兰州地区住宅建筑供暖能耗影响因素分析

为研究影响兰州地区住宅建筑供暖能耗的因素,在围护结构参数完全符合国家现行寒冷地区住宅建筑节能要求的前提下,以兰州市2栋住宅建筑为基准模型,运用De ST-h软件对供暖季的热负荷进行逐时模拟计算,分析窗墙比、体型系数、朝向三大因素对总供暖热负荷的影响,得到了兰州地区住宅建筑南偏西30°朝向与南偏东30°朝向、正南方向相比,总热负荷最小,但最大热负荷最大的结论,为南偏西建筑进行供热调节实现节能提供依据。南向墙面内凹的住宅建筑不宜通过面积热指标法来估算热负荷。     

The effect of solar radiation on dynamic thermal performance of floor heating systems

This paper presents a numerical investigation of transient heat transfer in floor heating systems using a three-dimensional explicit finite difference model. The study focused on the influence of the cover layer and incident solar radiation on floor temperature distribution and on energy consumption. Complete and partial (area) carpets were considered as well as hardwood cover layers over concrete or gypcrete thermal storage. Experimental and simulation results for an outdoor testroom reveal that solar beam radiation can cause a local floor surface temperature in the illuminated area 8°C higher than that in the shaded area. Partial carpet cover further increases floor surface temperature differences up to 15°C when solar radiation is absorbed. Solar radiation stored in the floor thermal mass was found to reduce heating energy consumption significantly (30% or more). Increase of thermal mass thickness from 5 cm to 10 cm did not lead to higher energy savings with conventional proportional-integral control. Advanced control algorithms need to be developed to maximize energy savings while maintaining good thermal comfort.     

太阳能建筑一体化集热器的研制和应用

在世界矿物能源枯竭和环境问题日益严重的时候，我们才意识到危机的来临。事实上放开眼界的话，环境污染问题必须考虑，而能源危机并不存在，因为来自太阳能的矿物能源用完了，我们还可以直接利用太阳能本身。把几千年来房屋只是人类居住、遮风挡雨、避寒暑、娱乐的简单     

平板-真空管式太阳能集热器及其在建筑上的应用

<正>一前言为解决太阳能集热器与建筑有机结合的问题,天润经过多年努力,研制出平板-真空管式太阳能集热器。该集热器的核心技术是把高效率的真空管太阳能集热器进行平板化设计,使之实现模块化。本文结合实际工程案例,介绍平板-真空管式太阳能集热器的结构、技术性能以及在建筑上的应用,供大家参考。     

集中供暖热计量模式多样化的必要性分析

通过工程实例对我国节能建筑集中供暖热计量系统设计所存在的问题进行讨论。目前我国居住建筑集中供暖系统热计量设计模式单一,没有充分考虑我国国情和不同类型居住建筑的特点,加之我国的供热体制改革滞后,使得新建居住建筑的节能效果无法保证,还增加了工程建设费用。相关的技术规程予以补充和完善。     

一种开孔被动式太阳能集热器热效率的研究

对一种具有多孔折线型的被动式太阳能集热器的热性能进行实验研究,探讨在受迫奈件下集热器热效率的计算公式。实测过渡季集热器出口温度、进口风速和太阳辐射强度3个参数。通过实验分析,这种折线型太阳能集热器的热效率可达59．4％,并且热效率随进口风速和太阳辐射强度的增加而提高。此外,集热器效率要先于太阳辐射强度达到当天最大值。     

热管真空管集热器及太阳能热水系统

热管真空管集热器是继闷晒式、平板式、全玻璃真空管集热器后的第四代太阳能集热产品．在太阳能领域得到了广泛的应用。分析了热管真空管的原理、结构及传热特性;以国外产品为例,论述了热管真空管集热器的特点及工作性能;对直流式热管真空管热水系统和典型的间接式供热供暖及泳池热水系统进行了分析。     

Modelling and performance of a copolymer solar water heating collector

The performance of a solar flat-plate thermal collector wholly manufactured in a copolymer material is studied. The influence of different parameters of the system such as the insulation thickness, the flow rate and the fluid layer thickness is analysed. Thermal performance, productivity and efficiency of such a solar system is presented for a Mediterranean site. Yearly mean efficiencies are about 56.5% in no wind and about 49.0% for a wind speed of 5 m s⁻¹. The use of polymer materials reduces the collector weight by 50% in comparison with a traditional metal collector, this renders easier installation.     

