Uncertainty in airflow rate calculations due to the use of surface-averaged pressure coefficients

Mean wind pressure coefficients (C_p) are key input parameters for air infiltration and ventilation studies. However, building energy simulation and stand-alone airflow network programs usually only provide and/or use a limited amount of C_p data, which are based on several assumptions. An important assumption consists of using surface-averaged C_p values instead of local C_p values with a high resolution in space. This paper provides information on the uncertainty in the calculated airflow rate due to the use of surface-averaged C_p data. The study is performed using published empirical data on pressure coefficients obtained from extensive wind tunnel experiments. The uncertainty is assessed based on the comparison of the airflow rate (?) calculated using the surface-averaged C_p values (?_AV) and the airflow rate calculated using local C_p values (?_LOC). The results indicate that the uncertainty with a confidence interval of 95% is high: 0.23 ?_AV < ?_LOC < 5.07 ?_AV. In cases with the largest surface-averaged ΔC_p, the underestimation or overestimation is smaller but not negligible: 0.52 ?_AV < ?_LOC < 1.42 ?_AV. These results provide boundaries for future improvements in C_p data quality, and new developments can be evaluated by comparison with the uncertainty of the current methods.     

高层建筑外部空间交通组织

通过对现有高层建筑外部空间交通状况的分析,引出有关方面的组织原则及要求,并结合具体实例,从几个方面详细介绍高层建筑外部空间交通的组织方法.     

基于BSG模型的BBL布局

布局是VLSI物理设计的关键步骤之一.对于一般的BBL布局,一个基本问题是如何对布局问题的解进行有效的表示,文献[1]提出了BSG模型并对non-slicing结构的BBL布局进行了成功的表示.文章对BSG模型进行了研究和实现,并在用模拟退火算法实现过程中进行了搜索策略的改进,得到了较好的实验结果.     

利用旧厂房改造微模块数据中心的问题及对策

本文主要介绍在旧厂房（仓库）改造微模块数据中心时,可能遇到的部分问题,以及针对这些问题的解决思路和解决方案。     

Towards zero carbon design in offices: Integrating smart facades,ventilation, and surface heating and cooling

This paper discusses an overall strategy for reducing energy demand in non-domestic buildings, mainly focusing on office developments. It considers four areas: reducing internal heat loads; addressing passive design through the building construction; using efficient and responsive HVAC systems and focusing on chilled (heated) surface systems; integrating renewable energy supply systems into the building design. The impact on energy use and carbon dioxide emissions will be discussed. The paper will draw from a range of design projects carried out in Europe, where this integrated approach has been applied, and then explore the benefits in relation to applications in the Middle East and China. Energy modeling results, to inform the design process will be presented, using energy simulation for three case study locations, in Zurich, the Chongqing and Abu Dhabi.     

A study of the thermal performance of reflective coatings for the urban environment

This paper presents the results of a comparative study aiming to investigate the effect of reflective coatings on lowering surface temperatures of buildings and other surfaces of the urban environment, and thus test their suitability to lower ambient temperatures and fight the heat island effect. In total, 14 types of reflective coatings, selected from the international market were studied, from August to October 2004, on a 24 h basis. These coatings are used in buildings and some of them are used or could be used in the future in other surfaces of the urban environment (sidewalks, parking lots, etc.). In order to investigate the thermal performance of the reflective coatings, surface temperature sensors and a data logging system as well as infrared thermography procedures were used. The spectral reflectance and the infrared emittance of the samples were also measured. The collected data have been extensively analyzed. It was demonstrated that the use of reflective coatings can reduce a white concrete tile’s surface temperature under hot summer conditions by 4 °C and during the night by 2 °C. It can be warmer, than the ambient air by only 2 °C during the day and cooler than the ambient air by 5.9 °C during the night. “Cool” coatings present superior thermal performance even compared to other “cool” materials. This study can assist in choosing more appropriate coatings for building envelopes and other surfaces of the urban environment, and thus contribute to the mitigation of the heat island effect as well as the reduction of cooling loads and electricity consumption of buildings.     

建筑节能技术保障体系探讨

以提高建筑能源利用效率为宗旨，阐述了能够实现建筑节能的若干技术措施和保障体系。     

Hybrid solar heating and ventilation: The monymusk housing project

The paper reports on recent research at Aberdeen University to predict, with the aid of transient systems simulation, the performance of a new hybrid solar sheltered housing development in Monymusk, Scotland. The proposed dwelling units embody several unique design concepts, including an entirely traditional exterior appearance indistinguishable from the local vernacular, a new optimised omni-directional solar roof collector system which combines both heating and ventilation functions, and the ability to automatically switch between a range of heating and/or ventilation modes when required.     

Extraction and Regularization of Various Building Boundaries with Complex Shapes Utilizing Distribution Characteristics of Airborne LIDAR Points

This study presents an approach for extracting boundaries of various buildings, which have concave boundaries, inner yards, non‐right‐angled corners, and nonlinear edges. The approach comprises four steps: building point segmentation, boundary tracing, boundary grouping, and regularization. In the second and third steps, conventional algorithms are improved for more accurate boundary extraction, and in the final step, a new algorithm is presented to extract nonlinear edges. The unique characteristics of airborne light detection and ranging (LIDAR) data are considered in some steps. The performance and practicality of the presented algorithm were evaluated for buildings of various shapes, and the average omission and commission error of building polygon areas were 0.038 and 0.033, respectively     

行业特色高校研究生党建模式探析

具有行业特色高校的研究生规模一般不大,但是却承担着培养行业精英的重任,许多行业的中高层领导和技术骨干均来自于这些高校,在新的社会和高校大发展的形势下,行业特色高校必须与时俱进,按照国家和行业发展的需要,加大创新力度,不断探析构建适合本校和本行业研究生培养的党建模式。