Refrigeration and cooling manual

7/30/2019 Refrigeration and cooling manual

1/15

1

GRUNDFOS IndustrY

ReFRiGeRatiON aNDcOOliNG maNUal


2/15

EnGInEErInG MAnuAL

copyrgh 2009 GRUNDFOS mngn a/S. a rghs rsrvd.

copyrgh w nd nrnon rs pro hs r. No pr of hs r

y rprodud n ny for or y ny ns whou pror wrn prsson fro

GRUNDFOS mngn a/S.

a rson r hs n kn o nsur h ury of h onn of hs r:

Howvr, GRUNDFOS sh no hd for ny osss whhr dr or ndr,

ndn or onsqun rsng ou of h us of or rn upon on ny onn of hs

r.


3/15

Geeal ............. .............. .............. ............. ..6

Denitions...................................................6

Refrigerants ................................................7

A typical refrigeration process ...................8

Process description (1 stage system) ..........9

Reciprocating compressor (Pson) Fg.8. ..11

Screw compressor Fig. 9. ............................11

Scroll compressor Fig. 10 ............................11 h logP chart (1 stage system)....................12

2 stage system ..............................................13

Process description (2 stage system) ........ 14

h logP chart (2 stage system)....................15

Absorption cooling ................................... 15

Absorption cooling technology ................16

Construction types.......................................17

Complete cooling plant ............................ 18

Cold side .................................................... 18

Warm side ................................................. 19

Cooling tower ................................................19

Construction ..................................................20

Picture of cooling towers ...........................21

Free cooling............................................... 22

Pumps........................................................ 22

Pump considerations...................................23

Glycol ...............................................................24

Ammonia (NH3)............................................24

Carbon dioxide (CO2) ..................................25

Regulation and control ............................. 25

Carbon dioxide (CO2) ................................ 26

table OF cONteNtS


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6

ReFRiGeRatiON aND cOOliNG maNUal

Geeal

th y of oong or frzng sohng s gro-

wng rk oh n h nufurng ndusry nd

n h r-ondonng rk. Grundfos s psd

o h prfrrd suppr of pups for oong sy-

ss for hs usors.

Grundfos pumps are reliable, efcient and cover a

wide performance range. As an experienced consul -

n n h pnon of pupng syss, w

ngg n pross of os prnrshp nd dogu

to nd the best solution for your system.

Grundfos s go nrprs wh wordwd sr-

vice network. When you need export or on-the-spot

dv n prur pr of h word, w hv h

technical expertise close by.

ths Rfrgron nd coong mnu dsrs how

yp rfrgron pn n h nufurng

ndusry s workng. i shoud so provd n d of

how so of h oponns usd n suh pn

oud ook k. Furhror w hopfuy gv you

n d of whh pups r ng usd nd whh o

propos o usor.

Denitions

Cooling

coong of sp or susn ov or down o h

n prur.

Refrigeration

coong of sp or susn ow h n

prur. ths s nory ow h n

temperature and down to 123C.

Cryogenics

The temperature below 123C. However, this will

no nond furhr n hs nu.

The denitions elaborated on in this manual is me -

hn oong nd rfrgron. mosy s s hs

pn h Grundfos offrs pups o; spy o h

sondry sd of h pn.

mhn oong nd rfrgron s prry n

ppon of hrodyns whr h oong

du, or rfrgrn, gos hrough y n ordr

o rovrd for rus. th oony usd s

ys s nor vpour-oprsson. ths y op-

rs wn wo prssur vs, whh rn

yy wn h qud phs nd h vpour

phs. ths pross provds nd ks nrgy.

Refrigerants

A lot of different uids can be used as refrigerants.

Whh rfrgrn s ng usd dpnds on o of

fors, .g. h dsrd prurs, h pn sz,

oon of h pn, g, .

