Modern Mechanical Engineering, 2013, 3, 171-180
Published Online November 2013 (http://www.scirp.org/journal/mme)
http://dx.doi.org/10.4236/mme.2013.34024
Open Access MME
Energy Efficiency Evaluation in Pumping System
Sharad P. Jagtap1, Anand N. Pawar2
1Mechanical Engineering Department, Government Polytechnic, Murtizapur, India
2Mechanical Engineering Department, Government Polytechnic, Amravati, India
Email: jagtapsp@rediffmail.com, anp5000@gmail.com
Received September 12, 2013; revised October 19, 2013; accepted November 7, 2013
Copyright © 2013 Sharad P. Jagtap, Anand N. Pawar. This is an open access article distributed under the Creative Commons Attri-
bution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
ABSTRACT
Like 3M’s (Man, Machine and Material), energy is one of the major inputs for economic development of the country. In
case of developing countries like India, the energy sector assumes critical importance in the view of the ever increasing
energy needs, requiring huge investments for new power plant erection. About 85% of total primary energy need comes
from fossil fuels. Particularly, oil contributes to 31% primary energy sources and the existence of it from domestic
source in India may last for only about 20 years only at the current reserve to production (R/P) ratio. Similarly, coal
contributes to 54% primary energy sources and may last for about 114 years at the current reserve to production (R/P)
ratio. Water Pumping System is one of the major utilities in SME’s as well as power & process industry, and consumes
about 10% - 15% electrical power in Industrial and Agricultural sector. As per TERI Energy data directory yearbook,
Industrial sector and Agricultural sector contribute to 45% and 7% of the total energy needed respectively in India. A
measurable amount of Industrial production is delivered from small and medium industries operated with inefficient
equipment, where it has been difficult to implement efficiency improvements. The objective of Water Pumping System
in most cases is either to transfer liquid from one reservoir to another or to circulate liquid across the heat exchanger
around a system. Since worldwide, centrifugal pumps account for the majority of electricity used by pumps, this paper
focuses on energy saving in centrifugal pumping system with a case study work carried out in an industry.
Keywords: Energy Audit; Energy Saving; Pumping System; Performance Evaluation of Pumping System
1. Introduction
The pumps come in a various sizes for wide applications.
It can be classified according to their operating principles
as dynamic or displacement type. Dynamic pumps can be
sub-classified as centrifugal and special effect pumps and
Displacement pumps can be classified by rotary and re-
ciprocating pumps. Out of all types of pumps, recipro-
cating pump is more energy efficient but increases main-
tenance cost, that’s why worldwide, centrifugal pumps
accounted for major electricity using equipment in palm-
ping system [1].
Due to ever increasing in economic growth for devel-
oping countries, product variation and its production rate
in process industry are continuously being changed;
hence pump is dynamic device which is not delivered to
the fixed volume of liquid as its pressure head changes.
Therefore, to attain the best performance from pumping
system, it is to be analyzed critically. Overall energy ef-
ficiency of plant would be achieved when energy inten-
sity in a specific product, process or area of production or
consumption is reduced without affecting output or com-
fort levels. Nowadays, such plant energy efficiency eva-
luation is carried out in “Energy Audit” projects.
2. Energy Conservation
Under the provisions of the Energy Conservation Act,
2001 The, Government of India setup Bureau of Energy
Efficiency (BEE), a statutory body under the ministry of
power on 1st March 2002, with the primary objective of
reducing energy intensity of the Indian economy. This
will be achieved with active participation of all stake-
holders, resulting in accelerated and sustained adoption
of energy efficiency in all sectors [2]. Pumping system is
used in wide application in industry as well as agriculture
sector. By the survey of few Energy Efficiency Projects
in India, there are many ways for enhancing energy effi-
ciency in pumping system which is directly depends on
its operation philosophy and capacity uses.
S. P. JAGTAP, A. N. PAWAR
172
Energy efficiency study (Energy Audit) means the
verification, monitoring and analysis of use of energy in-
cluding submission of technical report containing rec-
ommendations for improving energy efficiency with cost
benefit analysis and action plan to reduce energy con-
sumption. Energy audit helps to understand more about
the ways energy is used in the industry, and helps to
identify the area where energy waste & scope for impro-
vement can occur. It is carried out by following way.
