARE OF THIS DESIGN

MAJOR DEVELOPMENTS IN 210 MW SETSVARIANT B-- T4 PROFILE BLADING -- BIGGER SIZED INLET VALVES-- LP HEATER 1 EXTRACTION TAPPED BEFORE PENULTIMATE STAGE OF LPT -- WELL PROVEN & RELIABLE UNCHAHAR TPS, RAICHUR-7, KOTA-6 & PARICHHA PROJECTS

MAJOR DEVELOPMENTS IN 210 MW SETSVARIANT C-- BIGGER STEAM TURBINE MODULES-- SINGLE FLOW IP TURBINE -- T4 PROFILE BLADING-- LP HEATER 1 EXTRACTION STEAM TAPPED BEFORE PENULTIMATE STAGE OF LPT -- WELL PROVEN & RELIABLE-- BETTER HEAT RATE UNDER EXCELLENT OPERATION IN KHAPERKHEDA UNITS 3 & 4 OFFERED IN RAYALASEEMA-II & AMARKANTAK-5

MAJOR DEVELOPMENTS IN 250 MW SETSVARIANT A NOZZLE CONTROLLED SET HP TURBINE WITH REGULATING STAGE PARTIAL ARC ADMISSION SINGLE FLOW IP TURBINE DOUBLE FLOW LP TURBINE NOZZLE CUM THROTTLE GOVERNING UNDER OPERATION IN DAHANU UNIT 1 & 2 EXCELLENT PERFORMANCE PROVEDOFFERED FOR SANTALDIH-5

MAJOR DEVELOPMENTS IN 250 MW SETSVARIANT B THROTTLE CONTROL SET SINGLE FLOW HP & IP TURBINE DOUBLE FLOW LP TURBINE UNDER OPERATION IN KOTHAGUDEM SURATGARH & PANIPAT TPS EXCELLENT PERFORMANCE DEMONSTRATEDOFFERED IN BATHINDA, MEJIA, CHANDRAPURA, RAIGARH

MAJOR DEVELOPMENTS IN 250 MW SETSVARIANT C -- ADVANCED REACTION DESIGN HP TURBINE & IP TURBINE WITH LATEST STATE OF ART BLADING LP TURBINE WITH ADVANCED BLADING SIGNIFICANT HEATRATE IMPROVEMENT MORE ENVIRONMENT FRIENDLYOFFERED IN KORBA EAST

MAJOR DEVELOPMENTS IN 250 MW SETSVARIANT D -- REACTION DESIGN HP & IP TURBINE WITH T4 BLADING LP TURBINE WITH ADVANCED BLADING IMPROVED HEATRATE COST EFFECTIVE VARIANTOFFERED IN NEW PARLI, PARAS & BHILAI

MAJOR DEVELOPMENTS IN 500 MW SETS

VARIANT-A :FIRST DESIGN (4 VALVES) SMALLER HP & IP MODULES OLD SHAFT SEALING ARRANGEMENT T4 BLADING IN HP/IP/LP TURBINE SMALLER VALVES LARGE MARGINS OPERATING AT SINGRAULI, KORBA, RAMAGUNDAM, CHANDRAPUR & FARAKKA

MAJOR DEVELOPMENTS IN 500 MW SETS

VARIANT-B NEW DESIGN (2 VALVES) LARGER HP & IP MODULES MODIFIED SHAFT SEALING ARRANGEMENT T4 BLADING IN HP/IP/LP TURBINE LP TURBINE SAME AS VARIANT-A LARGER VALVES WITH REDUCED PRESSURE DROP OPTIMISED MARGINS OPERATING AT CHANDRAPUR-7 & VINDHYACHAL-II

MAJOR IMPROVEMENTS IN 500 MW SETS

VARIANT-C ADVANCED LP DESIGN HP & IP TURBINE AS IN VARIANT-B ADVANCED BLADING IN LP TURBINE PERFORMANCE PROVENOPERATING AT SIMHADRI, TALCHER-II , RAMAGUNDAM-7, RIHAND-IIOFFERED IN, VINDHYACHAL-III, BIRSINGHPUR-5

