Title:
HIGH EFFICIENCY MODULAR CRYOCOOLER WITH FLOATING PISTON EXPANDER
Document Type and Number:
WIPO Patent Application WO2001002781
Kind Code:
A9
Abstract:
A compact, modular, cryocooler (10) is provided for use in relatively small-scale applications, i.e., applications requiring less than approximately 10 Watts of cooling capacity at about 10 degrees K or less. The cryocooler (10) utilizes a recuperative heat exchanger (12) integrally combined with a floating piston expander having a piston (16) adapted for periodic movement within an expansion cylinder (18). The piston (16) is actuatable without an external drive mechanism, but rather by selective operation of processor controlled "smart", variable current pulse valves (24, 26, 28, 30) which serve to alternately couple working fluid and ballast fluid to opposite ends of the cylinder. The valves are actuated in response to output signals generated by a non-invasive inductive sensor, which detects the position of the piston within the cylinder. The floating piston expander and recuperative heat exchanger are fabricated as an integrated, modular unit, which facilitates scaling to N modular units.
Inventors:
SMITH JOSEPH L JR
Application Number:
PCT/US2000/016139
Publication Date:
August 02, 2001
Filing Date:
June 12, 2000
Export Citation:
Assignee:
MASSACHUSETTS INST TECHNOLOGY (US)
International Classes:
F25B9/06; F25B9/10; F25B9/14; F25J1/00; F28D7/02; (IPC1-7): F25B9/00
Download PDF: