SBIR-STTR Award

Todays Navy continues to see increased demand for more power applied from both on and off the ship. This need is largely driven by the continued development of high power density advanced weapons systems and sensors. Continued space and weight limitations for these ship applications will drive the need for new power solutions to be light and compact, easing installation on new ships and enabling upgrades on existing ones.To meet this need, highly efficient methods of transferring large amounts of power are being investigated by NSWC Carderock in Philadelphia through the use of High Temperature Superconductors (HTS). HTS technology provides dramatically increased current density over conventional conductors, but they do require cryogenic cooling to achieve the superconducting state. Low power Stirling based cryocoolers have been developed by the Navy to cool superconducting cables in low voltage DC applications such as degaussing. AC power cable applications will require larger capacity cryocoolers to manage the thermal loads associated with large input currents as well as the AC losses associated with superconductors during AC power transfer. These larger coolers will also need to be more efficient then their lower capacity predecessors if shipboard implementation is to be achieved.

The objective of this proposal is to fabricate and deliver to the Navy a new, highlyreliable, high efficiency, maintenance-free cryocooler to meet or exceed the goals outlined in theoriginal SBIR solicitation, while being rugged enough to deploy on a Navy surface combatantplatform. The specific objectives from the SBIR solicitation are as follows:?1.?Lifting 600 W of heat from 50 Kelvin, while rejecting to 50°C cooling water?2.?Maintaining an efficiency of 30% of the ideal Carnot thermodynamic cycle3. 1.5 W of heat lift per kg of cryocooler mass?4.?Meeting a $200/W of heat lift (@ 50 Kelvin) price point for the cryocooler and cryogen circulation / heat transport systemThis new cryocooler will enable new high temperature superconducting (HTS)applications on Navy vessels, to include power transmission and rotating machines (generatorsand motors), as well as support existing HTS applications such as degaussing and minesweeping.