Preliminary Audit/Walk through audit: By using ex-
isting data (energy bills and invoices) and general obser-
vations through walk through, establishes energy con-
sumption pattern and its baseline or reference point as
well as identify areas for more detail study/measure-
ments.
Targeted Energy Audit: It is often results from Pre-
liminary EA and provides detail analysis of targeted pro-
ject like pumping system, compressed air system, steam
and boiler system, lighting system, etc.
Detail Energy Audit: It is comprehensive energy study
of the plant constitute energy balance, detail measure-
ment and calculations for performance evaluation of kind
of systems in the plant. Identification of Energy Conser-
vation Opportunities (ENCON), Cost benefit analysis
and preparation of action plan for implementation of
ENCON measures is carried out. After implementation
of ENCON measures monitoring and periodic review
also carried out [3].
Detail energy efficiency study of a chemical industry
was carried out in India. In this paper energy efficiency
analysis of chilled water pumping system for Vapor Ab-
sorption Machine (VAM) has analyzed. The total con-
nected load of the entire plant was around 8700 kW. Stu-
died plant was a chemical industry therefore most of the
processes energy load were critical (affects production)
for power failure from electricity board hence power sup-
ply for such process were catered by two gas engines.
Figure 1 shows the average electrical energy demand of
Energy
used from
electricity
board
(lakhs kWh),
0.9,
27%
Energy
Generation
from Gas
engine
(lakhs
kWh), 2.41,
73%
Figure 1. Total Energy Consumption of the Plant.
entire plant. Energy generation per month for installed
gas engines ware studied from history recorded, the av-
erage energy generation per month was 2.41 lakhs units
(kWh) and simultaneously energy bills from electricity
board also analyzed which was shown average energy
consumed per month was 0.9 lakhs units (kWh).
3. Energy Conservation in Chilled Water
Pumping System of VAMs
Performance analysis and finding of suitable measures
for pumping system of VAM (Vapor Absorption Ma-
chine) is carried out as an actual case study work. Two
nos. of hot water driven Vapor Absorption Machines
were installed. Each VAM is dedicated with individual
Gas Engine jacket heat. Both the VAM operations are as
per plant demand. Radiator fans for Gas Engines were
available to reject the heat from hot water when the
chiller is not in operation. The installed lithium bromide-
Water pair VAM as shown in Figure 2 consists of five
basic components as per following.
1) Generator: The purpose of the generator is to de-
liver the refrigerant vapor to the rest of the system. It ac-
complishes this by separating the water (refrigerant) from
the lithium bromide-and-water solution. In the generator,
a high-temperature energy source, hot water from diesel
Engine jacket cooling flows through tubes that are im-
mersed in a dilute solution of refrigerant and absorbent.
The solution absorbs heat from the warmer water, caus-
ing the refrigerant to boil (vaporize) and separate from
the absorbent solution (Li-Br). As the refrigerant is
boiled away, the absorbent solution becomes more con-
centrated. The concentrated absorbent solution returns to
the absorber and the refrigerant vapor migrates to the
condenser.
2) Condenser: The purpose of condenser is to con-
dense the refrigerant vapors. Inside the condenser, cool-
ing water flows through tubes and the hot refrigerant
vapor fills the surrounding space. As heat transfers from
Chilled Water Out
Chilled Water in
Eva
p
orator
Absorbe
r
Coolin
g
Water in
Dilute Solution
Concentrated
Solution
Refri
g
erent
Va
p
o
r
Generato
r
Hot Water In
from Engine Jacket
Condenser
Cooling Water Out
Expansion
Va l v e
Condensed
Refrigerent
at HP
Figure 2. Components of VAM.
Open Access MME
S. P. JAGTAP, A. N. PAWAR 173
the refrigerant vapor to the water, refrigerant condenses
on the tube surfaces. The condensed liquid refrigerant
collects in the bottom of the condenser before traveling
to the expansion device. The cooling water system is
typically connected to a cooling tower. Generally, the ge-
nerator and condenser are contained inside of the same
shell.
