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Why does vacuum in steam condenser reduce or drop??

  1-High exhaust temperature: Vacuum drops or maintains at lower side due to high exhaust steam temperature flow into steam condenser. This high exhaust temperature is mainly due to 1-Operation of Turbine at lower loads 2-More clearance in labyrinth seals 3-Not operating exhaust hood sprays 4-More load on condenser 5-Breaking of ejector U loop 2-Low circulating cooling water flow Vacuum in condenser reduces due to inadequate cooling water flow through steam condenser. This is mainly due to; 1-Problems associated with pumps 2-Air pockets in pipe line 3-Leakages in cooling water line 4-Stuck of discharge valve of pump 3-High cooling water temperature at condenser inlet Higher cooling water temperature at condenser inlet results into reduction of vacuum due to poor heat transfer from steam to water 4-Poor heat transfer in condenser Very less or poor heat transfer in steam condenser reduces vacuum to very low level resulting into high exhaust temperature &am
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Why does load hunting occur in steam Turbines??

 If Turbine does not maintain the load as per set load, then this condition is called load hunting.Following are the some potential reasons for load hunting 1-Problems associated with actuators: These are related to leakages in actuators, piston stuck up, oil holes elongation etc. Because of these issues there will interruption or fluctuation of secondary oil flow through actuators, this creates the problems of actuator miss-operation & eventually load hunting. 2-Improper calibration of actuators: This results into mismatch of actuator opening & given set point or valve demand 3-Lower control oil pressure than required: Actuators are designed for specific pressure of control oil, if the control oil pressure at actuator inlet becomes less, then there will be more chances of mal function of actuator. 4-Fluctuation of control oil pressure/flow: Fluctuation of control oil pressure or flow due to malfunction of pump or line PRV may lead to actuator misoperation & h

Why does Boilers main steam temperature increase more than design?

  1-Decrease in Economiser inlet feed water temperature Upon decrease in economiser inlet feed water temperature, fuel consumption in furnace increases & hence main steam temperature increases more than desired. 2-Load on Boilers is more than design Main steam temperature increases if the steam generation is more than actual designed 3-Leakage in super heater (SH) coils If there is any leakages in SH coils, steam flow to SH coil decreases & hence main steam temperature increases. 4-Choking in Super heater coils Choking leads to less steam flow through coils resulting into higher main steam temperature. 5-Passing of start-up vent control valve Passing of start-up control valve loads more on Boiler steam generation, hence main steam temperature increases 6-Passing or pop up of drum safety valves : Lifting of drum safety valves lead to less steam flow to SH coils resulting into higher main steam temperature. 7-High moisture fuel: If the fuel moisture is more

Power plant and calculations

1- Powerplants thumb rules 2- Energy conservation in power plant 3-Calculation of PG cost in power plant 4-Steam condenser & vacuum 5-Boiler feed pumps QnA 6-Turbine practical questions & Answers 7-50-QnA on bearings 8- Power plant equipments efficiency calculations 9-Best practices to reduce power plant Auxiliary power consumption 10-Boiler safety valves QnA 11-QnA on fuel handling /belt conveyors 12-Reasons for machine vibrations 13-Thermal expansion in Boilers 14-30-things you must know about steam Turbines 15-QnA on power plant maintenance 16- 22-Questions & Answers on Boiler troubleshooting 17- HP dosing system capacity calculations 18-WTP thumb rules 19-WTP QnA 20- Power plant equipments safe preservation methods 21- Fundamental about nut bolts 22- QnA on rigging technology 23- Power generation calculations in steam turbine 24-QnA on spent wash Boilers 25-Questions & Answers on air compressors 26-Know about Valves 27- QnA on batteries 28- IBR forms, acts & Reg

Questions & Answers on Boiler feed pumps design , operation & maintenance

    DESIGN DATA FOR BOILER FEED PUMPS   Design data from site: Ø    Type of liquid handled and its maximum & minimum temperatures Ø    Water qualities like pH & Hardness Ø    Water Kinematic Viscosity (cst) Ø    Specific gravity of water at operating temperature Ø    Net positive suction head required (NPSHR)& available (NPSHA) Ø    Boiler capacity & operating pressure Ø    Maximum & operating blow down rate of Boiler Ø    Height of Steam drum Ø    Height of Deaerator (Water inlet source) Ø    Pressure drop in Economiser Ø    No.of valves used in feed water discharge line & corresponding pressure drop as per standard. Ø    Maximum & minimum suction pressure available at pump suction Ø    Type of cooling water & its maximum flow available for bearings cooling   Pump Design Data: Ø    Rated flow (M3/hr) Ø    Rated head (meters) Ø    Nominal speed & Effective speed (RPM) (NS > ES) Ø    NPSHR (meter) Ø    Pump
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