Nowdys h foowng rfrgrns: on

(NH3), carbon dioxide (CO2), hydrocarbon (HC), hy-

drouorocarbon (HFC) is being used. All refrigerantshv nur, .g. on hs h nur R-717

while carbon dioxide has the number R-744. Just re -

r h h ons nond hr r no h

ony souons.

a hr hs n d for rfrgrns d

h h ogP hr. ths hr dsrs n d on

whh sg h rfrgrn s on wh prssur. For

example, is it a liquid, is it vapour, what temperature

dos hv, nd wh s h nrgy onsupon. by

ns of hs hr you w so o h

refrigerants refrigeration effect. This is the specic


7


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8

Process description (1 stage system)

Now h w hv sn skh of sp 1 sg

sys, w w k ook wh hppns n h

ndvdu oponns nd dsr h y of rfr-

geration. The markings A, B, C, and D in g. 3 is provi-

ded for your reference in the explanation.

A-B (Fig. 4)

Throttle valve

th rfrgrn s for h hro on qud s

du o h hgh prssur. Whn s psss hrough

h hro o h vporor (ow prssur sd) pr

of h rfrgrn w sr ong. th pross ks

place with constant specic heat, which means no

nrgy s sord n h rfrgrn or rnspord

o h surroundngs (snhp pross).

The extent to which the throttle must open is con -

rod uoy, hr rony or h-

ny.

B-C (Fig. 5)

Evaporator

th rfrgrn sors h (nrgy) n h vpo-

ror, hr fro r or fro sondry rfrgrn,

.g. wr. Whn h rfrgrn vs h vpor-

or s vporsd. th prssur s h s n h pro-

ss nd s d n sor pross.

Basically the evaporator is a heat exchanger. When

ushed on the secondary side with air, it is called di-

rect cooling as seen from the picture and when us-

hd wh nohr qud s d ndr oong.

indr oong s ofn usd n h nufurng

ndusry n ordr o vod rnsporng h rfrgrn

whn udngs.

Example of an evaporator in a cooling room.

The evaporator can either be ooded or with dry

expansion. In case of dry expansion the refrigerant

Condenser

Evaporator

High pressure Low pressure

Receiver A

B

CD


heat capacity; hf in kilojoule where 1 kg of the uid

n sord whn psss hrough h vpo-

rator. An example of an h logP chart is shown in con-

non wh h pross dsrpon of h 1 nd 2

sg syss.

in pr, h grph s usd o sz h oong pn.

in h sns h on n drn h oun of

rfrgrn ndd o owr h prur gvn

nur of dgrs n h dsrd oun of wr. in

the end this helps to decide how big a ow the pumps

us o hnd.

A typical refrigeration process

in rfrgron pross h rfrgrn gos hrough

wo phss. th vporon pross nd h ondn-

son pross. th vporon nds nrgy nd h

condensation releases energy g. 1.

ths wo phss r rd y oong oprssor

or n sorpon un s h ong pon of qud

is related to a specic pressure as shown in gure 1.

In g. 2 a simple compressor cooling plant is shown.

in h vporor h prssur s ow, whh w k

h rfrgrn o nd sor nrgy fro h sur-

roundngs. in h ondnsr h prssur s rsd

wh h d of h oprssor. ths ks h rfr-grn ondns whh rss nrgy.

Compressor

Energy

Condenser Evaporator

Energy

ThrottlevalveReturntemp. 27C

Flow temp. 32C Flow temp. 6C

Returntemp. 11C

Liquid

Vapour

Condensationtemp.

36C

Evaporationtemp.

1C

Cooling tower

Liquid:water

Cooling tower

Liquid:water

Fg. 1

Fg. 2

Fg. 3

Fg. 4

Fg. 5

9


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10 11

s opy vporsd whn vng h vpor-

or. ths s nory usd n sr pns. i s vry

porn h of h rfrgron hs n ur-

nd no vpour s qud drops n h oprssor

w dsroy . On h ohr hnd you don wn o

ovrh us hgh prur w oh hr

the refrigerant and the compressor. In the ooded

evaporator the refrigerant is a mix between vapour

nd qud whn vs h vporor. ths ns

n go dry o h oprssor, u hs o

od n spror whr h vpour nd qud

are separated g. 6.