3) Expansion Valve: From the condenser, the liquid
refrigerant flows through an expansion device into the
evaporator. The expansion device is used to maintain the
pressure difference between the high-pressure (condenser)
and low-pressure (evaporator) sides of the refrigeration
system by creating a liquid seal that separates the high-
pressure and low pressure sides of the cycle. As the high-
pressure liquid refrigerant flows through the expansion
device, it causes a pressure drop that reduces the refrig-
erant pressure to that of the evaporator. This pressure
reduction causes a small portion of the liquid refrigerant
to boil off, cooling the remaining refrigerant to the de-
sired evaporator temperature. The cooled mixture of liq-
uid and vapor refrigerant then flows into the evaporator.
4) Evaporator: The purpose of evaporator is to cool
the circulating water (Chilled water). The evaporator
contains a bundle of tubes that carry the system water to
be cooled/chilled. High pressure liquid condensate (re-
frigerant) is throttled down to the evaporator pressure
(typically around 6.5 mm Hg absolute). At this low pres-
sure, the refrigerant absorbs heat from the circulating
water and evaporates. The refrigerant vapors thus formed
tend to increase the pressure in the vessel. This will in
turn increase the boiling temperature and the desired
cooling effect will not be obtained. So, it is necessary to
remove the refrigerant vapors from the vessel into the
lower pressure absorber. Physically, the evaporator and
absorber are contained inside the same shell, allowing
refrigerant vapors generated in the evaporator to migrate
continuously to the absorber.
5) Absorbe r: Inside the absorber, the refrigerant vapor
is absorbed by the lithium bromide solution. As the re-
frigerant vapor is absorbed, it condenses from a vapor to
a liquid, releasing the heat it acquired in the evaporator.
The absorption process creates a lower pressure within
the absorber. This lower pressure, along with the absor-
bent’s affinity for water, induces a continuous flow of re-
frigerant vapor from the evaporator. In addition, the ab-
sorption process condenses the refrigerant vapors and
releases the heat removed from the evaporator by the re-
frigerant. The heat released from the condensation of re-
frigerant vapors and their absorption in the solution is
removed to the cooling water that is circulated through
the absorber tube bundle. As the concentrated solution
absorbs more and more refrigerant; its absorption ability
decreases. The weak absorbent solution is then pumped
to the generator where heat is used to drive off the re-
frigerant. The hot refrigerant vapors created in the gen-
erator migrate to the condenser. The cooling tower water
circulating through the condenser turns the refrigerant
vapors to a liquid state and picks up the heat of conden-
sation, which it rejects to the cooling tower. The liquid
refrigerant returns to the evaporator and completes the
cycle.
Figure 3 shows the chilled water pumping arrange-
ment of VAMs. Primary chilled water pumps were
transferring water from primary chilled water storage to
evaporator of VAMs and get more chilled and stored it in
secondary chilled water storage, from where secondary
chilled water pumps transfer it to plant departments.
At most of the plants facility, it was observed that
without understanding the correct pressure drop in pum-
ping system causes oversized selection of pumps, result-
ing into running of pumps far away from duty point (best
efficiency point). Thus due to dynamic flow-head-effi-
ciency characteristics of centrifugal pumps, leads to sub-
stantial drop in operating efficiency. Besides, worn-out
parts and increased clearances over the period of time
also cause de rating in operating efficiency. As a thumb
rule, operating cost of a centrifugal pump is approxi-
mately 15 times higher than the initial cost. Due to these
reasons, study of pumping system generally offers maxi-
mum energy saving potential with attractive payback.
Theoretically capacity requirement for present pump-
ing system is analyzed i.e. actual required volume of
pumping water (m3/hr) with respective to required task
(i.e. energy load of heat exchanger, evaporator) and pres-
sure head (m) through its elevation from pump reference.
This theoretical study helped to compare the actual sys-
tem parameters of pumping system. Pump always de-
Pri. Chilled
Water Storage
Secondary
Chilled
Water Pumps
Sec. Chilled
Water Storage
Primary
Chilled
water
Pumps
Plant
Departments
Evaporator
Figure 3. Chilled water pumping arrangement.
