混合石蜡的热物性实验

对低熔点石蜡（十六烷、十八烷）与高熔点石蜡（54#石蜡、62#石蜡）混合物的传热性能进行了实验研究,用以替代价格较高的十八烷,用于立式集热板太阳能热气流电站的蓄热系统中.采用差示扫描量热仪（DSC）对不同质量分数的混合石蜡的相变潜热及相变温度进行了测量,结果表明：随着低熔点石蜡的加入,混合石蜡的相变温度在不断减小,相变潜热介于低熔点石蜡与高熔点石蜡之间;且混合后的石蜡具有良好的循环稳定性.采用热针法对不同质量分数的混合石蜡固态体系、液态体系的导热系数进行了测量,结果表明：混合之后石蜡的导热系数与低熔点石蜡相差不大,石蜡在固态时的导热系数要大于在液态时的导热系数.综合比较可知,混合石蜡可以满足储能需求,并能降低成本.

Experimental Research on Thermophysical Property of Paraffin Mixture

Low melting point paraffin（n hexadecane,n octadecane） and high melting point paraffin （54 # paraffin,62 # paraffin） were mixed together,and relevant experiments were conducted to study heat transfer performance of the mixture inorder to replace the more expensive octadecane in vertical panels of solar thermal power plant heat storage system.Phase change latent heat and phase transition temperature of paraffin mixture of different mass fraction were measured by DSC.The results showed that：As the mass fraction of low melting point paraffin increases,paraffin mixture＇s phase change temperature continues to decrease,and phase change latent heat is between low melting point paraffin and high melting point paraffin; Paraffin mixture has favorable cycle stability.The thermal conductivities of mixed paraffin in different mass fraction were measured by thermal probe method.The results showed that：The thermal conductivity of paraffin mixture was nearly the same as low melting point paraffin,and the thermal conductivity of paraffin in solid was higher than in liquid.It was concluded that the mixing paraffin wax can meet the demand of energy storage,and can reduce the cost.