While low-charge ammonia packaged and central systems were prevalent on the exhibit floor at the International Institute of Ammonia Refrigeration (IIAR) 2018 Natural Refrigeration Conference & Expo, in March, transcritical CO2 technology for industrial applications was also showcased by numerous companies.
The following is a roundup of some CO2 products and perspectives at the event.
Carnot: Unprecedented CO2 interest
Quebec OEM Carnot Refrigeration has seen an uptick in interest in its transcritical CO2 systems for industrial applications, said Marc-André Lesmerises. “I have never seen that before [at the IIAR Conference].” He attributes that partly to the IIAR “talking about natural refrigerants more than just ammonia.”
A Carnot transcritical system was recently installed in a cold storage area at an operating MaMa LaRosa Foods Italian-style dough plant in Taylor, Mich. “I believe strongly as an engineer that for most applications the best refrigerant is CO2 only,” said Lesmerises.
Carnot has developed its own “custom” ejector that it started using in transcritical systems; it can be employed to facilitate defrost. “I like the simplicity of our ejector,” said Lesmerises. “You can use it all year – not just when it’s hot – to gain benefits, even in Canada.”
Heatcraft: Scaling to industrial
Though Heatcraft Worldwide Refrigeration, Stone Mountain, Ga., showcased a commercial transcritical CO2 system at the IIAR Conference, the company plans to “scale it up to industrial,” said Grady McAdams, Heatcraft’s director of cold storage sales.
The industrial model would have a capacity ranging from 100-300 TR, he said.
McAdams said the company is seeing about equal interest from the industrial sector in both transcritical CO2 and ammonia/CO2 cascade systems, “though most people feel it’s a further leap to transcritical CO2.”
Hillphoenix: Quoting CO2
In addition to showing NXTCOLD low-charge ammonia packaged units, Hillphoenix, Conyers, Ga., was also marketing its industrial CO2 transcritical system. Transcritical “is growing – we’re quoting as much industrial transcritical CO2 as we are NXTCOLD,” said Tim Henderson, industrial program manager for Hillphoenix.
Most industrial transcritical CO2 systems offer about 150 TR for low temperatures and 200 TR for medium, he said. “If it needs to be bigger, it can go in multiple pieces.”
Zero Zone: Parallel compression and adiabatic condenser
Zero Zone, North Prairie, Wis., featured several CO2 industrial systems, including the ColdLoop transcritical chiller system, the ColdLoop subcritical system and the Edge XT condensing unit (water- or air-cooled).
“Customers who are using HFCs are feeling the pressure,” said John Collins, Zero Zone’s industrial sales manager. “With parallel compression and adiabatic condensers, we have much more viable [transcritical] options.”
Parallel compression and adiabatic technology “gets most of the lower 48 U.S. states into the range where it’s attractive to use CO2,” he added. “So we’re seeing a lot growth in our business in those product lines.”
GEA: CO2 compressor for U.S.
German manufacturer GEA discussed its Bock semi-hermetic transcritical CO2 compressor, which has been marketed in Europe and will be available in the U.S. in mid-2019, said Lawrence Bradley, director of solution sales – refrigeration for GEA North America. “We’re waiting for UL approval.”
In Europe, GEA has “built a good number of rack systems using Bock compressors in cooling and freezing applications,” he said.
Transcritical CO2 systems are set to grow five-fold by 2020, said Bradley. The growth of CO2 was evident at the IIAR Conference where in the past the emphasis would be just “ammonia, ammonia, ammonia,” he said.
“With parallel compression and adiabatic condensers, we have much more viable [transcritical] options.”John Collins, Zero Zone