复合聚苯乙烯颗粒保温砂浆的热湿传递性能及其对建筑能耗的影响

【作者】 刘芬；

【导师】 胡晓波；

【作者基本信息】 中南大学 ， 材料学， 2008， 硕士

【摘要】 建筑围护结构的保温隔热性能是建筑节能的重要方面。材料热湿传递特性影响建筑围护结构的导温和保温性能,其影响规律是目前建筑节能研究领域中重要方向。本文针对复合聚苯乙烯颗粒保温砂浆的吸湿性、不同含湿状态下的导热性能和热湿传递性质及它们的影响因素进行试验分析;结合一维热迁移、湿迁移微分方程和Luikov的墙体热湿耦合传递数学模型推导含湿状态的导热系数函数,并根据夏热冬冷地区的常用外保温结构及其热物理工作特点确定函数的具体系数,并与试验结果验证;将导热系数函数应用于DEST的热环境模拟简化模型,分析材料热湿传递给建筑能耗带来的变化。含湿导热系数函数的确立,为建筑的能耗模拟提供更实际的基本参数,可为建筑节能的设计、施工、材料的选择提供更有效的技术指导。本文的主要研究如下:(1)调整水泥用量、水胶比、膨胀珍珠岩掺量、聚苯乙烯颗粒级配和细砂掺量设计不同配合比复合聚苯乙烯颗粒保温砂浆;并通过试验得到各个配比的孔隙率、吸水率和吸湿率。实验结果表明:亲水性材料的分量增加,和配比参数不合理设置导致复合保温砂浆连续、贯通、开口的大孔隙的量增加,均能增大砂浆的吸湿能力。确定砂浆初始含湿和夏热冬冷气候条件对砂浆含湿状况的影响。(2)在夏热冬冷地区条件下,测试各个配比复合聚苯乙烯颗粒保温砂浆不同含湿率的导热系数,并分析各个因素对该性能的影响规律和影响程度。在本文研究原材料范围内,绝干状态的导热系数和干密度大的砂浆,含湿导热系数的变化比较明显;同样,掺膨胀珍珠岩时,环境条件下含湿率变化大,含湿导热系数的变化也比较明显。(3)以Luikov墙体热湿耦合传递数学模型为主控方程,推导瞬时热物性参数关于温、湿度的基础函数。命瞬时导热系数随湿度的变化系数为导热系数含湿变化因子δ_ω,结合一维状态热迁移、湿迁移微分方程和复合聚苯乙烯颗粒保温砂浆的含湿导热系数试验数据,确定含湿导热系数λ(U)及其含湿变化因子δ_ω的表达式。并推论其普适性,得到一个与绝干导热系数、比热、干密度有关的含湿导热系数的函数。(4)根据围护结构材料的导热系数对建筑能耗的影响特性,简化建筑能耗模拟软件DEST的数学模型,在相同边界条件下,计算比较热工规范提供的材料的计算导热系数和本文推导的含湿度导热系数函数的建筑模拟能耗差异。结果表明:模拟建筑能耗差异可达到建筑采暖年耗电量限值的13.25%。更多还原

【Abstract】 Insulation performance of building envelope is an important aspect of energy-saving construction.Heat and moisture transfer of material impact on the thermal and insulation performance of the building envelope,the law of the influence is an important direction of energy-saving research.Moisture absorption,the thermal conductivity and heat and moisture transfer and and their effects of compound EPS insulation mortar in different wet conditions.And then function of thermal conductivity of material in different wet state be launched from Luikov’s mathematical model of coupled heat and moisture transfer and one-dimensional partial differential equations of heat and moisture transfer,Specific factors of function be determined according to the thermal insulation structure and it’s working physical characteristics which commonly used in the region of hot summer and cold winter, and be checked through the experiment results.The function of thermal conductivity be used in simplified model of the thermal environment simulation DEST,and the influence of heat and moisture transfer bring to building energy consumption be analysised.The establishing of thermal conductivity function,can providing more realistic basic parameters for simulation of building energy consumption,and providing more effective technical guidance for building energy-efficient designing, construction,materials choosing.The article is researched main about:(1)Different formula of compound EPS insulation mortar be designed through adjust cement cosumption,water-cement ratio,perlite consumption,size distribution of EPS grains and thin sand consumption.Porosity,hygroscopic coefficient and specific absorption of different formula be researched based on experiment. Experiment results show that increasing of the proportion of hydrophilic material,and increasing of continuous,through,opening macropores because of unreasonable formula will increase the hygroscopicity of mortar.Determined the wet rate changing of mortar because of the influence of the initial rate of wet and weather conditions in region of hot summer and cold winter by experiment.(2)The thermal conductivity of compound EPS insulation mortar of different formula be researched in wet state like the materials in conditions of region of hot summer and cold winter,the law and degree of thermal conductivity of compound EPS insulation mortar be affected be analysised.Within the scope of the raw materials studing in this paper,the thermal conductivity in wet state of compound EPS insulation mortar with bigger thermal conductivity and density of dry state changed obviously,The same,the wet rate and hermal conductivity in wet state changing obviously when perlite added.(3)The foundation function of instantaneous physical parameters of thermal properties on the temperature and humidity be launched through the reverse derivation to the equations main controlled by Luikov’s.Order of the coefficient about the rate of instantaneous thermal conductivity be affected by the instantaneous changes in humidity asδ_ω.Expressions ofλ(U)andδ_ωbe determined based on One-dimensional partial differential equations of heat transfer,moisture transfer and experimental datas of thermal conductivity of compound EPS insulation mortar in wet state.The coefficientδ_ωof the functionλ(U).And deduct applicable forms of universal material,which is a function related to the thermal conductivity and density of dry material.(4)According to the characteristics that building energy consumption be affected by the thermal conductivity of envelope structure.The mathematical model of building energy simulation software DEST be simplified.Differences of building energy consumption of the calculation of thermal conductivity provided by the norms and the thermal conductivity function derived in this paper respectively be calculated and compared in the same boundary conditions.The results show that 13.25%of the building energy consumption be maded the thermal conductivity of materials in different wet state it can not be ignored.更多还原