寒冷地区近零能耗办公建筑负荷特性与能源系统运行优化研究(2019-2021)

近零能耗办公建筑的被动式设计已近最优,故能源系统在运行阶段的优化调适提升能效非常重要.本研究以北京市某近零能耗办公建筑为对象,使用TRNSYS软件,分析了其负荷特性及复合式可再生能源系统的运行优化.结果显示,建筑最大冷负荷为57.64 W/m2,最大热负荷27.64 W/m2,人员内扰对负荷影响更大.能源系统经过运行调适优化后,实际运行能耗较寒冷地区同类建筑分别降低70％以上.     

不同建筑热工分区办公建筑外围护结构负荷指标影响因素权重

为研究多因素对不同热工分区办公建筑总负荷指标的综合影响,在分析了单一因素对建筑总负荷指标影响规律的基础上,采用层次分析法对分别位于哈尔滨、兰州、重庆、广州的办公建筑负荷指标进行了评价。得到了窗户传热系数Kw、玻璃遮阳系数S_c、窗墙比R在不同热工分区办公建筑总负荷指标影响因素中的权重值,并对此进行了一致性检验。结果表明:对于严寒地区的哈尔滨和寒冷地区的兰州节能建筑,各因素重要程度为RK_wS_c;对于夏热冬冷地区的重庆和夏热冬暖地区的广州节能建筑,各因素重要程度为S_cRK_w。在建筑结构优化设计中应根据各热工分区负荷影响因素的比重不同进行优先控制相应因素。     

建筑窗墙比对办公建筑冷（热）负荷的影响分析

办公建筑冷（热）负荷影响因素较多,基于Dest软件,利用正交试验法对办公建筑室内的冷负荷影响因素进行了10个因素3个水平的分析,并重点分析了建筑窗墙比对办公建筑冷（热）负荷影响,得出建筑累计冷负荷值随着窗墙比变化的曲线,并应用曲线分析了冷负荷累计值的变化趋势。采用了最小二乘法,找出了冷负荷随着窗墙比变化的具体关系式,这种结果可为建筑师今后的设计提供有意义的参考。     

某玻璃幕墙建筑冷负荷的模拟计算与特性分析

对于集办公、酒店与商业为一体的玻璃幕墙建筑来说,影响空调冷负荷的主要因素是围护结构冷负荷和新风冷负荷。本文通过设定照明开关时间表、房间人员逐时在室率和电器设备逐时使用率,模拟计算了上海某大厦设计日逐时空调冷负荷,并对设计日空调负荷特性进行了分析。同时,本文对玻璃幕墙的遮阳系数与传热系数对空调负荷的影响做了定量分析,得出玻璃幕墙的遮阳系数是影响围护结构空调冷负荷的主要因素,而传热系数的影响几乎可以忽略不计的结论。     

对北京地区办公建筑设计冷负荷与耗冷量的分析

根据《公共建筑节能设计标准》(GB50189—2005)中关于建筑热工的规定,以北京地区某办公建筑模型为例,计算了冷负荷、新风负荷和耗冷量,分析了影响设计冷量的主要因素,给出冷指标的限制范围,并提出合理选择相关参数的建议。     

建筑窗墙比对办公建筑冷(热)负荷的影响分析

办公建筑冷(热)负荷影响因素较多,基于Dest软件,利用正交试验法对办公建筑室内的冷负荷影响因素进行了10个因素3个水平的分析,并重点分析了建筑窗墙比对办公建筑冷(热)负荷影响,得出建筑累计冷负荷值随着窗墙比变化的曲线,并应用曲线分析了冷负荷累计值的变化趋势.采用了最小二乘法,找出了冷负荷随着窗墙比变化的具体关系式,这种结果可为建筑师今后的设计提供有意义的参考.     

