An Improved Design for Air Removal from Aerospace Fluid Loop Coolant Systems 2003-01-2569

Aerospace applications with requirements for large capacity heat removal (launch vehicles, platforms, payloads, etc.) typically use a liquid coolant as a thermal transport media to increase efficiency and flexibility in vehicle design. An issue with these systems, however, is susceptibility to the presence of non-condensable gas (NCG) or air. The presence of air in a coolant loop can have one or more negative consequences. It can cause loss of centrifugal pump prime, interfere with sensor readings, inhibit heat transfer, and block coolant flow to remote systems. Hardware ground processing to remove this air is also cumbersome and time consuming which drives up these recurring costs. Current systems for maintaining the system free of air are tailored and have demonstrated only moderate success. One solution to mitigate these problems is the development and advancement of a passive gas removal device, or gas trap, installed in the flight cooling system to simplify the initial coolant fill procedure and maintain the system during operations. The proposed device would use commercially available membranes to increase reliability and reduce cost, and would address both current and anticipated applications. In addition, it would maintain current pressure drop, water loss, and size restrictions with increased tolerance for pressure increases due to gas build-up in the trap.