Energy Audit

r ~ ...... ~.----

i·COST Electronic &comll1unicmion proceedings 13·15 ja~O II

Energy Audit in Industry -A case study of Centrifugal Pumps

R.M.Hohnukhe K.D.Deshpande

Electrical Engineering DepartmentBharati Vidyapeeth Deemed UniversityCollege of Enggineering, Pune, India

E-mail: [email protected]

Electrical Engineering DepartmentBharati Vidyapeeth Deemed UniversityCollege of Enggineering, Pune, India

E-mail: rajeslunholmukhe@hotmaiLcom

Abstract-s-, Energy conservation litis 1l0W become a necessity. Considerable energy saving is possible throughproper choice of equiprnents, and their effective use. The-only feasible way to handle energy crisis, apart fromcapacity addition, is the efficient use of available energy. For this there is a need of optimizing energy, usingstandard systems and procedures so as to reduce energy requirements per unit of output.In this paper a case studyof centrifugal pump in industry for energy audit is presented. Keywords-energy audit,centrifuga!pumps

Modeling and Simulation of Buck boost Controller of Solar WindHybrid Energy System

IPatif S. N. 2S.S. Patif 't».R. C PrasadIAsst. Prof. in Electrical Engg. Dept., P. V.P.lT Bavdhan, Pune

lAsst. Prof. in Electrical Engg. Dept., Sinhagad Academy of Engineering, Pune,Jprof in Electrical Engg. Dept., College of Military Engineering, Pune

Ipatil sn@[email protected]

Abstract- Because of combustion of fossil fuels global warming caused by environmental problems, the raisingprices of crude oils and natural gases. They promote continuous effort to improve energy system and its efficiency.There is a need to search for abundant and clean energy sources due to the depleted and increasing prices of oil.Solar and wind energy acts as an alternative energy source.The objective is to design and simulate a controller for the unlimited solar power drawn from the sun and producea higher voltage output through the de-to-de converters (Buck-Boost Converter). The Photovoltaic cells have anon-linear V-I characteristics and adapts the Maximum Power Point Tracker (MPPT) to achieve the maximumpermissible power obtained. A controller circuit is design to track the maximum power of the photovoltaic at thepeak voltage and current level. De-to-De converters (Buck-Boost Converter) are necessary to produce a highervoltage due to the low input voltage drawn from the photovoltaic cells. The voltage is maintained at a constantvoltage at the output load by the switching control circuit. Wind controller circuitry comprises a non-inverting buckand boost converter circuit The result shows that the model can simulate the photovoltaic models, wind system andtrack the maximum power which helps to design and improve the power of solar wind energy system.

Keywords: Modeling, Photovoltaic System, Maximum Power Point Tracker, Buck-Boost Converter.

S.S.V.P.S.'s B.S.Deore college of Engineering & Polytechnic.Dhule. Page 28

Energy Audit in Industry -A case study of Centrifugal Pumps

RMHolmukheElectrical Engineering Department

Bharati Vidyapeeth Deemed UniversityCollege ofEnggineering, Pune, India


Abstract-. Energy conservation has now become anecessity. Considerable energy saving is possible throughprtIfIt!TduIia of ~ tBUltJuir eff~ I!SL 1h0III;y ftWSible ....., ID IuuuIk nID1:.F am.s. 1IJIIIIt.frotrtaqJIIdI:y IMI4iIimI. is tIu! ejJiL.inrt IISe of ~ I!III!I'V-

F", tIIis tlIen! is • .ed of opti-kirtg DIDV, IISiIrKsIIBIIItmI sy.sIDIB 11IIIIprot:a/IIrt!s :so lIS ID rrtIIu% DfDV

~ per IIIIiI of twtpwt I. litis JIIIIN!' • ccse sIIuIyof centrifugal pump in industry for energy audit ispresented.

Keywords-energy audit.centrifugal pumps

L lNrRoDUCl10N

An Energy Audit is the preliminary activity towardsinstituting energy efficient programs in the eslablishmentltconsists of activities that seek to identify conservation.Factors to be considered during energy audit are energyaccounting, better control of energy use, processoptimization for efficient energy use, creating awarness andfoUowing standard rules and reguJations.Gener.dIy anEnergy Audit includes survey of work place ,analysis ofenergy usagt;.SlUdyof energy use procedures,finding energyimprovement opportunities ,recommendations with costbenefit analysis..

