NASA SBIR 2003 Solicitation


PROPOSAL NUMBER: 03- II F3.02-8982
SUBTOPIC TITLE: Spaceport Cryogenic Fluids Handling and Storage Technologies
PROPOSAL TITLE: Cryogenic Cooling System for Zero-Venting Storage of Supercritical Air Packs

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Michael G Izenson
16 Great Hollow Road, P.O. Box 71
Hanover, NH 03755-0071
U.S. Citizen or Legal Resident: Yes

Supercritical air at cryogenic temperature is an attractive source of breathing air because of its very high density and low pressure. However, heat leak into the cryogenic tank causes the stored air to expand and vent, thus limiting the storage life of a charged system. We propose to develop a storage system for supercritical air packs that provides cryogenic cooling that will enable long-term storage of charged, supercritical air packs with zero venting. In Phase I we proved feasibility through design trade-off and optimization analyses that led to a conceptual design and operational description of a supercritical air storage system. The innovative, mechanical cryocooling system provides flexible coupling and quick disconnection, as well as high reliability and efficient, low-power operation. The system can be used to charge the tanks with supercritical air without the use of expendable cryogens. In Phase II we will build and demonstrate a prototype storage system for supercritical air self-contained breathing apparatus (SCBAs). Critical components will be designed and tested individually, then integrated to produce a complete cooling system. We will couple the Phase II prototype with a supercritical air pack and demonstrate long-term storage with zero venting.

By enabling long-term storage of fully charged SCBAs, our cryogenic cooling system will enable the use of supercritical air SCBA for a variety of terrestrial applications. Homeland security will particularly benefit. Supercritical air makes an ideal breathing air supply for SCBAs: large quantities can be stored at low pressure in a lightweight system, it operates independently of orientation, the quantity is easily gauged, and the system can provide body cooling. The commercial market for these systems includes firefighters, first responders, search-and-rescue personnel, and Level A HAZMAT teams. Supercritical air will be ideal for high-rise and subway firefighting and rescue operations.

NASA personnel use cryogenic air supplies for rocket propellant handling and emergency rescue from the shuttle launch pad. Supercritical air systems are lightweight, compact, and provide cooling, but the cryogenic tanks need to be frequently recharged. The cryogenic cooling system developed in Phase II will enable storage with zero venting and allow personnel to rapidly disconnect the tanks. All quick disconnects are warm for high seal reliability. The light weight, compact size, high reliability, and high efficiency of our mechanical cooling system will make it ideal for space exploration, enabling non-venting cryogen storage for future spacecraft and extraterrestrial bases.