Open Access MME
S. P. JAGTAP, A. N. PAWAR
Open Access MME
174
signs at certain operating point (flow rate in m3/hr and
pressure head in meter) at which if it is operated, gives
maximum energy efficiency. Theoretical required pres-
sure head study based on
Desired volume (m3/Hr) of liquid
It static head (Delivery elevation from reference of
Pump)
Dynamic head (Constitute Major and Minor pressure
Losses)
Major dynamic pressure head losses are the friction
loss in length of pipe line and pressure loss across the
equipment (heat exchanger, surface condensers, evapora-
tors, etc.) and minor dynamic pressure losses are caused
by fittings, bends, valves, etc.
Objectives of the work: The major objective of the
study is summarized hereunder.
Performance evaluation of process cooling water
pumping system
Identification of Energy Conservation Opportunities
(ENCON)
Operating Philosophy of Primary chilled water pump-
ing system:
When both the VAMs are in operation, a higher head
primary chilled water pump (MEGA-G-50-250) was run-
ning while smaller head primary chilled pump (MEGA-
G-50-160) is running when only one VAM is under op-
eration. Separate secondary chilled pumps are installed
for individual section where chilled water is demanded.
3.1. Installation Details
Specifications of hot water driven (from gas engine
jacket cooling) of both VAM in the plant were as per
Table 1.
As per chilled water arrangement shown in Figure 3,
there were two separate pumping water network (primary
and secondary). The installation details are shown in Ta -
ble 2.
For performance analysis of chilled water & hot water
pumps and capacity measurement of VAMs, the simul-
taneous measurements of water flow, pressure , power of
respective pump and temperature at various points of
VAMs is carried out by using ultra-sonic flow meter,
digital pressure gauge, three phase load analyzer and
digital temperature meter respectively.
3.2. Performance Analysis and
Recommendations for VAMs
Performance analysis of VAM-I: Basic analogy for
heat exchangers analysis is used by referring [4] and the
actual measurements and performance evaluation for dif-
ferent parameters for VAM-I was carried out is shown in
Table 3.
Performance analysis of VAM-II: Similarly actual
measurements and performance evaluation for different
Table 1. Design details for VAM’s.
Make Thermax
Model B511S
Capacity (TR) 95
COP 0.66
Refrigerant Water
Nos. 2
Design chilled water flow (m3/hr) 57.46
Design chilled water in/out temperature (˚C) 12/7
Design Chilled water pressure drop (Kg/cm2) 1
Design cooling water flow (m3/hr) 168
Design cooling water in/out temperature (˚C) 32/36.2
Design Cooling water pressure drop (Kg/cm2) 1
Design Hot Water flow (m3/hr) 44
Design hot water in/out temperature (˚C) 88/78
Table 2. Design details for Chilled water pumps.
Primary Chilled water pumps: 02 nos.
S.N. Particular Make Type/Model Flow (m3/hr) Head (m) Motor (KW) Speed (rpm)
KSB MEGA-G-50-25060 60 22 2945
1 Primary Pumps
KSB MEGA-G-50-16060 32 7.5 2880
Secondary Chilled water pumps: 04 nos.
1 Secondary Pump-A Beacon 50/160 30 40 7.5 2900
2 Secondary Pump-B Beacon 50/160 50 35 7.5 2865
3 Secondary Pump-C Beacon 50/160 30 40 7.5 2900
4 Secondary Pump-D Kirloskar DB 50/20 60 43 15 2900
S. P. JAGTAP, A. N. PAWAR 175
parameters for VAM-II was carried out is shown in Ta-
ble 4.
Recommendation for both the VAMs: As per Ta-
bles 3 and 4, both the VAM’s heat input were less com-
pared to design level as shown in Figure 4. Similarly it
was also observed that refrigeration effect of both the
VAM’s was less to their design. Hence the Co-efficient
of Performance (COP) of both VAMs-I and VAM-II is
reduced to expected design value of 0.66 as shown in
Figure 5. Therefore it was recommended to clean the hot
water and cooling water heat exchangers of both the
VAMs to improve the heat input rate (H1) and refrigera-
Table 3. Performance analysis of VAM-I.
