公共建筑中庭节能措施探究

通过对公共建筑中庭的实地调查,分析太阳辐射、热压、风压、机械通风对中庭能耗的影响,提出优化中庭布置、对屋顶透明部分进行遮阳、增大通风口面积、屋顶设排风机与可开启外窗、监测各进风口和中庭顶部的温度等节能措施。     

促进自然通风的采光中庭屋顶优化设计

以采光中庭的屋顶设计为例,在解析了中庭自然通风的方法、中庭热环境特征的基础上,通过对绿色中庭建筑案例的分析,阐述了通过屋顶形态的优化设计来促进中庭自然通风的各种手法。     

自然通风工况下的寒地复杂中庭空间热环境模拟与分析

研究旨在通过对寒地某高校图书馆中庭空间的实地测量与模拟,解析自然通风工况下,中庭空间形态对其热环境的影响,为寒地高校图书馆中庭设计提供参考。结果表明:自然通风工况下,通过在中庭空间中增设横向平台能显著降低平台下部区域的日照得热,缓解上部区域热气流汇聚程度,改善中庭内部热舒适水平,但也会削弱烟囱效应对周边连通空间热环境的改善作用。     

广州番禺图书馆共享大厅空间自然通风系统联动控制策略研究

中庭是图书馆建筑中的过渡空间和交通枢纽,在图书馆的建筑布局中起着重要的热环境调节作用。从过渡季节中庭区域的热舒适环境参数、通风系统组合联动模式的模拟结果对比,以及通风系统联动控制模式等3个方面介绍了番禺区图书馆的中庭自然通风系统设计理念及通风联动控制系统。     

某建筑中庭自然通风效果测定与评价

以上海一幢具有高大中庭的建筑为研究对象,通过实测,研究了供冷日和非供冷日、通风天窗开启与关闭时对中庭内温度分布的影响,同时实测了中庭自然通风能力。结果表明,通风天窗开启可使中庭室内顶部与室外温差比天窗关闭时降低达4℃以上。通风天窗开启时,自然通风量达到1万m3/h以上,通风效果良好。     

办公建筑中庭、边庭节能及多元通风设计的应用初探

随着办公建筑共享空间的大量采用,中庭和边庭既提供了有利于人们身心健康的环境,也会产生能耗高、热舒适性不稳定等问题。介绍了该类建筑通风空调系统的设计、热舒适性的处理以及节能措施的采用。在某工程项目中结合多元通风、热回收、置换通风等技术的具体应用进行了测试及分析,为今后进一步完善并充分发挥中庭和边庭在建筑物内的作用提供了技术参考。     

鄂尔多斯火车站站房高大空间自然通风应用研究

本文为了研究鄂尔多斯火车站自然通风对候车厅和集散厅舒适性的影响,在当地夏季气候条件下,应用零方程湍流模型对室外风条件和通风窗形式对高大空间连通体热环境的影响进行了模拟和分析。研究表明,合理利用室外风向、风速以及通风窗开启角度能够改善室内的热环境,既可提高人体的舒适性,又可达到节能的效果。     

教学楼中庭的自然通风与热环境分析

中庭的存在对建筑通风与热环境具有重要影响。通过对武汉地区某教学楼中庭内的温度场与室外微气候进行了现场实测,对所测的数据进行了分析整合,并应用CFD数值模拟方法对中庭垂直温度梯度等参数进行了模拟,研究表明:实测数据与模拟结果在允许的误差范围内能够很好地吻合,且中庭内的垂直温度梯度对自然通风影响很大,中庭外窗的充分开启有利于夏季自然通风和节能。     

上海地区某文化建筑中庭自然通风优化分析

采用CFD计算流体力学方法对上海市某文化建筑中庭室内自然通风进行了数值模拟计算,分析其室内中庭风速、空气龄分布情况,并设计三种优化方案改善其中庭内部自然通风效果.研究得出该建筑原设计方案中庭一层自然通风效果最好,随高度升高,二、三层自然通风效果逐渐变差.通过优化围护结构开口大小、开口高度两种设计参数能够显著改善二、三层自然通风效果和舒适性.可为本地区该类型建筑中庭的自然通风设计优化提供一定的参考.     

