Heat and humidity coupling non-steady state transfer model of multi-layer wall with additional air layer and its verification

doi:10.11949/0438-1157.20191272

Abstract

Abstract:

In order to predict the temperature and humidity distribution and dynamic change of multi-layer wall with additional air layer accurately, the transient coupling transfer law of heat and humidity in porous media wall is studied. Based on Luikov, Fick s law and other basic transfer theory, the transient coupling transfer control equation of hot and wet air in the wall is derived. Through the improvement of the driving potential of the governing equation and the coefficient of the equation term, taking the air moisture content and temperature as the driving potential, the coupled heat and humidity transfer instability model of the building porous media wall is established. The MATLAB simulation program is designed by using the implicit difference scheme of finite volume method. The corresponding initial conditions and boundary conditions are set up to calculate the distribution of temperature, humidity, heat transfer and moisture transfer with time in the multi-layer wall with additional air layer. Finally, the accuracy and feasibility of the model are verified by comparing the simulation results of the new model with those of WUFI software.

Key words: porous media, air layer, unstable state, coupled transfer of heat and humidity

摘要：

为准确预测附加空气层的多层墙体内的温湿度分布和动态变化，研究多孔介质墙体内的热湿耦合非稳态传递规律，基于Luikov、Fick定律等基础传递理论，推导出热湿空气在墙体内部的瞬态耦合传递控制方程。通过对控制方程驱动势、方程项系数的改进，以空气含湿量和温度为驱动势，建立了建筑多孔介质墙体热湿耦合传递非稳态模型。采用有限容积法隐式差分格式设计了MATLAB模拟计算程序，设置相应的初始条件和边界条件，计算附加空气层的多层墙体内温度、湿度、传热和传湿量随时间变化的分布规律。最后，通过对比新建模型模拟结果与WUFI软件的模拟计算结果，验证了模型的准确性和可行性。

关键词: 多孔介质, 空气层, 非稳态, 热、湿耦合传递

CLC Number:

TU 111.4

Xueqiong HE, Huibo ZHANG, Guojun YU, Chengnan SHI. Heat and humidity coupling non-steady state transfer model of multi-layer wall with additional air layer and its verification[J]. CIESC Journal, 2020, 71(S1): 114-119.

何雪琼, 张会波, 禹国军, 石诚楠. 附加空气层的多层墙体热湿耦合非稳态传递模型及验证[J]. 化工学报, 2020, 71(S1): 114-119.

Figures/Tables 11

References 12

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材料	D_v/ (kg·m^-1?s^-1?Pa^-1)	?	ρ_m/ (kg·m^-3)	m/ (kg·m^-1?s^-1)	λ/ (W·m^-1?K^-1)	c_vm/ (J·kg^-1?K^-1)
石膏板	5.81×10^-8	0.52	1266	9.46×10^-3	0.354	359
空气层	1.52×10^-6	1	1.3	0.2468	0.18	1000
混凝土	7.58×10^-9	0.18	2200	0.00123	1.6	850
玻璃棉	4.65×10^-13	0.25	166	7.57×10^-8	0.05	1000
水泥砂浆	1.39×10^-7	0.95	180	0.0226	0.16	1500

材料	D_v/ (kg·m^-1?s^-1?Pa^-1)	?	ρ_m/ (kg·m^-3)	m/ (kg·m^-1?s^-1)	λ/ (W·m^-1?K^-1)	c_vm/ (J·kg^-1?K^-1)
石膏板	5.81×10^-8	0.52	1266	9.46×10^-3	0.354	359
空气层	1.52×10^-6	1	1.3	0.2468	0.18	1000
混凝土	7.58×10^-9	0.18	2200	0.00123	1.6	850
玻璃棉	4.65×10^-13	0.25	166	7.57×10^-8	0.05	1000
水泥砂浆	1.39×10^-7	0.95	180	0.0226	0.16	1500

材料	φ<=0.9	φ>0.9
石膏板	ξ=-0.2072φ+0.1987	ξ=1.0236
空气层	ξ=0.017	ξ=0.017
混凝土	ξ=-0.0022φ+0.031	ξ=0.038636
玻璃棉	ξ=0.2841φ²-0.3272φ+0.0977	ξ=5.23×10⁵φ⁴-1.97×10⁶φ³+2.78×10⁶φ²-1.74×10⁶φ+4.10×10⁵
水泥砂浆	ξ=15.5345φ⁴-19.9624φ³+9.1392φ²-1.339φ+0.1182	ξ=7.91×10³φ³-2.07×10⁴φ²+1.80×10⁴φ-5240

材料	φ<=0.9	φ>0.9
石膏板	ξ=-0.2072φ+0.1987	ξ=1.0236
空气层	ξ=0.017	ξ=0.017
混凝土	ξ=-0.0022φ+0.031	ξ=0.038636
玻璃棉	ξ=0.2841φ²-0.3272φ+0.0977	ξ=5.23×10⁵φ⁴-1.97×10⁶φ³+2.78×10⁶φ²-1.74×10⁶φ+4.10×10⁵
水泥砂浆	ξ=15.5345φ⁴-19.9624φ³+9.1392φ²-1.339φ+0.1182	ξ=7.91×10³φ³-2.07×10⁴φ²+1.80×10⁴φ-5240

参数	室内侧	石膏板	室外侧
d/(kg·kg^-1)	0.011	0.006	0.003
T/K	293	288	283
v/(m·s^-1)	0.46	—	1.94
h_c/(W·m^-2?K^-1)	8	—	17
h_md/(kg·m^-2?s^-1)	0.00796	—	0.0169