我国天然采光的研究(英文)

本文简要地介绍了中国近４０年来天然采光的研究情况。文章的第一部分是一般概况。在这一部分中首先分析了我国天然光资源情况，接着阐述了建国以来我国天然采光研究的发展过程和取得的主要成就。第二部分是主要的研究课题： １．光气候的观测与研究； ２．天然采光标准的研究和制订； ３．天然采光设计的研究； ４．一些特殊建筑的天然采光方法； ５．建筑采光设备和材料的研究； ６．电子计算机在采光设计计算和模型试验中的应用； ７．采光窗的透光、保温隔热、隔声和气密水密性能的试验研究。 第三部分介绍了我国天然采光的学术研究机种和组织情况。 第四部分介绍了我国在天然采光方面的学术活动情况。最后作为附录介绍了我国５０年代以来发表的天然采光学术论文。     

Analysis of daylight factors and energy saving allowed by windows under overcast sky conditions

The aim of this research is to quantify the daylight factors produced inside a room for different models of windows, and to conduct an analysis of the results obtained. All trials were performed under overcast sky conditions, as these represent the worst case scenario for calculation. The shape, size and position of the window are variable, as is the reflectance of the inner surfaces of the room. A total of 28 simulations are provided by the lighting simulation program Daylight Visualizer 2.6, validated by the CIE test cases. After trials it was concluded that square windows produce daylight factors slightly higher than those obtained with horizontal windows and noticeably higher than those measured with vertical windows, considering the same surface of openings. It is confirmed that the daylight factors are directly proportional to the glass surface, except in the area near the window. It is also concluded that the windows in the upper position allow higher luminance at the back of the room than those in centered locations. Finally, the energy savings produced by the different models of windows is calculated.     

The role of the PASLINK test cell in the modelling and integrated simulation of an innovative window

The SOLVENT window is an innovative glazing system concept that involves the use of a rotating frame, an absorptive glazing and a naturally ventilated vertical channel, in order to improve the balance between the visual comfort and the energy efficiency of windows.     

German developments in guidance systems: an overview daylight

An overview is provided of recent developments in different daylighting systems. The systems range from a simple adaptation of venetian blinds for a better use of daylighting, to specially developed daylight-guiding venetian blinds, mirror louvers, optical mirror elements, ADO-Toplight, holographic optical elements, prismatic systems, Micro-Grates, Plexiglas Daylight, transparent insulation material, moveable glass louvers, a three-layer pipe-grid system and the ‘light sculptor’ in the cupola of the German Parliament. Most of these technologies are available in the market. Others, e.g. the ‘light sculptor’, were designed for a unique application.

Cet article présente les grandes lignes des développements récents en matière de systèmes d'éclairage naturel. Ces systèmes vont de la simple adaptation de stores vénitiens pour un meilleur usage de la lumière naturelle jusqu'à des stores vénitiens de conception spéciale à commande par la lumière du jour, en passant par des rideaux à lattes miroirs, des éléments de miroirs optiques, le système ADO-Toplight, des éléments optiques holographiques, des systèmes prismatiques, des microgrilles, des systèmes d'éclairage naturel en plexiglas, des matériaux isolants transparents, des systèmes à lattes de verre amovibles, un système à grille tubulaire à trois couches et le “sculpteur de lumière” qui équipe la coupole du Parlement allemand. La plupart de ces technologies sont disponibles sur le marché. D'autres, comme le “sculpteur de lumière” ont été conçus pour une application unique.     

Transmission of mirror light pipes with triangular, rectangular, rhombic and hexagonal cross section

This paper derives expressions for the transmission of mirror light pipes (MLP) with cross sections exhibiting congruent symmetry. These include rectangular, triangular, rhombic and hexagonal cross sections. For the case of rectangular MLP the transmissions calculated by this method are the same as the transmissions calculated by integrated ray trace methods. Measurements of the transmission of rectangular and triangular MLP were made and compared with calculated transmissions. It is shown that calculated transmissions are consistent with measured transmissions provided a reflectance that varies with incidence angle on the aperture of the MLP is used. A simple expression for this variation was found from the experimental measurements.     

Thermotropic glass with active dimming control for solar shading and daylighting

The effectiveness of an autonomous responsive dimming (thermotropic) glass panel fabricated with a transparent heating layer and an electrochromic layer to provide additional active dimming control is examined through preliminary experiments and simulations. Thermotropic glass consists of two panes of glass sandwiching a polymer gel that undergoes a transition from clear to cloudy at a threshold temperature. Winter temperatures can thus prevent the glass from dimming when required for solar shading. With appropriate control of the heating layer, however, the performance of the panel with respect to office solar-shading requirements is demonstrated to be superior to that without the heating layer, despite the simplicity of the system. The configuration requires relatively low electric power, utilizing solar radiation energy to maintain the cloudy state as required. In a different approach, application of electrochromic layer for active dimming control is proposed and verified in various aspects with wavelength characteristics considering simulation.     

