Abstract: 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.

Key words: paraffin emulsion, latent heat transportation, heat transfer

摘要： 石蜡乳状液高温潜热输送材料是一种在80～90℃之间存在相变的流体。由于相变潜热的存在，石蜡乳状液在相变区间内的储热、载热密度远大于水，且集储热与潜热输送于一体，适用于余热利用、太阳能利用和集中供热等领域，具有广阔的应用前景。研究了定热流条件下石蜡乳状液在管内的强制对流换热特性。结果表明，与纯水相比，虽然石蜡乳状液的有效比热大，但其对流传热系数低，且浓度越高，对流传热系数越低。实验发现入口温度对石蜡乳状液对流传热系数的影响不大，但随着入口温度升高，对流传热系数有增大的趋势。最后获得了石蜡乳状液对流换热量纲1关系式。

关键词: 石蜡乳状液, 潜热输送, 传热