Air Compressor System Efficiency and Performance

8/11/2019 Air Compressor System Efficiency and Performance

1/17

Improving Rutgers' Air Compressor SystemsEfficiency and Performance

David Kim

kimmaster@gmai!com

"ack #amiye

papape$@ao!co

Kye %urnssiver&uet(@optonine!net

)orie Rosetorgerrose@msn!com

"osep* +avodny,p-avodny@comcast!net

1. Abstract

)*e purpose of t*is pro,ect $asto detai and anay-e Rutgers'compressed air system. utimateyfinding $ays for Rutgers to save money&y using ess energy! /ur motivationfor t*is task $as to gain e0perience and a&etter understanding of t*e type ofpro&ems engineers face today! )o dot*is. $e first researc*ed $*at factorsaffect a compressed air systemsperformance and efficiency! 1it* t*iskno$edge. $e set out to find pro&ems$it* t*e compressed air system &yvisiting t*e Cogeneration 2Cogen3 Pantand severa of t*e &uidings it suppiescompressed air to!

1e discovered a num&er ofpro&ems $it* t*e system! Due to t*eack of time. *o$ever. $e coud notaccompis* everyt*ing $e set out to do!)*erefore. $e made recommendations

on *o$ t*e system coud consume essenergy and $*at t*e &est possi&esoution $oud &e for Rutgers to foo$using $*at data $e $ere a&e to gat*er!

/ur soution entais t*at Rutgers*ave t*e eaks in t*eir system repaired!After t*is. $e recommend t*e purc*aseof a ne$er. more efficient compressor to

repace t*e current centra compressor!

4inay. $e recommend t*at Rutgers cutoff its ongest distri&ution ines and t*atdistant &uidings esta&is* t*eir o$ncompressed air systems!

2. Introduction

Compressed air is commonyreferred to as t*e fourt* utiity! A utiityis somet*ing $*ic* is a &asic necessity!4or e0ampe.t*ree common utiities are

$ater. eectricity. and natura gas!5tiities pay a ma,or roe in t*e modern$ord 6 $it*out t*em. todaystec*noogicay advanced society coudnot function!

Compressed air is simpy air t*atis pressuri-ed &y an air compressor! It iskno$n as a utiity &ecause it is a type ofenergy source $*ic* is a &asic necessityin many industria environments! It can&e seen in over seventy percent of t*e

$ords industria faciities!At*oug* compressed air systems

are $idespread. t*ey are e0tremeyinefficient! Compressed air systemstypicay consume more energy and costmore to operate t*an anyt*ing ese inindustria environments!


2/17

1orking $it* our mentors at t*euniversitys Center for Advanced EnergySystems 2CAES3. $e traveed toRutgers Cogen Pant and severa&uidings on campus $*ic* use

compressed air! During t*is time. $ecoected data t*at $oud *ep us toevauate t*e system currenty in paceand to determine *o$ muc* moneymig*t &e saved &y making variousc*anges to t*e system!

3. Background

An air compressor is a mac*inedriven &y an eectric motor t*at

compresses air t*roug* a variety ofdifferent tec*ni7ues and tec*noogies!As a system. an air compressor *as avariety of appicationssuc* as operatingpneumatic toos and sand&asting. &utconstructing t*e system itsef iscompicated and must &e engineeredpropery to matc* t*e demand andac*ieve optima efficiency!

4irst. t*e system intakes air.usuay t*roug* a fiter. and sends it to a

primary compressor to pressuri-e t*e air!)*en t*is air is sent to an appropriatey8si-ed storage tank! 1*en compressed airis actuay needed. t*e storage tankreeases its air t*roug* eit*er refrigerantor desiccant dryers to remove any of itsmoisture! )*ese components. *o$ever.can &e set up as a series according to t*eneed and situation of t*e demand forcompressed air!

)*e t*ree most common types of

compressors are t*e rotary scre$. t*ecentrifuga. and t*e reciprocatingcompressor9 :(;

Rotary screw compressors

typicay use t$o to t*ree scre$st*at mes* toget*er to compress air

and force it out t*roug* a smaopening!

Centrifugal compressorsoften usesevera stages of rapidy spinning

impeers to provide a continuousfo$ of air! )*is type. *o$ever.re7uires an inter8stage cooing at*ig*er pressures in order to return itto its initia temperature &efore t*ene0t stage!