As shown on the gure the refrigerant returning from

the evaporator is a mix of vapour and l iquid.

th ggs dffrn nd dvng of hs sys

oprd o h 1 sg pn s:

The evaporators are ooded. This means that the

rfrgrn s no ovrhd nd hrfor h sy-

s s no unnssry ovrhd.

The compressor draws vapour from the top of the

spror. bus s fro h op hr s no

hn of qud n h oprssor.

anohr dffrn n hs sys s h ound r-

uon pup whh rus h rfrgrn n h

vporors. Dpndng on h rfrgrn, hs oud

cRN mg-Drv. Now w uy hv pup

pd n h prry sd of h pn. Grundfos

pups r nory no found hr. S or undrpups. Whn w r unhng h Rc pup for cr-

bon dioxide it will also be placed here.

C-D (Fig. 7.)

Compressor

th rfrgrn s ovd hrough h oprssor

whr h prssur s nrsd fro h vpor-

or prssur o ondnsr prssur. th pross s

snrop.

Condenser

Evaporator

High pressure Low pressure

Receiver

Fg. 6

Fg. 7


in h oprssor, or h or nrgy r ddd o

the refrigerant due to the compressor efciency. Had

n prf pross, h prssur woud nrs

without absorbing any energy as with the expansion

vv.

A typical compressor room.

th 3 os oon oprssor yps r h r-

prong oprssor (pson), h srw oprssor

nd h sro oprssor.

Reciprocating compressor (Piston) Fig.8.

th rprong oprssor s on of h os o-

ony usd oprssor yps n h nufurng

ndusry. i n onss of up o 12 yndrs. S h

pur of yp onsruon of rprong

oprssor.

th oprssor s nory onrod y rdung

h rvouons or y ung ou so of h yn-

drs. Whn h oprssor s srd os of h

yndrs nory r u ou n ordr o rdu h

sr urrn on h oor.

Screw compressor Fig. 9.

The screw compressor is used to a great extent in the

nufurng ndusry. is dvng s h sz; s

s, u hs g py. i n usd for os

rfrgrns. i s sy o rgu fro 10 o 100 %

wh sd vv.

Scroll compressor Fig. 10

th sro oprssor s sr oprssor nd

nory usd n hng nd wr oong pns.

i s vry sp oprssor yp wh os no

ovng hn prs, whh ns no n-

nn. th oprsson s d y wo s ros, on

xed and one orbiting scroll. See the gure to the

rgh.

Fg. 8

Fg. 9

Fg. 10


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12 13

Fg. 11

typ r-ood ondnsr.


if w k ook h oong pross n h hr,

h foowng ks p:

a-b: th prssur nd prur s droppng ovr

h nozz vv fro h hgh prssur sd o

h ow prssur sd n h sys. So of h

rfrgrn urn no vpour s w go fro h

area where everything is liquid to the mix area.

b-c: enrgy s ddd o h rfrgrn n h vpo-

ror nd or nd or of h rfrgrn urn

no vpour. and h nd of h vporor,

of h rfrgrn hv urnd no vpour nd

hv o ovrhd. th prur

will in this case increase around 8C.

c-D: in h oprssor h prssur w nrs

gn nd h rfrgrn w hd vn

more because of the efciency loss in the com-

prssor.

D-a: through h ondnsr h ovrhd rfr-

grn w ood down nd urn no qud

gn.

2 stage system

th sp 1 sg y rfrgron pn dsrd

ov nd so of h purs shown s fro

yp s pn n .g. suprrk. in ron o

nufurng ndusry rfrgron pns, 2 sg

syss r usu usd, nd hy n dsgnd nny dffrn wys, Fg. 12.

2 sg syss r so usd whr vry ow p-

rurs r dsrd. ths s hvd y soppng h

oprsson nd oong h gs for s ro-

prssd. th o oprsson nrgy s so ss. th

prur of h gs fro hgh prssur oprs-

sor w owr hn f oprsson ws don n 1

sg. ths so nsurs h h o for urng

nd oong h oprssor s no dsroyd s sy.