上海地区超低能耗建筑围护结构优化探索

文章收集调研夏热冬冷地区11个超低能耗建筑,对其采用的围护结构热工设计参数进行整理,提炼出该类建筑常用的围护设计参数范围。在此基础上,建立典型的上海办公建筑模型,以建筑负荷最低为优化目标,采用正交试验法,分析建筑空间设计因素、室内热扰等参数对超低能耗建筑围护结构热工参数设计的影响。结果显示,在负荷控制最低的前提下,气密性必须严格要求,围护结构传热系数、窗墙比及窗户太阳辐射得热系数等参数的选择与室内热扰大小、建筑平面面积有一定关联度。     

基于Dest软件对民用建筑围护结构的冷负荷模拟分析

建立了一个住宅类型建筑模型,从理论上分析了室内冷负荷与围护结构及内扰的关系,并基于Dest软件对住宅建筑室内的冷负荷与围护结构和内扰的关系进行验证,找出了冷负荷与传热系数的拟合关系式,进行了经济性分析,为建筑节能设计提供了参考。     

广州地区办公建筑外围护结构的热工性能与节能分析

办公建筑的空调能耗是围护结构的温差传热、室内热扰、太阳辐射等因素动态综合作用的复杂结果。本文采用DeST软件对广州地区某办公建筑围护结构的各项节能措施的节能效果进行分析,结果表明:降低外窗的遮阳系数、外墙和屋顶的传热系数对减少建筑全年空调能耗和最大空调冷负荷是有利的,但降低窗的传热系数对减少建筑全年空调能耗和最大空调冷负荷不利。建议在办公建筑节能设计过程中,模拟计算全年能耗,确定能耗低且技术经济合理的方案,尤其要慎重考虑是否采用低传热系数的窗。     

区域供冷负荷预测模型的建立

随着经济的发展,区域建筑越来越多,如何进行区域冷负荷预测是一个难题。传统的面积负荷指标法不能反映区域负荷的特点,预测结果往往偏大;而由于在区域规划阶段,很多建筑信息和参数都不全,采用软件进行详细的模拟计算也显得不可行。本文根据城市用地分类标准及建筑冷负荷特性将城市建筑进行分类,对每类建筑建立典型建筑模型并确立冷负荷的物理因素、内扰因素和外扰因素,应用DeST(Designer’s Simulation Toolkits)软件对典型建筑模型进行模拟,通过对模拟结果进行适当处理后得到城市建筑动态冷负荷数据库,为区域供冷冷负荷预测提供参考和依据。     

Small power equipment loads in UK office environments

This paper presents figures for the small power equipment loads encountered by the Welsh School of Architecture in UK offices while undertaking a programme of research and monitoring into the energy efficiency of air-conditioning systems in use. The findings are based on surveys undertaken in 30 air-conditioned offices between April 2000 and October 2002. Peak small power equipment loads were calculated using the CIBSE nameplate-ratio method. The results show that the small power loads averaged 17.5 W/m² with a range between 6 and 34 W/m² of treated floor area. When normalised for occupancy the calculated peak small power equipment loads averaged 158 W per person, with a range between 124 and 229 W per person. Current industry guidance could lead to the overestimation of small power equipment loads by as much as 650%, ultimately resulting in increased capital and running costs of air-conditioning plant and reduced thermal comfort. A more accurate method of estimating peak small power equipment loads in UK office buildings is suggested based on occupant density.     

Lighting energy consumption in ultra-low energy buildings: Using a simulation and measurement methodology to model occupant behavior and lighting controls

As building owners, designers, and operators aim to achieve significant reductions in overall energy consumption, understanding and evaluating the probable impacts of occupant behavior becomes a critical component of a holistic energy conservation strategy. This becomes significantly more pronounced in ultra-efficient buildings, where system loads such as heating, cooling, lighting, and ventilation are reduced or eliminated through high-performance building design and where occupant behavior-driven impacts reflect a large portion of end-use energy. Further, variation in behavior patterns can substantially impact the persistence of any performance gains. This paper describes a methodology of building occupant behavior modeling using simulation methods developed by the Building Energy Research Center (BERC) at Tsinghua University using measured energy consumption data collected by the University of Washington Integrated Design Lab (UW IDL). The Bullitt Center, a six-story 4831 m² (52,000 ft²) net-positive-energy urban office building in Seattle, WA, USA, is one of the most energy-efficient buildings in the world (2013 WAN Sustainable Building of the Year Winner). Its measured energy consumption in 2015 was approximately 34.8 kWh/(m²?yr) (11 kBtu/(ft²?yr)). Occupant behavior exerts an out-sized influence on the energy performance of the building. Nearly 33% of the end-use energy consumption at the Bullitt Center consists of unregulated miscellaneous electrical loads (plug-loads), which are directly attributable to occupant behavior and equipment procurement choices. Approximately 16% of end-use energy is attributable to electric lighting which is also largely determined by occupant behavior. Key to the building’s energy efficiency is employment of lighting controls and daylighting strategies to minimize the lighting load. This paper uses measured energy use in a 330 m² (3550 ft²) open office space in this building to inform occupant profiles that are then modified to create four scenarios to model the impact of behavior on lighting use. By using measured energy consumption and an energy model to simulate the energy performance of this space, this paper evaluates the potential energy savings based on different occupant behavior. This paper describes occupant behavior simulation methods and evaluates them using a robust dataset of 15 minute interval sub-metered energy consumption data. Lighting control strategies are compared via simulation results, in order to achieve the best match between occupant schedules, controls, and energy savings. Using these findings, we propose a simulation methodology that incorporates measured energy use data to generate occupant schedules and control schemes with the ultimate aim of using simulation results to evaluate energy saving measures that target occupant behavior.     