某大礼堂自然通风热舒适性分析

科学合理地利用自然通风可提高室内空气品质、减少建筑能耗,并能保证一定的热舒适性。理论分析了自然通风热压作用下某大学建于20世纪30年代大礼堂的通风量、通风路径和人体热舒适性情况。结果表明,热压作用下的中和面高度变化较小,气流流向稳定,在非极端气候下,通风量大,室内的热舒适性及空气品质良好。一些经典建筑的设计理念在现代技术的帮助下,依然能够为现代节能建筑所参考。     

Comparison of low-energy office buildings in summer using different thermal comfort criteria

Sustainable low-energy office buildings attempt to harness the buildings architecture and physics to provide a high quality working environment with the least possible primary energy consumption. A promising approach to condition those buildings in summer employs the utilization of the building's thermal storage activated by natural heat sinks (e.g., ambient air, ground water or soil) through night ventilation or thermally activated building systems (TABS). However, a certain room temperature cannot be guaranteed as occupants may influence the room energy balance by window opening, internal heat gains or sun shading control. Between 2001 and 2005, monitoring campaigns were carried out over 2 or 3 years in 12 low-energy office buildings which are located in three different summer climate zones in Germany. These climate zones are defined as summer-cool, moderate and summer-hot. The weather at the building site and the room temperatures in several office rooms were monitored by different scientific teams. The raw data are processed for data evaluation using a sophisticated method to remove errors and outliers from the database and to identify the time of occupancy. The comfort in all office rooms in each building is evaluated separately. For data presentation, these separate comfort votes per office room are averaged using the median instead of the arithmetic mean in order not to overestimate extremely cold or hot room temperatures. A comfort evaluation in these 12 low-energy office buildings indicates clearly, that buildings which use only natural heat sinks for cooling provide good thermal comfort during typical and warm summer periods in Germany. However, long heat waves such as during the extreme European summer of 2003 overstrain passively cooled buildings with air-driven cooling concepts in terms of thermal comfort.     

Application of Indoor Natural Ventilation Simulation in Residential Space Layout

Tatural ventilation of indoor air flow and thermal comfort space plays an important role, especial y in the interior design of passive cooling factors, indoor space layout, and the location of doors, windows and other factors on the indoor natural ventilation effect has great influence. Using the method of fluid mechanics, and Airpak3.0 software, indoor natural ventilation for residential buildings was simulated, and the thermal comfort of indoor natural ventilation in a residential building in Xuzhou City was analyzed to explore the effect of indoor spatial layout, location of doors, window opening types on indoor natural ventilation. The results showed that indoor spatial layout played an essential role in indoor natural ventilation, application of numerical simulation for the simulation of the indoor natural ventilation and assessment of indoor natural ventilation effect was a scientific instruction for the indoor spatial design.     

Passive cooling in hot,arid regions in developing countries by employing domed roofs and reducing the temperature of internal surfaces

Natural ventilation due to wind effects through buildings employing domed roofs was estimated by a flow network analysis. The dome was assumed to have an opening at its crown. When compared with flat roofs, the domed roofs always increase the air flow rate through the building. The increase in natural ventilation becomes significant in buildings with doors and windows all in one wall, or whenever the wind effects on the building envelope do not produce large pressure differences at the openings.The large air flow rate in the buildings with domed roofs may be utilized to store night air coolness in the structure more effectively and keep the mean radiant temperature of the interior surfaces low for thermal comfort in summer. The lowest internal surface temperatures can be obtained when the surfaces are kept moist and evaporatively cooled.Through a one-dimensional energy analysis the inside surface temperature of a horizontal slab was estimated for various slab materials and thicknesses and external and internal conditions. The inside surface temperature was compared with the case of employing a roof pond. It was found that lower temperatures can be obtained by evaporatively-cooled moist internal surfaces than that which can be obtained by unshaded roof ponds: For a building whose internal surfaces (walls and ceiling) are kept moist a large ventilation rate is needed to prevent water vapor build-up in the space. A domed roof with a hole in its crown can produce the necessary ventilation for such a building.     

A combined system of chilled ceiling,displacement ventilation and desiccant dehumidification

Different types of heating, ventilation, and air-conditioning (HVAC) systems consume different amounts of energy yet they deliver similar levels of acceptable indoor air quality (IAQ) and thermal comfort. It is desirable to provide buildings with an optimal HVAC system to create the best IAQ and thermal comfort with minimum energy consumption. In this paper, a combined system of chilled ceiling, displacement ventilation and desiccant dehumidification is designed and applied for space conditioning in a hot and humid climate. IAQ, thermal comfort, and energy saving potential of the combined system are estimated using a mathematical model of the system described in this paper. To confirm the feasibility of the combined system in a hot and humid climate, like China, and to evaluate the system performance, the mathematical model simulates an office building in Beijing and estimates IAQ, thermal comfort and energy consumption. We conclude that in comparison with a conventional all-air system the combined system saves 8.2% of total primary energy consumption in addition to achieving better IAQ and thermal comfort. Chilled ceiling, displacement ventilation and desiccant dehumidification respond consistently to cooling source demand and complement each other on indoor comfort and air quality. It is feasible to combine the three technologies for space conditioning of office building in a hot and humid climate.     