Reciprocating compressors2t*emost common type. especiay insmaer appications3 use an eectric

motor to turn a crank s*aft t*atoperates a series of pistons andvaves to intake. compress. andreease air into a storage tank!


3/17

Air compressors. *o$ever. arevery inefficient. usuay *aving adetermined energy efficiency of ony tento t$enty percent! :


4/17

1*ie t*e compressor itsef isinefficient. t*e system itsef can detractfrom t*e overa efficiency of acompressed air system! 4or e0ampe. aot of friction is created in ong

compressed air distri&ution ines and&ends in t*e ines! Beaks in t*ese inesgro$ as time passes and are t*e maincause for inefficiency and poorperformance! Energy is aso $asted$*en compressed air is usedinappropriatey! 4or e0ampe. one coudinappropriatey use compressed air todry to$es!

4urt*ermore. poory8maintainedsystems can resut in inevita&e pro&ems

in t*e future! It is important t*at a t*eparts to an air compressor system isc*ecked for eaks. premature $ear ofany parts. accumuation of contaminantsin t*e air compressor. etc! to ensure t*atma0imum efficiency andstorage=operating capacity is reac*ed!/ne pro&em past industries *ave facedis t*e accumuation of $ater in storagetanks t*at continue to gro$ and reducestorage capacity! )*erefore. simpenegigence to constanty c*eck on t*eentire air compressor system can ead to$asting energy and money!

)*ese a are t*e ma,or pro&emsfacing air compressor systems! 1*iecompressed air can &e a great resourcefor industry. t*e compicated nature ofits production and distri&ution *as ed tostudies concerning t*e possi&eimprovements of an air compressorsystem to o&tain *ig*er efficiency and&etter performance!:;

. !"perimental #esign

/n t*e Rutgers campus.&uidings t*at receive compressed airfrom t*e campus Cogeneration Po$erPant currenty receive air at a o$er

pressure t*an anticipated! )*ecompressors are designed to produce( PSI 2pounds per s7uare inc*. t*eunit t*at compressed air is measured ingauged &ased on t*e atmosp*eric

pressure3! Fo$ever. t*ere *ave &eensignificant PSI osses &et$een t*e Cogenpant and t*e &uidings it distri&utescompressed air to! )*ese osses arecaused &y &ot* eaks and t*e engt* oft*e ines! /ur researc* aims to identify asoution for t*e pressure oss due toeaks. as osses due to friction are a factof nature!:(;

In order to find $ays for Rutgersto o$er t*e cost of operating t*e

compressed air system. $e took mutipetrips to Rutgers' Cogen Pant and t*esevera of t*e &uidings it suppiescompressed air to! At t*e pant. $ecoected data pertaining to t*ecompressed air system! 1e measuredt*e capacities of t*e compressors andtanks! )*en. $e measured t*e pressuret*at t*e compressor $as supposed toproduce in contrast to *o$ muc* itactuay $as producing! 1e asodetermined t*e operating *ours as $eas t*e oad factor 2t*e percentage ofma0imum capacity at $*ic* t*ecompressor $as operating3 of t*ecompressors! After coecting t*e serianum&ers of t*e compressors. $e caedt*e manufacturers to get t*eirefficiencies! )*e manufacturers $ereuna&e to provide us $it* efficiency datafor some compressors. so $e *ad tomake educated guesses!

In t*e end. $e used our imitedkno$edge to discover a soution fort*ree simpe scenarios t*at represent t*emain pro&ems at t*e Cogen pant! It $asnecessary for us to simpify t*esescenarios!


5/17

.1 #etermining Cost of

$eaks

4irst. $e determined *o$ muc* it costs

to operate t*e current compressorsystem! )*is $as done using t*efoo$ing e7uations9

G 0 FP 0 B4 0 54 0 F E44$*ere.

G H num&er of compressorsFP H *orse po$er of compressors.

converted to kio$atts at a rate of

!< k1 per FPB4 H oad factor. ratio of actua oad toma0imum oad54 H utii-ation factor. ma0imum

demand of system over its capacityF H operating *ours of compressorsE44 H efficiency of compressor motor

Ge0t. $e determined t*e cost of t*econsumed energy using t*e e7uation

EC H E5 0 ER

$*ere.

