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.     

基于提前启动和建筑储能的VAV系统优化运行策略

基于建筑具有储能特性,该优化运行策略提前启动空调系统,其启动时间由BP模型预测得到,并将冷量储存于围护结构。在峰值电力期间,利用较低的围护结构表面辐射温度,在保证舒适性前提下,提高室内温度设定值。最后在TRNSYS仿真平台上对该运行策略进行仿真验证,并与常规运行方法进行比较。得出结论:该方案不仅达到了移峰添谷的目的,同时也有效地保证了室内舒适性。     

商场建筑新风节能技术探讨

通过分析各个新风量控制方法的特性,结合大型商场的能耗特点,提出以CO2浓度.焓差法来控制商场内新风量.这种方法在空调系统全年运行时,能够最大限度地节省能源和改善室内空气品质.同时,排风对新风具有很可观的预热或预冷作用,在商场建筑空调系统中应尽量加装热回收装置,以提高系统的能量利用率.     

供暖系统设计现状分析及节能对策

建筑供暖能耗约占国民经济总能耗的30％,左右,建筑节能势在必行,而供暖系统设计是供暖系统节能的龙头,为达到节能目的,分析了目前供暖系统设计中存在的问题,结合锅炉房及外网,单体建筑供暖系统的设计,提出了与之相对应的节能措施,诸如锅炉房采用自控节能新技术,外网采用保温管道直埋技术,而单体建筑则应优先采用双管系统,对室温进行自动控制等措施,建议对现行供暖室外计算温度进行重新修正。     

蒸发冷却与机械制冷复合空调在中湿度地区的运行模式研究

分析了在中湿度地区夏季间接蒸发冷却与机械制冷联合使用中,间接蒸发冷却对室外空气先预冷后与回风混合以及先与回风混合再预冷对机组整体的影响,并结合工程实例,从风系统平衡、热湿平衡及能耗方面比较了两者的优劣.研究了过渡季节及冬季的运行模式,为蒸发冷却与机械制冷复合空调在中湿度地区全年空调运行处理模式优化提供了理论和实践依据.     

转轮除湿与单元式空调机相结合的空气处理系统

本文介绍了转轮除湿与直接膨胀式单元机组相结合的复合空调系统的2种紧凑型组成形式:前置预冷与后置冷却,并在几种不同室外工况下,针对应用于独立新风系统,对比分析了这2种典型组成方案的性能特点。结果表明,这2种除湿方式在4种典型工况下的制冷能耗相差不明显,在10%以内;但后置冷却除湿在高温高湿工况下难以实现较大的单位除湿量,且再生空气温度高;而前置预冷除湿系统采用较小的除湿转轮尺寸,结构更紧凑,可明显降低初投资,且再生空气温度较低。因此,前置预冷除湿系统在较小流量空气处理应用方面更具优势,更具商品化发展潜力。     

Active pipe-embedded structures in buildings for utilizing low-grade energy sources: A review

Low-grade energy sources such as geothermal energy, favorable ambient air and industrial waste heat etc. exist widely. Sufficient utilization of these low-grade energy sources may reduce our daily dependence on high-grade energy sources such as electricity resulting in reduced emission of green house gas for environmental conservation. Active pipe-embedded structure as floor/ceiling usually with water as the medium to carry heat or coolth may utilize these low-grade energy sources for providing space air-conditioning. Compact arrangement of pipes in the structure may significantly enlarge heat transfer surface between the slab mass and water in the pipe allowing substantial heat flows even for relatively small temperature differences. Application of the heat or coolth storage capacity of this structure for preheating or pre-cooling is also one among the advantages of this structure for shifting load and exploiting the nighttime cheap electricity tariff in some regions. This paper presents the technology of the active pipe-embedded structure for utilizing widely existing low-grade energy sources following by a comprehensive review on the heat transfer calculation models of this structure and its practical applications in real building systems for space air-conditioning. This review shows that more works on the active structure, especially simple and transient models for dynamic and accurate performance prediction and easy integration with existing building energy simulation packages, are worthwhile for further promoting the practical application wherever the low-grade energy sources are favorable.     

