Pega Hrnjak 1/20

SOME EXTREME AND SPECIALIZED APPLICATIONS OF REFRIGERATION

Pega Hrnjakpega@illinois.edu

Director ACRC, Res. Professor,

University of Illinois, Urbana-Champaign, USA

President, CTS

Creative Thermal Solutions

Workshop:

Refrigerants and regulations, driving or stifling innovation?

Pega Hrnjak 2/20

Rhetorical question in the workshop title :Refrigerants and regulations, driving or stifling innovation?

• By definition: regulations regulate, thus reduce the freedom or field of operation, so we can say reduce innovation

• Good regulation: defines desired outcomes but leaves the paths to get there open - technology neutral

• In that way regulation helps innovation in the area that may not be only cost driven, but also have other desirable effects in social or environmental sense

Pega Hrnjak 3/20

Extreme and specialized applications?

•Wide title is a guarantee for missing something.

• So, I will be focused on SOME applications where I see opportunity for introduction of natural refrigerants (the theme of this conference).

• Also, refrigerants are related to mostly vapor compression cycles (including non Rankine and absorption) so I will not talk about magnetocaloric, thermoelectric or similar methods w/o refrigerant in .

Pega Hrnjak 4/20

When and why would regulatory body be interested in extreme and specialized applications?

• The interest is in reducing (here environmental) effects of refrigerants, typically seen as:

• Direct emission:

• Quantity of refrigerant leak

• Number of units

• Leak rate (usage profile, type of equipment)

• Refrigerant GWP (or other measure of interest)

• Indirect emission:

• Function of system efficiency (if CO2 is generated in the process)

• Emissions related to production (cradle to grave)

Pega Hrnjak 5/20

So it is logical to be focused on most important and common systems:• MAC:• Numerous, low charge but high leak rate (open shaft Cp,

vibrations…) – the greatest effect of reduction

• Supermarkets:• High charge, medium leak rate, high number, long operating

hours … - second target

• Small appliances (refrigerator/freezers)• Extremely numerous, low charge, low leak, high operating hours

– third target

• Small commercial applications• Numerous, low charge, medium leak, high operating hours –

easy target

Pega Hrnjak 6/20

Hesitation to push:

• RAC

• Numerous, med/low charge, medium leak, high operating hours – no easy replacement, strong opposition

• And definitively:

Extreme and specialized applications

Pega Hrnjak 7/20

Because extreme and specialized applications are:

•More difficult to engineer

• Industry has less experts to do the conversion

• Less effects for significant effort

•Why bother?

we see a bit slower pace.

Pega Hrnjak 8/20

Applications to discuss:

• Industrial (including cascade systems):

• Quick freezing - cascades with CO2 or air cycle

• Lyophilization (freeze drying) – R744 instead of R404a, …

• Sport complexes - ammonia (with CO2 )

•Medical and Pharmaceutical – CO2, HCs

• Test facilities (civilian and military) – ammonia, CO2,

Pega Hrnjak 9/20

Industrial

• The most significant changes:

• In order to maintain ammonia as refrigerant, industry is converting to self contained, prefabricated, low charges systems to:

• Reduce charge and potential consequences

• Reduce max possible leak

• Introduce savings by “mass” manufacturing

Pega Hrnjak 10/20

Instead of • Complexity

• Compressors

• Accompanying vessels

Pega Hrnjak 11/20

And this:

Pega Hrnjak 12/20

Many see prefabricated units, rooftops, …as a way to go

700 kW ammonia refrigeration package Courtesy of Nxtcold, Inc.

Courtesy of Evapco

Courtesy of Industrial Refrigeration Service, Inc

Air cooling

Factory built and checked

Pega Hrnjak 13/20

New type of cold storage: Long Beach port

Pega Hrnjak 14/20

Some are not afraid of MC options

• Air cooled unit on the roof

Courtesy of Zudek, Inc.

Pega Hrnjak 15/20

20 years of continuous development of ultra low charged ammonia chillers at CTS shows it is possible:

Microchannel

700 mm

270 mm

700 mm

270 mm

700 mm

270 mm

1996

Worlds first MC Cd for NH3

Charge 18 g/kW, 2.3 oz/Ton

2006-2012

Workhorse in tests of NH3

evaporators

2008-2009

Helping Mycom building first

chiller with hermetic NH3 Cp

2015-2016

Newly designed chiller with

MC condensers

Pega Hrnjak 16/20

For sport complexes or similar applicationsPrefabricated, low NH3 charge

• CO2 as a coolant - Can be applied beyond cold storage for:

• Process industry

• Central cooling

• Sport complexes

NewTonCourtesy of Mycom

Pega Hrnjak 17/20

Medical/Bio/Pharmaceutical:

• Large systems in production

• (treated as industrial refrigeration)

• Small systems for various applications:

• Various refrigerators -10 oC to -20 oC – R134a – to R600a (or CO2)

• ULT -70 oC to -100 oC – cascade R134a/R508b (R23, R503,..)

• HC combinations: R290 (or CO2)/R170 (Ethane)

• -150 oC to -160 oC – autocascade (various refrigerant mixtures)

• Probably will stay

Pega Hrnjak 18/20

Test facilities

• Ammonia/ CO2cooling

• Coolant ?

Pega Hrnjak 19/20

In conclusion

• Special applications will follow the “crowd”

• The best practices will be used

• Some users will drive the change, not regulators:

• Industrial refrigeration

• Pharmaceutical

• Medical

• …

Pega Hrnjak 20/20

Your thoughts, questions?