Evaluating diverse patterns of occupant behavior regarding control-based activities in energy performance simulation

Simulation is recognized as an effective tool for building energy performance assessment during design orretrofit processes. Nevertheless, simulation models yield deviating outcomes from the actual building performance and a significant portion of this deviation originates from the dynamic nature of occupant behavior. Literature on occupant behavior indicates that occupant behavior is not integrated into building energy performance assessment procedures with appropriate resolution, instead they are acceptedas as sumedand fixed data sets that usually represent the presence of occupants. This study attempts to evaluate the effect of diverse patterns of occupant behavior on energy performance simulation for office buildings. Diverse levels of sensitivity of occupant behavior on control-based activities such as using lighting apparatus, adjusting thermostat settings, and presence in space are employed through three diverse occupant behavior patterns. These occupancy patterns are correlated with three identical office spaces simulated within a conceptual office building. EDSL Tas is used to run building energy performance simulations. Effects of occupant behavior patterns on simulation outcomes are compared for five sample winter and summer workdays, with respect to heating and cooling loads. Results present findings on how diversity of occupancy profiles influences the consumption outcomes.     

Volatile Organic Compounds in Ventilating Air in Buildings at Different Sampling Points in the Buildings and their Relationship with the Prevalence of Occupant Symptoms

Total volatile organic compounds (TVOC) are determined in intake, room-supply and room air in 86 office rooms in 29 office buildings in northern Sweden. Measurements of formaldehyde were also made in room air. Building and room characteristics were identified and symptom reports collected from 1087 office workers. Concentrations of TVOC and formaldehyde in room air were low, with mean values of 71 µg/m³ and 31 µg/m³, respectively. The TVOC concentration was generally lower in room air than in supply air or intake air. The “loss” (difference in measured values) of TVOC from supply to room air was associated with raised concentrations of formaldehyde and raised prevalences of occupant symptoms. High TVOC concentrations in room air were associated with reduced prevalences of occupant symptoms.     

Climatic and internal factors affecting future UK office heating and cooling energy consumptions

There is a large consensus concerning the expected trend, if not the magnitude of change, of the UK climate in the coming decades [Climate Change 2007: Impacts, Adaptation and Vulnerability, Intergovernmental Panel on Climate Change, April 2007]. This study aims to quantify how such changes will have a direct effect on heating and cooling energy use in future office environments (i.e. by the year 2030). When considering future offices, it is also necessary to account for a change in the small power and lighting equipment being used, in this case by assuming an improved efficiency in both categories. This will also have a significant effect on the balance of heating and cooling an office. Furthermore, the subtle effect of a change in location within the UK can affect results further, with northern cities having substantially higher heating loads (and lower cooling loads) than southern locations. Such factors can influence approaches towards reducing future office energy demands and, in some cases, be the difference between a heating-dominated or cooling-dominated building. This study should also inform future choices for supplying energy to office buildings, in particular microgeneration options. It confirms the importance of dealing with demand-side changes before assessing the supply-side opportunities, with buildings having very different heating and cooling needs post-refurbishment. The study also highlights the importance, and possibilities, of adapting to future climates, and the benefits of promoting heating-dominated buildings instead of cooling-dominated.     

