Increasing Sublimated Water Vapor Collection Rates on an Engineered Cold Plate from Icy Lunar Regolith

View Video Presentation: https://doi.org/10.2514/6.2023-1417.vid This paper focuses on the experimental characterization of ice collection capacity on engineered cold plate for lunar ice collection during thermal mining. A 4 cm × 4 cm cold plate was used to collect ice at various degrees of sub-cooling and sublimation rates at cryogenic vacuum condition. The tests were performed in a vacuum chamber at 2.0 × 10-3 Torr pressure with a chamber temperature ~ 223 K. The sublimation chamber contained frozen deionized water where the operating condition was maintained in such a way that it gave continuous vapor feed to the system when required. The sublimation rate was measured by measuring the before and after weight of the ice chamber. The sublimation rate was increased from 2.89 g/hr. to 49.1 g/hr. by increasing the given heat to the frozen ice. The vapor was guided to the cold plate that later deposited on to it. A thin film heater underneath intermittently sublimates a thin ice layer and delaminates the deposited ice from the cold plate. A load cell was used to measure the weight of the delaminated ice inside the test chamber at a delamination heater power of ~ 2.5 W/cm2. To characterize the effect of various degrees of sub-cooling on the ice collection rate, the cold plate temperatures were maintained from 16 K to 96 K degree of sub-cooling. A maximum ice collection rate of 30.5 g/hr. was achieved on for a sub-cooling of 91.8 K. This represents approximately 66% ice collection efficiency for the 4 cm × 4 cm cold plate.