【作者】 李建光；

【导师】 童丽萍；

【作者基本信息】 郑州大学 ， 结构工程， 2012， 博士

【摘要】 建筑节能是当今建筑界共同面对的重要技术领域,改进建筑外围护结构的保温隔热性能、结构性能、耐久性能是外墙外保温技术发展的重要方向。本文针对当前外墙外保温系统存在的质量通病,以满足建筑节能标准,提高使用寿命并降低后期更换和维修成本、以及提高系统的结构性能、耐久性能为目的,研发了小框体复合外墙保温隔热系统。通过理论分析、数值模拟及在试点工程中长时间的跟踪观测,完成了如下几个方面的研究：(1)小框体复合外墙保温隔热系统的初步提出以国家规范推荐的技术做法为依据,将封闭空气夹层与保温材料优化组合,通过合理利用封闭空气夹层的热惰性来提升外墙外保温的整体保温隔热性能,既降低了对保温材料的需求量,减轻了系统的自重,降低了保温材料生产过程中的能源消耗,又减少了保温系统寿命到期后的垃圾处理；通过设计抗剪键削弱外饰面层的温度应力峰值并降低开裂机率,通过结构受力体系的设置使得保温隔热系统与主体结构的设计使用周期相匹配。从保温隔热分体系、结构分体系、连接构造分体系三个层面研发出小框体复合外墙保温隔热系统。基于以上成果已经获得国家专利2项。(2)推导了封闭空气层基于几何尺寸变化的当量导热系数计算方程根据空气层热迁移理论,引入当量导热系数,用傅立叶热传导公式的形式计算自然对流的传热量,本文研究了封闭空气层随厚度、高度、温度差等外界条件改变时其当量导热系数的变化规律,并获得了满足工程设计精度的封闭空气层随厚度、高度改变时的当量导热系数曲线方程,为小框体系统的设计应用提供了简便的导热系数计算方法。(3)获得了保温隔热分体系中封闭空气层的最优尺寸区间在固体保温材料与空气层这种特殊材料进行组合时,其保温隔热性能随空气层的尺寸、比例以及固体保温材料自身性能的不同而变化。通过计算分析,本文获得了空气层与不同保温材料组合时空气层的最优尺寸区间,变化敏感区域以及满足规范对外围护结构保温隔热性能要求时的最佳比例组合。为小框体系统的优化设计提供了理论依据。(4)小框体复合保温隔热系统的结构性能分析本文在大量调研的基础上建立住宅建筑中常见的带窗洞外墙的尺寸模型,以弹性力学为基础,主要模拟小框体复合外墙保温隔热系统在夏季极端高温、低温温度场作用下的应力变形规律,并与传统的外保温做法进行比较。结果表明窗洞四周的变形和应力值较大,温度应力δx、δy和txy是外饰面层开裂的主要原因。本文提出通过在外饰面层增设抗剪键的做法来降低在极端气候条件下的应力峰值,进而减少或推迟裂缝的产生,从而降低保温系统发生渗漏、开裂的机率,提高了结构性能,延长了使用寿命。(5)小框体复合保温隔热系统的热工性能分析依据围护结构评价指标,基于墙体非稳态传热的物理模型,以热力学能量理论建立了非稳态传热的导热微分方程,并根据房屋内外壁实测的温度拟合成简谐温度波作为外部扰量,采用第三类边界条件,计算出小框体复合保温隔热分体系的围护结构能耗评价指标：内壁面温度、热流密度、衰减倍数及延迟时间,通过与国家规范推荐做法的计算结果进行对比,证明了小框体自身保温隔热性能同比的优越性。(6)小框体复合保温隔热系统的模拟应用及实测验证为了更好的检验该系统的性能,本文在研发的基础上对该系统进行优化,并将其运用到郑州市的某试点工程。通过其在冬季和夏季分别基于不同朝向、保温层厚度、室内舒适度指标、区分时段采暖指标等进行能耗模拟,得出适合小框体复合保温隔热系统的工程应用方式。通过对试点工程两个对比房间的外墙热阻、表面温度、墙体热流、房间能耗指标进行240h的跟踪测试并与前文理论分析的结果进行对比,证明了理论分析、能耗模拟方法的正确性及小框体的适用性、优越性。(7)小框体复合外墙保温隔热系统的应用方法从五个方面给出小框体复合外墙保温隔热系统的应用方法：1研发系统的基本做法；2研发系统的适用范围；3研发系统的主要材料及技术要求；4研发系统的技术设计要点；5研发系统的施工方法。(8)小框体复合外墙保温隔热系统构造图集为了小框体复合外墙保温隔热系统的推广及应用,作者主编了《小框体复合外墙保温隔热系统构造图集》并收录了本文的部分研究成果,是河南省重大公益科研计划项目(081100910400)的科研成果之一(9)获得了小框体复合外墙保温隔热系统18种组合的热工指标根据拟合得到的小框体系统封闭空气层当量导热系数曲线方程,对小框体系统的保温隔热分体系进行优化,将封闭空气层与三种不同保温材料组合,并与目前常用的墙体外围护材料复合而成18种小框体复合外墙保温隔热系统,分别计算出上述各种小框体复合外墙保温隔热系统的热工计算指标,为该系统的后续推广及节能设计提供理论参考。更多还原

