太阳能总辐射仿真软件的设计及实地测量验证

文章依据太阳能辐射的相关理论，采用VB语言设计了基于任意地理位置的太阳能总辐射仿真软件，通过对徐州地区太阳能总辐射的实地测量研究，证实了该软件的有效性。     

如何将水平面上太阳总辐射转换成倾斜面上太阳总辐射

如何将水平面上太阳总辐射转换成倾斜面上太阳总辐射庄肃在太阳能利用中，为了使太阳能装置收集到更多的太阳辐射能，我们常将其倾斜安装，故需要计算到达倾斜面上的太阳总辐射能量。一般气象台站都有水平面上的太阳总辐射的观测资料，所以需将水平面上的太阳总辐射转换成...     

我国太阳能资源评价工作将有国家标准可遵循

简要叙述了《太阳能资源术语》、《太阳能资源测量方法总辐射》、《太阳能资源等级总辐射》三项太阳能资源评价相关国家标准的编制情况,重点介绍了《太阳能资源等级总辐射》标准的主要内容及其意义,并就促进我国太阳能资源科学开发利用提出了建议。     

新疆太阳能资源及区划

分析了新疆太阳能辐射年分布状况和月分布状况。通过月总辐射分布曲线、月直达辐射分布曲线、月散射辐射分布曲线,分析了不同地区、不同月份太阳能辐射分布状况。采用三级区划指标对新疆太阳能资源进行了区划。第一级区划采用太阳能资源年总量;第二级区划采用水平表面直达辐射量(Qb)与总辐射量(Q)的比值;第三级区划采用环境温度和日照时数大于6 h的天数。通过三级区划划分了太阳能资源带、区;分析了带、区季节分布特征、日照大6 h的天数和日照气温大于10℃的天数。全面了解和掌握新疆太阳能资源状况,可为本地区的太阳能利用提供可靠的资料。     

基于BSRN的呼和浩特市太阳辐射数据分析

利用BSRN3000型辐射观测系统对呼和浩特市的太阳能辐射资源进行观测,并对测得的数据进行处理及统计分析,得到呼浩特市一年中太阳辐射的变化情况及其影响因素。为了进一步分析各辐射之间的关系以及总辐射与其他天文因素的关系,文章使用统计分析软件SPSS对影响辐射的各因素进行相关性分析,结果表明云量和环境湿度是影响太阳辐射的两个主要因素。文章还分别对实测总辐射值与理论总辐射值、实测总辐射值与卫星总辐射值进行对比分析和相关性分析,结果相关性均较高,验证了BSRN3000型辐射观测系统所测数据的可靠性,为下一步的太阳能资源评估工作奠定了基础。     

郑州地区太阳辐射变化规律及分析

利用有关资料,分析了郑州地区太阳辐射能的年、月、日变化。分析表明:全年太阳能资源较为丰富且相对稳定,冬季太阳能资源利用潜力很大,应当合理利用直射、散射以及南向的太阳辐射;通过对太阳总辐射频数分布情况的分析得知:郑州地区超过100 W/m2的太阳总辐射占到年太阳总辐射的79%。     

基于WRF模式模拟上海地区月太阳总辐射的研究

利用WRF模式对上海地区2012年7月~2013年6月的逐月太阳总辐射量进行了模拟计算;分析了太阳能总辐射观测值和模式模拟值的统计关系;建立了模拟结果的统计订正模型,并将模拟区域各格点的模拟结果输入统计订正模型,得到各格点最终月太阳能总辐射值;用NCL软件将各月各格点上的值绘制成基于WRF模式计算的上海地区月太阳总辐射分布图。比较气候学计算和WRF模式计算出的月太能总辐射分布显示,各月的太阳总辐射值范围比较一致,这表明动力模式的模拟结果已取得初步成功,只是气候学计算的太阳总辐射最大值与最小值之差比模式计算的大。但是,用两种计算方法绘制出的月太阳总辐射高值中心与低值中心不太一致,须要进一步地研究改进。     

不可逆太阳能热泵系统性能优化及参数设计

考虑集热器辐射对流热损等多种不可逆因素,建立不可逆三热源太阳能热泵系统新模型,基于热力学分析方法,导出系统总性能系数与集热器工作温度关系的解析表达式,揭示了集热器的辐射对流热损、有限速率热传导和工质内部不可逆性等对系统性能特性的影响,分析和讨论了在最大总性能系数下太阳能热泵系统的优化设计参量。     

