Development of a Passive Gas Trap for Internal Thermal Control System

A passive gas removal device, i.e. gas trap is used in the Internal Thermal Control System (ITCS) of the International Space Station (ISS) to remove non-condensable gases to prevent the cavitation or air locking of the pump and malfunction of the pressure and flow sensors. Since the non-condensable gases are always ingested into the ITCS during the routine maintenance and/or replacement of components in the ITCS, it is necessary to have an efficient and reliable gas trap in the liquid coolant loop of the ITCS. To increase tolerance to particulate and microbial growth fouling, extend the operational life, reduce the cost and on-orbit maintenance, and decrease crew workload, an alternative gas trap composed of only one type of membrane is developed. This paper describes the efforts involved in this development, which include the design concept of the alternative gas trap, performance modeling, and the preliminary performance test of the alternative gas trap in the relevant environment.