[KSCI] Korea Science Citation Index Service

http://dx.doi.org/10.9714/psac.2013.15.3.049

Experimental study on natural circulation using liquid nitrogen for superconducting applications

Choi, Yeon Suk (Korea Basic Science Institute)

Publication Information

Progress in Superconductivity and Cryogenics / v.15, no.3, 2013 , pp. 49-52 More about this Journal

Abstract

An experiment to investigate the natural circulation of a cryogen has been performed. The study is motivated mainly by our recent development of cryogenic cooling system for prototype superconducting cyclotron without any circulating pump. In the natural circulation loop system, a cooling channel is attached on the outer surface of the aluminium block and the liquid nitrogen passes through inside of the channel to cool the block indirectly. A cryocooler as a heat sink is located at the top to re-condense cryogenic vapor coming from the aluminium block in which electrical heater is installed as a heat source. The main dimensions are determined using the relevant analysis and the natural circulation loop is successfully fabricated. The temperature distributions in the loop are measured during initial cool-down process and in steady state, from which the modified Grashof numbers are calculated and compared with the existing correlation estimated with one-dimensional analysis for steady state flow.

Keywords

Natural circulation; two-phase flow; cryogenic cooling; superconducting magnet;

Citations & Related Records

Reference

1	P. K. Vijayan, "Experimental observations on the general trends of the steady state and stability behavior of single-phase natural circulation loops," Nuclear Engineering and Design, vol. 215, pp. 139-152, 2002. DOI ScienceOn
2	R. Greif, "Natural circulation loops," Journal of Heat Transfer, vol. 110, pp. 1243-1258, 1988. DOI
3	M. R. Gartia, P. K. Vijayan and D. S. Pilkhwal, "A generalized flow correlation for two-phase natural circulation loops," Nuclear Engineering and Design, vol. 236, pp. 1800-1809, 2006. DOI ScienceOn
4	M. Maiani, W. J. Kruijf and W. Ambrosini, "An analytical model for the determination of stability boundaries in a natural circulation single-phase thermosyphon loop," Int. J. of Heat and Fluid Flow, vol. 24, pp. 853-863, 2003. DOI ScienceOn
5	A. K. Nayak, et al., "Study on the transient and stability of boiling two-phase natural circulation loop with $Al_2O_3$ nanofluids," Applied Thermal Engineering, vol. 31, pp. 1673-1681, 2011. DOI ScienceOn
6	M. Misale, P. Garibaldi, J. C. Passos and G. Bitencourt, "Experiments in a single-phase natural circulation mini-loop," Experimental Thermal and Fluid Science, vol. 31, pp. 1111-1120, 2007. DOI ScienceOn
7	M. Zhang, Z. Liu and G. Ma, "The experimental investigation on thermal performance of a flat two-phase thermosyphon," Int. J. Thermal Science, vol. 47, pp. 1195-1203, 2008. DOI ScienceOn
8	C. Brennen, Fundamentals of Multiphase flow, Cambridge University Press, 2005.