湿迁移对建筑墙体及室内环境的影响
发布时间：2018-12-15 06:52
【摘要】：我国华北寒冷地区夏季炎热,能源需求量大,准确计算制冷负荷,提高能源的综合利用效率,已成为亟待解决的课题之一。对建筑墙体传热过程的研究是建筑采暖空调系统设计的基础,也是建筑能耗分析的依据。建筑墙体利用自身多孔吸放湿特性可有效调节室内的温湿度,降低夏季空调能耗。对建筑墙体内部热湿迁移的精确分析有助于更好的理解墙体内部的温度及湿度变化及其对室内参数的影响,有效促进建筑节能。本文采用理论分析、数值模拟与实验研究相结合的方式探究了湿迁移对建筑墙体和室内环境的影响。通过对建筑墙体热湿空气耦合传热传质过程的分析,建立了以温度和相对湿度为驱动势的建筑墙体热湿空气耦合传递方程,并采用集中参数法建立室内环境热湿平衡方程;再以建筑墙体内壁面为桥梁,将建筑墙体模型和室内环境模型整合成为建筑物热湿空气耦合传递模型(HAM模型)。基于本文所建的HAM模型,采用有限元方法,模拟建筑墙体及室内环境的热湿耦合传递过程。首先对济南地区夏季典型建筑墙体的传热传质过程进行了研究,分别探讨了普通建筑墙体和含有调湿层的建筑墙体的热湿空气耦合传递过程,结果表明:当室外温度高于建筑墙体温度时,考虑传湿工况下的墙体内部温度上升幅度和上升速率小于不考虑传湿时;相变潜热量占总传热量的比重大;初始条件相同时,建筑墙体内层为调湿层的工况下通过内壁面的湿流密度值是普通建筑材料内层工况的1.12倍,且调湿层吸收的湿分大于普通内层;计算选取的3种调湿材料中,通过硅藻土内层壁面的湿流密度最大,硅藻土的调湿性能最好。然后对含调湿材料的建筑墙体吸放湿特性对室内环境的影响进行了研究分析,结果表明:当室内环境的温湿度因内部热源及湿源影响而出现波动时,利用调湿材料的吸放湿可以减弱室内环境温湿度的变化,室内参数的变化量与调湿材料性能密切相关;随厚度增加,调湿层的调湿能力增强,室内环境的温湿度场因外部扰动的波动明显减弱;室内温度和相对湿度受相同外界条件影响升高时,24小时内考虑建筑墙体内壁面与室内环境的湿迁移时的室内相对湿度值比不考虑湿迁移的低0.05左右、温度值比不考虑湿迁移的高0.07℃左右,湿迁移对室内环境的温湿度的影响不可以忽略。最后搭建了1.6m*1.6m*2m温湿度可控小室,实现室内精确的温湿度控制,在墙体内部不同深度及室内布置测点,并利用高精度的温度和湿度传感器对各测点进行温湿度监测,实验探讨建筑墙体及室内的温湿度变化规律,为数值模拟提供了相应的依据。
[Abstract]:The cold area of North China is hot in summer and the demand for energy is large. It has become one of the urgent problems to calculate the refrigeration load accurately and to improve the comprehensive utilization efficiency of energy. The research on the heat transfer process of building wall is the basis of the design of building heating and air conditioning system, and also the basis of building energy consumption analysis. The building wall can adjust indoor temperature and humidity effectively and reduce the energy consumption of air conditioning in summer by using the characteristics of porous moisture absorption and desorption. The accurate analysis of heat and moisture transfer in building wall is helpful to better understand the change of temperature and humidity inside wall and its influence on indoor parameters, and to promote building energy saving effectively. In this paper, the influence of wet migration on building wall and indoor environment is studied by means of theoretical analysis, numerical simulation and experimental study. Based on the analysis of the coupled heat and mass transfer process of the building wall, the coupled heat and humidity transfer equation with the driving force of temperature and relative humidity is established, and the indoor heat and moisture balance equation is established by using the concentrated parameter method. Then, the building wall model and the indoor environment model are integrated into the heat and wet air coupling transfer model (HAM model) with the inner wall surface of the building wall as the bridge. Based on the HAM model established in this paper, a finite element method is used to simulate the heat and moisture transfer process of building wall and indoor environment. Firstly, the heat and mass transfer process of typical building wall in Jinan area in summer is studied, and the coupled heat and humidity air transfer process between ordinary building wall and building wall with humidifying layer is discussed respectively. The results show that when the outdoor temperature is higher than the building wall temperature, the increasing range and the rising rate of the wall internal temperature under the condition of considering the moisture transfer are smaller than those without the consideration of the moisture transfer. The proportion of phase change latent heat in the total heat transfer is large; When the initial conditions are the same, the wet flow density through the inner wall is 1.12 times higher than that of the common building material under the condition that the inner layer of the building wall is a humidity-regulating layer, and the moisture absorption of the humidity-adjusting layer is larger than that of the common inner layer. Among the three humidifying materials, the wet flow density of diatomite inner wall is the largest, and diatomite has the best humidification performance. Then, the influence of moisture absorption and desorption characteristics on indoor environment is studied and analyzed. The results show that when the temperature and humidity of indoor environment fluctuate due to the influence of internal heat source and wet source, The change of indoor temperature and humidity can be weakened by moisture absorption and desorption of humidity-regulating material, and the change of indoor parameters is closely related to the properties of humidity-regulating material. With the increase of the thickness, the humidity-regulating ability of the humidity-regulating layer increases, and the temperature and humidity field in the indoor environment weakens obviously because of the external disturbance. When the indoor temperature and relative humidity are affected by the same external conditions, the indoor relative humidity values when the indoor wall surface and the indoor environment are taken into account within 24 hours are about 0.05 lower than those without considering the wet migration. The temperature value is about 0.07 鈩，
