Heat transfer characteristics of high melting point paraffin emulsions for latent heat transportation

The latent heat transportation materials with high melting points,paraffin emulsions,can be used as heat storage and transfer media.Because paraffin emulsions can store their latent heat during phase change process in the temperature range of 80—90℃,their heat storage density is higher than water.They can be applied for waste heat recovery,solar energy utilization or central heating systems.In the forced convection heat transfer experiments,the thermal boundary conditions of constant heat flux were imposed.Although the paraffin emulsions have higher effective specific heat capacity,the convective heat transfer coefficients are lower than that of water and decrease with the increase of concentration.The results also show that the convection heat transfer coefficient increases with temperature slightly.The correlations of Nusselt number for paraffin emulsions are obtained according to the experimental data.