Member news: Mirai Intex ultra-low temperature refrigeration system at the ACHEMA trade show in Germany
Mirai Intex, corporate member of the IIR, will present its MC 15 C/W/T closed-cycle refrigeration machine at the ACHEMA trade show in August 2022 in Germany.
Environmentally friendly alternatives to fluorinated refrigerants are still limited for ultra-low temperature (ULT) applications, partially because of the specific requirements of these systems configurations.  In an independent study conducted by the German engineering firm Refolution Industriekälte GmbH, three effective options for ultra-low temperatures were compared: compressor cascade system, liquid nitrogen, and air cycle refrigeration machines for ultra-low temperature applications developed by Mirai Intex, corporate member of the IIR. 
Cascade systems are quite efficient when operated close to ambient temperature. However, a loss of cooling capacity is observed due to the evaporator with fans and defroster heater. With open-air cycle machines, no evaporator or fans are needed, and heat generated by these components does not consume any cooling energy. When cascade systems operate at temperatures below 0°C, frost accumulates on the surface, therefore reducing heat transfer. The authors of the study estimate that in a cold room using a cascade system, about 30% of energy is used for defrosting at -20°C. MIRAI Intex air cycle technology does not require fans inside the cold room. Air circulates between the oil-free refrigeration machine and the cold room itself. There is no need for additional temperature differences to transfer heat in the heat exchanger.
Natural refrigerants are usually considered as alternatives to fluorinated refrigerants. When comparing ULT configurations based on safety, the authors indicate that liquid nitrogen and vapour systems require gas detectors and ventilation so that dangerous refrigerant leakage can be detected in time. Meanwhile, air cycle technology is safe and requires minimal safety maintenance.
 Mota-Babiloni, A., Joybari, M. M., Navarro-Esbrí, J., Mateu-Royo, C., Barragán-Cervera, A., Amat-Albuixech, M., & Molés, F. (2020). Ultralow-temperature refrigeration systems: Configurations and refrigerants to reduce the environmental impact. International Journal of Refrigeration, 111, 147-158. https://iifiir.org/en/fridoc/ultralow-temperature-refrigeration-systems-configurations-and-142085
 Refolution Industriekälte GmbH REPORT – the analysis and comparison of existing technologies for ULT applications. https://mirai-intex.com/news/refolution-industriekalte-gmbh-report-the-analysis-and-comparison-of-existing-technologies-for-ult-applications
 Mirai Intex at ACHEMA 2022. Come and visit us at the exhibition! https://mirai-intex.com/news/mirai-intex-at-achema-2022