大体积水工混凝土温控措施探讨

分析了水工混凝土产生温度应力的两个必要条件，并阐述了其危害，从降低水泥用量、混凝土预冷、骨料预冷、降低浇筑温度等方面论述了夏季大体积水工混凝土的温控措施，并提出了冬季大体积水工混凝土的温控措施，以保证混凝土工程质量。     

Making method and application of standards for energy consumption quota of civil buildings

Based on the energy consumption survey in Wuhan, the paper provides the civil building energy consumption quotas according to the three energy efficiency indicators, which include the limit value, the admission value and the advanced value. The paper also presents the uses of different energy consumption quotas and analyses the difference between them. Adopting a statistical analysis method, the paper analyses the limit values of 39 kinds of building using SPSS software. Adopting a simulation method and a device isolation method, the paper provides 15 kinds of admission values and advanced values using DeST simulation software based on energy efficiency design standards. The paper also analyses that judging and excluding outliers are the basis for accurately formulating energy quotas. According to the building energy efficiency and fair principle, the paper gives unit building area energy consumption indicators for buildings with 39 kinds of different functions, air conditioning and heating energy consumption accounts for the proportion of building energy consumption, the limit values of energy consumption indicators of annual per capita energy consumption, per household, per bed, per student which are concerned with building function and standard deviations of the limit values.     

Study on Auto-DR and pre-cooling of commercial buildings with thermal mass in California

This paper discusses how to optimize pre-cooling strategies for buildings in a hot California climate zone with the Demand Response Quick Assessment Tool (DRQAT), a building energy simulation tool. This paper outlines the procedure used to develop and calibrate DRQAT simulation models, and applies this procedure to eleven field test buildings. The results of a comparison between the measured demand savings during the peak period and the savings predicted by the simulation model indicate that the predicted demand shed match well with measured data for the corresponding auto-demand response (Auto-DR) days. The study shows that the accuracy of the simulation models is greatly improved after calibrating the initial models with measured data. These improved models can be used to predict load reductions for automated demand response events. The simulation results were compared with field test data to confirm the actual effect of demand response strategies. Results indicate that the optimal demand response strategies worked well for most of the buildings tested in this hot climate zone.     

肇庆市某办公楼建筑围护结构节能改造研究

结合肇庆市建筑节能现状和地区气候特征,对某办公楼现有围护结构热工性能及建筑能耗现状进行模拟分析研究,根据实际情况提出技术可行、经济合理的建筑围护结构节能改造方案,为在本地区推广建筑节能改造技术提供参考和示范。     

Simplified energy analysis methodology for commercial buildings

Commercial building energy analyses may be used for new building design, energy end use forecasting and energy audit calculations. Many building simulation programs, such as DOE 2.1A or BLAST, are quite complex and must be run by specialists on main frame computers. A simplified method of commercial building energy analysis has been developed that utilizes a database of previous DOE 2.1A simulations to predict the outcome of other simulations. We have applied this methodology to an office building in one climate region and have found that it predicts heating, cooling, and total energy use very accurately. The main advantage of this methodology is that less specialized skill is required and only a microcomputer is needed to perform the analyses. Therefore, energy analyses can be done cheaply and quickly.     

基于被动设计理念下的住区建筑生态化对策探究

如何在设计过程中有效降低能耗,尽可能利用自然能源,是建筑规划设计中面临的一个重要课题。文章以秦皇岛“在水一方”住宅小区为例分析了被动设计对于建筑节能降耗的重要作用,探讨了基于被动设计理念下的建筑生态节能对策。     

多区域变风量空调系统及其分配控制研究

在多区域变风量空调及其控制系统的分析研究基础上,根据ASHRAE通风标准对新风量的要求,针对混合送风系统仿真分析了4种新风及其分配的控制方案,综合考虑了各方案的新同分配以及系统能耗。结果表明,通过VAV末端再热控制并结合AHU送风温度优化的控制方案,可以较好地解决多区域VAV空调系统新风分配问题,同时能有效地降低系统的能耗。     

