DOI QR코드

DOI QR Code

Experimental study on the cryogenic thermal storage unit (TSU) below -70 ℃

  • Byeongchang Byeon (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Kyoung Joong Kim (Mechanical Engineering Department, Korea Advanced Institute of Science and Technology) ;
  • Sangkwon Jeong (Mechanical Engineering Department, Korea Advanced Institute of Science and Technology) ;
  • Dong min Kim (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Mo Se Kim (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Gi Dock Kim (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Jung Hun Kim (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Sang Yoon Lee (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Seong Woo Lee (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials) ;
  • Keun Tae Lee (LNG and Cryogenic Technology Center, Korea Institute of Machinery & Materials)
  • Received : 2024.02.26
  • Accepted : 2024.03.27
  • Published : 2024.03.31

Abstract

Over the past four years, as the COVID-19 pandemic has struck the world, cold chain of COVID-19 vaccination has become a hot topic. In order to overcome the pandemic situation, it is necessary to establish a cold chain that maintains a low-temperature environment below approximately 203K (-70℃), which is the appropriate storage temperature for vaccines, from vaccine suppliers to local hospitals. Usually, cryocoolers are used to maintain low temperatures, but it is difficult for small-scale local distribution to have cryocooler due to budget and power supply issues. Accordingly, in this paper, a cryogenic TSU (Thermal storage unit) system for vaccination cold chain is designed that can maintain low temperatures below -70℃C for a long time without using a cryocooler. The performance of the TSU system according to the energy storage material for using as TSU is experimentally evaluated. In the experiments, four types of cold storage materials were used: 20% DMSO aqueous solution, 30% DMSO aqueous solution, paraffin wax, and tofu. Prior to the experiment, the specific heat of the cold storage materials at low temperature were measured. Through this, the thermal diffusivity of the materials was calculated, and paraffin wax had the lowest value. As a result of the TSU system's low-temperature maintenance test, paraffin wax showed the best low-temperature maintenance performance. And it recorded a low-temperature maintenance time that was about 24% longer than other materials. As a result of analyzing the temperature trend by location within the TSU system, it was observed that heat intrusion from the outside was not well transmitted to the low temperature area due to the low thermal conductivity of paraffin wax. Therefore, in the TSU system for vaccine storage, it was experimentally verified that the lower the thermal diffusivity of the cold storage material, the better low temperature maintenance performance.

Keywords

Acknowledgement

This research is supported by the Ministry of Trade, Industry and Energy (MOTIE) and the Korea Energy Technology Evaluation and Planning (KETEP) (No. 20213030040460, Development of a Localization Model for Core technologies (CCS, BOG treatment, CHS system) of Liquid Hydrogen Carrier).

References

  1. S. S. DeRoo, N. J. Pudalov, and L. Y. Fu, "Planning for a COVID19 vaccination program," Jama, vol. 323, no. 24, pp. 2458-2459, 2020.  https://doi.org/10.1001/jama.2020.8711
  2. J. Jung, "Preparing for the Coronavirus Disease (COVID-19) Vaccination: Evidence, Plans, and Implications," Journal of Korean Medical Science, vol. 36, pp. 7, 2021. 
  3. Q. Lin, Q. Zhao, and B. Lev, "Cold chain transportation decision in the vaccine supply chain," European Journal of Operational Research, vol. 283, no. 1, pp. 182-195, 2020.  https://doi.org/10.1016/j.ejor.2019.11.005
  4. D. Bugby and B. Marland, "17 Cryogenic Thermal Storage Units," Spacecraft Thermal Control Handbook: Cryogenics, vol. 2, pp. 409, 2002. 
  5. L. E. Ehrlich, J. S. Feig, S. N. Schiffres, J. A. Malen, and Y. Rabin, "Large thermal conductivity differences between the crystalline and vitrified states of DMSO with applications to cryopreservation," PLoS One, vol. 10, no. 5, pp. e0125862, 2015. 
  6. M. T. Chaichan, S. H. Kamel, and A. N. M. Al-Ajeely, "Thermal conductivity enhancement by using nano-material in phase change material for latent heat thermal energy storage systems," Saussurea, vol. 5, no. 6, pp. 48-55, 2015. 
  7. O. D. Baik and G. S. Mittal, "Determination and modeling of thermal properties of tofu," International Journal of Food Properties, vol. 6, no. 1, pp. 9-24, 2003.  https://doi.org/10.1081/JFP-120016621
  8. J. Kim, H. Park, J. Bae, S. Jeong, and D. Chang, "Investigation of amorphous material with ice for cold thermal storage," Progress in Superconductivity and Cryogenics, vol. 21, no. 1, pp. 40-44, 2019.