1. Experimental Investigation on Energy
Efficiency of Electrical Utilities in
Process Industries through Standard
Energy Conservation Practices
Vyas Pareshkumar A,
Bhale Purnanad V.
1

2. INTRODUCTION
•
•
•
•
•
•
•
Surat textile cluster - @ 400 industries
Annual electricity consumption is 726 GWh,Gas consumption is 315
million SCM & Coal consumption is 2.3 million tones
i.e. 1.2 million TOE (tons of oil equivalents) of energy use.
Overall energy saving potential is 1.5 lakh TOE
Electrical and Thermal energy cost is 12 to 15 % of manufacturing
Cost.
Small And Medium Enterprise (SME’s) sector is characterised by
the use of outdated technologies.
As per BEE’s Study for SME Overall energy saving potential is @
72432 TOE i.e. 27.4 % of total energy consumption in SME’s
As an individual the SME’s may not have significant effect on
environment and resource use, but together they exert a substantial
effect.
2

3. Instruments used:
• Electrical Portable Load Manager ALM 10
• Hand held Ultrasonic flow meter
Focus area:
• Air compressor system
• Centrifugal pumping system
Energy Audit Activity:
• Pre audit meeting
• Familiarisation with manufacturing process and energy consuming
machineries
• Review of manuals,maintenace records
• Verification of calibration status of instruments, installation of
measuring instruments or other facilities
3

4. PROCESS DIAGRAM
Grey Cloth
Jet M/c
Rotary M/c
Loop M/c
(Raw Material)
(Dyeing)
(Printing Process)
(Drying & Color setting)
Stenter
(Heat setting)
Zero -Zero
Folding
Washing
Hydro
Packing
4

5. WATER DISTRIBUTION SYSTEM
Bore well
Overhead tank
Supply pump
Stenter M/c
Colour kitchen
Jet M/c
Rotary M/c
Drums ,zero-zero M/c
Printing M/c
Padding M/c
Office use
5

6. AIR DISTRIBUTION SYSTEM
Compressor 1
Stenter M/c
Compressor 2
Printing M/c
Rotary & Loop M/c
Compressor 3
Padding M/c
Jet M/c
Drum M/c
6

7. ENERGY AUDIT ACTIVITY
Air compressor & Centrifugal pumping system :
Following data are collected with measuring instruments and
calculations were made for Efficiency and Percentage air leakage.
•
•
•
•
•
•
•
Input voltage,current,power factor – Measured with portable load
analyser
Running hours – Installed Running hour meter
Tank volume - measured and compared with available data
Discharge air pressure – Measured with calibrated pressure gauge
Actual tank filling time – Measured with calibrated stop watch
Actual head – measured with calibrated pressure gauge
Actual discharge – measured with Ultrasonic flow meter
7

8. SNAPS
Modification of air distribution network & Installation of PID controller
8

9. Installation of Auto moisture drain & Setting of new discharge set points
9

10. AIR LEAKAGE TEST
T on Average on time (T)
min
=
38
T off Average Off Time (t)
min
=
28
% Air leakage
=
Annual cost of power for
comp. no 3 (Rs)
=
Unit rate× Annual power cons.
=
5.50 ×(674.3 × 26 × 12)
=
1157098
Annual power loss due to
leakages (Rs)
=
Annual power cost × % Air
leakage
=
666257
Power can be saved by
plugging leakage in %
=
75%
=
499693
=
1.2
Annual saving by leakage
prevention(Rs)
57.58
T/(T+ t) × 100
Power saved by plugging 75 %
leakage
Investment required in
plugging leakages (Rs)
=
50000
Payback in months
=
(Investment × 12) / savings
10

11. VOLUMETRIC EFFICIENCY MEASUREMENT
COMPRESSOR NO.
=
1
2
3
Hp
=
40
30
40
Motor RPM
=
1440
1440
1440
Voltage
=
410
412
414
Current
=
43
35
45
Power Factor
=
0.95
0.95
0.95
Power consumption per hour
=
[√3 x V x I x COSΦ]
=
29.01
23.73
30.65
Average working hrs
=
24
12
22
Compressor RPM
=
1440
1440
1440
4.4
2.94
5.4
1.076
1.076
1.076
Compressor
(m3/min)
Tank Volume (m3)
Capacity =
=
11