【Abstract】 Building energy saving is an important area of today’s construction industry, and to improve the insulation properties, structural performance, and durability of building envelope are important direction for the development of exterior insulation technology. Based on the current quality defects, in order to meet the energy efficiency standards, improve the service life, reduce the later replacement and maintenance costs, and improve the performance of the system’s structure and durability, this paper studies and develops a new composite external wall insulation system named xiaokuangti. Through theoretical analysis, numerical simulation and tracking test in the pilot project, the paper has completed a study of the following aspects:(1) The initial advance of xiaokuangti systemThe system, which optimally combines the closed air layer with insulation materials and enhances the thermal insulation performance of the overall system through the rational use of the closed air layer, can reduce the amount of insulation materials, the weight of the system, the energy consumption of the insulation material in the production process and waste disposal when its service life comes to an end. Through the design of the anti-shear key, the system can weaken the temperature stress of the outer facing layer and reduce the cracking probability. By using the structure system it can make the insulation system’s life match the design cycle of the main structure. Based on national standards, the paper invents the xiaokuangti system from three organic components including the thermal insulation, structural system, interconnect structure of sub-system. Two national patents have been granted on the basis of above achievement.(2) Derived the equivalent thermal conductivity calculating equations based on the geometric dimensions change of the closed air layerBased on heat transfer theory, by the introduction of the equivalent thermal conductivity and the calculation of the heat transfer amount of the natural convection in the form of Fourier heat conduction formula, the paper studies the equivalent thermal conductivity variation of the Air layer with its thickness, height variation, temperature and poor external conditions changing and has got the thermal conductivity curve equation access to meet the engineering design accuracy of the closed air layer with the changes of these factors, and provides a simple thermal conductivity calculation for the xiaokuangti system design applications.(3) Obtained the optimal size range of the air layer thickness in insulation systemWhile combing solid insulation materials with the special material-air layer, its thermal insulation properties will inevitably vary with the change of the size and the ratio of the air layer, and the solid insulation material performance. By calculation and analysis, the paper has obtained the optimal size of the air layer and the combination of different insulation materials, sensitive changing areas, and the best ratio combinations in the specification of external building envelope thermal insulation performance requirements. A theoretical basis for the optimization design of the xiaokuangti system is provided.(4) Structure performance analysis of the xiaokuangti systemThe paper mainly simulates the stress and deformation law of the system in the temperature field, and compares it with that of the traditional system. The results show that temperature stress is the main reason for cracking of the outer facing layer. In this paper, it proves the anti-shear key can reduce the stress peaks in the extreme weather conditions, or delay the cracks on the outer layer, thereby reducing the probability of the insulation system leakage, cracking, and improving the performance of the structure and extending its service life.(5) Thermal performance analysis of the xiaokuangti systemIn accordance with the building envelope evaluation index, based on the physical model of unsteady heat transfer, the unsteady heat-conduction differential equations under the third boundary on the principle of the thermodynamic theory were established. And in accordance with the measured temperature of the housing inside and outside wall fitted in harmonic temperature wave as the amount of external interference, the heat flux density, attenuation coefficient, delay time and other performance indicators of the xiaokuangti system were calculated and the results (compared by recommended practices with the national norms) proved the superiority of xiaokuangti external wall insulation system. (6) Simulating applications and experimental verification of xiaokuangti systemIn order to test the applicability of the system, based on the optimization of the xiaokuangti system, the paper produces the kind of insulation system and applied it to a pilot project in Zhengzhou City. Energy simulation based on different directions the thickness of the insulation layer, indoor comfort indicator to distinguish between periods of heating indicators in winter and summer respectively, has been done, so as to obtain the system’s engineering application pattern. A tracking test of 240h on the wall surface temperature, heat flow and room energy consumption has been taken. Through the comparison of test data and the theoretical results of the analysis, the superiority and the applicability of xiaokuangti is verified.(7) Application methods of xiaokuangti systemThe application methods of the xiaokuangti system composite exterior insulation system are introduced from five aspects:1. basic components; 2. range of applications; 3 main materials and technical requirements; 4. technical points of design; 5. the construction method(8) Constructed atlas of xiaokuangti systemThe research results of this paper are part of the xiaokuangti system constructed atlas. As one of the scientific research results of significant public interest research projects in Henan Province (081100910400), it has passed the evaluation of scientific research.(9) Obtained 18 composed thermal index of xiaokuangti systemAccording to the curved equation of equivalent heating conducting coefficient of closed air layer of xiaokuangti system, the optimization to the insulation has been taken to the system. The paper first combines closed air layer with three different insulation materials, then forms 18 xiaokuangti systems by combining them with the most commonly daily used wall external enclose materials, and separately calculates the thermal calculating index above, which provides a theoretical reference to the follow-up promotion and energy conversion calculation.更多还原