外墙外保温缺陷红外检测数值模拟方法研究

发布时间：2019-02-15 17:38

【摘要】：在建筑工程质量缺陷检测领域,红外热像法已经成为普遍使用的检测方法,红外热像检测技术也日趋成熟,相关协会和地方质量检测部门都制定了相应标准和检测技术规程。对红外热像技术的研究也由定性分析向定量分析趋势发展。目前红外热像技术对建筑工程质量的检测按对象不同主要分为三类：建筑缺陷检测、建筑节能检测、受潮与渗漏检测。从定量分析方法上又可以分为数值模拟、图像后处理和红外热诊断法三个方向。本文的主要工作是数值模拟分析有EPS板薄抹灰外保温缺失缺陷和粘结缺陷的外墙传热过程,从而为红外热像法现场检测提供理论依据和建议。本文以居住建筑节能检测标准中对红外热像技术检测外围护结构热工缺陷的要求和红外热像法检测建筑外墙饰面层粘结缺陷技术规程为依据,采用ANSYS有限元热分析软件分别对这两种类型缺陷的外墙建立了自然条件下的传热模型,数值模拟不同缺陷参数、墙体朝向、季节等多种组合情况下外墙的动态传热过程,分析了以上各种参数对外墙外表面温度分布的影响,结合实际红外热像检测条件,得出了红外热像仪对不同参数缺陷的检测能力以及不同季节下东、南、西、北墙的最佳检测时段,为现场检测保温缺失缺陷和粘结缺陷提供建议和依据。主要研究内容包括以下几个方面：(1)介绍红外热像技术的基础理论与分析外墙的传热过程,从而引出红外检测外墙外保温两种缺陷的检测原理,其中给出了重要参数(太阳辐射强度、日气温、综合温度)的计算式,为后续数值模拟中参数的计算做好准备。(2)分析了有限元的基本原理和ANSYS瞬态热分析的基本步骤,然后按照基本步骤,分别建立了自然条件下EPS板薄抹灰外保温缺失缺陷外墙模型和粘结空鼓缺陷外墙模型,并数值模拟了两模型的传热过程。在外保温缺失缺陷外墙模型传热过程热分析中,先研究了检测日前温度变化对检测日当天计算结果的影响,再分析了检测日外表面温度分布特征,提出了对检测日前温度变化的要求,得出了检测日当天的外墙外表面温度差值变化规律。在外保温粘结空鼓缺陷外墙模型传热过程热分析中,先对比分析了室外综合温度与正常区域外表面平均值,然后对正常区域外表面温度平均值与缺陷中心点对应外表面温度进行了对比研究,得出了检测日当天的外墙外表面温度差值变化规律。最后通过将两种模型的计算结果进行对比分析,理论分析温度差峰值的差别因缺陷面积、厚度不同所致。(3)用红外热像检测外保温缺失缺陷实验验证了此缺陷模型的可行性以及相应结论的正确性,通过实测数据数值模拟结果与实验结果对比,证明了缺陷面积、厚度对外表面温度差峰值影响的结论,并分析了实验结果和模拟结果误差的主要影响因素。通过数值模拟分析粘结空鼓缺陷尺寸对外表面温度差峰值的影响,得出与黄文浩论文中的红外热像法检测外饰面层粘结空鼓缺陷实验结果一致的结论,证明了粘结空鼓缺陷模型的可行性。(4)为了进一步分析缺陷参数(深度、厚度、面积)、墙体朝向、季节对保温缺失外墙外表面的温度分布的影响,在上述传热模型基础上,分别对缺陷参数(深度、厚度、面积)、墙体朝向、季节等多种组合情况下进行数值模拟,提取可检测缺陷区域面积,确定在四季典型日中东、南、西、北墙的最佳检测时段；根据缺陷区域面积和热工缺陷评定等级,结合实际拍摄条件确定红外热像仪的检测能力,从而为现场检测提供依据。(5)以外保温粘结空鼓缺陷的外墙传热模型为基础,模拟分析缺陷参数(厚度、面积)、墙体朝向、季节对外墙外表面温度分布的影响；并模拟了最新洒水降温辅助手段下的外墙外表面温度场,与自然情况下相比较,外墙外表面温差值大幅提升,证明了此手段的可行性。(6)总结前面章节中的重要结论,提出了研究中的不足之处。
[Abstract]:In the field of construction quality defect detection, the infrared thermal image method has become a widely used detection method, and the infrared thermal image detection technology is becoming more and more mature, and the relevant association and the local quality detection department have developed corresponding standards and detection technical regulations. The research of the infrared thermal image technology is also developed by qualitative analysis to the quantitative analysis trend. At present, the detection of the quality of the building works by the infrared thermal imaging technology is mainly divided into three categories: construction defect detection, energy-saving detection, moisture and leakage detection. The quantitative analysis method can be divided into three directions: numerical simulation, image post-processing and infrared thermal diagnosis. The main work of this paper is to analyze the heat transfer process of the external wall with the defects of the external thermal insulation and the bonding defect of the EPS board, so as to provide the theoretical basis and suggestions for the on-site detection of the infrared thermal imaging method. In this paper, the requirement of the thermal defect of the outer envelope structure and the technical specification for the detection of the bonding defect of the exterior wall of the building by the infrared thermal imaging method are based on the standard of building energy-saving detection of the living energy-saving. The heat transfer model of the external wall of the two types of defects is established by using the ANSYS finite element thermal analysis software, and the dynamic heat transfer process of the outer wall is simulated by the numerical simulation of various combinations of different defect parameters, wall orientation, season and the like, The influence of the above parameters on the outer surface temperature distribution of the outer wall is analyzed, the detection capability of the infrared thermal imager on the defects of different parameters and the optimal detection period of the east, the south, the west and the north wall in different seasons are obtained by combining the actual infrared thermal image detection condition, and provides advice and basis for on-site detection of heat insulation missing defects and bonding defects. The main research contents include the following aspects: (1) The basic theory of the infrared thermal image technology and the heat transfer process of the external wall are introduced, so that the detection principle of the two defects of the external thermal insulation of the external wall of the infrared detection is led out, and the important parameters (solar radiation intensity, day temperature, the calculation formula of the comprehensive temperature) is prepared for the calculation of the parameters