Research on Micro Channel Phase Change Heat Transfer

摘要

The fluctuations of temperature and pressure, which lead to random actions of bubbles growth, are typical characteristics for a system of micro channel flow boiling due to its confined space. The formula of the average radius over an ensemble bubbles is put forward on the conditions of equilibrium bubble diameter and initial value. As a result, the equation for bubble random growth is obtained on the basis of the correlations of random factorsand a potential function and probability density of the system are studied by the steady state solution to the obtained equation. Furthermore, the nucleate flow boiling heat transfer coefficient formula was put forward according to the conclusions of heat soliton. Phase change heat transfer experiments are carried out to investigate its feasibility by parallel vertical mini channels with cross section: 0.3 mm別2mm, 0.6mm別2mm and 2 mm別2mm respectively. A computer control system is established to ensure the subcooling deionised water section is less than 4% of the total stable length. Contrast figures were drawn between experimental data and theoretical results, which show the practicability of the proposed model.