Numerical Study of Heat Transfer on Flow Boiling in Vertical Tube by LB Method Simulation

In order to study the heat transfer on flow boiling and bubble behavior in vertical tubes, the lattice Boltzmann (LB) method was used to simulate the flow and heat transfer processes respectively by the improved pseudo potential model and the thermal model. The simulation results were compared with the empirical relationships to verify the correctness of the model. The influence of bubble behavior on boiling heat transfer coefficient was investigated. The results show that the heat transfer coefficient presents periodic fluctuations with the nucleation, growth, slip and detachment of bubbles. Finally, the effect of gravity acceleration on bubble behavior and boiling heat transfer was investigated. The larger the gravity, the shorter the growth cycle of the bubble, the greater the boiling heat transfer coefficient.