A

B

F

C

DG

Condenser

Evaporator

High pressure comp. Low pressure comp.

Receiver

Fg. 12

d-A

Condenser Fig. 11.

th h onsud n h rfrgrn fro h v-

poror pross nd n h oprssor us ro-

vd n h ondnsr. in h op of h ondnsr ony

h ovrhd nrgy s rovd. bu h ongr

psss down hrough h ondnsr, or nd or

urn no qud.

lk h vporor, h ondnsr s sy h

exchanger. It can be either ushed on the secondary

sd wh r s on h p ur. Or wh nohr qud,

.g. wr, s sn nory n h nufurng n-

dusry.

h logP chart (1 stage system)

In the chart you can see as follows:

The Y-axis shows the pressure of the refrigerant. The

X-axis shows the energy content of one kg of the re -

frgrn. th hn rd n ong down hr s h

rfrgrns prur. aov h g rd n h

rfrgrn s n n r d h sur r nd

w nory do no opr n hs r. (if you us

cO2 s rfrgrn you woud go no h r, u

hs pross s no dsrd n hs nu). in

h r ow hs n h rfrgrn s n

mix of liquid and vapour. In this area and below

h g rd n vryhng s qud. in hs r

nd ow h g rd n vryhng s vpo-

rsd.


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14 15

Process description (2 stage system)

a-b: th rfrgrn s qud nd s ng rnspord

o h nrdry rsrvor v v onro-

led expansion valve. This turns part of the ref-

rgrn no vpour whh w u hrough

h qud nd drwn no h hgh prssur

oprssor. Howvr, os of w rn n

h rsrvor s qud.

B-C: The liquid that ows to the nozzle C is at satu-

ron prur s h qud n h rvr

s ong.

c-D: th s pross for 1 sg sys ks p-

n h vporor. th nr rfrgrn urns

no vpour for s ng drwn no h ow

prssur oprssor.

D-e: th oprssor ovrhs h rfrgrn nd

pushs k no h rvr ow qud v

n h rvr. (and no s shown on h pu-

r). in h rvr h rfrgrn s ng ood

down o suron prur gn u pr

of so us hrough h qud nd s hn

drwn no h hgh prssur oprssor.

F-G: th s pross s for h 1 sg sys; h

outlet temperature of the refrigerant is just lo-wr n h 2 sg sys.

G-a:th s pross s n h 1 sg sys. How-

vr du o h owr rfrgrn prur

fro h oprssor, h ondnsr dos no

rqur s g py s n h 1 sg sys.


h logP chart (2 stage system)

if you opr h 2 sg sys nd h 1 sg

sys you n s h h oun of nrgy you

n k ou of h vporor (c-D) s ggr n h

2 sg sys. th prur fro h hgh prs-

sure compressor (F) is approx. 35C lower in the 2

sg sys. ths s posv for h oprssor, u

you so do no hv o us so uh oong nrgy

n h ondnsr.

Absorption cooling

an sorpon oong pn produs od fro h.

th onon of hng nd oong s nr-

sng for hos prs of h nufurng ndusry

whr rg hng nd oong rqurns r

prominent, e.g. nurseries, slaughterhouses and ofce

udngs. For h rgh onon of hng nd

oong nds, fvour ono nvronn

oud hvd y nsng n sorpon oong

pn oprd o sndrd oprssor oong

pn.