郑州地区太阳辐射能的初步分析

利用《中国建筑热环境分析专用气象数据集》分析郑州地区年、月、日太阳辐射能的变化。分析表明:该地区全年太阳能资源较为丰富且相对稳定,冬季太阳能资源利用潜力很大,应当合理利用直射、散射以及南向的太阳辐射;通过对太阳总辐射频数分布情况的分析得知:郑州地区超过100W/m2的太阳总辐射占到年太阳总辐射的79%。     

山东省太阳能集热器最佳倾角的研究

本文基于３０年的气象观测资料，从理论上导出了山东省各地月，季，年及典型时段太阳总辐射的最佳倾角。一般年最佳倾角与所处纬度差别不大，对于全年使用的太阳能集热器，为保证冬季更好地使用，将倾角加大２０°左右，在冬季可多接收总辐射量６％－１０％，而４－１０月间使用的集热器将倾角减少２０°左右，样增加辐射疸２％－６％。     

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.     

北京地区太阳紫外辐射的基本特征

1990年1月至1991年3月在中国科学院大气物理研究所香河观测站(北京东南70公里处)利用国产TBQ-4型分光辐射表及配套的智能辐射记录仪，对近地面太阳紫外辐射进行了观测，得到此间北京地区近地面太阳紫外辐射及其占太阳总辐射比例的变化特征，并分析了差异的原因。给出了1990年1月至1091年3月太阳紫外辐射的极值及对应的紫外辐射占总辐射的比例，后者同太阳总辐射存在反相关。     

晴天地面太阳紫外总辐射的观测结果和统计计算方法

利用１９９０年至１９９１年２４个月北京地区的太阳分光辐射观测资料和常规气象观测资料，分析了晴天条件下地面太阳紫外总辐射的变化规律，给出了用于计算晴天条件下到达地面的太阳紫外总辐射的两种公式，并计算了因臭氧总量减少引起地面太阳紫外总辐射增加的百分率。     

A cost-optimal solar thermal system for apartment buildings with district heating in a cold climate

Finding the global optimal combination of the main components for a solar thermal energy system is an important topic in utilising solar radiation in a cost-effective way. However, selecting an optimal solar thermal system in a cold climate condition is a challenging task due to the dependency on the heat demand and the limited availability of solar radiation. This research presents several sets of optimum combinations of a solar thermal collector and a hot water storage tank regarding energy efficiency and the life cycle cost. Since domestic hot water consumption forms the significant part of the heat demand in new energy efficient apartment buildings, the applied consumption information were extracted precisely according to measured data. The solar thermal system with cost-optimal component sizes was able to save district heat energy consumption up 24% to 34% and made 4 €/m^2 to 23 €/m^2 in financial profit.     

Solar district heating and cooling: A review

Both district heating and solar collector systems have been known and implemented for many years. However, the combination of the two, with solar collectors supplying heat to the district heating network, is relatively new, and no comprehensive review of scientific publications on this topic could be found. Thus, this paper summarizes the literature available on solar district heating and presents the state of the art and real experiences in this field. Given the lack of a generally accepted convention on the classification of solar district heating systems, this paper distinguishes centralized and decentralized solar district heating as well as block heating. For the different technologies, the paper describes commonly adopted control strategies, system configurations, types of installation, and integration. Real‐world examples are also given to provide a more detailed insight into how solar thermal technology can be integrated with district heating. Solar thermal technology combined with thermally driven chillers to provide cooling for cooling networks is also included in this paper. In order for a technology to spread successfully, not only technical but also economic issues need to be tackled. Hence, the paper identifies and describes different types of ownership and financing schemes currently used in this field.     

Theoretical variations of the thermal performance of different solar collectors and solar combi systems as function of the varying yearly weather conditions in Denmark

The thermal performances of solar collectors and solar combi systems with different solar fractions are studied under the influence of the Danish design reference year, DRY data file, and measured weather data from a solar radiation measurement station situated at the Technical University of Denmark in Kgs. Lyngby. The data from DRY data file are used for any location in Denmark. The thermal performances of the solar heating systems are calculated by means of validated computer models. The measured yearly solar radiation varies by approximately 23% in the period from 1990 until 2002, and the investigations show that it is not possible to predict the yearly solar radiation on a tilted surface based on the yearly global radiation.The annual thermal performance of solar combi systems cannot with reasonable approximation be fitted to a linear function of the annual total radiation on the solar collector or the annual global radiation. Solar combi systems with high efficient solar collectors are more influenced by weather variations from one year to another than systems with low efficient solar collectors.The annual thermal performance of solar collectors cannot be predicted from the global radiation, but both the annual thermal performance and the annual utilized solar energy can with a reasonable approximation be fitted to a linear function of the yearly solar radiation on the collector for both flat plate and evacuated tubular solar collectors. Also evacuated tubular solar collectors utilize less sunny years with large parts of diffuse radiation relatively better than flat plate collectors.     