The impact of auxiliary energy on the efficiency of the heating and cooling system: Monitoring of low-energy buildings

This paper presents a detailed meta-analysis of end and primary energy use for heating, cooling and ventilation of 11 low-energy non-residential buildings and one residential building in Germany that belong to the EnOB research program launched by the German Federal Ministry for Economy. In particular, the analysis emphasizes the substantial impact of auxiliary energy use on the efficiency of heating and cooling performance. The investigated buildings employ environmental energy sources and sinks - such as the ground, ground water, rainwater and the ambient air - in combination with thermo-active building systems. These concepts are promising approaches for slashing the primary energy use of buildings without violating occupant thermal comfort. A limited primary energy use of about 100 kWh_prim/(m²_neta) as a target for the complete building service technology (HVAC and lighting) was postulated for all buildings presented. With respect to this premise, a comprehensive long-term monitoring in high time resolution was carried out over the course of two to five years, with an accompanying commissioning of the building performance. Measurements include the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source and sink, and local climatic site conditions.     

Identification of key factors for uncertainty in the prediction of the thermal performance of an office building under climate change

There is growing concern about the potential impact of climate change on the thermal performance of buildings. Building simulation is well-suited to predict the behaviour of buildings in the future, and to quantify the risks for prime building functions like occupant productivity, occupant health, or energy use. However, on the time scales that are involved with climate change, different factors introduce uncertainties into the predictions: apart from uncertainties in the climate conditions forecast, factors like change of use, trends in electronic equipment and lighting, as well as building refurbishment / renovation and HVAC (heating, ventilation, and air conditioning) system upgrades need to be taken into account. This article presents the application of two-dimensional Monte Carlo analysis to an EnergyPlus model of an office building to identify the key factors for uncertainty in the prediction of overheating and energy use for the time horizons of 2020, 2050 and 2080. The office has mixed-mode ventilation and indirect evaporative cooling, and is studied using the UKCIP02 climate change scenarios. The results show that regarding the uncertainty in predicted heating energy, the dominant input factors are infiltration, lighting gain and equipment gain. For cooling energy and overheating the dominant factors for 2020 and 2050 are lighting gain and equipment gain, but with climate prediction becoming the one dominant factor for 2080. These factors will be the subject of further research by means of expert panel sessions, which will be used to gain a higher resolution of critical building simulation input.     

深圳市6栋写字楼集中空调系统逐时冷负荷与能耗分析

以深圳市6栋高层写字楼集中空调系统全年运行数据为依据，分析了写字楼集中空调系统制冷主机逐时输出的冷负荷及年运行能耗，得到了各楼主机全年输出的逐时冷负荷的最大值，分析比较了各大楼的建筑面积、入住率、单位空调面积负荷、单位空调面积空调能耗，并比较了各楼的主机选型方案。     

Inter-related effects of cooling strategies and building features on energy performance of office buildings

The paper compares effects on thermal performance and energy use of various pre-cooling and ventilation strategies, which might be used for reducing peak power demands in typical office buildings located in moderately warm climatic regions. Simulations were performed for different features of the building envelope, and for two levels of internal heat load.Results indicate: significant reductions of required daytime peak power loads may be obtained by cooling strategies that contribute to lowering internal mass temperatures. For buildings with large internal heat loads, intensive night pre-cooling is the most effective strategy for smoothing required power loads. However, for non-loaded buildings, it largely increases total energy loads, and night-time peak power loads. Intensive night ventilation reduces required peak power loads as well as total cooling energy loads for both building types. For non-loaded buildings, it is an extremely efficient strategy, whereas the efficacy of other pre-cooling strategies is highly questionable. Further research should include secondary effects (on required peak power loads, total energy loads, and electricity consumption) as they may decrease the efficiency differences between the two strategies.     

基于人行为影响的住区建筑多主体集成能耗模型

在城市建筑节能研究中,政府常常依赖城市能源与碳排放模型工具制定并评估节能策略。而当前的城市建筑能耗模型受限于开发技术等因素,尚存在诸多不足,例如,考虑人行为对建筑能耗的影响,建立行为、日常活动及与环境相关的综合能耗模型。关于此类模型合理的数学形式、参数选择的方法以及不同行为的模拟方式等问题还尚待进一步研究。采用多主体(Multi-Agent)建模技术,设计集成建筑能耗模型,以住区中的居民作为模型中活动的主体,模拟使用者行为习惯、活动对建筑能耗的影响;采用ISO 13790标准模拟建筑的供热和降温需求,并在集成环境中设计统一的描述框架,以相对独立的环境模拟、行为模拟模块形式进行交互,实现热环境模拟和基于主体活动的设备能耗模拟的有机结合。研究表明,住区居民的用能行为是影响城市建筑能耗密度变化的重要因素,实现对住区主体行为特征的引导是实现城市建筑节能目标的有效途径。