Energy Audit for Chiller Plants

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MGCS-Energy Audit Company
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CASE Study For Chiller Plant
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• Major Components for Energy Audit for HVAC
  Systems are
• Chillers
• Pumps
• Motors
• Cooling Towers
• Air Handling Units

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• Chillers
• Measuring all the operating parameters such as
  water flow inlet out water temperatures, gas
  suctions discharge pressure, Power Consumption
  etc.
• Calculation of operating Input KW per TR (IKW I
  TR) of Chiller(s) for each chiller.

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Case Study- Performance of Chiller Existing
Conditions-Two chillers are installed at one of
our client site with the operating principle of
vapor compression. Mostly two chillers are in
running condition due to climatic condition.
Cooling tower is Natural air cooling.
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Chiller Details
a) Rated Capacity in TR for Chiller 250 TR
b) Sr. No. of Chiller -- SHMM-035670
c) Model No KWF195.12
d) Make of Compressor -- YRWDWBT1555A
e) Type of Compressor -- Screw Compressor
f) No. of Stages -- Single Stage
g) Other Relevant Number Plate Refrigerant 134a, Oil Flooded, RPM of compressor 2950 RPM, Direct Drive type, step less capacity control.
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Motor Details
a) Make of Electric Motor -- York maxe
b) Sr. No. of Motor -- F00580SG03
c) Connected Motor Kw -- 170 kW
d) Rated RPM -- NA rpm
e) Rated Efficiency of Electric Motor 92
f) With or Without VFD / Type of Starter Without VFD
g) Type of Transmission in Motor Comp. Directly Coupled
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The performance assessment of the chiller The performance assessment of the chiller The performance assessment of the chiller
SPC, COP EER Calculations from Condenser Circulation Data SPC, COP EER Calculations from Condenser Circulation Data SPC, COP EER Calculations from Condenser Circulation Data
Measured Data Analysis Chiller-1
Compressor Speed
Ambient dry bulb temperature -- C 29 29
Ambient wet bulb temperature -- C 26 26
Water Flow rate through condenser, m3/hr 180 202
Cooling Water density kg/cm3 1000 1000
Specific heat of Cooling Water kcal/kgC 1 1
Water temperature at inlet to Condenser C 28 30.5
Water temperature at outlet to Condenser C 33 32.83
Heat Rejected Through Condenser Kcal/hr 900000 470660
Heat Rejected Through Condenser TR 297.619 155.64
Condenser pressure kg/cm2 9.37 9.56
Condenser saturation temperature C 40.16 40.8
Sub cooling temperature C -11.3 -15
Power input to motor kW 87 89.00
Likely motor efficiency 90.6 90.60
Likely drive transmission efficiency 98 98.00
Estimated Compressor shaft power kW 77.24556 79.02
Coefficient of Performance, COP 12.007 6.138
Energy Efficiency Ratio, EER  Btu/h-W 40.945 20.931
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SPC, COP EER Calculations from Evaporator Circulation Data SPC, COP EER Calculations from Evaporator Circulation Data SPC, COP EER Calculations from Evaporator Circulation Data
Measured Data Analysis-CHILLER 2 Measured Data Analysis-CHILLER 2 Measured Data Analysis-CHILLER 2
Compressor Speed -- RPM
Ambient dry bulb temperature -- C 29.0 29
Ambient wet bulb temperature -- C 26.0 26
Water Flow Rate through Evaporator m3/hr 292.0 305
Density of Water kg/cm3 1000.0 1000
Specific heat of Water kcal/kgC 1.0 1
Water temperature at inlet to Evaporator C 16.4 13.05
Water temperature at outlet to Evaporator C 14.2 11.7
Refrigeration Effect kcal/hr 642400.0 411750
Refrigeration Effect TR 212.4 136.161
Evaporator pressure kg/cm3 4.07 3.3
Saturation temperature C 11 15.7
Power input to motor kW 87.00 89.00
Likely motor efficiency 90.60 90.60
Likely drive transmission efficiency 98.00 98.00
Estimated Compressor shaft power kW 77.25 79.02
Coefficient of Performance, COP 8.571 5.370
Energy Efficiency Ratio, EER Btu/h-W 29.226 18.311
Specific power consumption, SPC kW/TR 0.410 0.654
Evaporator to Condenser TR Ratio kW/TR 0.714 0.875
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OUTCOME 1 Lift is difference between the
evaporator pressure and condenser pressure.
Greater the pressure, more energy for given
load. Lift for Chiller 1 is 5.3 Lift for Chiller
2 is 6.26   It shows that condenser in chiller 2
condensers is fouled as it requires more energy
to do the work.   OUTCOME 2 Condenser approach
should be between 0-2 (Liquid refringent
temperature Condenser outlet temperature) Conden
ser approach for Chiller-1 1.44
Condenser approach for Chiller-2 4.47 so it can
conclude that condenser in chiller-2 is fouled.  
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Energy Saving Recommendation Chiller-2 condenser
need to cleaned. Result of the
outcome Chiller-2 efficiency will improve and
approach too. Present Scenario Condenser
approach4.47 After technical recommendation
Condenser approach lt 2    
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Proposed Energy/Electricity Saving Saving
Calculation Consumption 87 kW Energy
Saving _at_ improving 4 of efficiency 3.48
kW Energy saving per annum 3.48 X10 X
240 ( 10 hours ,240 days of working)
8352
kWh Monetary Saving
Rs 93125/- Expected Pay
back Immediate    
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This way, we helped our client in saving money by
taking the corrective action through our detailed
auditing for the chiller plants.     Note The
above information is only for knowledge sharing
and MGCS has its sole right and proprietorship of
above technical data.    
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• We have got BEE (Bureau of Energy Efficiency)
  Certified Energy Auditors on board to help you on
  Energy Management System
• We use all gadgets and instruments from leading
  brands across the globe for fine accuracy and
  precision

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Energy Conservation-need of the hour
Contact us now save on Energy Money
Write us at hina.gupta_at_mgcs.net.in for
any query L
-011-49040941/42/43