Calculation of long term solar collector heating system performance

A calculation of system performance is necessary for an economic analysis of solar space heating systems, but is made difficult by the complexity of the system and weather parameters. The system studies in the literature have in general employed detailed computer analyses which, although informative, require detailed weather records and tend to be costly in computer time. To overcome these difficulties, a simplified technique to predict yearly system performance was developed. This simplified method is based on a computation of the system performance for a single “average” day of each month, modifying this result with a correction factor, and summing the results over each month of the heating season. The result is that system performance can be calculated easily, by hand or with trivial computer cost. A comparison with detailed numerical analyses in the literature for systems in the cities of Phoenix, Charleston, Madison and Boston shows excellent agreement. Results are also presented for systems in Salt Lake City.     

Use of solar assisted geothermal heat pump and small wind turbine systems for heating agricultural and residential buildings

The main objective of the present study is twofold: (i) to analyze thermal loads of the geothermally and passively heated solar greenhouses; and (ii) to investigate wind energy utilization in greenhouse heating which is modeled as a hybrid solar assisted geothermal heat pump and a small wind turbine system which is separately installed in the Solar Energy Institute of Ege University, Izmir, Turkey. The study shows 3.13% of the total yearly electricity energy consumption of the modeled system (3568 kWh) or 12.53% of the total yearly electricity energy consumptions of secondary water pumping, brine pumping, and fan coil (892 kWh) can be met by using small wind turbine system (SWTS) theoretically. According to this result, modeled passive solar pre heating technique and combined with geothermal heat pump system (GHPS) and SWTS can be economically preferable to the conventional space heating/cooling systems used in agricultural and residential building heating applications if these buildings are installed in a region, which has a good wind resource.     

Optimal use of solar collectors for residential buildings

Solar radiation is an abundant free resource which may be used in the form of solar heated water. This is achieved in solar collectors which, unfortunately, are expensive devices and, further, the warm water must be stored in accumulators—items which also cost money. This paper shows how we have optimized the situation for a block‐of‐flats in Sweden. In order to find this point we have used the minimum life‐cycle cost (LCC) concept as a criterion. The best solution is therefore found when that cost finds its lowest value. It is also examined under which conditions solar collectors are part of the optimal solution and further it is calculated what happens if this optimal point is abandoned, i.e. how much will the LCC increase if other than optimal solutions are chosen. LCC optimization for multi‐family buildings almost always results in a heating system with low operating costs such as district heating or dual‐fuel systems where a heat pump takes care of the base load and an oil boiler the peak. The installation cost must, however, be kept to a reasonable level. Expensive solar panel systems are therefore normally avoided if the lowest LCC shall be reached, at least for Swedish conditions. This is so even if the solar system has a very low operating cost. For buildings where the only alternative energy source is electricity, solar collectors seem to be on the rim of profitability, i.e. for an energy price of about 0.6 SEK kWh^?1. Copyright © 2001 John Wiley & Sons, Ltd.     

Integrated evaluation of radiative heating systems for residential buildings

Based on the need to reduce CO₂ emissions and minimize energy dependency, the EU Member States have set ambitious energy policies goals and have developed respective, specific regulations, in order to improve the energy performance of the building sector. Thus, specific measures regarding the buildings’ envelope, the use of efficient HVAC technologies and the integration of renewable energy systems are being constantly studied and promoted. The effective combination of these three main aspects will consequently result in maximum energy efficiency. Germany has played a key role in this development, with intensive work focusing in the improvement of the energy behaviour of the residential building stock. In this paper, the use of radiative heating systems placing special emphasis on infrared is being studied as part of the energy renovation of residential buildings from the 1970’s. This is done by applying an integrated assessment model to evaluate specific interventions regarding the improvement of the energy behaviour of the buildings’ envelope and the use of radiative heating systems, based on a thorough Life Cycle Analysis according to criteria of energy, economic and environmental performance, as well as thermal comfort.     

