Phase Change Heat Exchanger Project (Phase Change HX) - 03.29.17
Maintaining safe temperatures is difficult in space, where there is no atmosphere to provide warmth in the shade or protection from the sun’s heat. Phase-change material heat exchangers can help by freezing or thawing a material to maintain critical temperatures inside a spacecraft, protecting crew members and equipment. Phase Change Heat Exchanger Project (Phase Change HX) tests a new type of heat exchanger that could help offset heat on future spacecraft, enabling future missions to better regulate temperatures. The test bed brings a new capability to the International Space Station (ISS) where test articles, requiring sub-zero fluid temperatures, can be tested on ISS. The Phase Change HX Payload includes a plug and play design allowing common interfaces for future payloads that require fluid temperature between -10°C to 30°C with flow rates between 50-300 lb/hr. Science Results for Everyone
Information Pending Experiment Details
OpNom: Phase Change HX
Rubik Sheth, M.S., NASA Johnson Space Center, Houston, TX, United States
Thomas Ahlstrom, NASA Johnson Space Center, Houston, TX, United States
Jacobs Engineering, Houston, TX, United States
NASA Johnson Space Center, Crew and Thermal Systems Division, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Technology Demonstration Office (TDO)
Scientific Discovery, Space Exploration, Earth Benefits
ISS Expedition Duration
March 2016 - September 2017
- Creating a unique test platform using the EXPRESS Rack on the ISS for testing phase change material heat exchangers (PCM HX).
- PCM HXs store energy by thawing a phase change material (i.e. wax or water) via hot coolant.
- The vehicle’s radiators are capable of cooling the coolant, then refreezes the PCM for later use.
- Providing the ability to run numerous thaw/freeze cycles for the PCM HX while logging data from numerous temperature and pressure sensors.
- Sending the collected data to the ground team for processing and assessing how the PCM HX is performing in a micro-gravity environment.
- Removing the currently tested PCM HX within the experiment and installing a new PCM HX prototype with a different phase change material (i.e. water vs wax). This change-out will be capable of being performed by the on-orbit crew.
- Advancing the technology readiness level of phase change heat exchangers for use on future exploration missions.
- Assessing the performance of phase change heat exchangers in a micro-gravity environment.
- The ability to test numerous phase change heat exchangers capable of being installed by the on-orbit crew.
- Providing a low temperature loop (down to -10°C) that could be used in the future for other experiments in need of a lower temperatures than the ISS can currently provide.
- Entire experiment is contained within an EXPRESS Rack double locker.
- Utilizes the Moderate Temperature Loop (MTL), Low Temperature Loop (LTL), two EXPRESS Rack power connections, and one EXPRESS Rack data connection.
- Includes a contained Propylene Glycol Water (PGW) loop and a Thermal Electric Cooler (TEC) HX which provides the -10°C fluid used to freeze the PCM Heat Sink.
- The TEC HX includes strip heaters which provide the maximum 30°C fluid used to melt the PCM heat sink.
- Includes an avionics box which is cooled by the MTL and provides all data monitoring/logging and the software interface required to run the experiment from the ground workstation.
Wax-based phase-change heat exchangers have been used in space before, including on the Apollo lunar rover and the former Skylab space station, but with inconsistent results. A water-based phase-change heat exchanger has significantly better energy storage than wax, but it has not yet been tested in space. This investigation tests these heat exchangers in a microgravity environment, providing data needed to use phase-change heat exchangers on future space missions.
Phase-change heat exchangers are a low-energy means to control temperatures in chemical plants, power plants and other settings. By using materials that change phase from liquid to vapor depending on the temperature, facilities like power plants and factories can more easily move heat into areas that must be warmed by removing heat from areas that must be cooled. While this investigation is geared to space-based use, results improve basic research on phase-change heat exchangers.
Operational Requirements and Protocols
Decadal Survey Recommendations
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