Cascade Co2_nh3 Refrigeration

7/25/2019 Cascade Co2_nh3 Refrigeration

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ASustainableRefrigeratingSystem

forthePRWIndustry

2012Heartland

Chapter

Meeting

Chicago,IL.October34,2012

CascadeCO2

/NH3

Refrigeration


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RefrigerationThen

1924 Ball Horizontal Dual Acting Compressor

2


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RefrigerationThen

Rotary Blade Booster

Compressors

Reciprocating High Stage

Compressors

3


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RefrigerationNow

Screw Compressor and Reciprocating Compressor

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ModernRefrigerationEngine

Room

Cascade CO2/NH3 System

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ShouldIChoseCO2

(R744)formyRefrigerating

System? Whattemperaturesdoyouneedtomaintain?

Arethereproductfreezingrequirements?

IsmaintainingareducedAmmoniasystem

chargecritical?

Isno

contaminating

refrigerants

in

the

food

storage,processingandemployeeworkareas

desirableor

needed?

And,isprovidingaGreen

refrigeration

system

important?

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RefrigerationSystem FirstCost

SingleStageEconomizedSystem(Lowest)

CascadeCO2

/NH3

System(Mid

Range)

TwoStageAmmoniaSystem(Highest)

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Independent3rd

PartyStudySystem Efficiency Results

Cascade CO2 vs. Two Stage NH3

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Independent3rd

PartyStudy

2StageNH3

Reference

System[kW/TR]

CO2/NH3

CascadeSystem

[kW/TR]

%Improvement

InEfficiency

20FSuctionGroup 0.8 0.7 12.3

58FSuctionGroup 1.6 1.0 37.3

Combined

20Fand

58F

Suction

Groups 1.2 0.9 28.7

HighTempSuctionGroup 0.7 0.8 8.5

TotalSystemkW/TR(Compressors) 1.7 1.6 8.1

Total

System

kW/TR

(Compressors

and

Condenser) 1.9 1.8 6.8

TotalSystemkW/TR(Compressors,

CondenserandAirUnits) 2.4 2.3 5.8

System Efficiency Results

Cascade CO2 vs. Two Stage NH3

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FieldTestMeasurement/Instrumentation

Flow Meters

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CO2

SystemAdvantagesOperating

0.80

1.00

1.20

1.40

1.60

1.80

2.00

2.20

-70 -65 -60 -55 -50 -45 -40 -35 -30 -25 -20

COP

Evaporating temp [deg F]

COP comparison of CO2/Ammonia withconventionel Ammonia Systems at full load

CO2/AmmoniaDT cascade = 9F

Single stage withopen economizer

Two stage withopen inter-midiate cooler

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CO2


COP comparison of CO2/Ammonia with

conventionel Ammonia Systems at 50% load

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

2.20

2.40

-65 -60 -55 -50 -45 -40 -35 -30 -25 -20

Evaporating temp [deg F]

COP

CO2/Ammonia

DT cascade = 6F

Single stage with

open economizer

Two stage with

open inter-

midiate cooler

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CO2


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CO2


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CO2


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RefrigerationSystem

Ammoniacompressor

CO2

compressor

Ammoniacondenser

CO2

/NH3

heatexchanger(cascade

cooler)

CO2

receiver(pump

separator)

CO2

evaporator

CO2

liquidpump

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CO2

Application ColdStorage

NH3 Surge

Drum

NH3 Screw

11 / 95F

Evap. Condenser

CP-Receiver

(Economizer)NH3/CO2 Cascade

Heat Exchangers

CO2

VPR

-55F

CO2

VPR

-30F

Blast FreezerFreezer

NH3 Screw

11 / 95F

CO2 HPR

20FCO2 Recip

-55/ 20F

CO2 Recip-55/ 20F

CO2 Recip

-30/ 20F

CO2 Recip-30/ 20F

Drier

CoolerDock

OilRectifier

OilRectifie

r

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CO2

SystemsBackgroundDrivers

Refrigerantsituation

Ammoniacharge

restrictions

Ammoniasdamagingeffects

Electricity

costs Lowerfirstcost

Refrigerant

cost Lowertemperaturesatreasonablecosts

Lessspacerequired

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CO2

SystemsFactsonCO2

(R744)

CO2

isalreadyintheatmosphere

CO2

isnon

toxic

and

non

flammable

CO2

isusedtoputoutfires

A

major

leak

will

not

damage

products OnlyCO2

snow(DryIce)willfalldownon

products

Dryicesublimatetovaporandwillnotleavea

wetsurface

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CO2

SystemsFactsOnEmissions

CO2CascadeSystemsreduceCO2emission

lb.less

CO2emission

for

each

kWh

saved

1mileinanaveragecarproducesonepound

ofCO2

emission

Cryogenicfreezingtypicallyuses2lbs.ofCO2

foreachpoundofproductfrozen

InaCO2cascadesystemstheCO2

iskept

insidetheclosedloop

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CO2

SystemAdvantagesLowerFirstCost

LowerCosts

Compressors(LTside)

Suctionanddischargepiping,valvesinsulation,etc.

