水平遮阳方式在住宅建筑南窗遮阳应用上的探讨

太阳辐射得热是夏季空调负荷的重要组成部分,同时也是冬季采暖负荷的安全系数。因此,合理的遮阳就成为暖通空调领域节能的一个途径。该文以平均遮阳系数作为衡量遮阳效果的指标,以住宅建筑的南窗为研究对象,针对水平遮阳方式,定量分析了我国一些地区水平遮阳板构型尺寸对冬夏季遮阳效果的影响程度。并在综合考虑多方面因素的基础上,给出了这些地区南窗遮阳板构型设计的最佳尺寸。     

中国传统民居外窗遮阳系数研究

分析了传统民居屋檐、檐廊以及建筑布局对南向外窗的遮阳作用。通过对典型建筑实例计算后发现:传统民居的屋檐的遮阳效果随其挑出长度而增大,当挑出长度为0.5m时,外窗平均综合遮阳系数不大于0.5;当挑出长度为1.5m而成为檐廊时,综合遮阳系数不大于0.35;东、西侧建筑分别在午前和午后对与其正交相邻的外窗具有很好的遮阳效果,两者距离越近,遮阳作用越明显;南侧对面建筑对其北侧建筑外窗的遮阳作用不大。     

建筑外窗热工性能对空调能耗与节能的影响分析

利用建筑环境模拟软件DeST-c,对广州某办公建筑外窗热工性能对空调能耗的影响进行了计算,计算结果表明减小外窗遮阳系数能显著降低空调能耗,当遮阳系数从0.9减小至0.2时空调耗冷量可降低26%;而外窗传热系数对空调能耗影响较小.并通过对全年逐时空调节能率进行分析,研究了遮阳系数影响空调能耗的机理,发现遮阳系数减小引起较...     

窗框对遮阳系数的影响研究

为研究窗框对遮阳系数的影响,本文使用"幕墙门窗热工性能计算软件"对20种窗进行模拟计算,通过相关公式计算出窗框的遮阳系数,分析了窗框遮阳系数的影响因素,结果表明,窗框传热系数是影响其遮阳系数的关键因素。本次研究为窗框的发展指明了方向,为窗的节能设计提供了参考。     

建筑节能有关法规及热工计算方法探讨（下）

为了定量地说明体型系数、窗墙比、建筑朝向、窗户材质、外墙及屋顶的保温及遮阳等对于该模型综合指标的影响程度，我们做了大量的计算，并总结出如下规律。利用这些规律，对于类似的建筑，我们可以不通过计算就能基本定量地进行评估。     

纺织空调新风窗遮阳的节能

目前纺织行业空调的新风窗,习惯上都采用侧窗进风,无遮阳措施。由于新风窗面积较大,所造成的日照射热增加了冷负荷。本文就如何利用建筑物本身的外遮阳来减少日射热的冷负荷,作一探讨。宁波地理位于东经121°43′北纬29°48′以8月21日16点窗面太刚方位-4°视在高度角32°,西向日射热最大值D_(J_max)为463kcal/(m~2·h),热负荷系数C_(cL)为0.54。南区日射热最大值为149kcal/(m~2·h),冷负荷系数为0.52。水平凸出物每米所造成的影长为0.625米。综合遮阳系数C_Z为0.30。这样透过新风窗的日照射所增冷负荷计算公式为:     

考虑源荷协调优化的交直流混合微网 随机规划方法研究

摘要： 为充分发挥交直流混合微网中交、直流两种供电模式的互补优势,在需求侧优化各类负荷供电方式的选择（接入交流或直流母线工作）以提高微网供用电效率,并与供电侧分布式电源、储能设备的优化调度共同构成源荷协调优化运行方法。在研究源荷供用电效率的基础上,综合考虑源荷协调优化对微网运行费用与功率损耗的影响,分别以功率损耗最小和运行费用最小为上、下层优化目标,建立基于不确定二层规划的源荷协调优化模型。仿真算例验证了所提方法能在保证微网运行经济性与环保性的同时,更好地符合节能降损的要求。     

计及配电网设备利用率的源荷匹配评价

为了快捷有效评估光伏并网后设备利用率变化情况,丰富现有源荷匹配评估指标体系,本文建立了一套考虑配电网设备利用率的源荷匹配评估方法。首先对分布式光伏与负荷特征、设备利用率指标进行分析,构建了包含波动匹配度、电量匹配度、消纳匹配度与负荷偏移度的源荷匹配评估模型,借助拉开档次法进行指标赋权并得出源荷匹配综合得分,依据综合结果直接判断分布式光伏并网对设备利用率的影响程度。最后,依据江苏某工业园区电力用户源荷数据进行指标计算并进行设备利用率变化评估,对照设备利用率指标验证了评估指标体系合理性与有效性。     