The effect of chemical coatings on the performance of solar collector plates

This paper presents the results of the investigation of the effect of chemical coatings on the performance of solar collector plates. The three metallic plates used are aluminium, copper and iron sheets. Their absorptance and reflectance before and after the application of chemical coatings were investigated. Two types of chemicals were used: cupric nitrate (Cu(NO₃)₂·3H₂O) for CuO coating, and carbon black for carbon black coating. The methods used in these coatings are spraying pyrolysis and painting methods, respectively. The results show increases in solar absorptance and decreases in reflectance with chemical coatings.     

On the effects of solar radiation variations on solar heating system performances

The effect of solar radiation availability on the performance of different solar heating systems has been studied. The systems include a solar water heater, passive solar houses and district solar heating systems with seasonal heat storage. Also, different collector orientations and collector types have been investigated. The hourly radiation data were generated by a simple computational simulation procedure. It was found that district solar heating systems with concentrating collectors and passive solar houses showed the largest variations for the given conditions.     

Estimation of incident radiation on a novel spherical solar collector

Most solar collectors commonly used are of the flat-plate type. In the present work, a novel type of solar collector, namely, spherical collector, is proposed. It consists of a stationary spherical body with a cover and an absorbing surface. The receiving hemisphere, normal to the incident beam radiation, keeps on shifting with the apparent position of the sun. The main advantage of this type of collector is its ability to effectively track the sun, without any actual mechanical movement. Both daily and hourly variations of incident radiation on such a spherical solar collector are calculated on the basis of available data. The results are compared with that on an equivalent flat-plate collector for different angles of tilt and latitude. From the results, the spherical collectors are found to be more effective in receiving solar radiation over equivalent flat-plate counterparts throughout the year.     

The oblateness effect on the extraterrestrial solar radiation

Calculations of the daily solar radiation incident at the top of the Earth's atmosphere, with and without the effect of the oblateness, are presented in a figure illustrating the seasonal and latitudinal variation of the ratio of both insolations. It is shown that, in summer, the daily insolation of an oblate Earth is slightly increased in two regions symmetric with respect to the summer solstice. In winter, the flattening effect results in a somewhat more extensive polar region, the solar energy input being always reduced (in some cases by more than 2 per cent) when compared to a spherical one. In addition, we also numerically studied the mean daily solar radiation. It is found that the mean summer daily insolation is scarcely increased between the equator and the subsolar point, but decreased poleward of the above mentioned limit. In winter, however, the mean daily insolation is always reduced, the maximum loss of insolation attaining as much as 1 per cent in the 55–85° latitude interval. The partial gain of the mean summertime insolation being much smaller than the reduction during winter season evidently yields a mean annual daily insolation which is decreased, maximally by about 0.3 per cent, at all latitudes.     

The optimisation of the angle of inclination of a solar collector to maximise the incident solar radiation

Irradiation data, recorded on vertical surfaces facing north, south, east and west and on a horizontal surface every ten minutes during daylight hours from January–December 1992 in Valencia, Spain, have been compared with estimated solar irradiation from inclined-surface models. Results show that Hays model most accurately reproduces the variation in irradiation on all vertical surfaces.Hays model has been used to find the hourly variation in the optimum tilt angle for a South-facing solar collector in Valencia, Spain, and also to calculate the yearly average of this angle. This method has been compared with the results provided by another model that uses average monthly values of daily irradiation derived from the same experimental data, to calculate average monthly values of the optimum tilt angle. The results show that the method involving monthly averages is more accurate and easier to work with.     

太阳能中央热水系统集热器的经济分析

介绍医院病房大楼太阳能热水集热器选择及辅助热设备选用技术的比较，选择平板式全紫铜板芯，不锈钢储热水箱，二级提升水温全自动运行，不需专人管理，节能、节支，经济效益明显。