Development of Pumps for Two-Phase Fluid Loops 901273

Toshiba, under contract to NASDA is studying two-phase fluid loops (TPFL) as a thermal management system for future space platforms. For these fluid loops, two types of volumetric pumps, a trochoid gear pump and a scroll pump, are being developed, because volumetric pumps are, among others, less sensitive to cavitation.

Recently, we designed and fabricated a scroll pump for our 5kW heat rejection TPFL in order to achieve a continuous and quiet operation of the system, which is required for space use. This scroll pump has four scroll vanes, two fixed and two orbiting ones, to reduce pulsation of flow. This paper reports the performance test results of a bread board model (BBM). The trochoid gear pump completed up to the BBM level, is also designed under the same requirements for comparison. Component tests of the pumps are carried out prior to installation into the TPFL. As expected, the scroll pump showed weaker vibration and lower noise. Because this is the first model, the efficiency is not yet as high as that of the trochoid gear pumps. We intend to improve it in the near future.