外遮阳技术在节能建筑中的应用研究

分析外遮阳对建筑物全年采暖空调能耗的影响,介绍通常采用的几种外窗遮阳技术：内遮阳、本体遮阳和外遮阳及其热工性能指标．并采用建筑能耗模拟分析软件DeST,对外遮阳技术应用于上海地区典型多层住宅、生态办公和住宅示范楼的节能效果进行了模拟分析。     

基于Ecotect的太阳能光伏外遮阳结构的数值模拟研究

文章基于Ecotect软件和Radiance软件的协作交互,研究了光伏外遮阳(外置光伏板和光伏百叶结构)的变化对室内采光效果和光伏发电量的影响。研究结果表明:在南京地区,外置光伏板长度的变化对DA和DF影响较大;光伏百叶结构透明度的增大能够显著提升DA和DF;当采用光伏外遮阳时,适宜的窗墙比可使室内仅依靠自然采光达到最低采光限度(300 lux)的时间占比达到70%以上。此外,不同的光伏外遮阳倾角对各月发电量的影响不同,当光伏外遮阳的倾角为15°时,各月发电量均高于光伏外遮阳倾角为90°的工况,因此,可每月通过调整光伏外遮阳倾角来保证光伏外遮阳获得年最大发电量。     

Fenestration devices for energy conservation—I. Energy savings during the cooling season

Equations are presented for estimating heat transfer through seven types of fenestrations using the properties of the shading devices and the conditions of the interior and exterior environments. The results have been employed to determine energy savings during the cooling season for buildings located in the transition climatic region of San Diego County. Life-cycle costs for installing various types of shading devices are estimated on the assumption that the shading devices are removed during the heating season or else have no effect on heating-season requirements.     

ShadingPlus—a fast simulation tool for building shading analysis

Shading system plays a significant role in reducing building energy demand. To analyse the performance of a shading system, traditional method is either conducting experimental tests for solar heat gain coefficient (SHGC) or through detailed energy simulation for energy saving during specific period. But no simulation tool is able to accomplish the two objectives at the same time, and the latter is always too detailed and cumbersome with traditional simulation tools. To help architects analyse the shading system in a more comprehensive and simple way, a fast simulation programme—ShadingPlus—is proposed and developed in this work. With EnergyPlus as its core simulation engine, ShadingPlus applies an optimal methodology to calculate SHGC. Moreover, annual energy saving calculation is also available with ShadingPlus which reflects shading system in a more realistic way. It is expected that the analysis for shading system can be greatly simplified using this tool. Case studies are also given to illustrate the way ShadingPlus works.     

Direction Dependence of Savings on Cooling and Heating Loads by Energy Efficient Windows

The energy saving performance of energy efficient windows has strong dependence on window direction. Transmitted insolation level definitely affected the cooling and heating load. Simple simulation on the decrement of cooling load and the increment of heating load of a shading window compared with those of a transparent window show the prospect of energy saving effect clearly.From southeastward to southwestward, shading window even enlarges total heating and cooling loads when the thermal transmission is the same. However, if the shading coefficient of window is switched between summer and winter, total cooling and heating load can be reduced. This result clarifies the importance of ＂smart window＂.     

Hot-cool box calorimetric determination of the solar heat gain coefficient and the <Emphasis Type="Italic">U</Emphasis>-value of internal shading devices

In several developing countries, energy performance rating programs are currently in progress. Complex fenestration systems (CFS) are building components that play a key role in reducing energy consumption. The development and testing of equipment is central for beginning the energy efficiency rating process of complex glazing systems in these countries. This paper validates the use of a low-cost hot-cold box calorimeter for measurement of the solar heat gain coefficient (SGHC) and overall heat transfer coefficient (U-value) of interior shading systems. This work aims to determine the energy performance of three types of often employed shading systems: solar control films, interior horizontal venetian blinds, and indoor drapery curtains. Results show that the energy performance of solar shading devices studied depends on both their morphological and optical properties. The shading systems analyzed present similar U-values, where technological features are represented by the thickness and the thermal conductivity of the material. SHGC is mainly defined by the transmittance and, to a lesser extent, the absorptance of the systems, which differ significantly according to the analyzed shading device. The three types of curtains analyzed demonstrate an SHGC dependent on the fabrics openness factor: jacquard curtains (openness factor 0.05) present a SHGC of 0.7, whereas organza curtains (openness factor 0.45) have a SHGC of 0.82. The SHGC of the venetian blinds analyzed varies on average 36% according to the slat tilt (0°–45°). The solar control films examined modify their solar gain according to their spectral selectivity.     

