Article ID: 24-27LG
In air conditioning systems where the transition to environmentally friendly refrigerants is progressing, the challenge is to use refrigerants with a temperature gradient. Refrigerants with a temperature gradient have different compositions in the liquid and gas phases, so the bias in the gas-liquid distribution at the pipe branch has a significant impact on controllability. In this study, we conducted a gas-liquid two-phase flow analysis using Large eddy simulation (LES) for a shape that branches from a horizontal pipe in the vertical upward direction, and clarified the effect of the length of the outlet pipe on the gas-liquid distribution characteristics. In addition, by expressing the outlet dryness obtained by LES with a one-dimensional model based on the length of the outlet pipe, we developed a simple distribution prediction formula that can be applied to the analysis of the entire air conditioning system.