EC H energy costE5 H energy usageER H rate of efficiency 2k1=*r3

1e simuated Rutgers' currentsystem using compressed air from onecentrai-ed compressor. outputting air at( PSI! 4or t*e sake of simpicity.$e ony incude t*ree of t*e &uidings on

campus! )*e system pressure at eac*&uiding is ess t*an (PSI as a resutof eaks and t*e engt* of ines! Systempressure varies from &uiding to &uiding&ecause eaks are not eveny distri&utedt*roug*out t*e system. and &ecausesome &uidings are furt*er from t*eCogen Pant t*an ot*ers!


6/17

Figure 1: This diagram shows different

pressure loss situations for three

different buildings each being suppliedcompressed air at 100 psig.

.2 Centrali%ed &ersus

#ecentrali%ed

)*e second scenario $as motivated &your findings at t*e separate &uidings!1e visited Smit*ers Fa. t*e Bi&rary ofScience and #edicine 2BS#3. and

5niversity of #edicine and Dentistry ofGe$ "ersey 25#DG"3! A of t*ese&uidings $e visited *ad t*eir o$ncompressors! Some &uidings used t*esecompressors as a &ack up to t*ecentrai-ed Cogen system. $*ie ot*ersused t*em as primary compressors. $it*t*e Cogen ine as a &ack up! )*e&uidings decentrai-ed compressors&roug*t up a good point! )*e centrai-edsystem at t*e Cogen pant may notactuay &e necessary!


7/17

Figure 2: This diagram shows a

centralized system with one compressor

operating at 200 horse power supplying100 HP and 0 HP worth of compressed

air to three different buildings.

1e decided to determine $*et*er it $asmore efficient to keep t*e centrai-ed

system t*at $as in pace. *aving t*e onecompressor operating at FP at t*epant suppy compressed air to a of t*e

&uidings. or to cut off t*e po$er panta toget*er and put a compressed airsystem t*at met eac* individua demandin eac* &uiding as s*o$n in 4igure J!


8/17

Figure !: This diagram shows eachbuilding with its own compressor that

operates at the e"act horsepower to

produce the amount of compressed airthat it re#uires.

)o determine $*ic* scenario

$oud &e more efficient $e caedmanufacturing companies to find out t*emotor efficiencies of t*e centrai-ed FP compressor versus t*e individua (FP and FP compressors!

'. Results

In order for us to &e a&e toanay-e Rutgers compressor air system.

it $as necessary to gat*er data and earna&out t*e current system in pace! 1e&egan our data coection at t*e Cogen.$*ic* is t*e center of Rutgers'compressed air system! /ur first task$as to find a compressor8reatede7uipment and to sketc* t*e ayout oft*e system! Fad t*e main compressor

&een functioning. $e $oud *aveinstaed data oggers to monitor t*esystem! At*oug* it $as not possi&e forus to do t*is. Rutgers' CAES provided us$it* t*eir og data! Additionay. $eac7uired a ist of compaints $it* t*ecurrent system and came across some

key pro&ems! 4inay. $e discussed andanay-ed our data. proposing a num&erof scenarios for t*e compressed airsystem!

'.1 C()!* +lantRutgers *as five air compressors

in t*e Cogen Pant! )*e maincompressor is a rotary scre$ compressormade &y Atas8Copco! )*ere is aso areciprocating compressor made &yIngerso8Rand. $*ic* $as t*e maincompressor unti Rutgers purc*ased t*eAtas! )*is Ingerso8Rand no$functions as a &ackup compressor!Rutgers aso o$ns t*ree smareciprocating compressors made &yuincy! )*ese are used $*en startingup t*e Cogen Pant! )*ere are t$o