Assessment of fixed shading devices with integrated PV for efficient energy use

The use of external fixed shading devices to adjust solar influx radiation and to save energy is well known. However, fixed shading devices can reduce daylight availability, increase artificial light needs and block the beneficial winter solar radiation.This paper is part of a research on the characteristics of the optimum shading device. The aim is to investigate the balance between the energy needs for heating and cooling the space that the shading device is used for and the energy that is used for lighting the same space and the energy that the shading device can produce.In order to investigate the balance between the above mentioned parameters, thirteen types of fixed shading devices have been studied and categorized according to their energy performance, for a single occupant office room. The same office room is tested for two different Mediterranean latitudes in Athens and in Chania, Crete in Greece and for two different south facing windows’ sizes.The thermal behavior of the devices is assessed through computer simulation application and the daylight analysis is assessed with both computer simulation and physical modeling. Stable parameters were the internal loads in the office room, the south orientation of the façade and the type of glazing. Variable parameter was the type of the fixed shading device.The study shows that all shading devices with integrated south facing PV can efficiently produce electricity which may be used for lighting. The study highlights the fact that shading devices such as Surrounding shading, Brise–Soleil full façade and Canopy inclined double work efficiently against thermal and cooling loads and may be used to produce sufficient electricity and control daylight. The study defines the geometrical parameters that will be incorporated to the overall characteristics of the optimum fixed shading device and proposes new fields of development for the BIPV technologies.     

Test room measurements and computer simulations of the micro-light guiding shade daylight redirecting device

The micro-light guiding shade is a device that acts to both shade the façade from direct sunlight and distribute daylight deep into sub-tropical buildings. The device was created in response to the need for daylighting technologies that can utilise direct sunlight while maintaining visual and thermal comfort in sub-tropical buildings. The created device has the form of a fixed panel with similar thickness and outward appearance as existing shades, yet performs the dual purposes of shading and light redirection.Experiments and computer lighting simulations were performed to assess the device’s performance in terms of effectiveness, efficiency, implementation, cost and construction issues. Experimental results show that the device provides favourable illumination deep within a room, while reducing glare for room occupants. Computer simulations compare favourably with experimental measurements, and have been used to find the optimal configuration of the panels in various situations. Installation of the device on high rise commercial buildings will reduce reliance on artificial lighting while improving the visual performance of office workers.     

Optimum design and analysis of the application of the air slot on the building horizontal sun-shading board

The sun-shading board is an important way to improve the indoor thermal environment. And air slot is the critical component to improve ventilation effect of sun-shading board. It not only can promote heat dissipation of sun-shading board but also can improve ventilation effect of building window. The shading coefficient of shading board and vorticity influence of air slot are the main principles of designing configuration and size of air slot. The horizontal sun-shading board of residential building south window in Nanjing is the study object. The shading and ventilation effect of shading board with various configurations and size is analyzed quantitatively. And appropriate configuration and size are obtained on the basis of comprehensive consideration of various factors.     

Effect of different earth surface treatments on sub-soil temperatures

The effect of different earth surface treatments for lowering the subsurface earth temperature has been experimentally investigated. The surface treatments studied include lime covered surface, stone covered surface and tree bark covered surface. The effects of shading and wetting the above treated surfaces on the subsoil temperature have also been investigated. It is found that wetting of the bare surface is most effective for reducing the average value of the subsoil temperature and that the wetted tree bark covered surface is equally effective in reducing the diurnal swings of the earth temperature. The measured subsoil temperature and the measured climatic data (ambient temperature, wet bulb temperature and global radiation) are used to estimate the surface heat transfer coefficient h_o and the thermophysical properties of the earth (K, α₁ and ρC).     

Simulation for an optimal application of BIPV through parameter variation

The degree of efficiency of Building Integrated Photovoltaic (BIPV) as a shading device and the variation of the electrical power generation over 1 year in a real building has already been experimentally investigated in my earlier research. In this paper, the influence of the angle of the solar cell panel, albedo of earth, building azimuth, and of solar cell panels under shading on the power generation are theoretically studied to further optimize BIPV implementation. For the validation of the theoretical work, experimental results of the Samsung Institute of Engineering and Construction Company building are used with a wind velocity of the weather data (TRY, test reference year) of Suwon area, Korea. The efficiency of the BIPV system as a shading device was compared at different months. In this work, the simulation program SOLCEL, for the calculation of a shading/sunlit area on solar cell module and facade, surface temperature of solar cell module, effective solar irradiance on solar cell module and the power generation of a BIPV as a shading device, was developed and validated. The SOLCEL can be applied to develop a multi functional Building Integrated Photovoltaic which could improve power generation, thermal comfort, natural lighting, cooling and heating, etc.