广州移动通信枢纽楼生态节能设计理念介绍

广州移动通信枢纽楼是根据常规的建造技术、运用生态节能建筑理念进行设计的综合性办公建筑,是一次建筑设计走向环保与节能趋势下的有效实践。该项目和OVEARUP公司进行了采光日照、自然通风、围护结构、地道送风、中庭热舒适度、计算流体力学(CFD)和动态热模拟(DTM)等多项工作的合作研究,并且将大部分研究成果用于该建筑设计之中。     

Thermal characteristics of a double-glazed external wall system with roll screen in cooling season

A double-skin system (double-glazed external wall) is an effective passive system that can be used to decrease solar heat gain into buildings. Detailed information on the thermal distribution of double-skin facades is necessary to design better systems that can provide thermal comfort and conserve energy. In this study, the three-dimensional thermal characteristics of double-skin facades that had the ventilation opening installed partially and were screened partially by the adjacent buildings were investigated by field measurements. To that end, field measurements were carried out on the double-skin exterior wall (9.4 m high and 27.0 m wide) installed in an atrium located in the west of an existing building during cooling period for typical summer conditions. Maximum air change rate of natural ventilation through the bottom opening up to the top opening is about 20–25 [1/h], the reduction ratio of total solar heat gain compared with those of non-natural ventilation is about 25%. The exhaust solar heat gain is about 100 W/m² per inner glass surface area of the double-skin facades. Air temperature distribution of air space in the double skin was ranged from 30 °C to 44 °C, and heat gain difference ranged from 50 W/m² to 130 W/m². The influence of the ventilation openings and the shade conditions on temperature distribution of double skin is found to be significant and the double-skin system was verified to reduce the cooling loads effectively.     

某报告厅空调系统的设计及其能耗分析

介绍了西安某办公楼报告厅空调系统的设计。分别应用置换通风与混合通风两种通风方式，在室外和室内设计参数相同的情况下，充分比较了它们在送风量、新风量、能耗以及室内空气品质的不同。结果表明在某些应用场合，置换通风在空气品质提高和能耗降低上有明显的优势，同时这种优势不以牺牲热舒适性为代价，因此建议使用置换通风系统。     

Improving energy performance of school buildings while ensuring indoor air quality ventilation

Energy conscious design of school buildings, as well as deemed-to-satisfy provisions in a Performance Based Energy Code, should address the problem known as the energy efficiency—thermal comfort—indoor air quality dilemma (EE-TC-IAQ Dilemma). In warm and moderate climates, the large internal heat sources usually found in school buildings prevent achieving thermal comfort without active cooling in summer, but are not sufficient to eliminate the need for heating in winter. Commonly used air-conditioners do not improve air quality, while natural ventilation induces uncontrolled energy losses. In this study, a step by step process was used for the development of deemed-to-satisfy design solutions, which cope with the EE-TC-IAQ Dilemma, for a performance based code. A distinction is made between improving building design variables and improving ventilation schemes. Results indicate that implementation of improved ventilation schemes in an otherwise well designed energy-conscious building result in savings of 28–30% and 17–18% for northern and southern classroom orientations, respectively.     

空调建筑无组织通风的实测分析

对四栋不同朝向、不同体型、不同空调系统形式的办公建筑进行了无组织通风测试,从典型房间和建筑物整体分析了开窗、开门和通风系统设计不当产生的无组织通风量的大小及其对空调能耗的影响。     

Predicting thermal and energy performance of mixed-mode ventilation using an integrated simulation approach

Mixed-mode ventilation can effectively reduce energy consumption in buildings, as well as improve thermal comfort and productivity of occupants. This study predicts thermal and energy performance of mixed-mode ventilation by integrating computational fluid dynamics (CFD) with energy simulation. In the simulation of change-over mixed-mode ventilation, it is critical to determine whether outdoor conditions are suitable for natural ventilation at each time step. This study uses CFD simulations to search for the outdoor temperature thresholds when natural ventilation alone is adequate for thermal comfort. The temperature thresholds for wind-driven natural ventilation are identified by a heat balance model, in which air change rate (ACH) is explicitly computed by CFD considering the influence of the surrounding buildings. In buoyancy-driven natural ventilation, the outdoor temperature thresholds are obtained directly from CFD-based parametric analysis. The integrated approach takes advantage of both the CFD algorithm and energy simulation while maintaining low levels of complexity, enabling building designers to utilize this method for early-stage decisionmaking. This paper first describes the workflow of the proposed integrated approach, followed by two case studies, which are presented using a three-floor office building in an urban context. The results are compared with those using an energy simulation program with built-in multizone modules for natural ventilation. Additionally, adaptive thermal comfort models are applied in these case studies, which shows the possibility of further reducing the electricity used for cooling.