9/15

16 17

Absorption cooling technology

an sorpon oong pn ypy oprss four

n oponns:

Concentrator

Condenser

Evaporator

Absorber

th hnqu n sorpon oong nd oprs-

sor oong s or or ss h s. in hn

oong hn oprssor s nudd nsd

of n sorpon oong whr hr oprs-

sor onssng of onnror, n sorr nd

throttle valve is installed, g. 13:

to opr h pn, h us ddd o h on-

centrator from an external source

(urn, gs ngn, ws h, .). and h us

rovd hrough oong owr.

th oong pross s nd y ddng h o h

onnror. ths ks h onnron o nd

h rfrgrn (.g. wr n lbr/H2O pn) w

d o h ondnsr. in nohr ru h rnng

solution, now poor in refrigerant, ows from the con-

centrator to the absorber through a heat exchanger

nd hro vv (prssur rduon).

th vpord rfrgrn fro h onnror s

ondnsd n h ondnsr nd pssd hrough nexpansion valve (pressure reduction) to the evapora-

or. th s pross ks p s n oprssor

oong pn.

Fro h vporor h rfrgrn, ng op-

y vporsd y now, s d o h sorr. Hr h

rfrgrn s sord n h souon durng h r-

s of h.

The solution, now relled again with the refrigerant,

is pumped through a heat exchanger and back to the

onnror.

ths ru s onnd nd h pross gns gn.

In g. 14 you can see a picture and a gure of an ab -

sorpon pn.

Construction types

bsy wo yps of sorpon oong pns r

v on h rk. On yp s sd on qud

mixture of lithium bromide and water, and the other

on wr nd on.

in wr / on pn, h on s s

rfrgrn nd h wr s n sorr.

ths ns h hs pn yps r o produ

oong vry ow prurs

(< -30C). This is the default mix used in the manufac-

urng ndusry.

th lbr / H2O pn, howvr, s h os oon

type of plant. With this mixture you can produce

cooling with temperatures down to approx. 5C as

h wr s s rfrgrn nd h hu ro-

d s n sorr.

ths yp of onsruon s nory usd for ofor

oong or for food rfrgron.

Absorption cooling plants can, just as compressor

oong pns, onsrud s 1 or 2 sg syss.


Throttle valve

Cooling

water

Cooling waterto proces

Condenser

Concentrator

Heat exchanger

Throttle valve

Absorber

Evaporator

Heat

Coolingwater

Fg. 13

Fg. 14


10/15

18 19

Warm side

On h sondry sd of h ondnsr, r or wr s

wys usd wh so knd of nfrz.

ar s nory hosn for sr pns, .g. for

oong udng.

Wr s usd n h nufurng ndusry, whr

nory s pupd fro h ondnsr o oong

owr o rov h h. On shps or nsons

os o k or h s, h ondnsr n ood

wh wr dry fro hos sours.

Cooling tower

th prnp s vry sp oong owrs work

y vporng s pr of h rud oong

wr. th owrs r nory rfrrd o s vpo-

ron owrs. in n vporon oong owr h

rud oong wr os no dr on

wh r fro h osphr.

To obtain great efciency, it is important that the wa -

r s rd s uh s poss o on rg

on surf wn h wr nd h r. ths

ks so of h wr vpor nd, s sn un-

dr h funon of h vporor, hs pross r-

qurs nrgy, nd s rsu h wr prur

w drs. Ps no h n oong owr you

w hv o dd wr du o h vporon. in Dn-

rk, n nnu vrg oun of k-up wr sapprox. 1, 12 m3/h per MW cooling capacity.

In g. 18 two different cooling towers; the only dif-

frn s h oon of h vnon fn. Ps

no h f h fn s od s on h p ur o h

rgh, h oor nd fn r surroundd wh vpour

.

Complete cooling plant

aov w hv ovrd how h rfrgrn pross

on prry sd of h oong sys works. bu s

can be seen from g. 15, all the pumps are normally

pd on h sondry sd (wr nd od sd).

W w ook no h now.

Cold side

Wh hppns on h sondry sd of h vpo-

ror dpnds vry uh n whh ndusry h pn

s nsd.

In relation to temperatures above 0C and down to

approx. -30C, water with some kind of glycol is nor-

y hosn.

th ppons n so of h foowng:

Breweries

Dairies

Slaughterhouses

Cooling of building with ventilation plants

Dehumidication in industry buildings,

so wh vnon

Machine cooling

Etc.

