energy conservation strategies in cooling towers
DESCRIPTION
ENERGY CONSERVATIONSTRATEGIES IN COOLINGTOWERSTRANSCRIPT
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ENERGY CONSERVATION STRATEGIES IN COOLING
TOWERS
A Presentation by
Kunal Mukherjee
Vice President (South)
ENERGY CONSERVATION STRATEGIES IN COOLING
TOWERS
A Presentation by
Kunal Mukherjee
Vice President (South)
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ENERGY CONSERVATION CHALLENGES
Optimal energy consumption during Cooling Tower operations
ANDAND
Efficient cooling performance to fac
ENERGY CONSERVATION CHALLENGES
Optimal energy consumption during Cooling Tower operations
ANDAND
facilitate process energy efficiencies
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THE COOLING TOWERTHE COOLING TOWER
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ENERGY CONSERVATION AVENUES1. WATER HANDLING ARRANGEMENTS
2. AIR HANDLING ARRANGEMENTS
3. HEAT TRANSFER SURFACES
4. DRIVE ARRANGEMENTS
ENERGY CONSERVATION AVENUESWATER HANDLING ARRANGEMENTS
AIR HANDLING ARRANGEMENTS
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WATER HANDLINGIF WATER DISTRIBUTION IS NOT UNIFORM
IT MAY NOT AFFECT THE POWER CONSUMPTION OF THE COOLING TOWER
BUT
IT WILL AFFECT THE COOLING PERFORMANCE AND YIELD WARMER WATER
WHICH IN TURN
WILL AFFECT THE PROCESS EFFICIENCY
RESULTING IN
INCREASED ENERGY DEMAND FOR THE SAME PROCESS OUTPUT
WATER HANDLINGIF WATER DISTRIBUTION IS NOT UNIFORM
IT MAY NOT AFFECT THE POWER CONSUMPTION OF THE COOLING TOWER
BUT
IT WILL AFFECT THE COOLING PERFORMANCE AND YIELD WARMER WATER
WHICH IN TURN
WILL AFFECT THE PROCESS EFFICIENCY
RESULTING IN
INCREASED ENERGY DEMAND FOR THE SAME PROCESS OUTPUT
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WATER HANDLING
properly designed
contribute tocontribute to
Thermal Performance
% in a typical
Cooling Tower.
WATER HANDLING
designed nozzle could
improving theimproving the
Performance by up
typical film-fill type
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AIR HANDLINGIMPROVEMENTS / OPTIMISA
ADJUSTMENT OF BLADE PITCH ANGLE
USE OF VELOCITY RECOVERY FANDROP
CHANGE TO HIGHER RATEDCONFIGURATIONS
AIR HANDLINGISATION POSSIBLE THROUGH
ANGLE FOR SUPERIOR AIR DELIVERY
FAN CYLINDERS TO REDUCE PRESSURE
RATED AND/OR SPECIAL MOTORS
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AIR HANDLINGAIR HANDLING
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AIR HANDLINGTip Clearance Optimise to reducetake care to avoid mechanical interferenceexpansion of blades. Also Fancontracta create additional turbulencedropdrop
Vertical Location of Fan Planeallowing formation of vertical streamto contact with fan blades
Velocity Recovery Fan Stack To harnessvelocity pressure and minimizingoptimization also necessary to minimize
AIR HANDLINGreduce creation of air-vortex at tips BUT
interference especially due to thermaltips operating beyond the vena
turbulence and hence increase pressure
To maximize air-travel distancestream (for minimum energy loss) prior
harness the venturi effect, reducingstatic pressure drop. Stack height
minimize dead-load & wind load
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HEAT TRANSFER SURFACESCooling tower works on the principle
The more efficiently it can extractthe more efficient the cooling tower
The fill surface is designed tomaximize heat transfer from everymaximize heat transfer from every
The fill configuration, design anddroplet profile inside the cooling tower
By maximizing the heat transfer areaevaporative cooling is achieved withair ..
