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45th KGH Congress, Belgrade 3-5 Dec 2014

Latest trend in industrial refrigeration

Pega Hrnjakpega@illinois.eduCo-Director ACRC,

Will Stoecker Res. Professor, University of Illinois, Urbana-Champaign, USA

President, CTSCreative Thermal Solutions

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I plan to talk about:

• Situation in industrial refrigeration• Direction industry is taking to move towards

lower charges, safer, simpler and more cost effective solutions

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Industrial refrigeration• Typically applied in:

– Cold stores– Process industry, …

• Custom designed and built (onsite)• Steel is major material• High capacities, large components, huge refrigerant charges• Mostly uses ammonia (NH3)• Requires professional personnel• Well trained technicians and engineers to respond to safety

challenges: real and perceived • Let me illustrate:

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Large sizes

• Compressors• Accompanying vessels

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Big vessels = huge charges

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Equipment is on the roof too

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Numerous and multiple

evaporators

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This very safe industry had some bad days

• Recent accidents in China took several lives• Difficult to come close to urban areas where cold

storage would be beneficial, or large central cooling plants, sport complexes,…

• Very strong pressure for sound environmental solutions strengthens the position of ammonia

• Are we waiting for a big earthquakes in California, Japan,… to realize that not only nukes could be a problem?

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Direction: decentralization

• Multiple units - lower capacities • Smaller sizes • Reduced charges• Safer• Possibly less expensive (serial production)• Redundancy

There are various options to fit different applications:

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First step: self contained large facility

• 700 kW ammonia refrigeration packageCourtesy of Industrial Refrigeration Service, Inc.

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Another option: preassembled systems with CO2 or other coolants

• Can be applied beyond cold storage for:

• Process industry• Central cooling• Sport complexes

NewTonCourtesy of Mycom

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Rooftop ammonia units are getting

more popular

• Cooling air • Cold stores• Prep rooms

• 150-300 kW ammonia refrigeration units

Courtesy of Evapco

Courtesy of Nextcold, Inc.

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Some are not afraid of MC options

• Air cooled unit on the roof

Courtesy of Zudek, Inc.

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Rooftop could be water cooled or organized as chillers

With plate and frame Evap and Cd

With shell & plate Evap and Cd

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Hermetic ammonia compressors help competiveness of ammonia solutions

for smaller systems -chillers

700 mm

270 mm

700 mm

270 mm

700 mm

270 mm

Courtesy Mycom, Inc.

35 kW NH3 scroll

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The first real NH3 chiller with hermetic compressor and MC Cd

Courtesy Mycom, Inc.

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The capacities are getting greater for very low charged NH3 chillers

Courtesy Mycom, Inc.

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We started air cooled ammonia chillers 15 years ago 18g/kW

Condenser in wind tunnel

Compressor

Accumulator

Plate evaporator

Receiver

Flow meter

Microchannel condenser

Axial fan

Compressor behind

Pressure transducers

Pressure cut-offs

And

cont

inue

de

velo

pmen

t

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Conclusions

• Ammonia industrial refrigeration demonstrates vitality and evolution

• Decentralized systems with very low charges are main direction

• Variety of solutions address diversified requirements

• Extremely low charges are next