The Transient, Steady-State, and Stability Behavior of a Toroidal Thermosyphon With a Parallel-Flow Heat Exchanger

Abstract

The transient and steady-state heat transfer, fluid flow, and stability of a toroidal thermosyphon have been studied theoretically. The thermosyphon is heated over the lower half and cooled over the upper half by an annular parallel-flow heat exchanger. Under some conditions the system becomes unstable and the interaction between the fluids in the thermosyphon and in the heat exchanger is of special interest. Indeed, two neutrally stable curves are obtained for the same heat exchanger conditions. Detailed results and discussion are presented for the stability of the system as well as for the temperature, velocity, pressure drop, and efficiency.