Development of a Sensor for High-Quality Two-Phase Flow

摘要

The monitoring of the quality of the two-phase mixture at various locations in the system is a valuable, possibly indispensable, part of the control system needed to properly operate a two-phase heat transport system for large spacecraft. Based on trade-off of various quality monitoring concepts, NLR started to develop a dedicated quality sensor of the axial capacitance principle. Its theoretically demonstrated feasibility as quality and wetting sensor was experimentally confirmed by preliminary experiments using liquid layer simulating plastic sheets and annular air/liquid flow. Experiments in a two-phase freon test loop show the sensor to be an accurate, fastly responding, sensitive instrument. Recently it has been accepted for further development as a critical component of the Two-Phase Heat Transport System developed by the European Space Agency. A review of the development is presented. Performance figures, obtained by calibrations in a new freon 114 loop, are given. Recommendations for future work and applications foreseen are indicated.