机构地区: 清华大学建筑学院建筑技术科学系
出 处: 《清华大学学报(自然科学版)》 2003年第6期829-832,共4页
摘 要: 为研究固液相变强化传热机理,通过有内热源的稳态导热与固液相变传热之间的比较,对一维圆筒壁和球壁在等温(第一类)边界条件下的导热问题进行了理论分析。揭示了该种情况下固液相变强化传热的机理,推导出以无内热源稳态和瞬态传热速率为基准的相变界面换热强化度的解析表达式。结果表明,当几何尺寸给定时,影响相变界面换热强化度的因素有:相变材料的导热系数、定压比热容、融解热、密度、以及相变温度与接触表面的温度差;且Stefan数及Fourier数越小,相变界面强化传热的程度就越大。 Phase change heat transfer in a cylindrical or spherical wall was analyzed based on the analogy between steadystate thermal conduction with an internal heat source and solidliquid phasechange heat transfer. For isothermal boundary conditions, two kinds of enhanced interfacial heat transfer were analyzed with phase change in a cylindrical or spherical wall using steady and unsteady thermal conduction analyses. The results showed that for the given sizes, the factors influencing the solidliquid phasechange enhanced heat transfer were the thermal conductivity, the specific heat capacity, the latent heat, the density, and the temperature difference between the phasechange temperature and the contact surface temperature. The heat transfer enhancement at the phase change interface increased with decreasing Stefan number and Fourier number.
关 键 词: 热传导 相变传热 圆筒壁 球壁 固液相变 强化传热机理 传热速率 换热强化度
领 域: [动力工程及工程热物理] [动力工程及工程热物理]