本文编号：2380168
[Abstract]:The cold area of North China is hot in summer and the demand for energy is large. It has become one of the urgent problems to calculate the refrigeration load accurately and to improve the comprehensive utilization efficiency of energy. The research on the heat transfer process of building wall is the basis of the design of building heating and air conditioning system, and also the basis of building energy consumption analysis. The building wall can adjust indoor temperature and humidity effectively and reduce the energy consumption of air conditioning in summer by using the characteristics of porous moisture absorption and desorption. The accurate analysis of heat and moisture transfer in building wall is helpful to better understand the change of temperature and humidity inside wall and its influence on indoor parameters, and to promote building energy saving effectively. In this paper, the influence of wet migration on building wall and indoor environment is studied by means of theoretical analysis, numerical simulation and experimental study. Based on the analysis of the coupled heat and mass transfer process of the building wall, the coupled heat and humidity transfer equation with the driving force of temperature and relative humidity is established, and the indoor heat and moisture balance equation is established by using the concentrated parameter method. Then, the building wall model and the indoor environment model are integrated into the heat and wet air coupling transfer model (HAM model) with the inner wall surface of the building wall as the bridge. Based on the HAM model established in this paper, a finite element method is used to simulate the heat and moisture transfer process of building wall and indoor environment. Firstly, the heat and mass transfer process of typical building wall in Jinan area in summer is studied, and the coupled heat and humidity air transfer process between ordinary building wall and building wall with humidifying layer is discussed respectively. The results show that when the outdoor temperature is higher than the building wall temperature, the increasing range and the rising rate of the wall internal temperature under the condition of considering the moisture transfer are smaller than those without the consideration of the moisture transfer. The proportion of phase change latent heat in the total heat transfer is large; When the initial conditions are the same, the wet flow density through the inner wall is 1.12 times higher than that of the common building material under the condition that the inner layer of the building wall is a humidity-regulating layer, and the moisture absorption of the humidity-adjusting layer is larger than that of the common inner layer. Among the three humidifying materials, the wet flow density of diatomite inner wall is the largest, and diatomite has the best humidification performance. Then, the influence of moisture absorption and desorption characteristics on indoor environment is studied and analyzed. The results show that when the temperature and humidity of indoor environment fluctuate due to the influence of internal heat source and wet source, The change of indoor temperature and humidity can be weakened by moisture absorption and desorption of humidity-regulating material, and the change of indoor parameters is closely related to the properties of humidity-regulating material. With the increase of the thickness, the humidity-regulating ability of the humidity-regulating layer increases, and the temperature and humidity field in the indoor environment weakens obviously because of the external disturbance. When the indoor temperature and relative humidity are affected by the same external conditions, the indoor relative humidity values when the indoor wall surface and the indoor environment are taken into account within 24 hours are about 0.05 lower than those without considering the wet migration. The temperature value is about 0.07 鈩，
本文编号：2380168
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