SELECTION OF PUMPSFOR SELECTION OF ANY PUMPS THE FOLLOWING TWO PARAMETERS ARE ESSENTIAL IN ADDITION TO OTHERS

THE CAPACITY TO BE HANDLEDTHE HEAD TO BE DEVELOPED

CW PUMPSFOR CIRULATING WATER PUMPS

THE CAPACITY TO BE HANDLED IS LARGETHE HEAD TO BE DEVELOPED IS LOW

DETERMINING THE CAPACITYCAPACITY IS DETERMINED BASED ON THE HEAT TO BE REMOVED FROM THE CONDENSERIN ANY POWER PLANT ARROUND 55 % OF THE TOTAL HEAT INPUT IS REMOVED IN THE CONDENSERTHIS HEAT IS DISCHARGED BY THE CIRCULATING WATER

THE SCHEME

THE Q OUTFOR A 210 MW POWER PLANT THE Q OUT IS ARROUND 248325000 KILO CALORIES PER HOUR

CONSIDERING A T OF 9 C THE FLOW REQUIRED IS 27591666.66 Kgs/Hr ie 27591.6 M3/Hr

WITH A 10 % MARGIN IT IS ARROUND 30500 M3/Hr

THIS IS THE CAPACITY WE HAVE

THE T THE T IS THE RANGE OF COOLING CONSIDERED IN COOLING TOWERFOR A LESSER RANGE MORE WATER HAS TO FLOWFOR MORE WATER FLOW MORE SHOULD BE THE SIZE OF CONDENSERHENCE OPTIMAL VALUE HAS TO BE CHOSEN

THE APPROACHTHE RANGE IS ALSO DEPENDING ON THE APPROACHie APPROACH TO THE WET BULB TEMPERATUREWET BULB TEMPERATURE IS DECIDED BY NATURE FOR A GIVEN AREA

THE HEAD REQUIREDTHE HEAD REQUIRED BY THE CW PUMP IS THE STATIC HEAD AND THE FRICTION HEAD IN THE CW CIRCUITTHE FRICTION HEAD INCLUDES THE HEAD LOSS IN PIPE LINES, CONDENSER, COOLING TOWER VALVES ETC

THE HEAD REQUIREDTHE HEAD REQUIRED FOR CIRCULATING WATER IS OPTIMISED ARROUND 16 TO 28 METERS

FOR THE 210 MW UNITS IN NEYVELI IT IS ARROUND 24 METERS

THE PUMP SELECTIONONCE THE CAPACITY AND HEAD OF THE PUMPS ARE CALCULATED THE PUMP CAN BE SELECTEDTHE CAPACITY AND HEAD ARE THE TWO VITAL PARAMETERS FOR PUMP SELECTION

THE CW PUMPTHE CAPCITY IS HIGH AND THE HEAD IS LOWFOR THIS TWO TYPES OF PUMPS CAN BE SELECTEDTHE MIXED FLOW PUMP ORTHE AXIAL FLOW PUMP

THE MIXED FLOW IMPELLER

THE AXIAL FLOW IMPELLER

H-Q CURVE OF MIXED FLOW PUMPS

H-Q CURVE OF AXIAL FLOW PUMPS

THE CHOICEAMONG THE TWO THE MIXED FLOW IMPELLER IS THE PREFERED CHOICEFROM THE H-Q CURVE IT IS OBSERVED THAT POWER CONSUMPTION OPTIMAL AT THE OPERATING POINT FOR THE MIXED FLOW PUMPS

IN CASE OF AXIAL FLOW PUMPS IT HAS TO STARTED WITH A PARTIALY OPEN VALVETHIS IS NOT ESSENTIAL FOR MIXED FLOW PUMPSFURTHER THE MOTOR RATING FOR THE MIXED FLOW PUMP CAN BE OPTIMAL

PUMP CONSTRUCTION DEPENDING ON THE QUALITY OF WATER THE PUMP CAN BEPULL OUT TYPE OR NON PULL OUT TYPE IN CASE OF PULL OUT TYPE THE LINE SHAFT BEARINGS ARE LUBRICATED WITH SEPARATE CLEAN WATER

OTHER CHOICES WHEN THE CAPACITY TO BE HANDLED IS LARGE ANOTHER OPTION AVAILABLE IS CONCRETE VOLUITE PUMPSTHE 500 MW SETS USE CONCRETE VOLUTE PUMPS