A refrigeration system that keeps food and beverages cool uses carbon dioxide instead of hydrofluorocarbons, a common refrigerant made from fluorine, carbon, and hydrogen, which is also prone to leaking.
ORNL developed and tested the refrigeration system in collaboration with industry partner Hillphoenix more than a decade ago and it’s widely used in supermarkets across North America today.
Why it matters:
This innovative refrigerant source provides an energy-efficient and cost-saving alternative to traditional hydrofluorocarbons.
The innovation:
Researchers at Oak Ridge National Laboratory worked with Hillphoenix to test and evaluate carbon dioxide as the refrigerant.
- Booster system: Carbon dioxide utilizes two stages of compression, where low-temperature compressors act as a booster for the medium temperature compressors to enhance system efficiency.
- Transcritical state: Carbon dioxide can operate supercritically where it has properties of both a liquid and a gas.
By utilizing a transcritical booster carbon dioxide refrigeration system, impacts due to leaks are minimized while energy efficiency is increased.
Real-world impact:
This research enabled the installation of Hillphoenix’s Second Nature Advansor system in more than 130 supermarkets in North America within two years. Hillphoenix developed and introduced the carbon dioxide-based Advansor refrigeration system for European supermarkets. Before the same concept could be introduced to North American supermarkets, further testing was required. ORNL researchers, utilizing refrigeration chamber testing capabilities at the Building Technologies Research and Integration Center, proved the system’s performance.
The benefits:
- 25% increase in energy savings
- Minimizes impacts of leaks
- 24/7 performance
Backed by science:
This work was supported by the U.S. Department of Energy’s Building Technologies Office.
Research was conducted at DOE’s Building Technologies Research and Integration Center.
Deep dive:
Learn more about ORNL’s building equipment technologies research and experimental testing capabilities.
The big picture:
This validation paved the way for a new refrigeration system to be installed in U.S. supermarkets. The carbon dioxide-based refrigeration system is energy efficient, lowers utility costs, and minimizes impacts of leaks.