用于墙体内保温的离心玻璃棉热湿传递特性研究

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3.0 侯斌 2024-11-19 4 4 2.99MB 68 页 15积分
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随着社会的不断进步和人类生产的迅速发展,能耗问题越来越严重。我国建
筑所耗能源占社会总能耗的比重达 33%这就要求我们在建筑节能方面采取有效
的措施,其中对建外墙进行保温是其中重要措施之一。离心玻璃棉相对于其
类型的保温隔热材料,防火性高,环保及导热系数小等优点,可将其用作内
保温复合墙体的保温材料。
在我国夏热冬冷地区,墙体结构内部的热湿传递直接影响着建筑外体的热
工性能、室生活环境品质及建筑运行耗。为了研究离心玻璃棉应用于外墙内
保温的效果,首先需要了解其热湿物性参数和热湿传递机理。与常规的建筑材料
不同,离心玻璃棉保温材料孔隙较大,材料经过防水处理,且随着生产工艺的提
高,早期对材料特性的研究结果不能直接作为参考。因此,本课题采用实验和理
论相结合的方法,以热质传递理论为基础,及在夏热冬冷地区内保温墙体的应用
背景下,研究了离心玻璃棉保温材料自身的吸湿及热湿传递特性,并对离心玻璃
棉在内保温复合墙体中的应用进行了研究。
本文首先建立了多孔介质单层及多层一维稳态传热传质简化数学模型,并通
过实验在等温条件下测试了离心玻璃棉保温材料的吸湿性能。其次,搭建小模型
实验台,研究了离心玻璃棉在夏热冬冷地区内保温墙体具体应用条件下的热湿传
递过程,分析了水蒸气分压力差及温度梯度对离心玻璃棉热湿传递的影响,验证
了稳态传热传质方程对离心玻璃棉保温材料的适用性。最后,研究了离心玻璃棉
在夏热冬冷地区内保温复合墙体中的具体应用,分析了室内温湿度环境、保温材
料厚度及隔汽层对内保温复合墙体结露的影响。
实验结果表明,离心玻璃棉保温材料吸湿量小,水蒸气渗透系数较大,且水
蒸气渗透系数测试值在不同水蒸气分压力差下差别不大,温度对离心玻璃棉湿传
递的影响很小,可以忽略。对离心玻璃棉内保温复合墙体内温度和湿度分布的计
算结果表明,未加隔汽层时,随着保温材料厚度的增加,室内相对湿度的增加,
墙体结露风险都将增大,波及范围更广;而在离心玻璃棉保温材料热侧加一层
汽层时,在室内温度为 22℃,相对湿度为 30%~60%时,墙体内都不会发生结露,
该计算结果为工程实践提供了一定的参考。
关键词:离心玻璃棉 热湿传递特性 夏热冬冷地区 内保温墙体
ABSTRACT
With the rapid development of social progress and human production, the energy
consumption has been a growing problem. Proportion of building energy consumption
in our country to total energy consumption reached 33%, which requires us to take
effective measures in terms of building energy saving, with external wall insulation
technologies becoming one of the very important elements. Centrifugal glass fiber
compared with other insulation materials, has advantages of good fire-proof
performance, low thermal conductivity, environmental protection and so on, which can
be used as interior insulation material.
In hot-summer and cold-winter zones, the heat and moisture transfer inside the
wall directly affects the energy consumption, thermal performance of the building
envelope and indoor air quality. In order to study the validity of centrifugal glass fiber
used as thermal insulation material in exterior wall, firstly it is needed to study its heat
and moisture transfer mechanism and thermal physical parameters. Different from
traditional materials, the centrifugal glass fiber with large pores has been waterproofed.
Furthermore, with the improvement of technology for producing, the early research
results of material properties cannot be used directly as a reference. Therefore, by
combining the experimental and theoretical methods and being based on the theory of
heat and moisture transfer, this paper studies the moisture absorption and heat and
moisture transfer static and practical performance of centrifugal glass fiber, used as the
thermal insulation material of external wall in hot-summer and cold-winter zones.