Chilled water flow (m3/Hr.) 43.7 Difference
Chilled water temp. diff. (˚C) 12.2 7.44.8
Chilled water pressure drop (kg/cm2) 2.8 1.61.2
Cooling water flow (m3/Hr.) 135
Cooling water temp. diff. (˚C) 29.2 32.93.7
Cooling water pressure drop (kg/cm2) 1.4 0.50.9
Hot water flow (m3/Hr.) 50
Hot water temp. diff. (˚C) 78.5 71.76.8
Hot water pressure drop (kg/cm2) 2.2 1.60.6
Actual Capacity (TR) 69.37
Heat Input: H1 (Kcal/Hr.) 340,000
Heat absorbed through chilled water : H2 (Kcal/Hr.) 209,760
COP 0.62
Table 4. Performance analysis of VAM-II.
Chilled water flow (m3/Hr.) 42 Difference
Chilled water temp. diff. (˚C) 14.7 9.55.2
Chilled water pressure drop (kg/cm2) 2.5 1.3 1.2
Cooling water flow (m3/Hr.) 125
Cooling water temp. diff. (˚C) 28.2 313.7
Cooling water pressure drop (kg/cm2) 1.0 0.4 0.6
Hot water flow (m3/Hr.) 54
Hot water temp. diff. (˚C) 73.6 676.6
Hot water pressure drop (kg/cm2) 2.4 1.0 1.4
Actual Capacity (TR) 72.22
Heat Input : H1 (Kcal/Hr.) 356,400
Heat absorbed through chilled water: H2 (Kcal/Hr.) 218,400
COP 0.61
Heat Input: H1
(Kcal/hr)
Refrigeration Capacity:
H2(Kcal/hr)
500,000
450,000
400,000
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
(kCal/Hr)
VA M -I
VA M -II
Design
VAM-I
VA M -II
Design
Figure 4. Heat rate analysis for both VAMs.
Desi gn
COP of both VAMs
Design
VA M - I I
VA M - I
VA M - I I
VA M - I
COP
0.58 0.60 0.62 0.64 0.66
Figure 5. Comparison of actual COP with design COP.
tion Capacity (H2), and hence consequently the COP of
both VAMs would be improved.
3.3. Performance Analysis and
Recommendations for Chilled Water Pumps
3.3.1. Pe rformance Analysis and Rec omm endations
for Primary Chilled Water Pumps
With the help of ultrasonic flow meter and digital pres-
sure gauge and electrical power analyzer chilled water
flow rate (m3/Hr.), pressure (m) and electrical power (kW)
respectively were measured. The measured values are
plotted in following Table 5.
Two pumps of same flow rate (60 m3/Hr) but different
design pressure head (60 m and 32 m) were installed.
The higher pressure head pump was used when both the
VAMs were in operation for catering chilled water cir-
culation in evaporators of both VAMs. The necessary
pressure head, flow rate and their electrical power con-
Open Access MME
S. P. JAGTAP, A. N. PAWAR
176
sumption were measured with the help of respective
measuring instrument and summarized in Table 5.
During site survey and taking measurements, it was
observed that, when low design head Primary Chilled
Water pump (MEGA-G-50-160) in operation, the pri-
mary pump discharge pressure at 43 m3/Hr flows is 33 m
and the pressure at the inlet of VAM m/c is 28 m, which
indicated 6 m of pressure drop in supply line. Similar
was the case observed with high design head capacity
pump operation (MEGA-G-50-250 as per operating phi-
losophy of VAM), When both the chillers are in opera-
tion, the primary pump discharge pressure at capacity of
56 m3/hr indicated 10 m of pressure drop in supply line.
This was also counterchecked with existing 100 mm di-
ameter pipe and proposed retrofitted 150 mm diameter
pipe with the help of Hazen-Williams Formula [5] as
shown in Table 6.