II. THE ROLE OF AN ENERGY AUDIT

Identify areas in the establishment consumingunnecessarily too much energy.Assess energy saving opportunities so as to savemoney where it counts the most.In the factory, an energy audit increases awarenessamong plant personnel of energy issues.An energy audit gauges the energy efficiency of theplant against "best practices", when used as a"baseline" for tracking yearly programs againsttargets.h is the f"lTSt step towards saving money in theproduction pIanL

llI. CONTENTS OF AN AUDIT

An energy audit seeks to document things like energy beingused on site per year which includes use of energy and

K.D.DeshpandeElectrical Engineering Department

Bharati Vidyapeeth Deemed UniversityCollege ofEnggineering, Pune, India


opporturuties for savings.In the process it assesses theeffectiveness of management structure for controlling energyuse and impIement:iI1g cbaoges.The energy audit reportestabIisbes the need for plant metering and monitoring.Theplant Manager then instititutionaIize the practices thus savingmoney fur the years to come:nM! energy audit action planIisIs the steps and sets the preliminaIy budget fur-the energymanaganent progranL

IV. ANALYSIS OF ENERGY USE

Identifying areas where energy used is most useful.Thisenables to focus OIl areas where the andit should be focusedand raises awareness of energy use and cost.The resultscould be used in the review of management stroctures andprocedures fur controlling energy use.

V. IMPORTANT POINTS TO CONSIDER WHEN COLLECTINGSITE LOAD DATA

Operating hours: It is collected from plantpersonnel..This data sbouJd be accurate so as toestimate energy savings correctly.Duty Cycle: Machines, such as large inductionmotors have varying loads with different powerrequirements.Hence duty cycle is very importantActual Power Consumed: For electric power users,this is based on either 3-phase current/voltagereadings or power analyzer measurements(e.g.direct KW which incorporatespower factor).

For fuel users, tank readings of monthlyconsumption estimatesand flow meters with totalization can be source ofmeasurement.

VI. !DENTIFICA TlON OF ENERGY PROJECTS

In identifying energy ~ it is impor1ant to focus onmajor eIiergy users and areas.Always apply 80120 rule, focusOIl opportunities that provide XO'"/e of the savings but require2()O/e inpuLSpeod more time on those projects which haveshorter payback period.

YH COSTBENEFITANALySIS

The identififxJ energy conservation opportunities should beanaiyzl:d in tenns of the costs of iq)IemeoIing the ~versus the benefits that can be ~ makes a sense to go011 with the project if there is a net positive benefit from theproject.

VIII ACTION PLAN TOSET IMPLEMENTATION PRIORITY

After passing the cost benefit analysis test, an action planshould be developed to ensure that the opportunitiesidentified are implemented.The action plan should include allthe major steps for implementing the opportunity as well asthe people responsible. Furthermore, there should be a plan tomonitor the results.

IX TYPES OF ENERGY AUDTr

TypesofE.ergy AIlCIitsThe term Energy Audit tries to identify the alternative energyefficient measures that would also satisfY the financialcriteria of the investors A demiled specification of the scopeof work: is necessary to speU out the requirement of the audit.

There are three common audit programs which aredescribed in next pages.

Prdimilary A.ditThe preliminary audit also called as a simple audit, screeningaudit 01" walk: through audit, is the simplest and quicker typeof auditsJt involves minimal interviews with the siteoperating personneI.a brief review of the fuciJity utility billsand other operating data, and a walk-through of the facilityto become familiar with the plant operation and identifyareas of energy waste or inefficiency .Major problem areaswill be uncovered during this type of audit..Correctivemeasures are briefly described and estimates ofimplementation costs, potential operating cost savings, andsimple pay back periods are provided.This helps to priotizeenergy efficient project and detennine the need for a moredetailed audit.

Geaentl AllditGeoeraJ audit or a mini audit/site energy at~it expands onthe preliminary audit.More detailed information aboutfacility operation is collected so as to perform a moredetailed evaluation of energy conservation measuresidentified. Utility bills for a period of 12 to 36 months arecoUected to evaluate the fucility's energy/demand ratesIructures and energy wage profiIesAdditiooal metering ofspecific energy- consuming systems is often performed tosupplement utility data..ln-depth interviews with facilityoperating personnel are conducted to understand majorenergy consuming systems as well as insight into variationsin daily and annual energy consumption and demand. Adetailed financial analysis is performed for each measures tojustify project implementation.

lnvestment- Grade Audit

Facility's energy infiasbucture must compete with non-energy related investment fur fur capital fimding Both energyand DOD-eIIeIgy investnlents are rated on a single set offinancial criteria that generally stress the expected Return onJnveslmen1(ROI)..Retm:n 011 Investment =Net Profit aftertaxesITotaJ InvestmentIhe projected operating savings fiumthe ~Jemetdation of energy savings should provideconfidence to the investors.The investment-grade audit alsoknown as a comprehensive audit,detailed audit, maxi audit ortechnical analysis audit expands on general audit providing adynamic model of energy use of existing facility and allenergy conservation measures identified.