And hence, optimize operating
HEAT TRANSFER SURFACESprinciple of evaporative heat transfer
extract heat from each droplet of water,tower is
manipulate input water flow toevery micro-droplet thereofevery micro-droplet thereof
wet-behavior optimizes the watertower
area achieved by each water droplet,with the minimum quantum of input
energy
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HEAT TRANSFER SURFACESHEAT TRANSFER SURFACES
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HEAT TRANSFER SURFACESWOOD
FLOW (USGPM) 15000
HWT (OF) 115HWT ( F) 115
CWT (OF) 90
WBT (OF) 78
FAN BHP 165
SAVINGS IN CONSUMED POWER > 18%
HEAT TRANSFER SURFACESWOOD LATH PVC V-BARS
15000 15000
115 115115 115
90 90
78 78
165 135
SAVINGS IN CONSUMED POWER > 18%
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DRIFT ELIMINATORTO REDUCE DRIFT ANDPRESSURE DROP
TYPICAL TYPES WOOD LATH,TYPICAL TYPES WOOD LATH,EXTRUDED PVC, CELLULAR PVC
OPTIMAL CONFIGURATION LAST PASS SHOULD DIRECT AIRUPWARDS TO THE FAN TOAVOID FAN PLENUM LOSSES UPTO 8-10%
DRIFT ELIMINATOR
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DRIVE ARRANGEMENTSUSE OF AUTOMATED ON-OFF CONTROLDESIRED RANGE
USE OF DUAL SPEED MOTOR BETTERLOADS
USE OF AUTO VARIABLE SPEED DRIVEFREQUENCY
DRIVE ARRANGEMENTSCONTROL MAINTAIN CWT WITHIN
BETTER UTILISATION OF OFF-SEASON
DRIVE AIR FLOW QQQQ RPM QQQQ SUPPLY
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FAN POWER FACTS & FICTIONTHE FAN POWER EQUATION IS
FHP = V x Pt / (6356N), wherewhere
FHP = FAN HORSE-POWER
V = AIR FLOW RATE IN CFM
Pt = FAN PRESSURE DROP IN inWC
N = FAN EFFICIENCY
FACTS & FICTIONAGAIN, Pt = Ps + Pv, WHERE
Ps = STATIC PRESSURE
= f(CFM, CT Model)
Pv = VELOCITY PRESSUREPv = VELOCITY PRESSURE
= f(CFM, NDA)
THEREFORE FHP = f(CFM, N, NDA, CT Model), WHERE AGAIN
CT MODEL DEFINES THE HEAT TRANSFER CHARACTERISTICS
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FAN POWER FACTS & FICTIONTHE POWER AT MOTOR TERMINALSLOSSES
ENTRY LOSS
SKIN FRICTIONAL LOSSSKIN FRICTIONAL LOSS
TIP CLEARANCE LOSS
TRANSMISSION LOSS (FOR GRDR /
MOTOR EFFICIENCY
BEARING LOSS
OF THESE, ONLY BEARING LOSS DEPENDS ON THE WEIGHT OF THE FAN
FACTS & FICTIONTERMINALS CONSIDERS THE FOLLOWING
BELTS)
OF THESE, ONLY BEARING LOSS DEPENDS ON THE WEIGHT OF THE FAN
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FAN POWER FACTS & FICTION
Weight of each blade
Number of blades
Total blade weight
Weight of Fan HubWeight of Fan Hub
Total weight of Fan assembly
Co-efficient of friction for simple ball-bearing
Drive shaft diameter
Fan speed
Bearing Loss
THE FHP IN THIS EXAMPLE WAS 39 WHICH MEANS THE ADDITIONAL BEARING LOSS WAS ONLY
0.27%
FACTS & FICTIONALUMINIUM FRP
Kg 20 16
8 6
Kg 160 96
Kg 200 200Kg 200 200
Kg 360 296
Co-efficient of friction for simple ball-bearing 0.0015 0.0015
cm 10 10
RPM 260 260
HP 0.588 0.484
THE FHP IN THIS EXAMPLE WAS 39 WHICH MEANS THE ADDITIONAL BEARING LOSS WAS ONLY
0.27%
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FAN POWER FACTS & FICTIONCLAIM : 30% REDUCTION IN FAN PO
Suppose original Fan efficiency = 75%
For 30% reduction in fan power, efficiency of new fan has to be =For 30% reduction in fan power, efficiency of new fan has to be =
0.75 x (1/0.7) = 1.07
i.e. 107%
FACTS & FICTIONN POWER WITH SAME AIR DELIVERY
Suppose original Fan efficiency = 75%
For 30% reduction in fan power, efficiency of new fan has to be =For 30% reduction in fan power, efficiency of new fan has to be =
0.75 x (1/0.7) = 1.07
i.e. 107%
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FAN POWER FACTS & FICTIONCLAIMS OF 25-30% REDUCED FANNEW-AGE HOLLOW FRP BLADESSOME
USUALLY FAN CHANGES ARE MADETESTING OF SUCH CLAIMS IS DONEFITTINGFITTING
FAN CFM IS ADJUSTED TO CLAIMEDANGLES
SINCE WBT IS LOWER THAN DESIGNTOWER PERFORMANCE IS FOUNDCFM
FACTS & FICTIONFAN POWER CONSUMPTION BY USING
IS A SCAM BEING PERPETRATED BY
MADE DURING OFF-PEAK SEASONS ANDDONE IMMEDIATELY AFTER RETRO
CLAIMED BHP BY ADJUSTING PITCH
DESIGN WBT AT THIS TIME, COOLINGFOUND SATISFACTORY EVEN WITH LOWER
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FAN POWER FACTS & FICTION IT IS ONLY DURING THE NEXT
TOWER PERFORMANCE INADEQUACIES
EMERGENCY CORRECTIVE ACTION
BLADE PITCH ANGLES WITH
INCREASESINCREASES
SUCH SITUATIONS ARE RARELY
UTILITIES ENGINEER, OR EVEN
ADMIT TO HAVING BEEN THE
TECHNOLOGY SCAM ?
FACTS & FICTIONNEXT SUMMER SEASON THAT
INADEQUACIES GET NOTICED
ACTION IS TAKEN BY ADJUSTING
WITH WHICH CONSUMED POWER
RARELY HIGHLIGHTED WHICH
EVEN CHIEF ENGINEER, WILL EVER
THE VICTIM OF AN ELABORATE
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Mr. G. Venkataraman @ 99401
For enquiries in Tamil Nadu, please contact -
Mr. S. Venketaraman @ 94449
Mail [email protected]
99401 31973
For enquiries in Tamil Nadu, please
94449 91387
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