温湿度对墙体热工性能的影响

阐述了目前墙体热工性能检测过程中存在的问题,主要是未考虑温湿度对墙体热工性能的影响。首先对几种常用保温材料在不同温湿度下的导热系数进行试验研究,结合实际检测方法,得出由于温度的影响对检测结果带来的误差,以及人工环境中风和热辐射对检测结果的影响;另一点是在检测时未考虑墙体正常使用湿度所造成的误差。     

秸秆生态复合墙体热工性能试验研究

为了研究秸秆生态复合墙体的热工性能,在力学试验保障墙体受力性能的前提下,选择合适的秸秆掺入比例制作了秸秆生态复合墙体。热工性能检测方面采用目前比较成熟的标定热箱检测法并用得到的数据与ABAQUS热工模拟数据进行了对比分析,由此最终确定秸秆复合墙体的热工性能明显优于普通混凝土墙体。     

墙体热工性能现场检测的传热反问题方法研究

简要介绍了建筑围护结构导热系数的现场检测方法,指出了现有检测方法存在的局限性。基于谐波反应法,提出了一种求解单层均质墙体导热系数和体积比热的传热学反问题方法,并进行了模拟验证和实验验证。结果表明,此方法应用于导热系数和体积比热的现场检测时,具有一定的可行性和便捷性。     

墙体热工缺陷及传热系数现场检测技术研究

对建筑工程建成后的实际节能效果进行评价应结合现场检测获得的相关结果开展。结合红外热像法确定广西新型墙材节能建筑示范项目围护结构的热工缺陷,同时,利用温控箱-热流计法测试围护结构的传热系数,结果表明,在合理控制现场条件的情况下,红外热像法和温控箱-热流计法的配合使用,可以有效反应实际建筑工程围护结构的节能效果,检测结果较为可靠。     

墙体传热系数现场检测及热工缺陷红外热像检测技术研究

分析目前建筑墙体传热系数现场检测方法存在的问题．指出节能建筑验收时，仅仅依据测试1个建筑单元的墙体传热系数值，来判断1幢楼甚至1个小区的建筑墙体是否满足节能的要求．其科学性令人怀疑。介绍能迅速和全面地诊断建筑小区内所有建筑墙体热工缺陷的红外热像技术，以及运用红外热像技术进行定量化测试研究课题的主要内容。     

建筑围护结构热工性能现场检测技术探讨

对建筑围护结构热工性能现场检测技术进行了总结,指出为了系统全面地评价围护结构节能效果,应对现场测试装置进行改进,并检测更多的热工参数,为建筑物的运行能耗分析提供依据。     

真空绝热板热工性能的研究

介绍真空绝热板的构造及加工工艺,对其高效绝热性能进行理论分析及实验数据测试,运用数理统计及计算机数值模拟的方法分析热工性能随其自身参数及制造工艺的变化规律,提出产品生产、施工及使用中应注意的问题和改进意见。     

建筑玻璃光学热工性能现场检测技术研究

门窗、玻璃幕墙是建筑围护结构的薄弱环节,其热工性能是影响建筑节能效果的重要因素之一.对于已经安装的建筑玻璃的节能性能指标,业内一直没有找到方便快捷并且准确的现场检测方法进行评价.研究使用的玻璃现场检测技术,通过与6家实验室比对,发现现场检测与各实验室检测测值偏差最大的数据均在误差范围,其中,可见光透射比偏差为1.4％、...     

浅谈建筑节能工程现场热工性能检测

1前言我国在1998年1月1日起实行《中华人民共和国节约能源法》,接着相关的技术规范、行业标准也陆续出台,不断完善。江苏省也在2002年编写了建筑节能     

新型热流计在外墙热工性能现场测试中的应用

介绍了一套新型便捷式现场检测装置,通过与传统检测装置进行比较,验证了该检测装置的准确性:应用该装置针对不同墙体住宅建筑的外墙体热工性能进行现场检测.通过对不同墙体节能效果的评价,以选择和研究更为节能的墙体新型材料,使建筑围护结构的节能效果达到国家标准的要求.     

Determination of the convective heat transfer coefficient in three-dimensional inverse heat conduction problems

A thin steel plate probe (24 mm wide×24 mm long×3 mm thick) surrounded by insulation except for the exposed surface was constructed. Using the temperature measurements of the steel plate and the heat flux measured by a Gardon gauge and with the assistance of numerical calculations, two methods based on three-dimensional inverse conduction problems are developed to determine the convective heat transfer coefficient in fire experiments. The first one is based on optimisation of the predictions of the temperature of the steel plate using different heat transfer coefficients, while the second adopts a “predictor–corrector” method to determine the instantaneous heat transfer coefficient. Validation of both methods is accomplished by performing experiments in the cone calorimeter at a known constant heat flux. Subsequently, the two methods are applied to experiments in enclosures to examine the sensitivities of the two methods.     

被动式蓄热相变墙体热工性能的研究

选用石蜡与液态石蜡的二元混合物作为相变材料,按不同比例复合在墙体中,制成被动式蓄热相变墙体.实验分析了不同比例相变材料复合相变墙体的传热性能和节能效果,并与普通墙体进行比较,优选出相变材料最适合的复合比例.结果显示:在加热阶段,不同比例相变材料制备的相变墙体表面温度和热流均小于普通墙体,且温度和热流变化平缓、波动小,存在延迟和衰减现象;在停止加热阶段,普通墙体的温度和热流很快下降,而相变墙体表面温度和热流下降较为缓慢.试验数据为相变墙体的实际应用提供基础和依据.     