Liquidseparatorvessels(plusinsulation)

Refrigerant HigherCosts

Cascadeheatexchangerinsteadofintermediatecooler

vessel Liquidpiping,valvesinsulation,etc.

Higherpressureratingforsomecomponents

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CO2


0.3

3.0

30

300

-67 -58 -49 -40 -31

Evaporating temperature (o

F)

Capacity(TR)

CO2

NH3

HighPressureCompressor

HPO28

StandardCompressor

CMO28

Condensing temperature at 14oF

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CO2


Liquid, 300ft pipeLiquid, 300ft pipe

Pipe sizePipe size TemperatureTemperaturedropdrop

PressurePressuredropdrop

VelocityVelocity

InchInch FF PSIPSI ft / secft / sec

AmmoniaAmmonia 22"" 1.41.4 1.41.4 3.63.6

CO2CO2 4"4" 0.30.3 1.051.05 3.53.5

Discharge, 100ft pipeDischarge, 100ft pipe



VelocityVelocity


AmmoniaAmmonia 6"6" 0.210.21 0.20.2 7979

CO2CO2 4"4" 0.140.14 0.90.9 2929

Wet suction, 300ft pipe, two 90 bends, one stop valveWet suction, 300ft pipe, two 90 bends, one stop valve



VelocityVelocity


AmmoniaAmmonia 12"12" 1.011.01 0.310.31 5454

CO2CO2 6"6" 0.960.96 2.852.85 2323

Dry suction, 100ft pipe, two 90 bends, one stop valveDry suction, 100ft pipe, two 90 bends, one stop valve



VelocityVelocity


AmmoniaAmmonia 12"12" 0.290.29 0.0890.089 6868

CO2CO2 6"6" 0.330.33 11 3939

Piping example 300TR at -40F

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CO2

SystemAdvantagesCharge/Leaks

Lowammoniacharge

Ammonialimitedtoengineroom

CO2

doesnotdamageproducts

CO2

isnontoxicandnonflammable

However!!

Longtermexposurelimitis1%concentrationofCO2

Shorttermexposurelimitis3%concentrationofCO2

10 20%concentrationofCO2

ishealthandlife

threatening

CO2

detectors

are

required24


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CO2

SystemAdvantages

Service/Maint. Norecoveryunitorwaterbasinsrequiredforopening

systemcomponent

Nosmell

NooildrainageonCO2

side

Alwayspositiveoperatingpressure

However!!

Becarefulwithtrappedliquid.Ifthetemperatureisincreasedby

7F,thepressureincreasestotheyieldlimitofsteelpipes!

Becareful

with

trapped

liquid/gas.

Saturated

liquid/gas

at

room

temperature e.g.68F=812 PSIG

Componentevacuationforair/moisturerequiredafterservice

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CO2

SystemAdvantagesValveGroups

Penthouses,

piping and valvegroups on roof

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CO2

SystemAdvantagesPiping

Condenserand

mainpiping

on

roof

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CO2

RefrigerationSystems

CO2

Compressors

8cyl.206TR

4cyl.103TR

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CO2


Ammonia

Compressors

Screw222TR

Screw

307

TR

Applications Typ. Cold Storage - Example

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CO2


NH3

Surge

Acc.CascadeCO2Condenser

HPR&

LPR


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CO2


Economizer(CPR)

Glycolfloorwarming

heatedbyoilcoolers

CO2

HPR

(Highpressure

receiver)


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CO2


Oil Rectifier

Oil reservoir

Oil heater and

Temp. sensor

Oil return

Oil float switch


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CO2


Large PRWs utilizing Cascade

CO2

Refrigerating Systems

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CCCCCCCCCCCCCCCCCCCCRRRRCCC

CCCCCCCCCCCCCCCCCCCLLLLCCCCCCCCCCCCCCCCCCCCCCCCCCCLLLLLL

LUCK

ThankYou

ChuckToogood

M&MRefrigeration,

Inc.

[email protected]

(410)7548005

34
mailto:[email protected]:[email protected]:[email protected]

Cascade Co2_nh3 Refrigeration

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