Two-phase Pumped Loop for Spacecraft Thermal Control

In response to NASA SBIR Topic S3.07, "Thermal Control Systems", Advanced Cooling Technologies, Inc. (ACT) proposes the development of an active Two-phase Thermal Management System (TPTMS) that relies on a single-phase liquid pump to drive two-phase flow through multiple heat sources and sinks distributed in parallel and in series while providing phase management using the momentum of the working fluid. This system is designed to address challenges discussed in the NASA Thermal Management Systems Roadmap, Technology Area (TA) 14. The use of a liquid pump to drive the system allows the working fluid to overcome large pressure drops with low power consumption. This feature, in turn, provides the ability to transfer waste heat over large distances, which is defined as a top technical challenge in TA14, Section 1.4. Additionally, flow can be driven through multiple heat exchangers or cold plates to either collect or release thermal energy. Arranged properly, this feature allows for heat load sharing, which is also defined as a top technical challenge. Added to these benefits are those intrinsic to two-phase heat transfer: near-isothermal operation, a two order of magnitude increase in the heat transferred per unit mass (TA14) and the ability to handle high heat fluxes with the appropriate heat exchanger design. Lastly, Section 2.2.3.2 of TA14 discusses the need for microgravity separators, which is an integral part of the proposed TPTMS.