Transient heat conduction in multi-layer walls: An efficient strategy for Laplace's method

Enhancing load calculation tools into building simulation programs requires an in-depth revision and fine tuning of the load calculation assumptions prior to the addition of the HVAC system modelling routines. It is of special interest the analysis of transient heat conduction through multi-layer walls where, in order to improve the coupling between the passive elements of the building and the HVAC systems, an improvement of the time resolution in the calculation becomes critical. Several methods have been historically used, although recently Laplace's method has been displaced by the State Space method.This paper proposes a new strategy for fine time resolution on the calculation of the response factors through Laplace's method considering a comparison with the performance of the State Space method when used to calculate conduction transfer functions. Our analysis shows that in order to achieve similar accuracy with both approaches, the State Space method requires significant additional computational time.     

现场热响应试验测定导热系数的影响因素分析

通过对嘉兴市一试验井分别进行连续15 d和6.25 d的岩土热响应试验,研究了测试时间、舍弃初始时间、加热功率对埋管深度范围内岩土体导热系数测试的影响。结果表明,测试时间为72~96 h时测得的导热系数比较稳定;确定舍弃初始时间时要结合加热功率;加热功率越大,导热系数越小。     

An inverse solution of the lifetime-oriented design problem

This paper presents a new solution of the lifetime-oriented design problem. This solution is based on a point-to-point allocation between the space of the design parameters and the space of structural responses. Each point in the space of the design parameters defines a feasible or non-feasible design, and all feasible designs guarantee compliance with a predetermined lifetime. From the set of feasible designs, one or more designs may be selected with the aid of technical or economic criteria. The presented solution permits the consideration of non-statistical data uncertainty, thereby leading to an uncertain lifetime. Because of the unavoidable information deficit, for example incomplete data in practical problems, the application of non-statistical data uncertainty is more realistic than the application of stochastic data models. The selection of feasible design variants is based on methods of explorative data analysis.     

外保温墙体阳台传热分析

外墙外保温墙体的阳台部位，由于内有楼板，外有阳台板，其热桥很难避免。结合哈尔滨泰海小区节能住宅外保温墙体的阳台构造进行热工计算分析。分析结果表明，在哈尔滨地区不考虑封闭阳台内部温度有所升高的情况下，阳台窗和阳台板内部没有结露的危险，但阳台门下部有结露的可能。提出：最好采用挑梁，阳台板横向搭在挑梁上，而且挑梁宜避开阳台门位置，计算外保温墙体平均传热系数必须以一个单元或一栋楼为计算对象，而不能以一个开间为计算对象。     

Fire detection, location and heat release rate through inverse problem solution. Part I: Theory

A proposed method of detecting, locating and sizing accidental fires, based on the solution of an inverse heat transfer problem, is described. The inverse heat transfer problem to be solved is that of the convective heating of a compartment ceiling by the hot plume of combustion gases rising from an accidental fire. The inverse problem solution algorithm employs transient temperature data gathered at the ceiling of the compartment to determine the location and heat release rate of the fire. An evaluation of the proposed fire detection system, demonstrating the limits on the accuracy of the inverse problem solution algorithm, is presented. The evaluation involves operating the inverse problem solution algorithm on transient temperature data from computer simulated compartment fires. The simulated fire data are generated assuming fires with quadratic growth rates, burning in a 20 m wide by 20 m deep by 3 m high enclosure with a smooth, adiabatic ceiling. The accuracy of the inverse problem solution algorithm in determining the location of a fire is shown to be insensitive to the errors in the fire model used in the forward problem solution, but sensitive to errors in the measured temperature data. The accuracy of the heat release rate of the fire is sensitive to both errors in the fire model and errors in the temperature data. The validity of the use of computer simulated data in the evaluation is verified with a second evaluation using fire data interpolated from published measurements taken in large-scale compartment fire burns.     

Fire detection, location and heat release rate through inverse problem solution. Part II: Experiment

The design and fabrication of a prototype video fire detection system, which can locate a fire and determine its heat release rate, is described. The operation of the prototype system is demonstrated in a series of small-scale tests. The system utilizes a video camera to monitor an array of passive sensors distributed around the compartment to be protected. Each of the sensors is made up of a temperature-sensitive sheet that changes color at a prescribed temperature. In the event of an accidental fire, the plume of hot combustion gases rising from the fire will cause the temperature-sensitive sensors to be activated and change color. The times and locations of sensors changing color are used as data for an inverse problem solution algorithm, which determines the location and the heat release rate of the fire. A small-scale evaluation of the prototype video system is presented in which the prototype system is used to detect, locate and determine the heat release rate of a 2·4 kW burner placed in a 2·75 m wide by 2·75 m deep by 1·5 m high test enclosure. The accuracy of the prototype system in locating and determining the heat release rate of the small flame source placed in the reduced-scale enclosure is reported. In addition, the ability of the prototype system to make approximate measurements of the optical thickness of smoke in the enclosure, along camera-sensor lines-of-sight and then to use these measurements to locate and track the growth of a smoke plume is demonstrated.     

建筑幕墙的安全问题及评估方法

玻璃及石材幕墙作为新兴建筑材料正得到越来越广泛的应用,但是随着使用年限的增加,很多安全问题逐渐暴露了出来。文中对国内外多年来面临的主要安全问题及有关责任和保险问题进行了归纳概述,同时对幕墙的安全及耐久性的检查和评估方法作了概括,并提出了有关建议。