低气压下水蒸气渗透系数变化对建筑外墙热湿性能影响模拟研究  

Simulation Study on the Influence of Reduced Air Pressure on Vapor Permeability Coefficient and the Hygrothermal Performance of Building Exterior Walls

作　　者：周孟丽 方巾中 陈向晖 楼华鼎 高姗 冯驰 ZHOU Mengli;FANG Jinzhong;CHEN Xianghui;LOU Huading;GAO Shan;FENG Chi(School of Architecture,Southeast University,Nanjing 210096,China;Key Laboratory of Urban and Architectural Heritage Conservation of Ministry of Education,Southeast University,Nanjing 210096,China;School of Architecture and Urban Planning,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China)

机构地区：[1]东南大学建筑学院,南京210096 [2]东南大学城市与建筑遗产保护教育部重点实验室,南京210096 [3]重庆大学建筑城规学院,重庆400045 [4]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《建筑科学》2025年第2期167-174,共8页Building Science

基　　金：国家自然科学基金面上项目“多孔建筑材料全湿度区间全吸放湿过程湿迁移机理研究”(52178065)。

摘　　要：高海拔地区气压较低,多孔建筑材料的热湿物理性质可能与常压时不同。因此,基于常压下所测得的数据研究高海拔地区建筑围护结构的热湿性能可能存在较大偏差。前期实验结果表明:降低气压,多孔建筑材料仅水蒸气渗透系数明显增加;其他热湿物理性质基本不变。因此,本文利用由实验测试得到的多孔建筑材料水蒸气渗透系数随气压变化规律,对高海拔城市拉萨和昆明典型办公建筑外墙的热湿性能进行数值模拟,对比分析考虑和忽略气压对水蒸气渗透系数影响时,建筑外墙内部温度、相对湿度、热流湿流和发霉情况的差异;最后对低气压下存在内部冷凝风险的外墙隔汽层水蒸气渗透等效空气层厚度sd的合理取值进行了讨论。模拟结果表明,当忽略气压影响时,外墙内部全年平均相对湿度被轻微低估,通过外墙的全年累计传湿量被低估了4.53%~53.82%,拉萨地区采用岩棉内保温构造的办公建筑外墙内部全年霉菌生长指数被低估且存在冷凝风险,建议设置隔汽层,且sd≥5 m。本研究可为高海拔地区建筑的保温及防潮优化设计提供数据及理论基础。With lower air pressure in high-altitude areas,hygrothermal properties of porous building materials may differ from those at normal pressure.Therefore,studying the hygrothermal performance of building envelopes in high-altitude areas based on the data measured at atmospheric pressure may deviate significantly from reality.Preliminary experimental results showed that when the air pressure was reduced,only the vapor permeability coefficient of porous building materials increased significantly;other hygrothermal properties remained basically unchanged.Therefore,based on variations in the vapor permeability of porous building materials with air pressure obtained from tests,numerical simulations were performed to investigate the hygrothermal performance of the exterior walls of the typical office buildings in the high-altitude cities of Lhasa and Kunming,and comparisons were conducted between scenarios of considering and neglecting the air pressure on the vapor permeability of porous building materials,involving differences in annual temperatures,relative humidity,heat and moisture flow,and mold growth;finally,it was discussed how to set reasonable values for the permeability resistance sa of the vapor barrier for exterior walls with internal condensation risk under low air pressure.The simulation results indicated that when the influence of air pressure was neglected,the average relative humidity inside the exterior walls were slightly underestimated,and the annual cumulative moisture transfer was underestimated by 4.53%to 53.82%.The annual internal mold growth index for the exterior walls with mineral wool internal insulation in Lasha has been underestimated and there is risk of condensation.Therefore,it is recommended that a vapor barrier be set,with sd≥5 m.This study can provide data and a theoretical basis for the optimal design of the thermal insulation and moisture-proofing of buildings in high-altitude areas.

关 键 词：热湿性能 建筑外墙 水蒸气渗透系数 低气压 数值模拟 

分 类 号：TU111.2[建筑科学—建筑理论]