Natural convection heat transfer from a discrete heat source coupled with conduction dominated phase change

摘要

A numerical study has been conducted for the heat transfer from a discrete heat source by natural convection in air above coupled with conduction dominated melting of a phase change material (PCM) below via a wall of finite thermal diffusivity.Results indicate that the presence of a PCM layer underneath the wall significantly delays the temperature rise of the heat source. The time delay increases as the thermal diffusivity of the wall material decreases and as the thickness of the PCM layerincreases. For high thermal conductivity wall materials k{sub}w/k{sub}m≥ 100 the steady state heat source temperatures are similar and independent of the PCM layer. On the other hand, for k{sub}w/k{sub}m≤ 10, the steady state temperatures are higher and dependent on the thickness of the PCM layer. A correlation is proposed in terms of the thickness of the PCM layer and the thermal conductivity ratio of the wall.