Development of a Two-Phased Accumulator for a Space-Based Ammonia Thermal Bus System

A two-phase accumulator for use in two-phase active thermal control systems has been developed and successfully tested as part of the Grumman Prototype Two-Phase Thermal Bus system. The two-phase accumulator works on the principle of direct energy transfer out of and into the vapor space of the accumulator via subcooled liquid spray and warm vapor addition. Analysis and design of this unique accumulator are discussed, as well as the test results obtained during ambient testing in the NASA-JSC Thermal Test Bed. Test results indicated the ability of the accumulator to control bus setpoint within 2°F over a wide variety of load and environmental conditions.