墙体热阻现场测试仪器开发及双面热流计法的应用

发布时间：2018-07-13 17:11

【摘要】：随着我国发展进程的不断加快,经济总量的持续稳步增长,能源的供需关系对经济发展的影响日益凸显,能源问题也成为制约我国经济持续健康发展的重要因素。在能源消耗总量中,建筑能耗占据很大的比例,所以积极开展建筑节能工作,是未来控制我国能源消耗、有效降低建筑能耗的关键所在,而建筑围护结构的热阻是建筑物的重要热工性能之一,很大程度上影响着建筑能耗,准确检测建筑围护结构的热阻对减少建筑能耗意义重大。本文介绍了目前几种常见的墙体热阻测试方法,同时对它们分别应用于现场测试时的优点和局限性做了详细的对比。此外,本文在被广泛使用的热流计法的基本原理之上提出了一种新型围护结构热阻现场检测方法。在此基础上对测试设备设计改进,使得新型测试方法的设备在现场测试过程中便携性和可操作性大大提高,为墙体热阻现场测试提供了极大地便利。对新型测试系统的主要设备以及各自的工作原理做了详细介绍,说明了各个设备的现场安装方法及安装过程的注意事项,同时介绍了数据的采集过程和处理方法。文章还分析了墙体内部和墙体表面的传热过程,根据墙体的传热过程推测有可能对测试造成影响的因素。在测试过程中选择有效的方式避免这些不利因素对测试结果带来的影响。借助强大的数值模拟工具—ANSYS模拟新型测试系统测试过程中墙体的传热过程。对真实的测试系统做相应的简化,建立数值模拟的实物模型,划分网格并对应实际测试条件设置模型的边界条件,对稳态和非稳态的过程分别进行数值分析。观察各个墙面上的温度和热流密度的分布情况,探讨分析了围护结构传热现象中的三维性以及围护结构受加热中心区域的热流沿其传递方向的变化。为新型围护结构热阻检测方法提供一定的理论支撑。利用新型的测试方法实测不同类型的墙体,在数据处理过程中采取双面热流计法——计算热流采用热侧墙面和冷侧墙面热流的平均值而非单侧墙面测试的热流值计算测试墙体的热阻,对比计算结果,发现双面热流计法可以显著的提高测试的准确度。分析平均热流的表现特性,可以看到平均热流的稳定时间比单侧热流的稳定时间快很多,对于测试环境多变的现场测试而言,尽快的达到稳定状态可以缩短测试时间,这对于避开对测试造成重大影响的不利因素有重要的意义。
[Abstract]:With the rapid development of China's development process, the continuous and steady growth of economic total, the influence of energy supply and demand on economic development has become increasingly prominent. Energy problems have also become an important factor restricting the sustained and healthy development of our economy. In the total amount of energy consumption, building energy consumption is a large proportion, so building energy conservation workers are actively carried out. It is the key to control the energy consumption in the future and effectively reduce the energy consumption of the building. The thermal resistance of the building enclosure is one of the important thermal properties of the building, which greatly affects the energy consumption of the building. It is of great significance to accurately detect the thermal resistance of the building enclosure structure to reduce the building energy consumption. This paper introduces several common walls at present. On the basis of the basic principle of the widely used heat flow meter, this paper puts forward a new method of detecting the thermal resistance of a new enclosure structure on the basis of the basic principle of the widely used heat flow meter. On this basis, the design of the test equipment is improved and the new test party is made. The portability and maneuverability of the equipment are greatly improved in the process of field testing, which provides great convenience for the field test of wall thermal resistance. The main equipment and the working principle of the new test system are introduced in detail, and the methods of installation and the attention of the installation process are explained, and the number of the equipment is also introduced. According to the process of collecting and processing, the heat transfer process of the wall and the wall surface is analyzed. According to the heat transfer process of the wall, the factors that may affect the test are speculated. In the process of testing, the effective way is chosen to avoid the influence of these unfavorable factors on the test results. With the help of a powerful numerical simulation tool, A NSYS simulated the heat transfer process of the wall in the testing process of the new test system. The actual test system was simplified, the physical model of the numerical simulation was established, the grid was divided and the boundary conditions of the model were set up corresponding to the actual test conditions. The numerical analysis on the steady state and the unsteady state process was carried out respectively. The temperature on each wall surface was observed and the temperature was observed. The distribution of heat flow density is discussed and analyzed. The three-dimensional character of the heat transfer in the enclosure structure and the change of the heat flow along the heating center of the enclosure structure are discussed. It provides a certain theoretical support for the new type of enclosure structure thermal resistance detection method. The two-sided heat flow meter is used to calculate the heat flow of the heat flow using the hot side wall surface and the cold side wall surface instead of the heat flow value of the single side wall test. The results show that the double side heat flow meter can significantly improve the accuracy of the test. The stability time of the heat flow is much faster than the stable time of the single side heat flow. For the field testing of the changeable test environment, it can shorten the test time as soon as possible, which is of great significance to avoid the adverse factors which have a significant impact on the test.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU111.3

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