Hd = [6.1961 × 103 × (Q × δ/60)1.852]/[100 × C1.852
× Dh 4.87]
Where,
Hd Pressure head drop (m)
C Design coefficient determined for the type of
pipe or tube—the higher the factor, the smoother the pipe
or tube
Q Flow rate (m3/Hr)
δ Density of liquid (for Water—1000 kg/m3)
Dh Inside hydraulic diameter (mm)
From the analysis of Pressure head loss for 100 mm
and 150 mm diameter pipeline of Primary chilled water
pumping system as shown in Figure 6, It was recom-
Table 5. Actual Measurements and performance evaluation
for Prim ary Ch illed Water Pum ps.
S.N. Pump no. Capacity
(m3/hr) Total Head
(m) Power
(kW) Efficiency
(%)
1 MEGA-G-50-250 56.2 66 20.9 56.9*
2 MEGA-G-50-160 43.7 33 8.12 56.9
*Efficiency = Total Head (m) × Flow rate (m3/hr)/{367 × Eff.Motor × Input
Electrical Power (kW)}.
Table 6. Pressure Head loss evaluation for different diame-
ter pipelin e.
Particular Low design
head pump
Higher design
head pump
Length of pipe line (m) 140 140
Flow in pipe line (m3/hr) 43 56
Pipe line diameter (mm) 150 150
Friction factor (.C) (Refer Annexure-I) 100 100
Press. Head Loss when 100 mm
pipe diameter (m) line (mm) 6.058 9.880
Press. Head Loss when 150 mm
pipe diameter (m) line (mm) 0.84 1.37
mended laying of 150 mm diameter pipeline (instead of
100 mm installed) with insulation. Also it was recom-
mended to replace of both primary pumps with following
rating.
Desired pressure head losses in pipeline after retrofit-
ting of correct sized pipeline laying:
Desired total head: (Static Head) + (Chilled water
pressure drop in evaporator) + (Discharge line friction) +
(#Minor Losses)
(# Minor pressure head losses were very less compares
to other components in present VAM system, hence ne-
glected.)
Proposed pump specification and power Consump-
tion for MEGA-G-50-160 model
Static head : 5 m
Chilled water pressure drop in evaporator
for small pump operation : 12 m
Discharge line friction for small pump : 1 m
Total Pressure head for Small pump : 18 m
Required Capacity as per VAM : 45 m3/Hr
Efficiency (from market survey) : 72%
Assume Electrical Motor Eff. : 85%
Power consumption for above pump : 3.61 kW
Proposed pump specification and power Consumption for
MEGA-G-50-250 model
Total Pressure head for Big pump : 36 m
Required Capacity as per VAM : 90 m3/Hr
Efficiency (from market survey) : 78%
(Refer Annexure-II)
Power consumption for above pump : 13.32 kW
Existing power consumption : (20.9 + 8.12)/2*
: 14.51 kW
*For calculation of saving potential, single VAM and two VAM’s
operation at a time is considered 50% - 50% as per operation history.
Proposed power consumption : (3.61 + 13.32)/2
: 8.46 kW
Heat loss
at 150 mm
Dia. Pipe
Head loss in m
35 40 45 50 55 60
Flow rate (m
3
/Hr.)
Heat loss
at 100 mm
Dia. Pipe
12
10
8
6
4
2
0
Figure 6. Analysis of Head Loss in pipeline.
Open Access MME
S. P. JAGTAP, A. N. PAWAR 177
3.3.2. Pe rformance Analysis and Rec omm endations
for Secondary Chilled Water Pumps
With the help of measuring instruments, actual parame-
ters of secondary chilled water pumps are measured and
analysis for its performance was carried out as shown in
Table 7.
From above analysis, it is clear that the efficiencies of
Secondary Pump-A & Secondary Pump -B are very poor
and recommended to replace with energy efficient new
pump. Hence it was recommended to replace the existing
pump with following proposed rating.
