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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

Steam turbine practical questions & answers for Turbine engineers & operators

STEAM TURBINE QUESTIONS AND ANSWERS FOR TURBINE ENGINEERS & OPERATORS 1-Why do the U loop is provided at the inter condenser drain line of ejector? U loop is to seal the ejector & steam condenser pressure as there is very less pressure difference around 0.25 to 0.3   kg/cm2. So for such low pressure difference U loop seal is economic & practical 2-Why do the float valve are provided at the after condenser of ejector condensate line? Know about vacuum troubleshooting in steam Turbines Float valve is used to seal the ejector & steam condenser pressure as there will be around 0.89 to 0.95 kg/cm2 pressure difference. For such high pressure difference float valve is most practical arrangement. 3-Generally, where the pressure relief valves are fitted at ejector systems?                              There two pressure relief valve in SJAE (Steam jet air ejector) one is fitted at ejector nozzle chamber & other is fitted at condens

Boiler feed pumps (BFP) questions & answers for interview

Boiler feed pumps (BFP) questions & answers for interview: 1-What is the function of Boiler feed pumps (BFP) in power plant? Functions: To supply the feed water to boilers To conduct the Boiler hydraulic tests To supply the desuperheating & attemperator water required for process steam lines & boilers respectively TOP-6 BEST POWER PLANT O&M BOOKS Boiler calculations for Boiler operation engineer (BOE) exam Viva Questions & answers for preparation of BOE exam & interview  2- What are the type of prime movers (drives) used for BFPs? Prime movers: LT drive (415 V) HT drive (11 KV) Turbo drive (Steam driven) 3-What are the auxiliaries associated with BFP? BFP auxiliaries Cooling water pump & lines Lube oil system ARC valve Mechanical seal flushing system Balance leak off line & its PRV 4-What are the various pipe lines connected to BFP? Questions & Answers on AFBC Boilers Suction pipe line D

25 most frequently asked viva questions & answers on Boiler safety valves

Boiler safety valves question & answers: 1-Which type of safety valves are used in modern high pressure Boilers? Open yoke, spring loaded, Semi Nozzle & full lift type 2-What is the over pressure range for safety valves? It is around 6 to 7% of operating pressure of particular line/vessel 3-What is the recommended % of blow down for Boiler safety valves? It is around 2 to 3% 4-How do you calculate safety valves blow down? Blow down = SV (Set pressure – Reseat pressure) X 100 / Set pressure 5-What is the MOC of safety valve disc & spindle? Disc: Stain less steel with 13% chromium & Spindle: SS 316 6-What happens if drum safety valve set at lower pressure than super heater safety valves? Upon blowing of drum safety valve first, all the steam formed will blows out through the drum safety valves causing less or no steam flow to the super heater coils. This situation will lead to the failure of super heater coils. 7-When should be gags for safety v
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