浅析我国宏观建筑能耗评价指标体系

我国建筑能耗问题迫在眉睫。本文从宏观的角度运用生命周期能耗理论较全面地分析了我国建筑能耗问题,提出了一套宏观建筑能耗指标体系,并对我国2001-2005年宏观建筑能耗问题进行了实证研究。     

A tool for integrated hvac,building, energy and control analysis Part 1: overview of QUICKcontrol

This paper describes a tool called QUICKcontrol. The new, simplified, yet extensively verified building model made an efficient integrated tool possible. The system simulation is done using simplified though accurate component models. A unique simulation tool resulted.Any building, any HVAC system, and any control strategy can now quickly be built up using a graphical user interface. The integrated building, HVAC and control problem is then solved iteratively. Energy balances for each component, and for the system as a whole, are obtained. HVAC systems and controls can now be designed, optimised, and commissioned with ease and confidence.The software has already been successfully verified by eight case studies. The results proved to be sufficiently accurate for design, as well as control and energy analyses. For example, energy predictions calculated each minute are generally within 10% of measured values, while zone temperatures are within 1°C for 90% of the time.A new user typically takes a day to master the use of the software. Computing time for a very involved building, HVAC system, and complex energy management controls is approximately 10 min on a 133 MHz Pentium PC with 16 MByte RAM and 40 time steps per h. It is thus easy and practical to investigate a range of alternative control strategies and demonstrate their financial advantages to clients.     

中国建筑节能市场投融资环境分析

作为中国建筑节能市场的重要组成部分,投融资环境直接影响到建筑节能市场整体的效率和资金流动。目前相关研究较少且多集中在理论的定性分析。因此,本项研究采用定性分析与定量分析相结合的研究方法,运用动态参与者网络分析(DANA)概念建模工具,建立建筑节能市场投融资环境概念模型,剖析投融资环境的现状,结合调查研究识别建筑节能市场投融资环境的主要影响因素,进一步完善投融资环境的分析模型,探讨投融资环境改善和优化的有效途径。研究结果表明,推动中国建筑节能市场投融资环境演变和发展的关键在于:政府相关激励政策的制定、建筑节能运行管理体制的健全、建筑节能服务体系的完善和社会公众对建筑节能认知的提升。     

Double cooling coil model for non-linear HVAC system using RLF method

The purpose of heating, ventilating and air conditioning (HVAC) system is to provide and maintain a comfortable indoor temperature and humidity. The objective of this work is to model building structure, including equipments of HVAC system. The hybrid HVAC model is built with physical and empirical functions of thermal inertia quantity. Physical laws are used to build the sub-model for subsystems that have low thermal inertia while the empirical method is used to build the sub-model for subsystems with high thermal inertia. The residential load factor (RLF) is modeled by residential heat balance (RHB). RLF is required to calculate a cooling/heating load depending upon the indoor/outdoor temperature. The transparency, functionality of indoor/outdoor temperatures and simplicity of RLF makes it suitable for modeling. Furthermore, the parameters of the model can be calculated differently from room to room and are appropriate for variable air volume (VAV) factor. Nowadays, a VAV system is universally accepted as means of achieving both energy efficiency and comfortable building environment. In this research work, a pre-cooling coil is added to humidify the incoming air, which controls the humidity more efficiently inside conditioned space. The model presented here is verified with both theoretical and numerical methods.     

武汉写字楼的能源管理与节能改造分析

根据2007年武汉市能源审计结果,分析了写字楼的能源管理现状.对某写字楼进行了能耗模拟和节能改造模拟.能耗模拟结果表明,机组选型偏大,系统运行调节存在问题.建议提高系统综合能效比、实施照明控制和安装外遮阳;能耗模拟要考虑周边建筑的阴影.     

工业建筑节能设计探索：深圳美丝化纤厂节能设计

工业建筑节能设计是建筑节能的重要领域.设计中,与建筑节能有关的技术问题受到多方面因素的影响与制约.本文分析了工业建筑节能设计的难点,阐述了深圳美丝化纤厂的节能设计,实践表明该节能设计效益显著,值得推广.