Secondary p u m p - A :
Capacity (m3/hr) 15
Pressure (m) 45
Efficiency (%) 55
Proposed power consumption (kW): 3.93
Secondary p u m p - B :
Capacity (m3/hr) 65
Pressure (m) 22
Efficiency (%) 77
Proposed power consumption (kWh): 5.95
Proposed power consumption in Secondary chilled
water pumps = 3.93 + 5.95 + 6.2 + 10.4
= 26.48 kW
3.3.3. Cost -Benefit Anal y si s
Overall analysis of power consumption reduction was
carried out by comparing existing and proposed measures
for both primary and secondary chilled water system
which is summarized in Table 8 . Overall about 21% po-
wers could be reduced by proposed measures as shown in
Table 8.
Operational hours per day: 16
Operating days per annum: 350
Total operating hours per annum: 5600
Energy cost (Rs./kWh): 6.25
Energy Saving potential (Rs./year): 321,650
Tentative Investment (Rs.): 450,000
Payback (months): 17
Table 7. Actual Measurements and performance evaluation
for Secondary Chilled Water Pumps.
S.N. Particular Pump
Identity
Capacity
(m3/Hr)
Total
Head (m)
Power
(kW)
Efficiency
(%)
1 Secondary
Pump-A PA-639B 13.4 41 5 35.2
2 Secondary
Pump-B PA-638A 60.3 19 8.0245.8
3 Secondary
Pump-C PA-637B 37 33 6.2 63.1
4 Secondary
Pump-D PA-634A 38 52 10.460.9
Existing total power consumption 29.62
Table 8. Power consumption reduction in Chilled water sys-
tem.
S.N.Pump Existing
Power (kW)
Proposed
Power (kW)
Power Saving
(kWh)
Power
Saving (%)
1Primary
Chilled water14.51 8.46 6.05
2Secondary
Chilled water29.62 26.48 3.14
Total 44.13 34.94 9.19
20.82
4. Result and Discussion
Through detail study, performance analysis of chilled
water pumping system for VAMs of the industry was
indicating remarkable saving opportunities in installed
pumps. Installed primary and secondary chilled water
pumps were not selected at proper duty point and also
pipe diameter design in pipeline network was undersized.
Overall chilled water pumping system consumes 44.13
kWh electrical units while that of proposed pumps would
consume only 34.94 electrical units. Almost 21% elec-
trical power could be saved. Also in VAMs observation,
the pressure drop across the evaporator is 1.2 kg/cm2
compares to manufacturers design it should be 1.0 kg/
cm2. This indicates evaporator tubes to maintain cleaned
periodically.
5. Conclusion
The present study is honestly tried elaborate effort to
examine the performance of a pumping system of VAM
of a chemical industry. Energy audit as per Energy Con-
servation Act 2002 is an effective tool in identifying and
perusing a comprehensive energy management program.
A systematic approach to comprehensive understanding
of any type of industry with their different processes can
give the industry a plan with which it can effectively
manage the industrial energy with its minimum cost. This
approach could be useful for an industry in combating
essential energy cost and also tapping many other bene-
fits like improved production cost, higher profit and most
important satisfaction for contributing in world energy
saving.
REFERENCES
[1] Bureau of Energy Efficiency, “General Aspects of Energy
Management and Energy Audit,” Guide Books-01.
[2] Bureau of Energy Efficiency, “Energy Efficiency in Elec-
trical Utilities” Guide Books-03, Chapter-01,02, Chap-
ter-06,04.
[3] N. R. Kumbhar and R. R. Joshi, “An Industrial Energy
Auditing: Basic Approach,” International Journal of
Modern Engineering Research (IJMER), Vol. 2, No.1, pp.
313-315.
Open Access MME
S. P. JAGTAP, A. N. PAWAR
Open Access MME
178
[4] Çengel Y.A. and Boles M.A., “The Second Law of Ther-
modynamics,” In: Thermodynamics an Engineering Ap-
proach, 7th Edition, Chapter No. 06, McGraw Hill Com-
panies Publication Book, New York.
[5] S. W. Bedford, “Fluid Mechanics,” 9th Edition, Tata
McGraw Hill Edu. Pvt. Ltd., New Delhi.
S. P. JAGTAP, A. N. PAWAR 179
Annexure-I
Table. Hazen-Williams’s coefficients.
