Automated Assessment of Early Concept Designs

Building information modelling (BIM) is a powerful tool for clients and architects alike, particularly when clients have ongoing complex programmatic requirements. Chuck Eastman describes how with his team* at the AEC Integration Laboratory at the College of Architecture at the Georgia Institute of Technology he was commissioned by the US federal government's General Service Administration (GSA) to automate the design guidelines for all US courthouses in such a way that preliminary designs by architects could be assessed and checked against specific criteria. Copyright © 2009 John Wiley & Sons, Ltd.     

The cooling and heating potential of an earth tube system in buildings

A new module was developed for and implemented in the EnergyPlus program for the simulation of earth tubes. The model was validated against and showed good agreement with both theoretical and experimental data. Using the new module, a parametric analysis was carried out to investigate the effect of pipe radius, pipe length, air flow rate and pipe depth on the overall performance of the earth tube under various conditions during cooling season. Pipe length and pipe depth turned out to affect the overall cooling rate of the earth tube, while pipe radius and air flow rate mainly affect earth tube inlet temperature. The cooling and heating potential of earth tubes in four different locations were also investigated. Whether or not an earth tube is beneficial turned out to be heavily dependent on the climate of the location.     

基于负荷动态模拟的冰蓄冷系统优化控制分析

目的 研究一种在理论上接近最优控制结果,而在实际工程中又切实可行的冰蓄冷系统优化控制模型.方法 运用全能耗模拟软件EnergyPlus,根据优化控制单纯型求解方法,对北京某实际工程的冰蓄冷空调系统在不同控制策略下的全年运行费进行分析比较.结果 得到整个供冷季办公楼空调系统在冷机优先运行和优化运行两种工况下运行的电费,通过分析比较可知,实行优化控制后全年节省的运行电费主要来源于非设计条件,尤其在过渡季节.结论 基于负荷模拟的结果对冰蓄冷系统控制进行模拟优化,可以指导运行节能,较大幅度地减少运行费用,该研究对公共建筑空调系统进行控制策略优化提供依据.     

某游泳馆下送风空调系统能耗的影响因素研究

本文以上海某游泳馆为研究对象,采用流体力学软件CFD与能耗分析软件EnergyPlus交互运用的方法,对游泳馆进行数值模拟和能耗分析.首先运用EnergyPlus对游泳馆下送风气流组织进行设计日模拟,并以模拟数据作为边界条件,利用CFD对游泳馆热湿环境进一步模拟分析,将分析数据作为EnergyPlus的输人参数.然后分析讨论影响建筑能耗的主要因素:玻璃幕墙遮阳性能、新风比、机组性能系数(COP)等,采用EnergyPlus对游泳馆进行能耗模拟并计算全年能耗费用.结果表明,在保持其他影响因素不变的前提下,分别单独改变某一种影响因素,耗电量分别减少4.3%,6.8%,21.2%;耗气量在新风比因素改变的情况下减少50%,其他因素影响变化不大;全年总能耗费用分别减少1.3%,34.6%,7.6%.     

能耗模拟在建筑节能改造中的应用

建筑节能已成为国内建设节约型社会和发展循环经济的重要内容,对既有公建的节能改造是开展节能工作的重点.介绍了天津某科技馆的建筑节能改造工程和当前比较流行的能耗模拟软件EnergyPlus,通过对科技馆典型房间的模拟得出了该房间的动态冷热负荷.模拟结果和计算结果的对比表明,该软件可应用于节能改造工程的动态负荷计算.     

A green roof model for building energy simulation programs

A physically based model of the energy balance of a vegetated rooftop has been developed and integrated into the EnergyPlus building energy simulation program. This green roof module allows the energy modeler to explore green roof design options including growing media thermal properties and depth, and vegetation characteristics such as plant type, height and leaf area index. The model has been tested successfully using observations from a monitored green roof in Florida. A preliminary set of parametric tests has been conducted on prototypical 4000 m² office buildings in Chicago IL and Houston TX. These tests focus on evaluating the role of growing media depth, irrigation, and vegetation density (leaf area index) on both natural gas and electricity consumption. Building energy consumption was found to vary significantly in response to variations in these parameters. Further, this response depended significantly on building location (climate). Hence, it is evident that the green roof simulation tool presented here can serve a valuable role in informing green roof design decisions.     

西藏地区太阳能采暖建筑热工性能优化研究

西藏地区太阳能资源非常丰富且冬季温度低,该地区非常适合大面积推广太阳能采暖系统,以达到节能减排的目的。但是由于实际大部分太阳能采暖工程,忽略了建筑围护对太阳能主动式采暖系统初投资与运行费用的影响,造成了太阳能主动式采暖系统初投资过高、太阳能保证率低。为了分析建筑热工性能对太阳能主动式采暖系统的影响,笔者利用数值模拟方法,将建筑热工性能与主动式太阳能采暖系统作为一个整体进行计算分析,利用初投资费用最低与全寿命周期总费用最低两个目标函数,对主动式太阳能采暖建筑热工性能的保温性能进行优化。结果表明,提高建筑围护结构热工性能,不仅可以降低太阳能采暖建筑的采暖运行费用,而且可降低整个系统的初投资。     

基于分时电价的建筑虚拟储能利用

定义了两个指标,分别从填谷功率和调峰功率来说明虚拟储能的填谷能力和调峰能力。采用建筑能耗模拟软件EnergyPlus对一栋二层办公楼进行模拟,通过设置时间计划表来量化建筑虚拟储能的能力,从而实现对建筑虚拟储能的利用。模型得出了虚拟储能的关键性指标,其中填谷功率为40.9 kW,调峰功率为43.8 kW。根据分时电价制定策略,在虚拟储能运行策略下建筑空调电费单日节省34.6元,节省率为12.7%。虚拟储能净效益为1.8%。     

上海地区建筑能耗计算用典型年气象数据的研究

以同济大学某教学楼为研究对象,对比了用EnergyPlus模拟计算得到的全年耗电量和实测耗电量,研究了用于建筑能耗动态计算的5套典型年气象数据的可靠性,得出了CTYW气象数据最接近现实情况的结论。对其中影响较大的参数如室外气温、湿度和太阳辐射量进行分析和比较,指出所用5套典型年气象数据间的差异来自观测值的缺损和统计处理模型的不完善,特别是日射模型存在一定缺陷。     

Multi-criteria analysis for the integrated performance assessment of complex fenestration systems

Complex fenestration systems (CFS) designed to collect and redirect daylight from the sky-vault are generally placed on the upper part of a window in order to improve the distribution of indoor daylight. Due to their additional function as solar protection, their use might contribute to the mitigation of the unfavourable effects that the admission of daylight signifies, especially in buildings located in prevailing sunny climates (risk of glare and overheating). An appropriate selection of the CFS that better contributes to improve the interior daylight environment would imply an integrated performance assessment taking into account relevant aspects such as indoor daylight distribution and the visual and thermal comfort of occupants. However, such an assessment implies the use of performance criteria with different targets; therefore, in order to evaluate their overall performance, a multi-criteria analysis is applied in this study. The method presented here describes a comprehensive evaluation to determine those CFS that better contribute to an improved indoor daylighting environment in a building located in a prevailing sunny climate. The CFS performance assessment was undertaken with computer simulations using their bi-directional transmission distribution function (BTDF).