9/17

storage tanks. one for t*e Atas and onefor t*e Ingerso8Rand! Rutgers o$nst$o air dryers. one of $*ic* is amec*anica refrigerant dryerL t*e ot*er isa desiccant dryer! /nce air is

compressed. it enters one of t$o storagetanks! Air t*en fo$s t*roug* t*e

mec*anica dryer. t*en t*roug* t*edesiccant dryer! After eaving t*edesiccant dryer. compressed air eavest*e Cogen Pant! Fere is a roug*diagram of t*e compressed air

e7uipment at Rutgers Cogen Pant

Control AirControl Air

Atlas Copco Air

Compressor

,torage

-ank

,torage

-ank

.uincy

Compressors

.uincy

Compressors

Ingersall /

Rand

Compressor

Ingersall /

Rand

Compressor

,torage

-ank

,torage

-ank

#ec*anica

Dryer

#ec*anica

Dryer

,chematic of Cogen +lant0s Air Compressor ,ystem


10/17

'.2 #ata $oggingCompressor data $as measured

and ogged using a type of data ogger

kno$n as a >F/%/?! System pressureand in one case eectrica current dra$&y t*e compressor $as ogged! )*is

data $as provided &y t*e mem&ers ofCAES. $*o *ad recenty recorded t*edata &efore $e ,oined t*e pro,ect! 1e

grap*ed t*e data so t*at it $oud &eeasier to anay-e! Gotice in t*e first t*reegrap*s t*at pressure tends to varyt*roug* t*e nig*t!


11/17

'.3 +roblems and

Complaints at Rutgers

In order to anay-e and improve t*eefficiency of Rutgers compressed airsystem. it $as vita to tak to managersand ask 7uestions! Fo$ever. t*is turnedout to &e a ma,or o&stace aong t*ecourse of our pro,ectL most peope $ereuna&e to ans$er our 7uestions! Fereare some of t*e fe$ pieces ofinformation $e earned9

)*e Atas compressor fais often.especiay in summer

)*e Cogen Pant is *aving trou&emeeting pressure re7uirements

BS# *as trou&e $it* o$ pressurecaused &y eaks in t*e system

1aksman. t*e fart*est &uiding fromt*e Cogen Pant. *as t*e most

compaints )*ey are *aving trou&e $it*

$ater in t*e ines Rutgers is $iing and ooking to &uy

a ne$ compressor It is possi&e to move t*e intake and

e0*aust ines from t*e compressorsat t*e C/EG Pant

Some of t*e ma,or 7uestions $*ic*coud not &e ans$ered9

Fo$ often t*e compressore7uipment is serviced 1*en t*e system $as ast c*ecked

for eaks


12/17


13/17


14/17

. #iscussionConclusions

)*e compressed air system atRutgers *as muc* room forimprovement! 4irst. it is necessary forRutgers to *ave t*e ma,ority of eaksrepaired as soon as possi&e! Beaks areresponsi&e for t*e ma,ority of $astedenergyL fi0ing t*em $i resut in t*egreatest cost savings!

1e proposet*at a t*e &uidings$*ic* are far from t*e Cogen pant &ecut off from t*e centrai-ed compressed

air system. $*ie a t*e near&y &uidingsremain connected to t*e currentcentrai-ed air system! )*is is so t*at t*ema,ority of &uidings on campus can&enefit from a more efficient. centrai-edcompressor! It is a good idea todisconnected distant &uidings &ecauset*e onger ines are t*e second argest$aste of energy $it* eaks &eing t*efirst!

1e *ave concuded t*at t*e &est

course of action is to eiminate t*e ongcompressed air ines to 5#DG" andBS# in favor of a decentrai-ed system.providing &ot* faciities $it* t*eir o$nin8*ouse compressors! )*e &uidingscoser to t*e Cogen pant. t*at aree0periencing &etter compressed airservice. $i keep t*e centrai-ed suppy&ecause our cacuations for t*ecentrai-ed system *ave proved morecost effective! )*e centra compressor

$oud t*en &e repaced in favor of asmaer. more efficient compressor t*at$oud do t*e same ,o& of t*e currentAtas compressor. assuming most eaks*ad &een repaired! A ne$ centracompressor s*oud &e purc*ased &ecausemore efficient motor $i save additiona

M(. a year. and &ecause t*e Atas is

not $orking propery!4inay. Rutgers can ac*ieveadditiona savings &y moving air intakes!According to our temperaturemeasurements. t*e Cogen Pants airtemperature is roug*y O degrees4a*ren*eit! )*e air temperature outsideis muc* ess. especiay during t*e$inter season! )*e potentia for energysavings. ,ust &y moving t*e intakeoutside t*e pant. is tremendous! 4or

e0ampe. in t*e $inter t*e aircompressor system may take in air t*atis degrees 4a*ren*eit instead of Odegrees 4a*ren*eit! )*e air compressor$oud consume O!(N ess energy duringt*e $inter t*an it does currenty in t*esummer!