in the subsequent numerical simulation. (2) The basic principle of the finite element and the basic step of the transient thermal analysis of ANSYS are analyzed, and then the external wall model of the external thermal insulation of the EPS board and the model of the outer wall of the bonded air drum are set up according to the basic steps, and the heat transfer process of the two models is simulated numerically. in that heat analysis of the heat transfer process of the external wall model of the external thermal insulation defect, the influence of the temperature change before the detection date on the calculation result of the day of detection is studied, the characteristic of the outside surface temperature distribution of the detection day is analyzed, the requirement of the temperature change before the detection date is put forward, The variation law of the outer surface temperature difference of the outer wall on the day of the test was obtained. in that heat analysis of the heat transfer process of the outer wall model of the external heat-insulation bonded air-drum defect, the average value of the outdoor comprehensive temperature and the outside surface of the normal area is analyzed firstly, the average value of the outside surface temperature of the normal area and the outer surface temperature of the defect central point are compared and researched, The variation law of the outer surface temperature difference of the outer wall on the day of the test was obtained. In the end, the results of the two models are compared and analyzed, and the difference of the peak of the temperature difference of the theoretical analysis is caused by the defect area and the thickness. (3) The feasibility of the defect model and the validity of the corresponding conclusions are verified by using the infrared thermal image to detect the defect of the external thermal insulation defect. The results of the numerical simulation of the measured data are compared with the experimental results, and the conclusions of the influence of the defect area and the thickness on the temperature difference of the outer surface of the external surface are proved. The main influencing factors of the experimental results and the error of the simulation results are also analyzed. By means of numerical simulation, the influence of the temperature difference on the external surface temperature difference of the bonded air drum is analyzed, and the conclusion that the test result of the defect of the bonded air drum of the outer facing layer is detected by the infrared thermal image method in Huang Wen-ho's paper proves the feasibility of the defect model of the bonded air drum. (4) In order to further analyze the influence of the defect parameters (depth, thickness, area), wall orientation and season on the temperature distribution of the outer surface of the thermal insulation missing outer wall, on the basis of the heat transfer model, the defect parameters (depth, thickness, area), wall orientation, the numerical simulation is carried out in a plurality of combinations such as a season and the like, the area of the defect area can be detected, the optimal detection period of the middle east, the south, the west and the north wall in the four seasons is determined; and according to the defect area area and the thermal defect assessment level, and the detection capability of the infrared thermal imager is determined according to the actual shooting conditions, thereby providing the basis for on-site detection. (5) The external wall heat transfer model of the defect of the thermal insulation bonded air drum is based on the external wall heat transfer model, and the influence of the defect parameters (thickness, area), the wall orientation and the season on the outer surface temperature distribution of the outer wall is simulated, and the outer surface temperature field of the outer wall under the latest water spraying and cooling auxiliary means is simulated, Compared with the natural condition, the temperature difference of the outer surface of the outer wall is greatly improved, and the feasibility of the method is proved. (6) The important conclusions in the previous chapters are summarized, and the deficiencies in the study are put forward.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU761.12

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