An analysis of freezing/thawing process in building wall

(1)推导了适用于冻融过程的热湿同步传递控制方程。讨论了方程的闭合性。(2)为了关闭控制方程，给出了冻结状态下液态水含量与水（化学）势的平衡关系，并讨论了如何测量和估计。与此同时，凝固点的下降显示为水分（化学）势的函数。(3)在热湿联传方程的基础上，导出了拟线性化方程。所导出的方程是线性的，但具有时变性质，方程的系数是在特定但任意的边界条件下通过求解原始非线性方程得到的。(4)以模拟为例，数值分析了内墙采用玻璃棉保温，外表面采用防潮层分层的建筑墙体冻融过程。(5)提出了一种考虑滞后效应的瞬态温度和水分传递的数值分析方法。

(1) Governing equations are derived for simultaneoous heat and moisture transfer which can be applied to freezing and thawing processes. Closing of the equations is discusse.(2) For closing the governing equations, equilibrium relations of the liquid water content and moisture (chemical) potential under freezing regime are presented and discussed how to measure or how to estimate. Along with, the freezing point depression is shown as a function of moisture (chemical) potential.(3) A quasi-linearized equation are derived, based on simautaneous heat and moisture transfer equations. The equations derived are Linear but time variant and coefficients of the equations are obtained by solving original nonlinaer equations on the paticular but arbitrary boundary conditions.(4) As an example of simulation, freezing and thawing process in the building wall, thermally insulated by glass wool on inner side of the wall and layered by moisture barrier at outer surface, is numerically analyzed.(5) A numerical method to analyze transient beat and moisture transfer considering hysteresis effects are presented.