Fg. 16 shows on souon, u n of ours pu

oghr n ny dffrn wys.

In big plants g. 17, e.g. air condition or industry

pns, ny pups n usd n svr dff-

rn vs. buffr nks r so usd o uu

oong py. buffr nk szs vry fro s o

vry rg nks. thy y pd on h ground

or urd . Pups usd r nory 1 sg pups,

u usg y so usd. th pup szs

vry fro h rgs Nb/NK s prry pups o h

s UPS pups n h ss oong oops.

Coolingtowerpump

Warm side Cold side

Chillerpumps

Chillerunit

Buffertank

Maincirculatorpumpssystems

Airoutlet

Airinlet

Spray guard

Sprayramp

Heat exchangesurface(packing)

Centrifugalfan

Overflowpipe

Incomingwatertobecooled

Propellerfan

Automaticlevelmonitoring

Cooledwater

Emptyingblowdown

Make-uptreatedwater

Chiller unit

Production

E

DP

M

PR

M

PR

Chillerunit

Buffertank

Secondarypumps

Pressure

Cooling

Coolingceiling

Coolingsurface

Heat Fan

Primary

M

M

M


Fg. 15

Fg. 18

Fg. 16

Fg. 17


11/15

20

Dpndng on h ppon you sos rus

some of the heat in the condenser, as shown in g. 19.

Construction

Fg. 19 shows prnp skh of oong owr

onnd o h ondnsr. On h skh h vn-

on fn s so shown owng h r gns h

wr dron. in hs sys, n-orrosvs r

so ddd o h owr.

in rg pns uffr nk s ofn nsd. th sy-

stem can be constructed as shown in g. 20.

th uffr nk s dvdd n wo; od nd wr

sd. th oong owr rus h wr fro h

wr sd n h nk nd hrough h oong owr

nd k o h od sd of h nk. in h hr or

ondnsr h ruon ks p n h oppos

dron. Fro h od sd of h nk, hrough h

ondnsr, nd k o h wr sd of h nk.

The buffer tank on the gure is a little bit misdrawn.

th nr w dos no go h wy o h op of

h nk, u s owr hn h wr n o ow h

water to oat from one side to the other.


Condenser

Chiller

E

P

PR

High

Low

Heat recovery

Cooling

t=40-

t=27-

t=32

t=27

Heat recovery

Cooling

tower

Fg. 19

Fg. 20

21

Pictures of Two cooling towers

at a power plant:


12/15

22

Free cooling

Whn h oong usnss, h fous s nrsngy

on nrgy rduon k n ohr ps. th word

or pross fr oong s ong or nd or

popur. bsy h phnonon fr oong

ns oong n nur wy whou usng -

chanical cooling. In g. 21 is shown a picture of how

o onsru fr oong pn.

and s you n s s h oong s spy d d-

ry fro h pross o h oong owr. as you

n gn you r vry dpndn on h oudoor

prur nd h for how ow you n go

wh rgrd o prur s rv hgh.

Free cooling is normally used to cool ofce buildings

nd so on.

Pumps

in onnon wh pups on h sondry sd, h-

r r no ny rqurns. i s os ony h Q

nd h whh r sng h dnds. bu s or

advises under pump considerations, next page. The

pups oud Nb/NK, tP, cR nd so on.

On the primary side it is a little bit more difcult.bsy w do no dvr pups for hs sd, u

s sn ov, usors sos nd pup

for hs sd. Whhr or no Grundfos s p of

dvrng h pup, dpnds vry uh on h rfr-

grn yp. if h dsrd rfrgrn s on w

n pup wh cR pup wh dou shf s or

y usng mg-Drv souon. bu gn dpnds

vry uh on h rfrgrn yp, nd f you r n

dou ook n h Pup lqud gud.

th szs of h pups dffr of ours vry uh

dpndng on h ppon. bsy yps of

pups fro h ss UP pup ovr h hgh

prssur cR hgh spd pups, nd up o h HS

pups r ng usd.

