Stability analysis and maldistribution control of two-phase flow in parallel evaporating channels

摘要: Parallel channel heat transfer system is an attractive means to enhance by increasing the total surface area in exchanger. Uniform distribution of flow channels important operation attribute order avoid dryout and subsequent hot spots possible device failure. For operating single-phase regime, uniform a stable equilib- rium. However, two-phase boiling equilibrium bifurcates - becomes unstable, new or unstable non-uniform distributions, maldistributions, equilibria emerge. As result, parallel exchangers typically operate single phase regime such ''maldistribution instability''. This paper presents stability analysis active tempera- ture control evaporator pumped loop. We show that for identical channels, uncontrollable with pump alone unobservable from overall rate measurement. A conventional solution involves introducing additional valve-induced pressure drop, but drawback resulting higher pumping power. present new, somewhat sur- prising, result if characteristics are all distinct, actually controllable observable loop rate. non-identical systems, we controller design approach demonstrate its efficacy through simulation example.