NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 B3.01-8041
SUBTOPIC TITLE: Environmental Control of Spacecraft Cabin Atmosphere
PROPOSAL TITLE: Heat Pipe Heat Exchangers with Double Isolation Layers for Prevention of Interpath Leakage

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Advanced Cooling Technologies, Inc.
1046 New Holland Avenue
Lancaster, PA 17601-5688

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
David Sarraf
1046 New Holland Ave.
Lancaster, PA 17601-5668

Current manned spacecraft heat rejection systems use two heat exchangers and an intermediate fluid loop to provide isolation between the crew compartment air and the exterior fluid loop. Isolation is required because the fluids used are either toxic or can cause suffocation. The extra hardware doubles the mass of the system, consumes more power, and reduces reliability. Advanced Cooling Technologies, Inc., supported by Hamilton Sundstrand, proposes to use a heat pipe heat exchanger to provide two levels of isolation between the two fluid streams. This will allow the safe use of the otherwise toxic or harmful exterior fluids with no danger to the crew and will avoid the mass and power penalty of the existing approach. This approach is also potentially lower mass than an incremental improvement to the existing exchanger. The Phase I work will include conceptual design of a liquid/liquid and liquid/air replacement for the existing exchangers and a liquid/air exchanger that replaces both system exchangers. A system-level trade study will be conducted to assess the impact of the new exchanger designs on power and volume consumption and on thermal performance. Representative exchanger segments will be fabricated and tested to demonstrate readiness of the technology.

Potential NASA applications involve life support system for manned spacecraft. If successful, the program will allow the use of heat rejection systems using thermally-favorable fluids such as ammonia or Freon while avoiding the risk of contaminating the crew compartment with those fluids. This will reduce the mass, volume, and power consumption of the cooling system

Non-NASA Commercial applications of the technology include bleed air coolers and oil coolers for Navy vessels, heat exchangers for ammonia refrigeration plants, and heat exchangers for food and pharmaceutical processing. The Navy expects to need between 10 and 50 bleed air coolers and at least 200 oil coolers per year. They require absolute isolation between the seawater coolant and the fluid stream being cooled to assure availability of the systems and to prevent catastrophic damage to other equipment.