Research on Density Wave Instability in Parallel Dual-channels under the Conditions of Natural Circulation

In this paper, we studied on flow instability in parallel dual-channels under the conditions of natural circulation by relap5, the effect of pressure and inlet temperature on flow instability, it is found that the system will be more stable when the pressure and inlet temperature rise, and in the same time, the system has a smaller pulsation. It is also found that in the natural circulation system, the two kinds of instability, density wave oscillations (DWOs) and fluctuation between tubes will transform into each other, in the research, the main reason for this transform is that the quantity of heating of parallel channels are different, and when we compare the results of research and experiments under the same condition, it is in good agreement with experimental results.