12. Air pressure (Kg/cm2)
=
6
Total air volume (m3)
=
(Tank Volume × Air Pressure)
=
6.456
7.532
4.304
Actual Tank filling time (Sec)
=
105
162
52
Actual air generation (m3/min)
=
(Total Air Volume ÷ Actual Tank Filling Time) × 60
=
3.69
=
(Total Air Volume ÷ Compressor Capacity) × 60
=
88.04
=
(Actual air generation ÷ Compressor Capacity) × 100
=
83.84
Required tank filling time (sec)
% Efficiency
Existing specific power =
consumption (m3/min per kWh)
=
7
2.79
153.71
94.89
4
4.97
47.82
91.97
Actual air generation ÷ power consumption per hour
0.127
0.118
0.162
12

13. Proposed
specific
power =
3
consumption. (m /min per kWh)
compressor capacity ÷ Power consumption per
hour
=
0.152
=
(100-eff/100) × power consumption per hr × avg.
working hrs
=
112.48
=
Power loss per day (kWh) × cost of power (Rs)
=
618.62
80.09
298.00
Annual power loss (Rs)
=
193011
24989
92975
Investment (Rs)
=
20000
0
0
Payback in months
=
(Investment (Rs) x 12 ) ÷ (Annual power loss (Rs))
=
1.24
Power loss per day (kWh)
Power loss per day ( Rs)
0.124
14.56
0
0.176
54.18
0
13

14. CENTRIFUGAL PUMPING SYSTEM
SNAPS :
OLD PUMP 1
OLD PUMP 2
OLD PUMP 3
NEW PUMP IN
SUMP SUMP
SUMP
OLD PUMP 1
NEW PUMP
OLD PUMP 2
Set up of old and new transfer and supply pump
14

15. Transfer pump
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Pump No.
Rated motor efficiency
Hp
RPM
Measured voltage
Measured current
Existing pump running hours
Calculated input kW / hr
[√3 x V x I x cosΦ]
Pump input kW / hr
Actual head (m)
Measured flow (m3/hr)
PROPOSED FLOW(m3)=
AFTER UNIT / HR
AFTER WORKING HR
=
=
=
=
=
=
=
1
0.8
10
2800
409
14
2
2
0.8
10
2800
408
10.3
14
3
0.8
10
2800
407
10.2
24
=
9.8
7.2
7.1
= calculated input kW / hr × rated motor eff.
=
=
=
115
=
=
7.85
24
48
5.76
24
38
5.69
24
25
11
11
15

16. Present water discharge per day
= measured flow (m3/hr) × existing pump running
hrs
= 96
Existing pump efficiency (%)
532
600
= 0.4
0.431
0.286
Hydraulic power = Q (m3/s) × Total head, hd - hs (m) × Density (kg/m3) × g (m2/s) ÷ 1000
Electrical input power = Pump shaft power ÷ Motor efficiency
Pump shaft power = Hydraulic power ÷ Pump efficiency
Proposed
minimum
efficiency (%)
pump = 0.7
Existing overall efficiency (%)
= existing pump efficiency × rated motor efficiency
= 0.32
Proposed overall efficiency (%)
0.34
0.23
= Proposed minimum pump efficiency × Rated
motor efficiency
= 0.56
Existing specific power
consumption (m3/kW)
= (measured flow m3) ÷ calculated input kW / hr
= 4.89
5.27
3.51
16

17. Existing unit consumption = calculated input kW / hr × existing pump running hrs
per day
= 19.64
Total unit consumption
100.88
170.84
= 19.60 +100.94 +171.36 = 291.36
Afterunit consumption/day = after unit kW/hr × after pump running hrs
(single pump)
= 121
Saving in unit/day
= 291.36 – 121 = 170.36
Saving achieved per day = Saving in unit/day × Price per unit (Rs)
(Rs)
= 170.36 X 5.5
= 936.96
Annual Saving (Rs)
= 936.96 × 26 ×12 =
292332.70
Investment required (Rs)
= 35000
Payback in months
= (Investment required (Rs) × 12 ) ÷ Saving per year
= 1.44
17

18. RESULTS AND DISCUSSION
Air compressor system :
• Three nos. Air compressors
• PID controller is installed and different air pressure setting is set.
• Air distribution network rearranged.
• Automatic moisture drain valve installed
• Air leakages arrested.
Centrifugal Pumping system :
• Instead of Three nos 10 hp ; 24 meter head; Different discharge
capacity Transfer pump, One Single Energy efficient 10 hp;20 meter
head;100 m3/hr capacity pump installed.
• Instead of Two nos 10 hp ; 22 meter head; Different discharge
capacity Supply pump, One Single Energy efficient 3 hp;6 meter
head;100 m3/hr capacity pump installed.
18

