New air-based refrigeration system developed to replace harmful refrigerants

The Korea Institute of Power Analysis (KIER) has developed, for the primary time within the nation, a refrigeration expertise that makes use of air as a refrigerant as an alternative of Freon fuel, hydrofluorocarbons (HFCs), and different refrigerants that trigger international warming.

The European Union’s revised regulation on fluorinated greenhouse gases (F-gases) took impact in March this 12 months. Beginning in 2025, the gross sales of the merchandise containing F-gases will likely be regularly phased out. Moreover, laws on processes utilizing F-gases are anticipated to be strengthened. Since F-gases are utilized in key Korean export merchandise resembling air conditionerscars, and semiconductor processes, there’s a pressing have to develop different applied sciences.

The analysis crew efficiently developed an built-in ultra-high-speed compander utilized in air refrigeration and, for the primary time in Korea, created an air cooling system. Through the use of this method, it’s doable to attain a temperature setting of -60 levels Celsius utilizing air as a refrigerant.

Conventional refrigeration and cooling techniques have primarily used the vapor compression cycle. On this technique, cooling is achieved because the liquid refrigerant evaporates and absorbs warmth. On account of its easy construction and design, it’s broadly used throughout varied fields. Nevertheless, a key downside is its dependence on fluorinated greenhouse gases as coolants, resulting in the influence of worldwide warming.

In response, the analysis crew centered on implementing a cooling system based mostly on the reverse-Brayton cycle, which makes use of air because the refrigerant. Not like the standard technique that includes evaporating a liquid, this method compresses a fuel after which goes by warmth alternate and growth to supply a low-temperature fuel, enabling cooling with out the necessity for liquid refrigerants.

Nevertheless, the complexity of designing and constructing such a system has been a big problem, stopping its software in refrigeration techniques till now. The compander have to be designed with excessive precision as a result of ultra-high-speed rotation through the cooling course of. As an illustration, the gaps between elements and shaft displacement require a tolerance inside 0.1 millimeters.

To implement the reverse-Brayton cycle system, the analysis crew devised a compander system that connects the compressor, expander, and motor on a single shaft. Though the compressor and expander are related to a single shaft, every system should function at its personal most effectivity. Moreover, the shaft system design ensures secure operation even at ultra-high rotational speeds, additional enhancing the reliability and efficiency of the system.

The cooling system using the developed compander efficiently cooled air to under -60 levels Celsius inside only one hour. Notably, when producing chilly temperatures under -50 levels Celsius, the system demonstrated increased refrigeration effectivity in comparison with conventional vapor compression techniques. Theoretically, it’s able to cooling all the way down to -100 levels Celsius, and at that temperature, the refrigeration effectivity is predicted to enhance by greater than 50% in comparison with vapor compression techniques.

Dr. Beom Joon Lee, the lead researcher, said, “On account of environmental regulations, refrigeration systems that primarily use refrigerants with a high global warming potential are rapidly transitioning to the use of eco-friendly refrigerants.”

He added, “We are currently working on improving the system’s performance to enable the production of cold temperatures below -100 degrees Celsius. We anticipate that this technology will be applied in fields that require ultra-low temperatures, such as semiconductor processes, pharmaceuticals, and biotechnology.”