Cost-Effective Acoustic-Stirling Cryocooler with Flexibly Attached Remote Coldhead

High-Temperature Superconducting (HTS) devices, needed for the modernization and expansion of America¿s electricity delivery system, require efficient, reliable, and affordable cryogenic cooling of large cryostats. Commercial cryocoolers of appropriate capacity and temperature for transformers and cables miss the target on one or more of these parameters. This project will continue the development of a novel high-capacity cryocooler for transformer and cable applications (HTS-3 and HTS-4 applications). In recent demonstrations in small acoustic-Stirling cryocoolers, the new cryocooler exhibited high efficiency, reliability, and affordability. The cryocooler will be combined with a newly-invented, flexibly-attached remote coldhead, to provide practical cryostat integration at low cost. Phase I will adapt and upscale the remote coldhead innovation to make an acoustic-Stirling cryocooler of 300 watts capacity and a multi-head version of 900-1200 watts. This will be accomplished by using simulation codes to produce a detailed design and manufacturing process for the 300-watt (HTS-3) unit. Then, the resulting design and manufacturing process will be used along with cost data for related baseline coolers to verify feasibility, with a plan for hardware verification in Phase II. Commercial Applications and Other Benefits as described by the awardee: The new cryocooler should enable practical and reliable HTS power equipment, bringing economic, environmental, and enhanced security benefits to the electric power industry and its customers. In addition, the new cryocooler would be significantly superior (in efficiency, reliability, and practicality) to existing coolers now sold for medical and scientific imaging, gas recondensation or liquefaction, and large-scale cryopumping in vacuum-based manufacturing systems. The current world market for these cryocoolers is 2-3,000 units per year, with healthy growth expected.