O 4a*ren*eit 243 H J! Cesius 2C3 4 H ! C

J!J C H J!J Kevin 2K3! C H ! K

! K = J!J K H O!ONO!(N difference

. Related 4ork

)*is pro,ect is centered arounddetermining t*e most efficient mode ofa compressed air system. especiay

focusing on t*e most cost8effective!1*ie t*is is a common goa in industry$*ere compressed air is invoved. onesuc* case at a &otting pant &ears a coseresem&ance to our issue at t*e RutgersCogen faciity! )*e Sout*easternContainer Company. a &o$n pastic&otte production faciity. $as ooking to


15/17

drasticay increase t*e efficiency of itscompressor system and su&se7uenty cutoperating costs! Enisting t*e *ep ofGCS5s Industria E0tension Service.t*ey $ere a&e to manipuate t*e system

and make severa improvements t*atended up saving t*e company overM(. a year in operating costs inregard onlyto t*e operation of t*ecompressor system! :; )*roug*GCS5s coa&orative study $it*Sout*eastern Container Company. t*ey$ere a&e to determine t*at ma,or eaksand a ack of efficient moisture removafrom t*e compressed air ed to pooroperations and issues ater on do$n t*e

&otting ine! )*e addition of a dryerand a compre*ensive compressed aireak study and repair *eped t*e &ottingpant to recover costs! Aso. distri&utingt*e oad of t*e t$o compressors onto at*ird. ne$ compressor *eped to actuayo$er costs to save t*e company asu&stantia amount of money. t*e pro,ectony producing a &uy8&ack of ess t*an*af a year! :;

As $as our goa at t*e onset oft*e pro,ect. $e $ere ooking todetermine t*e causes of mafunction anda ma,or cause of inefficiency $it*in t*eRutgers compressed air system. as $eas determine $*ic* system configurationis superior! /ur pro,ect differed fromt*e &otte production pant in t*at $e$ere focused on air distri&uted tomutipe &uidings $*ie t*e productionpant contained e0posed ines providingeasy and via&e fi0es! 1*ie t*e systemsdiffer. recommendations t*at $e *opedto make are simiar in t*at t*eir effect isaimed at reducing over8e0penditureenergy8$ise in t*e pant and *opefuy.significanty reducing costs!

5. 6uture 4ork

1e $oud *ave iked todetermine t*e e0act engt* ofcompressed air ine at $*ic* deiveringt*e compressed air from a centrai-edcompressor &ecomes more inefficient

t*an a ocai-ed compressor! 4rom t*is$e coud determine t*e propercompressed air distri&ution sc*eme fort*e %usc* campus as $e as 5#DG"!1e aso $oud *ave iked to ac7uire aine diagram for t*e campus as $e asdetermine t*e e0act amount of eakageand frictiona osses t*at occur $it*in t*eine! Aso. $e $oud *ave iked to s*utoff t*e entire system to estimate t*eseverity of t*e eaks present! Fo$ever.

&ecause Rutgers is a researc* university.compressed air is re7uired &y manyresearc* faciities at $*ic* suc* $ork*as &een ongoing for decades!)*erefore. suc* a disruption in service$oud ruin decades $ort* of researc*!Since s*utting do$n t*e entire system isnot possi&e. $e $oud *ave iked tos*ut off at east one of t*e &uidings ont*e %usc* campus to compressed air too&tain an estimate as to t*e eakageinside t*e &uiding $*ic* is s*o$n &yoss in pressure!

1e aso $oud *ave iked todetermine t*e cost savings of drying air&efore t*e compressed air tank &ypacing an air dryer &efore t*ecompressed air tank as $e as *o$ t*isconfiguration $oud ma0imi-e t*e use oft*e air tank! If t*e factor is considera&e.t*en dryers s*oud &e paced &efore t*etank $*enever possi&e! Fo$ever. somecompressed air appications re7uirecompetey dry air! In t*is case. t*e dryermust &e paced &efore t*e tank so t*att*e stored air is dry and ready to &e usedin t*e case of a spike in oad! 1e $oud*ave iked to determine t*e amount ofmoisture t*at &uids up inside t*e tank ineac* case of dryer pacement and *o$


16/17

often drainage of t*e $ater $oud &ere7uired!