Firstly, this paper establishes the single-layer and multilayer porous medium
one-dimensional steady-state heat and mass transfer mathematical model, and tests the
hygroscopicity of centrifugal glass fiber under isothermal condition by experiments.
Secondly, a small experimental model is built to study the heat and moisture transfer
process of centrifugal glass fiber under specific conditions of being as thermal
insulation material in external wall in the hot-summer and cold-winter zones. Through
the experiment, the effect of the water vapor partial pressure difference and temperature
gradient on the heat and moisture transfer of centrifugal glass fiber is analyzed, and the
experiment results verifies the suitability of the steady-state heat and moisture transfer
mathematical model on the centrifugal glass fiber. Finally, the application of centrifugal
glass fiber in the interior insulation wall is studied with analyzing the effect of
insulation thickness and vapor barrier on the wall condensation.
The experimental results show that, the amount of moisture absorbed by
centrifugal glass fiber is small, the water vapor permeability coefficient is large, and the
temperature has little effect on the moisture transfer. The calculated results of the
temperature and humidity distribution in the internal thermal insulation composite wall,
show that the condensation risk increases with the increasing of the insulation thickness
and indoor relative humidity without vapor barrier, and the condensation will not
happen under the condition of indoor temperature being 22 and relative humidity
being 30%~60% with vapor barrier.
Key Word: Centrifugal glass fiber, Heat and moisture transfer
performance, Hot-summer and cold-winter zone, Interior
insulation Wall
中文摘要
ABSTRACT
第一章 ................................................................................................................ 1
1.1 研究的背景及意义 .............................................................................................. 1
1.2 国内外研究现状 .................................................................................................. 4
1.2.1 多孔介质热湿迁移理论研究 ......................................................................... 4
1.2.2 保温墙体的结露研究 ..................................................................................... 6
1.2.3 玻璃棉发展历程 ............................................................................................. 8
1.3 多孔介质热湿传递理论基础 .............................................................................. 9
1.3.1 热湿传递理论 ................................................................................................. 9
1.3.2 本构方程 ....................................................................................................... 14
1.4 本课题主要工作 ................................................................................................ 15
1.4.1 需要解决问题 ............................................................................................... 15
1.4.2 主要研究方法及内容 ................................................................................... 15
1.5 本章小结 ............................................................................................................ 16
第二章 多孔介质的结构特性及热湿传递简化模型 .................................................. 17
2.1 多孔材料的定义及分类 .................................................................................... 17
2.1.1 多孔材料的定义 ........................................................................................... 17
2.1.2 多孔材料的分类 ........................................................................................... 17
2.2 多孔材料的结构特性 ........................................................................................ 18
2.2.1 孔隙与孔隙率 ............................................................................................... 18
2.2.2 比表面 ........................................................................................................... 19
2.2.3 弯曲率 ........................................................................................................... 19
2.2.4 液相饱和度 ................................................................................................... 20
2.2.5 含水率 ........................................................................................................... 20
2.3 多孔介质一维稳态传质过程分析 .................................................................... 20
2.3.1 单层墙体稳态传质 ....................................................................................... 21
2.3.2 多层墙体稳态传质 ....................................................................................... 21
2.4 多孔介质一维稳态传热过程分析 .................................................................... 22
2.4.1 单层墙体稳态传热 ....................................................................................... 22
2.4.2 多层墙体稳态传热 ....................................................................................... 23
2.5 边界条件及湿参数的确定 ................................................................................ 23
2.5.1 边界条件 ....................................................................................................... 23
2.5.2 水蒸气渗透系数 ........................................................................................... 24
