Material compatibility and simulation testing for the Brayton engine solar receiver for the NASA Space Station Freedom solar dynamic option

Experimental investigations have been conducted in the areas of material compatibility and solar simulation testing for the heat receiver assembly (HRA) in the Brayton engine for the solar dynamic option for Space Station Freedom. The HRA configuration is a cylindrical receiver lined with tubes; each tube is surrounded by phase change material (PCM). The Brayton-cycle working fluid flows inside the tubes. The material compatibility investigation involved the high-temperature cycling of a series of PCM-filled containment canisters. At various intervals, canisters were removed from the high-temperature furnace, sectioned, and analyzed. For the solar simulation testing, a section of a full-size receiver tube was fabricated and assembled. The test results were compared with the predictions derived from a detailed thermal model of the test section. The results substantiated the viability of the configuration from both the fabrication and operational points of view