A comparison of daily solar radiation estimates for the Northeastern United States using the Northeast Regional Climate Center and National Renewable Energy Laboratory models

Observed solar radiation data at three sites in the northeastern United States are compared with values estimated for nearby airport locations using the National Renewable Energy Laboratory (NREL) and Northeast Regional Climate Center (NRCC) models. A tendency toward considerable overestimation of relatively low values of observed solar radiation is evident in the NREL model. This bias is apparently regardless of season. A similar bias is not detected in the NRCC model. For moderate to high values of solar radiation both models produce estimates with similar accuracy for most practical applications. However, these models both tend to underestimate observed solar radiation on days when near maximum possible radiation levels are received. The tendency for the NREL model to overestimate low solar radiation values appears to be linked to the use of total sky cover, rather than the combination of cloud coverage and cloud base height information. Although total sky coverage data may be superior for estimates of moderate to high daily solar radiation values, it appears that information regarding the height of low overcast layers and the presence of obstructions to visibility, such as fog or haze, is required to accurately estimate low daily solar radiation totals.     

Investigation of the effect of weather conditions on solar radiation in Brunei Darussalam

The amount of solar radiation received on the earth's surface is known to be highly influenced by the weather conditions and the geography of a particular area. This paper presents some results of an investigation that was carried out to find the effects of weather patterns on the solar radiation in Brunei Darussalam, a small country that experiences equatorial climate due to its geographical location. Weather data were collected at a suitable location in the University Brunei Darussalam (UBD) and were compared with the available data provided by the Brunei Darussalam Meteorological Services (BDMS). It has been found that the solar radiation is directly proportional to the atmospheric temperature while it is inversely proportional to the relative humidity. It has also been found that wind speed has little influence on solar radiation. Functional relationships between the solar radiation and the atmospheric temperature, and between the solar radiation and the relative humidity have also been developed from the BDMS weather data. Finally, an artificial neural network (ANN) model has been developed for training and testing the solar radiation data with the inputs of temperature and relative humidity, and a coefficient of determination of around 99% was achieved. This set of data containing all the aforementioned results may serve as a guideline on the solar radiation pattern in the geographical areas around the equator.     

A model for calculating hourly global solar radiation from satellite data in the tropics

A model for calculating global solar radiation from geostationary satellite data is presented. The model is designed to calculate the monthly average hourly global radiation in the tropics with high aerosol load. This model represents a physical relation between the earth-atmospheric albedo derived from GMS5 satellite data and the absorption and scattering coefficients of various atmospheric constituents. The absorption of solar radiation by water vapour which is important for the tropics, was calculated from ambient temperature and relative humidity. The relationship between the visibility and solar radiation depletion due to aerosols was developed for a high aerosol load environment. This relationship was used to calculate solar radiation depletion by aerosols in the model. The total column ozone from TOMS/EP satellite was employed for the determination of solar radiation absorbed by ozone. Solar radiation from four pyranometer stations was used to formulate the relationship between the satellite band earth-atmospheric albedo and broadband earth-atmospheric albedo required by the model. To test its performance, the model was used to compute the monthly average hourly global radiation at 25 solar radiation monitoring stations in tropical areas in Thailand. It was found that the values of monthly average of hourly global radiations calculated from the model were in good agreement with those obtained from the measurements, with the root mean square difference of 10%. After the validation the model was employed to generate hourly solar radiation maps of Thailand. These maps reveal the diurnal and season variation of solar radiation over the country.     

The assessment of different models to predict the global solar radiation on a surface tilted to the south

Global and diffuse solar radiation intensities are, in general, measured on horizontal surfaces, whereas stationary solar conversion systems (both flat plate solar collector and PV) are tilted towards the sun in order to maximize the amount of solar radiation incident on the collector surface. Consequently, the solar radiation incident on a tilted surface must be determined by converting the solar radiation intensities measured on a horizontal surface to that incident on the tilted surface of interest. There exist a large number of models designed to perform such a conversion. 11 such models have been tested utilizing data measured in Beer Sheva, Israel. The data consist of hourly global and diffuse solar radiation on a horizontal surface, normal incidence beam and global radiation on a south-oriented surface tilted at 40°. The horizontal diffuse radiation measured using a shadow ring was corrected using four different correction models. This resulted in 44 model permutations. The individual model performance is assessed by an inter-comparison between the calculated and measured solar global radiation on the south-oriented surface tilted at 40° using both graphical and statistical methods. The relative performance of the different models under different sky conditions has been studied. Different grading systems have been applied in an attempt to score the relative performance of the models.