Cryogenic refrigeration technology, which can be used for superconducting cables and LNG carriers, has been developed for the first time in the country 

- KIMM develops Turbo-Brayton cryogenic refrigeration system with cooling capacity of 10kW 

- New technology expected to be utilized in various industry sectors to achieve carbon neutrality

□ The full-cycle technology for Turbo-Brayton cryogenic refrigeration systems, which are the basis of cryogenic plants including hydrogen liquefaction plants and LNG liquefaction plants, has been developed for the first time in the nation. 

□ The research team led by Principal Researcher Hankil Yeom of the Department of Thermal-Fluid Machinery of the Korea Institute of Machinery and Materials (President Sang-jin Park, hereinafter referred to as KIMM), an institute under the jurisdiction of the Ministry of Science and ICT, developed a Turbo-Brayton cryogenic refrigeration system with cooling capacity of 10kW at a temperature of minus 196 degrees Celsius* and completed a commissioning test of the system. The technology for the entire process, from the designing of a refrigeration system to the construction thereof, has been developed for the first time in the country.

*A Turbo-Brayton cryogenic refrigeration system is a Brayton refrigeration system that uses a turbo machine. Composed of a compressor, an expander and a heat exchanger, the system provides a high capacity of cryogenic cooling. Cryogenic temperature is achieved through the thermodynamic cycle of compression, heat exchange and expansion of gases. 

□ The refrigerants used in the newly developed refrigeration system include helium, neon, and nitrogen, which do not cause global warming. Another advantage of the system is that it is capable of providing cooling on a large scale within a broad range of temperatures from minus 40 to minus 250 degrees Celsius. Therefore, the system is expected to provide industries such as semiconductor or gas industries, which require extremely precise temperature control, with environment-friendly refrigeration technology. 

□ Meanwhile, the technology for Turbo-Brayton cryogenic refrigeration systems is the core and fundamental technology for cryogenic plants such as hydrogen liquefaction plants, LNG liquefaction plants, helium liquefaction plants, and superconducting electric power device cooling systems. A wide variety of industry sectors have been requiring large-scale cryogenic and ultra-low temperature refrigeration. Centrifugal compressors and turbo expanders, which rotate at extreme-high speed in cryogenic operating temperatures, are the essential parts for cryogenic refrigeration systems, but they have relied entirely on imports due to the lack of domestic technology. 

□ The research team has succeeded in the development of the centrifugal compressor and turbo expander. As a result of the newest development, the team has domestically secured all the technologies necessary for design, manufacturing, construction, operation and control of turbo-Brayton cryogenic refrigeration systems. The newly developed technology is anticipated to be utilized for cooling system of superconducting cables, a next-generation electric power technology, as well as for re-liquefaction system of LNG carriers. 

□ Principal Researcher Hankil Yeom of the KIMM was quoted as saying, “With the latest technology, we are now capable of developing turbo machines that are required by various cryogenic and ultra-low temperature refrigeration plants.” Researcher Yeom added, “We hope to be able to contribute to various industry sectors where the demand for cryogenic and ultra-low temperature refrigeration is growing.” 

□ Meanwhile, this research was carried out with the support of the project for the “Cryogenic refrigeration system for future energy,” one of the KIMM’s basic projects.