2.5.3 导热系数 ....................................................................................................... 24
2.6 本章小结 ............................................................................................................ 25
第三章 离心玻璃棉吸湿特性实验研究 ...................................................................... 26
3.1 实验目的 ............................................................................................................ 26
3.2 吸湿特性实验方案与原理 ................................................................................ 26
3.2.1 材料的含湿率 ............................................................................................... 26
3.2.2 等温吸放湿曲线 ........................................................................................... 26
3.2.3 实验准备 ....................................................................................................... 27
3.2.4 实验步骤 ....................................................................................................... 29
3.3 实验结果与分析 ................................................................................................ 30
3.3.1 吸湿性能实验结果及分析 ........................................................................... 30
3.3.2 散湿速率实验及结果分析 ........................................................................... 31
3.4 本章小结 ............................................................................................................ 33
第四章 离心玻璃棉热湿传递特性实验 ...................................................................... 34
4.1 实验目的 ............................................................................................................ 34
4.2 实验方案与原理 ................................................................................................ 34
4.3 实验装置构造 .................................................................................................... 35
4.3.1 电子天平的数据采集 ................................................................................... 35
4.3.2 电加热 PID 控制 ........................................................................................... 36
4.3.3 蒸汽加湿 PID 控制装置 ............................................................................... 37
4.3.4 温湿度测点的标定与采集 ........................................................................... 39
4.3.5 实验小箱体及实验组合装置 ....................................................................... 40
4.4 实验过程 .............................................................................................................. 42
4.4.1 实验工况的确定 ........................................................................................... 42
4.4.2 实验步骤 ....................................................................................................... 42
4.5 离心玻璃棉热湿传递特性实验结果与分析 ...................................................... 43
4.5.1 不同水蒸气分压力差下湿传递特性 ........................................................... 43
4.5.2 温度对离心玻璃棉湿传递的影响 ............................................................... 44
4.5.3 离心玻璃棉热湿传递简化模型的验证 ....................................................... 45
4.6 本章小结 ............................................................................................................ 46
第五章 离心玻璃棉在内保温墙体中的应用研究 ...................................................... 47
5.1 保温材料不同厚度时墙体内的温度分布 ........................................................ 47
5.2 无隔汽层时内保温墙体结露分析 .................................................................... 49
5.2.1 保温材料厚度为 1cm 时墙体结露情况 ...................................................... 50
5.2.2 保温材料厚度为 2cm 时墙体结露情况 ...................................................... 50
5.2.3 保温材料厚度为 3cm 时墙体结露情况 ...................................................... 51
5.2.4 保温材料厚度为 4cm 时墙体结露情况 ...................................................... 52
5.2.5 保温材料厚度为 5cm 时墙体结露情况 ...................................................... 53
5.3 加隔汽层时内保温墙体结露分析 .................................................................... 53
5.4 本章小结 ............................................................................................................ 56
第六章 总结与展望 ...................................................................................................... 57
6.1 本文主要研究成果 ............................................................................................ 57
6.2 进一步工作展望 ................................................................................................ 58
参考文献 ........................................................................................................................ 59
在读期间公开发表的论文和承担科研项目及取得成果 ............................................ 63
.............................................................................................................................. 64
摘要:

摘要随着社会的不断进步和人类生产的迅速发展,能耗问题越来越严重。我国建筑所耗能源占社会总能耗的比重达33%,这就要求我们在建筑节能方面采取有效的措施,其中对建筑外墙进行保温是其中重要的措施之一。离心玻璃棉相对于其他类型的保温隔热材料,具防火性高,环保及导热系数小等优点,可将其用作内保温复合墙体的保温材料。在我国夏热冬冷地区,墙体结构内部的热湿传递直接影响着建筑外墙体的热工性能、室内生活环境品质及建筑运行能耗。为了研究离心玻璃棉应用于外墙内保温的效果,首先需要了解其热湿物性参数和热湿传递机理。与常规的建筑材料不同,离心玻璃棉保温材料孔隙较大,材料经过防水处理,且随着生产工艺的提高,早期对材料特性...

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作者:侯斌 分类:高等教育资料 价格:15积分 属性:68 页 大小:2.99MB 格式:PDF 时间:2024-11-19

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