X PUMP ENERGYREDUCTION

Pump system account for 13% of Electrical EnergyConsumption in India.When analyzing the life cycle ofpwnping equipment, the energy cost in operation is 85% forlarge water utility pumps.Selecting a bigher efficiency pwnpwill reduce power consumpIion, but by improving the designof the pwnp system and cootrolling the interaction betweenthe pwnp & the system would acbieve greater improvement,

I'-- I

;~ II «DlI!l -, ), ~'\.,/-..-,---

\

Figure NO.1. Pump system identification

If pwnp systems are initially designed on an energy efficientbasis and pmnps are correctly operated & sized, the energysavings will often be in excess of 50%.lDe reasons forenergy inefficient pumping system are Poor SystemDesign,over sizing of pump,pump and system mismatching,pipe work layouts.Significant savings can be made inexisting system by carrying out systematic audit & betteroperation eontrol.A study indicates that greatest energyconsumption by pumps is in application in commercial &public buildings(41%), water & sewerage facilities(14%)and others (9010) as shown in fig.

EnergJCcnsuqIIion bv ~orOIaldGi15 IIII!ria;; aid~"UhIaI••••• :11 ~A

Figure o2J~DagyCOIl5UIDp6on by sedor"

Xl CARRYING 0 A SYSTEM AUDIT

Purpose of energy audit is to reduce 'operating costs byreducing energy consumption. Energy audits carried out byIPMA shows that savings in the range 30 to 50% are notunusual.By reviewing utility bills one can get an indicationof the savings to be made and the estimate of investment tobe made into auditing process.In most industrial sites twothirds of the energy is consumed by electric motors.The costof energy consumed by motor during its life time may be100 times its purchase cost.Through modem designtechniques, this loss can be reduced to 30%.Many pumps &motors are operated at full power constantly, irrespective ofprocess needs, and in some sites this offers the potential oflarge cost reductions.An energy audit is a significantinvestment and many man-hours are needed to find outwhere energy is consumed. A thorough log of consumptionon each spur is made because excess energy is sometimesused in most unlikely place.An energy audit identifiessavings to be made by resizing or retrofitting pumps whichare operating away from their best efficiencypoints.Variable speed motors in place of standard motorscan be used to control pump operations.By studying processrequirement, energy audit can identify requirement ofenergy consumption and compares it with actualconsumption.lf every pump and motor is working at themaxm. efficiency, great savings can beachieved. Performance data for the equipment as originallysupplied or manufacturers curves are required to carry outthe audit.From the name plates of the pump and motor datacan be recorded.Determination of actual flows and pressuresmay be difficult at site due to non-availability of pressuregauge and flow meters. Power readings on site may often be

inaccurate.However the vananons form the originalspecified duty is so large that estimated actual performancefiom data which is available is sufficieut to to guide actionsfor energy reduction.. Trimming cost of an impeller inSteadof Ibrottling can be recovered in a few days..For large pmnpswhere saving potentiaI are high. a specialists is employedwho insIaUs tempotaay insmurc:adalions to accuratelymeasure perlOnnance.

Figure No3. Pump

XII. A CASE STUDY OF CENTRIFUGAL PUMPS

Existing pump details:Kirioskar pump model DB50/20,size (65x50)mm,Pump sr. no.9370757,58Head: 46 mtrsDischarge: 6 IpsPump efficiency: 47%BKW: 5.75Motor: 7.5KW/IOHP,TEFC induction motor

Observations: 1Pumps operating 6hrs per day2Pumps operated at full capacity

Suggested pumpKirloskar Pump Model DB 40/20,size (65x40)mmHead: 46 mtrsDischarge: 61psPump efficiency: 54%BKW:5KWMotor recommended 5.5KW/7.5HP TEFCindustion motor

Cost Benefit AnalysisC =(n2-nl) x PxZxSx 0.746/n]C= (54-47)xlOx2J90x7.5xO.746/54 = Rs 14825 peryearCost of new pump type DB 40/20 with 5.5HPmotor = Rs 12030Pay back period = 10 months.Total saving during full life(15 yrs) = Rs 2,22,375each pump.

RESULTS

l'--··---·---·-·····---··--~l..II

~/

I '.I.. t

ACKNOWLEDG lENT

Bharati Vidyapeeth Deemed UniversityEngineering, Pune.

College of

REFERENCES

[I] Field Visitsin various industries[2] Manuals of Kirloskar motors and pumps.[3] Handbook of Energy Conservation.[4] Various IEEE papers on motors and pumps.

Documents

Energy Audit