1e aso $oud *ave iked toe0periment $it* *o$ t*e use of avaria&e fre7uency drive 24D3. $*ic*

modifies t*e fre7uency of t*e aternatingcurrent po$er source. $oud optimi-eefficiency and save money $*ieoperating a partiay oaded compressor!A 4D increases efficiency of t*ecompressor &y o$ering t*e motor RP#as oad decreases. causing t*e motor touse ess energy!

7. Conclusion

/ur groups task $as simpyanay-ing Rutgers air compressorsystem and making recommendations on$*at t*e university coud do to savemoney! )o do t*is. $e set out to coectand anay-e data from Rutgers aircompressor system and severa of t*e&uidings it suppied compressed air to!Despite t*e o&staces $e faced. $e used$*at data $e coud ac7uire to comparet*e appro0imate costs for different

systems Rutgers coud impement! Afterfiguring out t*e pros and cons of eac*one. $e decided t*at using acom&ination of a centrai-ed air

compressor and a num&er of individua2decentrai-ed3 air compressors $oud &eRutgers &est soution to its currentsystem!

In retrospect. $e discovered t*at

an appropriate anaysis of any topic 2inour case. an air compressor system3re7uired t*e consideration of a possi&efactors t*at affected it! /ur researc* may*ave pointed out t*e o&viousimprovements t*at coud &e made $it*Rutgers air compressor system. yet t*esoution $e suggested for Rutgers $asony deveoped &y considering rea8ifepro&ems t*at t*eoretica informationcoud not cover!

Despite our findings andrecommendations. *o$ever. $e fee as if$e coud *ave improved ourperformance if $e *ad more time andinformation avaia&e to us! If $e $ereto visit t*is pro&em again. per*aps $ecoud investigate t*e intensity of eaks int*e air compressor system at Rutgers ordeveop a muc*8needed pan to eiminatet*e need for ong deivery ines! /net*ing for certain is t*at t*is pro,ectopened our eyes to t*e magnitude ofsocietys many pro&ems! Qet $e areengineers 6 its our ,o& to go out andaddress t*em!


17/17

18. Acknowledgments

)*ank you to a $*o made t*is researc*possi&e9

)*e overnor's Sc*oo of Engineeringand )ec*noogy 2SE)39Dean %ro$n. %ase 5r. )*e overnorsSc*oo %oard of /verseersCae& 1iiams1*o coordinated t*e effort for t*isresearc* pro,ect!

)*e Center for Advanced EnergySystems 2CAES3 Pro,ect Advisors9

8#ike Cesarano8"os*ua Kace8#aik Ka*n8Don Kasten8Dr! #ic*ae #uer. "i #esonas4or suppying us $it* a of t*e re7uiredkno$edge. resources. and site8visits topursue our researc*!

Sponsors9Rutgers 5niversity. Rutgers 5niversity

Center for Advanced Energy Systems

Citations

(! >Compressed Air )erminoogy!? Air)ec*noogy! (J "uy !*ttp9==$$$!airtec*noogy!co!uk=compressedairterms!*tm!

! >Air Compressor 5ses!? AirCompressor E7uipment Company! (J"uy ! *ttp9==$$$!acec8ark!com=)ec*info=5ses=uses!*tm!

J! >as Compressor? 1ikipedia!((!"uy!!*ttp9==en!$ikipedia!org=$iki=Aircompressor

! >etting t*e #ost for Qour #oney!?

Pant Engineering! (J "uy !*ttp9==$$$!*ig*&eam!com=PantEngineering=pu&ications!asp0!

! >Sout*easterncontainer!pdf?Sout*eastern Container!*ttp9==$$$(!eere!energy!gov=industry=&estpractices=pdfs=sout*easterncontainer!pdf

J(J(!pdf? GCDEGR!*ttp9==$$$!ppays!org=ref=J=J(J(!pdf

! >)ec*nica Artice Program? Cagi!*ttp9==$$$!cagi!org=pdfs=tap(

Air Compressor System Efficiency and Performance

Documents

Transcript of Air Compressor System Efficiency and Performance