The Interaction of Control Valves with Oscillations Generated in a Large Water to Hydrogen Heat Exchanger

Abstract

A number of tests which produced sustained thermally induced flow and pressure oscillations in a large H₂O-H₂ heat exchanger have been made at the Nuclear Rocket Development Station (NRDS), northwest of Las Vegas, Nevada. The heat exchanger operates very smoothly at design conditions of 1000 psia and 12.5 lb/sec/duct when liquid hydrogen is heated to 520°R. The oscillation experiments were performed at off design conditions at pressures in the range of 100 to 300 psia and flow rates on the order of 2 lb/sec/duct. These experiments were performed in order to investigate the limiting conditions for the stable operation of the 4.46-in. ID heat exchanger. The stability limits were observed to be compatible with the oscillation inception correlation of Thurston et al. [¹], which was based on a ¼-in. ID test section, and with the inlet throttling effects reported by Bartiit et al. [²] for a 4-in. ID H₂O-H₂ heat exchanger. However, when the heat exchanger was operated with flow oscillations and functioning inlet and outlet control valves, unusually large amplitudes were produced within the heat exchanger. The interaction of control valves, at the inlet and outlet of a heat exchanger, with oscillations developed within the heat exchanger is the subject of this note.

Work performed under the auspices of the U.S. Atomic Energy Commission.