If we for example talk standard industrial cooling to-

wers we normally see a ow between 25 m3/h and

2000 m3/h. For example the biggest cooling tower on

a 700 MW coal red power plant needs a circulated

wr oun of up o 71600 3/h.

Pump considerations

Whn hoosng pup for oong ppon, h-

r r so sndrd hngs you w wys nd o

know for you sr szng h pup, ..

Flow

Head

Liquid type

Temperature of the liquid

Concentration of the liquid

Viscosity

Density

Additives added to the liquid

Whn you g rqus for rn qud s wys

good d o ook for n h Pup lqud gud.

aos quds w hv vr pupd n Grundfos

r sd hr, h progr w rond who k no onsdron whn hoosng rn

qud. mny of h gyos usd n h rfrgron

and cooling industry you can also nd in the engine-

ering manual Viscosity and Density placed in the

Ssns rry.

Below you will nd some pieces of informations and

rondons rgrdng pupng so of h

os rdon quds.


23

PR

Production

Fg. 21


13/15

24


Glycol

The density and viscosity vary very much depending

on h onnron nd h prur of h -

qud. You gh nd n ovrszd oor.

If it is a NB/NK or a TP pump you use, its normally

rond o hoos shf s wh rdu-

d s fs. th sndrd rrdg s n cR

n usd for gyo

Normally cast iron pumps are used but be aware

h sos hy dd ddvs o n h oong

wr so you nd o us snss s pups.

The temperature of glycol is normally very, but can

so wr, so you hv o sur h h pup

n d wh h.

Glycol is in some situations used as a cleaning agent

; if a system has not be thoroughly ushed before,

h os nd fs w us pros wh h s

during the rst operation hours.

Ammonia (NH3)

The density and viscosity are different from that of

wr. bus h vsosy s round 0.3 2/S

you hv o sur h h pup n op wh

h. my h uron of h pup woudn

ssfory. a cR s oky for on.

Ammonia has a low boiling point, which can easily

us von n h n of h pup. So k

sure the inlet pressure is high sufciently.

Ammonia is toxic so a back to back shaft seal or a

mg-Drv s rondd. When ammonia is used in refrigeration plants it has

wys onnron of 100 %. Whn you hr

ammonia mixed with water it is normally used as

houshod nsr nd n h nufur of

wide variety of products, including textiles, rayon,

rur, frzr, nd ps. coppr nd oppr

oys hv ony d rssn o onu

hydroxide.

Carbon dioxide (CO2)

The viscosity of carbon dioxide is so low that you

n pup wh sndrd pup do o h ow

uron py. th pup for hs qud

shoud Rc pups, s h s pg.

Regulation and control

To run a refrigeration process properly, both nanci-

y u so o nsur sf opron, so uo-

on nd onorng qupn us ns-

led. The complexity of the automatic regulation and

control depends to a great extent on the size of the

sys nd whr s nsd. th os porn

sks for h rguon nd onro r h foowng:

Cold side

Evaporator pressure regulation.

Capacity regulation on the compressor.

Flow regulation (not so common).

Warm side

The advantage of regulating the warm side is appli-

cation-specic.

Others

Correct distribution of the refrigerant in the system.

Regulation of secondary refrigerant to the conden-

sr. (wr or r) Defrosting of the evaporator if the secondary side

s r.

Monitoring equipment (overpressure, underpres-

sur nd o prssur)

Protection of electrical motors.

25


14/15

26

Carbon dioxide (CO2)

a nwor whn h rfrgron ndusry nd

Grundfos s cO2 pup. i s nw pup dvopd

y Grundfos for h prry sd of h rfrgron

pn.

For or qusons or nforon on h cO2 pup,

ps on

Product Manager Mr. Bjarne Dindler Rasmussen (RSU)



15/15


GRUNDFOS A/SPoul Due Jensens Vej 7DK-8850 Bjerringbro

www.grundfos.o

bng rspons s our foundon

thnkng hd ks poss

innovon s h ssn

Ver01.06/04/2010

Refrigeration and cooling manual

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