Two-Stage Cryocooler Development for Liquid Hydrogen Systems A project supported by NASA Hydrogen Research at Florida Universities

CURRENT SYSTEMS Current launch vehicles use common approach to cryogenic ground storage, handling and vehicle loading –Offsite propellant production and tanker transport to launch pad storage facility –Normal boiling point (NBP) storage at pad All heat leak into system leads to boil off losses –Countdown loading process consists of chill down, slow fill, fast fill, and replenish LOX chill down and boil off losses vented LH2 chill down and boil off losses burned in flare stack –Launch scrub drainback to pad storage by gravity feed Courtesy of Mr. Bill Notardonato, NASA KSC

PROPOSED SYSTEM Integrated cryogenic refrigeration and storage system –Uses state-of-the-art Reverse Brayton Cycle refrigerator Continuous operation minimizes refrigeration capacity Most efficient process currently in use (Carnot efficiency of 35-40%) Only input is electrical power, requires no cryogenic consumables Ambient temperature compressors are oil lubricated Working fluid is neon and helium, no wet expanders necessary Scheduled downtime is 1 week per year for routine maintenance Courtesy of Mr. Bill Notardonato, NASA KSC

PAD SCHEMATIC Courtesy of Mr. Bill Notardonato, NASA KSC

Cryocooler Applications and Operating Regions

Courtesy of Marty Nisenoff