19. Description
hp
m3/min
Air
compressor
#1
40
4.4
83.84
Air
compressor
#2
30
2.94
Air
compressor
#3
40
5.4
Energy-Saving
Measures
%
volumetric
efficiency
Annual
power loss
( Rs)
Investment
required (Rs)
7.62
193011
20000
1.24
94.89
7.08
24989
0
0
91.97
9.72
92975
0
0
Investment (Rs)
Specific
power
consumption
(kwh/m3)
Annual Savings
(Rs)
Simple Payback
Period (Months)
Pay back
period
(months)
Expected Lifetime
(operating hours)
Improve Efficiency
of Compressor #. 1
20000
193011
1.24
14400
Stop Air Leakages
in Department.
50000
499693
1.20
Req. Regular
Maintaince
Total
70000
692704
19

20. CENTRIFUGAL PUMPING SYSTEM
Transfer pump :
Descripti
on
hp
Head
(meter)
Flow
(m3/hr)
Current
(amp)
Input
kW/hr
% Efficiency % overall
Efficiency
Transfer
pump # 1
10
24
48
14
7.85
40.0
32
Transfer
pump # 2
10
24
38
10.3
5.76
43.1
34
Transfer
pump # 3
10
24
25
10.2
5.69
28.6
23
Energy saving
measure
Investment
(Rs)
Annual savings
(Rs)
Simple
Payback
Expected
lifetime
(operating hrs)
Replace Transfer
pump 1,2 and 3by
single Energy
efficient pump
35000
292332
1.44
14400
Total
35000
292332
20

21. Supply pump
Descripti
on
hp
Head
(meter)
Flow
(m3/hr)
Current
(amp)
Input
kW/hr
%
Efficiency
% overall
Efficiency
Supply
pump # 1
10
22
42
10.5
5.26
50
40
Supply
pump # 2
10
22
45
10.2
5.13
55
44
Energy saving
measure
Investment
(Rs)
Annual savings
(Rs)
Simple
Payback
Expected
lifetime
(operating hrs)
Replace supply
pump 1 and 2 by
single Energy
efficient pump
30000
230000
1.57
14400
Total
30000
230000
21

22. SUMMARY OF IMPLEMENTED RESULTS
Steps taken
Saving In
Units
(kWh /
Year
Actual
investment
(Rs)
Energy cost
saving per year
(Rs)
Pay back
(month)
Single Energy efficient
pump of 3 HP ; 6 meter
head ; 100 m3/hr discharge
capacity is installed (supply
pump)
41817
30000
230000
1.57
Single mono sub pump of
10 hp ;20 meter head ;100
m3/hr discharge capacity is
installed (transfer pump)
53152
35000
292332
1.44
PID controller is installed;
Different air pressure
setting is set for three
different compressors. Air
line network rearranged
(common header )
Automatic moisture drain
valve also installed
134400
180000
821338
2.67
Total
229369
245000
1343670
22

23. REFERENCES
[1]
http://www.business-standard.com/india/news/energy-effeciency-plan-for-sm
[2] Guide book for National Certification Examination for Energy Managers
and Auditors. “General aspects of energy management and audit.
www.beeindia.nic.in
[3] Kapur, Shilpi , Plannet Earth , Fiscal reforms, SMEs'hope , Date: 10
October 2011, http://www.teriin.org/index.php?
option=com_featurearticle&task
[4] Ali,Hasanbeigi ,China Energy Group,Energy Analysis Department,
Environmental Energy Technologies Division “energy- efficiency
improvement opportunities for the textile industry”,E.O. Lawrence
Berkeley National Laboratory,Washington, DC Resource Dynamics
Corporation
[5] Facts air distribution,”druckluft effizient’,07 compressed air
facts,www.druckluft-effizient.de.
[6] Kaya D, Phelan P, Chau D, Sarac HI. Energy conservation in
compressed-air systems. International Journal of Energy Research
2002;26:837–49.
23

24. [7] Galitsky C, Worrell E. Energy efficiency improvement and cost saving
opportunities for the vehicle assembly industry. Lawrence Berkeley
National Laboratory 2008 [LBNL-50939-Revision].
[8] U.S. DOE. Minimize compressed air leaks; 2010, Available online at:
http://www.energystar.gov/ia/business/industry/compressed_air3.pdf
[Accessed:24.09.11].
[9] Saidur R, Rahim NA, Hasanuzzaman M. A review on compressed-air
energy use and energy savings. Renewable and Sustainable Energy
Reviews 2010;14:1135–53
[10] PS (Plant Support). Compressed air ultrasonic leak detection guide;
2010,Available online at:
http://www.plantsupport.com/download/UCAGuide.pdf[Accessed
24.09.11].
24

25. It is never too late to practice energy
modesty and efficiency otherwise …
Year 1900
Year 1800
Year 2000
Year 2050
Year 2020
25