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Showing posts from July, 2021

TURBINE TRIP PROTECTIONS

 There are the following turbine trip protections are given:-   Emergency push button trip from desk & operator work station (OWS) Channel-1 Channel-2 Channel-3 Fire Protection (Channel-1 & Channel -2) from control desk & OWS Channel-1,Channel-2 & Channel-3. & MBLD 1 & 2 (from MOT room & TG floor) Condenser vacuum low trip 2/3 (2 out of 3 logic). Lubricating Oil pressure very low 2/3 (2 out of 3 logic). HP exhaust steam temperature. Very high 2/3 (2 out of 3 logic).        Axial shift Very high 2/3 (2 out of 3 logic). HP Casing top bottom differential Temperature Very high (2 out of 2 logic) & load greater than 20% of rated load IP casing Front & Rear Top-bottom differential Temperature Very high (2 out of 2 logic) & load greater than 20% of rated load. Cold gas temperature after H 2 cooler high (2 out of 3 logic). Seal oil temperature after cooler high (2 out of 3 logic).   Liquid level in main leads high (2 out of 3 logic). Hot air temperatu

BOILER FEED PUMP OPERATING INSTRUCTION

PREPARATION FOR STARTING Check the Deaerator is filled to normal working level. Check that the control air and electrical supply are available for the instrumentation, leak-off equipment and valve. Check that the recirculation valve and isolating valve are open. Check that all the instrumentation tapping points and isolating valve are open and that all drains equalizing valves are shut. Open feed pump drive end and non-drive end mechanical seal cooler circulation water inlet and outlet isolating valve. Check that the pump set discharge isolating valve is open. Crack open the pump set suction isolating valve. Open the booster stage air vent valve and vent any trapped air or gases from the pump casing. Shut the booster pump air vent valve when water issues freely from it. Note the interconnecting pipework and the boiler feed pump discharge pipework should also be primed and vented. Vent the feed pump mechanical and the cooler Fully open the pump set suction valve. Ensure that the clarifi

NATURAL DRAFT HYPERBOLIC COOLING TOWER IN THERMAL POWER PLANT

Typical power-plant cycles which incorporate the natural-draft hyperbolic cooling tower are shown in the schematics. FIGURE  Introduction:- Note that only 40% of heat-energy input is converted to power in the fossil-fuel plant , while 45% is discharged to condenser cooling water ; the remaining 15% is lost up the stack & in the ash . A nuclear plant is even less efficient , converting only about 33% of its heat energy input into power , with 62% discharged to cooling water & 5% lost. Remember, nonetheless, that heat discharges from electric power plants are among the lowest of all energy-conversion processes.   A natural draft hyperbolic cooling tower are evaporative in design , they contain no fans. Working principle:- Flow of air through shell is created by the density difference between atmospheric air and that inside the tower which has been warmed by the hot water from plant condensers. As with the mechanical-draft-type, two basic airflow schemes in relation

CONDENSATE EXTRACTION PUMP (CEP) IN A THERMAL POWER PLANT

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CONDENSATE EXTRACTION PUMP (CEP) Its Importance in Thermal Power Plant It handles water from hot well. The characteristic of that pump is that it handles water from vacuum.  Berceuse the condenser and the hot well are in vacuum bellow atmospheric pressure. No other pump has this characteristic to handle in such condition. It takes water from vacuum pressure and delivered above atmospheric pressure.   It is a vertical turbine type pump which is multi stage. It deliver water from hot well to deaerator. They may be used to pump the condensate produced from latent water vapors in any of the following mixtures: Steam condensed (exhaust from LP turbine) in condenser Make up water (dumped in condenser hot well from condensate storage tank) Flash box water LPDFT water HPDFT water Drip from ejector Drip from LPFWH   CEP for a 200 MW unit:- Each unit has been equipped with three nos. of condensate pumps installed vertically at minus four meter level in to the turbine hall.

Cooling Towers

     In a power plant large amount of heat is rejected  which is a byproduct. This heat can not ignored & it is rejected from the primary system (CW system)  to a secondary system (atmosphere).      Physically atmosphere is treated as a heat sink in which heat is dumped  with the help of air or water. Cooling system are three distinct types:- Once-through cooling :- Waste heat is transfer  with the help of cooling water which is receive & discharge to a rivers or lakes sea.   Evaporative cooling:- Waste heat is dissipated to the atmosphere by evaporation of a small portion of the cooling water. it require cooling towers. Dry cooling:- Heat is dissipated directly to the atmosphere. it require air cooled heat exchangers.      In once through cooling system water is taken from natural resources & after cooling process hot water is dumped in to the again in natural resources so there is a thermal effect on the natural water resources.      So once through cooling is then rep