管内の非定常沸騰流に関するシミュレーション

抄録

A novel heat exchanger using parallel small refrigerant channels has recently been developed for air conditioning systems. Boiling flow in parallel channels is, however, subject to unstable flows. The unstable flows trigger dryout even under low time-averaged quality conditions and result in deterioration of heat transfer capacity of the heat exchanger. The authors developed a simulation model which predicts heat transfer capacity of the parallel channel heat exchanger under unstable boiling flows. In this paper, to confirm applicability of the model, the simulation results for pressure drop oscillation and density wave oscillation in a single channel tube were presented and compared with the conventional experiments. The simulation model reproduced well the periodical changes of mass flow rate and pressure drop in the pressure drop oscillation and stability boundary for the density wave oscillation.