MAJOR IMPROVEMENTS IN 500 MW SETS

VARIANT-D ADVANCED DESIGN ADVANCED BLADING IN LP TURBINE LATEST STATE OF ART BLADING IN HP & IP TURBINEOFFERED IN KAHALGAON-II, SIPAT-II & BELLARYALSO OFFERED IN MANGALORE (507.5 MW)

COMBINED CYLINDER CONCEPT COMPACT LAYOUT SUPPORTED ON THREE BEARINGS LOWER MECHANICAL LOSSES FIXED PEDESTAL ARRANGEMENT MINIMIZES CASING DEFORMATIONS BETTER HEATRATE CAN BE OFFERED UPTO 400 MW BEING OFFERED IN NEW 300/350 MW PROJECTS

CROSS SECTIONAL ARRANGEMENT COMPACT HP-IP TURBINE

EFFICIENCY IMPROVEMENTS BY ADVANCED STEAM CONDITIONSUPERCRITICAL PARAMETERS ==>INLET STEAM PARAMETERS MORE THAN CRITICAL STATE STEAM PRESSURE > 221.2 BAR STEAM TEMPERATURE > 374.15 Deg CULTRA SUPERCRITICAL PRESSURE( 300 BAR)INCREASE OF MAIN & REHEAT TEMPERATURESIGNIFICANT IMPROVEMENT IN HEATRATE

800 MW SUPERCRITICAL SETSPARAMETERS:MAIN STEAM: 246 ata/ 565 Deg C, RH: 593 Deg CCYCLE: 8 HEATERS WITH EXT. FROM HP TURBINECONSTRUCTION:-- ADVANCED PROFILE BLADING-- 1 HPT/ 1 IPT/ 2 LPT -- LP HEATERS 1 & 2 INSIDE CONDENSER-- TURBINE & CYCLE DESIGN BEING FIRMED UP

ADVANCED DESIGN BLADES

ACHIEVING OPTIMUM PERFORMANCE DURING OPERATIONTG CYCLE CLOSER TO THE DESIGNRATED TERMINAL PARAMETERS CONTINUOUS EFFORT TO REDUCE SYSTEM LEAKAGEATTENDING VALVE LEAKAGE & PASSINGMINIMIZATION OF FLUCTUATIONSMINIMIZATION OF SUPERHEATER/ REHEATER SPRAYPERIODICAL RECORDING & MONITORING OF TURBINE EFFICIENCY

RETROFITTING & UPGRADATION OF OLDER SETS COST EFFECTIVE MODIFICATIONS IN TURBINE INTERNALS ONLY OUTERCASING, PIPINGS, VALVES, PEDESTAL FIXING ARRANGEMENT , STEAM PARAMETERS & FOUNDATION DETAILS UNALTERED INCREASE IN POWER OUTPUT WITH MINIMUM CHANGES SHORTEST POSSIBLE OUTAGE TIME INCREMENTAL MODIFICATIONS FEASIBLE

RETROFITTING & UPGRADATION OF OLDER SETSPRE-REQUISITEIDENTIFY THE HEALTH OF THE UNITPRESENT LEVEL OF PERFORMANCEREFERENCE PERFORMANCE AUDITRESIDUAL LIFE ASSESSMENT STUDY OF CRITICAL COMPONENTSANALYSIS OF HISTORY & OPERATING DETAILS

RETROFITTING & UPGRADATION OF OLDER SETSMAJOR MODIFICATIONS IN GUIDE & MOVING BLADE (LATEST STATE OF ART PROFILES) STEAM FLOWPATH ROTORS & INNER CASINGS OF TURBINE SHAFT SEALINGSADVANTAGE IN HEATRATE/OUTPUT CAN BE WORKED OUT ON CASE TO CASE BASIS

CONCLUSIONADVANTAGEOUS TO OPT FOR MORE EFFICIENT TURBINEBENEFICIAL & TECHNO-ECONOMIC IN THE LONG RUNECO-FRIENDLY, PROVIDING CLEAN AIR MORE RELIABLEBHEL HARIDWAR IS POISED TO SUPPLY CUSTOMIZED & EFFICIENT STEAM TURBINES / SPARES WITH SHORTEST DELIVERY SCHEDULE & TIMELY TECHNICAL SUPPORT.