THE APPLICATIONS OF RENEWABLE ENERGY TECHNOLOGIES IN BUILDINGS

Considerable opportunities exist, most particularly (though by no means exclusively) in the design of new buildings, to integrate renewable energy technologies and thus reduce or even replace conventional energy sources. These technologies can include passive and active solar heating and cooling, and photovoltaic power. Such strategies to improve the energetic performance of buildings and to reduce their environmental impact will always be complemented by conservation and energy efficiency measures.

Passive heating, natural cooling and daylighting represent a spectrum of strategies whose applicability is modified by region and building type, and whose contribution varies from the modest fraction by which most buildings already benefit, to that in well-designed new buildings where the solar energy contribution may represent more than half (and in suitable cases, when combined with other solar techniques, all) of the energy conventionally required to provide comfortable thermal and visual environments. Active solar heating systems have achieved considerable maturity, and developed commercial markets already exist in a number of countries. And building-integrated photovoltaic systems promise to make significant impact within the coming decade.

This paper outlines R&D programmes undertaken within the European Communities to improve our understanding of the science and engineering of these technologies, and to advance the design and industrial adaptation necessary to bring about widespread implementation of renewable energy technologies in European buildings.     

INTEGRATED PREDICTIVE ADAPTIVE CONTROL OF HEATING,COOLING, VENTILATION,DAYLIGHTING AND ELECTRICAL LIGHTING IN BUILDINGS

The present energy consumption of European Buildings is higher than necessary, given the developments in control engineering. Optimization and integration of smart control into building systems can save substantial quantities of energy on a European scale while improving the standards for indoor comfort. Many tools are available for the simulation of one or some of the following aspects: (a) heating, cooling and indoor thermal comfort, (b) ventilation and indoor air quality, (c) daylighting, electrical lighting and light quality, (d) installations, local control and fault detection, (e) Genetic optimized Neuro-Fuzzy control. The interaction between these aspects, however, is very relevant and cannot be neglected. Therefore, an integrated software tool is required. TNO together with the University of Delft develops such an integrated tool. This paper describes the first results of the utilization of this tool and the development of an integrated, predictive, adaptive building system for indoor climate control.     

PCM-facade-panel for daylighting and room heating

Double glazings combined with phase change materials (PCM) result in daylighting elements with promising properties. Light transmittances in the range of 0.4 can be achieved with such facade panels. Compared to a double glazing without PCM, a facade panel with PCM shows about 30% less heat losses in south oriented facades. Solar heat gains are also reduced by about 50%. This results in calculated U_eff-values of −0.3 to −0.5 W m⁻² K⁻¹, depending on PCM used. For an optimised panel, we calculated an U_eff-value of −0.6 W m⁻² K⁻¹. Although the U_eff-value of a double glazing is −0.8 W m⁻² K⁻¹, the PCM-systems may prove advantageous in lightweight constructed buildings due to their equalised energy balance during the course of day. Facade panels with PCM improve thermal comfort considerably in winter, especially during evenings. In summer, such systems show low heat gains, which reduces peak cooling loads during the day. Additional heat gains in the evening can be drawn off by night-time ventilation. If a PCM with a low melting temperature of up to 30 °C is used, thermal comfort in summer will also improve during the day, compared to a double glazing without or with inner sun protection. A homogeneous appearance of the PCM-systems is achievable by use of a concealment, like a screen-print glazing.     

Experimental investigation of performance of a multi-purpose PV-slat window

This paper reports on experimental investigation of performance of a new type of PV-slat window (PV-SW). The main functions of this PV-SW are as follows: to admit sufficient daylight, to act as a shading device for decreasing direct heat gain through window glazing and to ensure indoor air movement, which improves resident's thermal comfort. To assess the performance of this PV-SW, two test rooms of 1×1×1.5 m³ (H:W:L) volume were built using plywood and gypsum boards. At the first, the PV-SW of 0.5×0.6 m² surface area was located at the south-facing wall whereas the other room was equipped with a commercial transparent slat window of the same size.The PV-SW consists of six PV slats. The photovoltaic cells were connected in series giving a maximum electrical power output of 36 W (12 V×3 A). The circuit was connected to a direct current axial fan, located inside the room, that requires a maximum power of 43 W. The analysis of performance of this PV-SW was investigated based on power output, daylight factor and temperature difference between indoor and ambient.The experimental results showed that this multi-purpose PV-SW is extremely interesting as it can produce power up to 15 W, decrease indoor temperature and provide sufficient light for housing. The maximum indoor illumination was about 750 lx with slats angle of 68°. The room temperature was about 2–3^oC lower than that of room equipped with transparent slats.