Comparison of the calculated and measured stability of a NbTi cable-in-conduit conductor

Conference · Thu Oct 13 04:00:00 EDT 1994

OSTI ID:26569

Wong, R L ^[1]; Yeaw, C T ^[2]

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1. Lawrence Livermore National Lab., CA (United States)
2. Univ. of Wisconsin, Madison, WI (United States). Nuclear Engineering and Engineering Physics

Calculated curves of cable-in-conduit conductor energy stability margins vs. current are compared to experimental curves obtained at Oak Ridge National Laboratory for NbTi single triplex conductors. The conductors ranged in length from 1.8 m to 4.8 m, and had no imposed helium flow. The initiating heat pulse was applied for 16.7 ms over the entire conductor length. The calculated stability curves display the large decrease in energy margin from the low current and high energy margin {open_quotes}well-cooled{close_quotes} stability region, to the high current and low energy margin {open_quotes}ill-cooled{close_quotes} region that was determined experimentally. The calculated {open_quotes}limiting current{close_quotes} of 250 A (boundary between the ill-cooled and well-cooled regions) also agrees with experiment. The multi-valued stability margins measured for lengths of 3.1 and 3.8 m could not be obtained by the computer model. Excluding the multiple stabilities, the calculated margins are generally 30% lower than the experimental values. The decrease in energy margin in the ill-cooled region was found to be due to the low critical to operating temperature difference (2.2 K at 250 A). This prevents an initiating pulse in the ill-cooled region from being able to generate significant Joule heating without quenching, limiting the energy margin.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 26569
• Report Number(s): UCRL-JC--116965; CONF-941013--26; ON: DE95007964
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
99 GENERAL AND MISCELLANEOUS
C CODES
COMPUTERIZED SIMULATION
HEAT TRANSFER
STABILITY
SUPERCONDUCTING CABLES
TURBULENT FLOW