Comparative performance of two different designs of heat exchangers for the Vapor Cooled Current Leads

The performance of vapor cooled conventional current leads is a strong function of the heat transfer coefficient between the coolant and the available metallic surface. Designers always look for the best-optimized design concept of heat exchanger for the higher ratio of wotted area to current carrying cross-sectional area along with acceptable pressure drop and liquid helium consumption. At IPR, two different design configurations of heat exchangers have been adopted for comparison in which one of them is shell and rods with baffles and other one is rods in tubes. A (+/-) pair current leads has been tested and characterized for different current values up to 10kA. Test results show that, the shell and rod heat exchanger with baffles configuration is ∼ 20% more efficient as compared to tube and rod heat exchanger, which is a good margin on a cryogenic system.