NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 S2.03-8242
SUBTOPIC TITLE: Cryogenic Systems
PROPOSAL TITLE: High Effectiveness Heat Exchanger for Cryogenic Refrigerators

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Micro Cooling Concepts, Inc.
7522 Slater Ave #122
Huntington Beach, CA 92647-7738

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Jack Fryer
7522 Slater Ave #122
Huntington Beach, CA 92647-7738

We propose an innovative high performance cryogenic heat exchanger manufactured of titanium by photo-etching and diffusion bonding. This is a parallel plate design of thin laminated titanium foils. Titanium is used because of it low thermal conductivity which allows more compact heat exchangers with lower parasitic heat loss. Photo-etched patterns in the foils create the flow passages for the hot and cold flows with solid barrier foils separating the streams. A difficult problem with high performance heat exchangers is balancing the mass flow rate between multiple flow passages required for all but the smallest levels of cooling; this problem can degrade exchanger ineffectiveness by factors of more then 3. Our manufacturing technique allows us to include flow balancing features within the flow passages to automatically balance the flow rates. Recuperative cycle cryocoolers, such as reverse Brayton, Joule-Thomson or their hybrids, require high effectiveness heat exchangers to reach cryogenic temperatures. Higher effectiveness leads directly to improved system efficiency or allows lower temperatures to be reached. Improved heat exchanger performance will directly lead to lower input power cryocoolers particularly for the 4-10 K temperature range where cryocooler system efficiencies are very low.

Multiple future NASA space missions require technology advances to cryogenic cooling to enable their missions. These include TPF (Terrestrial Planet Finder), Con-X (Constellation-X), SAFIR (Single Aperture Far Infrared), SPIRIT (Space Infrared Interferometry Trailblazer), and SPECS (Submillimeter Probe of the Evolution of Cosmic Structure). Even though these missions cover diverse areas of the Electromagnetic Spectrum from X-Rays to far infra-red to submillimeter, each of them requires advances to 4-6 K cryocoolers (or cryogenic refrigerators) for the cooling of their detectors.

Closed cycle refrigerators (CCR) for wireless network products. The Pentagon's Joint Tactical Radio System (JTRS) contract for wireless radios could require cryocoolers if superconducting devices are used or for improved performance of the A/D converters. Additionally, The Pentagon is developing a constellation of missile tracking satellites called the Space Based Infrared System - Low Segment (SBIRS-Low), which requires cooling of detectors and optics located on a telescope.