Recommended C Value
Pipe Material New Pipes@ Design Purpose
Unlined Metallic Pipes
Cast Iron, Ductile Iron 130 100
Mild Steel 140 100
Galvanized Iron above 50 mm dia.# 120 100
Galvanized Iron 50 mm dia and below used for house service connections.# 120 55
Centrifugally Lined Metallic
Cast Iron, Ductile Iron and Mild Steel Pipes lined with cement mortar or Epoxy Up to 12,000 mm dia 140 140
Above 1200 145 145
Projection Methose Cement Mortar Lined Metallic Pipes
Car Cast Iron, Ductile Iron and Mild Steel Pipes 130* 110**
Non Metallic Pipes
RCC Spun Concrete
Pre stressed Concrete
Up to 1200 mm dia 140 140
Above 1200 mm dia 145 145
Asbestos Cement 150 140
PVC, GRP and other Plastic Pipes. 150 145
Note: @ The C values for new pipes included in the Table 6.1 are for determining the acceptability of surface finish of new pipelines. The user agency may
specify that flow test may be conducted for determining the C value of laid pipelines. #the quality of galvanizing should be in accordance with the relevant
standards to ensure resistance to corrosion throughout its design life. *For pipes of diameter 500 mm and above; the range of C values may be from 90 to 125
for pipes less than 500 mm. **In the absence of specific data, this value is recommended. However, in case authentic field data is available, higher values up to
130 may be adopted.
Annexure-II
Pump performance Data sheet
Customer : Quote Number :
Customer Reference : Size : CE50/16
Item No : 02 Stage : 01
Uses Territory : Based on Curve No : HD18811CAD Rev 1
Quantity : 01 Date Last Saved : 10 May 2011, 7:07 AM
Operation Conditions Liquid
Flow Rated :75.00 m3/Hr Liquid Type :
Differential Head/Pressure Rated (required) : 35 m Additional liquid description : Water
Differential Head/Pressure Rated (actual) : 35.1 m Solids diameter Max. : 0.00 mm
Suction pressure rated/Max : 0.00/0.00 bar g Temperature Max. : 20.00 deg C
NPSH available, rated : Ample Fluid density rated/Max : 1.000/1.000 SG
Frequency : 50 Hz Viscosity rated : 1.00 cST
Open Access MME
S. P. JAGTAP, A. N. PAWAR
Open Access MME
180
Continued
Vapor pressure rated : 0.00 bar a
Performance Material
Speed rated : 2900 rpm Material requested: 01
Impeller diameter Rated : 164 mm MOC C1260(012)/C1260(012)/CS40C8(053)
Impeller diameter Maximum : 174 mm Material Selected : 01
Impeller diameter minimum : 135 mm MOC C1260(012)/C1260(012)/CS40C8(053)
Efficiency : 79% Pressure Data
NPSH required/ margin required : 4.32/0.50 m Maximum working pressure : 3.73 bar g
nq (imp. Eye flow)/ S (imp. Eye flow) : 28/141 metric units Maximum allowable working pressure : 5.59 bar g
Minimum continuous safe flow (MCSF) : 8.80 m3/Hr Maximum allowable suction pressure : 1.96 bar g
Head Maximum, rated diameter : 38.01 m Maximum test pressure : 5.59 bar g
Flow Best Efficiency Point 9BEP) : 81.01 m3/Hr Driver and power data
Flow ratio (rated/BEP) : 92.54% Driver sizing specification : Rated Power
Diameter ratio (rated/max) : 94.25% Margin over specification : 10%
Head ratio (rated dia./max dia.) : 85.71% Service factor : 1.00 (used)
Cq/Ch/Ce [ANSI/HI9.6.7-2004] : 1.00/1.00/1.00 Power hydraulic : 7.14 kW
Selection status : Acceptable Power rated : 9.09 kW
Power Maximum, rated diameter : 12.68 kW
Minimum recommended Motor rating : 11.00 kW/14.75 hp
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
Flow m
3
/H
r
50
45
40
35
30
25
20
15
10
5
0
16
12
8
4
0
16
8
0
N
PSH
r
Power
Minimum Continuous Flow
HEAD (m)
POWER (kW)
N
PSHr (m)