太阳辐射计算讲座第二讲相对于斜面的太阳位置计算

在第一讲中,主要介绍平面上太阳位置的计算。由于大多数太阳能装置都是倾斜放置的,故本讲着重讨论这种情况下的太阳位置计算问题,具体又可区分为朝向赤道方向和任意朝向两种情况。１朝向赤道（即正南）方向假设北纬５０°某地有一朝向赤道呈３０°倾斜放置的太阳集热器,其相对于太阳光线的入射状况与北纬２０°地区水平放置的集热器的入射状况相当,这一点从图１中可以清楚地看到。推而广之,也可以说在纬度为φ的某地朝向赤道方向是β倾斜放置的太阳能装置,其相对于太阳光线的入射状况与纬度为φ－β地区水平放置的装置的入射状况一致…     

不同朝向太阳辐射测试及应用对策分析

在太阳能建筑设计、建筑能耗模拟时,逐时的太阳辐射气象数据是最重要的基本参数。我国严寒和寒冷地区居住建筑节能设计标准规定,采暖期的计算需要准确的不同朝向的太阳辐射照度,但是,我国目前尚未广泛地进行不同朝向的太阳辐射观测工作。文章制定了一套不同朝向的太阳辐射测量方案,通过对数据进行处理分析,得出不同朝向的太阳辐射变化规律,验证了方案的可行性。基于分朝向的太阳辐射变化,提出了相应的建筑设计策略,为建筑节能提供更准确的理论依据。     

倾斜面太阳辐射量计算方法研究

倾斜面辐射数据是保证准确设计太阳能利用系统的基础数据,一般由水平面数据计算得出。针对现有计算模型误差较大的现状考虑,试验测试了水平面及不同倾角斜面上的太阳辐射数据,提出了针对直接辐射转换系数的修正方法;通过倾斜面散射辐射数据的计算和分析,在散射辐射模型的基础上,建立耦合计算模型。试验与模型计算结果表明,散射辐射的各向同性受天气工况的影响,耦合模型具有较高的准确性,计算值与实测值的偏差可控制在5.3%以内。     

北京地区的太阳辐射分析

根据北京市1958年-2000年的太阳辐射和日照时间的日值数据资料,对北京市的年太阳辐射历年平均 值进行了计算,分析了北京市太阳辐射量的长期变化;研究了太阳总辐射和日照时间之间的关系以及散射辐射 与总辐射之间的关系,分别得到了估算太阳总辐射和散射辐射的经验公式,研究中对所得到的经验公式进行了 误差统计,结果表明能满足工程应用的要求。     

用非参数统计法评估太阳辐射模型的性能优劣

非参数统计法是一种理想的评估太阳辐射模型性能优劣的方法。     

太阳辐射测量国际标尺传递的试验研究

本文报道了采用准直光阑传递太阳辐射测量标尺的理论及实验结果。理论计算和实验表明,可以使用一个通用化的准直光阑把太阳辐射测量标尺传递到各种型号的总日射表,并且该方法的校准精确度比传统的遮光盘法高一个数量级。     

太阳模拟器在太阳能光热领域的测试研究

太阳模拟器能够提供长期稳定的实验条件,为产品在开发过程中提供稳定的实验平台,缩短产品开发周期。通过测试发现,太阳模拟器对真空管型集热器的测试与室外跟踪台基本一致。     

用于移动式太阳辐射计的高精度太阳跟踪方法

叙述了根据Reda和Andreas太阳跟踪的高精度算法,利用GPS进行实地测量,对适用于移动式太阳辐射计的高精度太阳跟踪软件的开发设计以及以合肥市某处为例进行太阳位置和日出日落时间的应用性计算和验证的结果。     

计算水平地面月平均日总太阳辐射量的日照类模型

本文评述了基于日照对数，用于计算水平地面月平均总太阳辐射量的三类日照类模型，并对其进行了比较。     

基于MATLAB的太阳辐射资源计算

运用MATLAB软件编程,计算了太阳辐射穿过大气层后到达地面的强度,综合考虑海拔高度、大气透明度系数的影响,建立了太阳辐射强度数学计算模型。模型计算得到的理论数据与用MS4型太阳能资源测试仪测试获得的数据进行了对比分析,相对误差在0.002%～9.981%之间,验证了计算模型的合理性。     

太阳辐射计算讲座问题解答

自从本刊２０００年第４期的两次问题解答发表以后,陆续收到读者提的一些问题,本文就此继续进行解答。计算太阳赤纬、时差和日地距离订正系数的程序,地理经度的订正如何具体操作？这个问题提得很好,在讲座中未及详谈。这里的地经度订正,实际上仍是将当地时间转换成格林尼治间所必须的步骤之一。在问题解答之一中,我们曾指过,计算这些参数都是以格林尼治时间０点时刻为准。即使对格林尼治当地来说,也不可能列表给出任意刻的这些参数来。任意时刻的具体参数只能借助于差。对于其它地点来说,上述天文参数不仅会因地点地理经度的不同有…     

太阳辐射计算讲座第五讲地表斜面上辐射量的计算

在太阳能利用工作中 ,太阳辐射计算十分重要。为了帮助读者掌握太阳辐射计算方法 ,我们请长期从事太阳辐射研究工作的中国气象科学研究院王炳忠研究员编写了《太阳辐射计算讲座》 ,供大家学习、参考。—编者—     

Measurements of solar radiation and illuminance on vertical surfaces and daylighting implications

There is a growing concern about the rapid development of infrastructure and building projects and their likely impacts on the environment. Particular concerns have been raised about office building developments and energy consumption issues. In recent years, there has been increasing interest in using daylight to save energy in buildings. Lighting control integrated with daylighting is recognised as an important and useful strategy in terms of energy-efficient building design. It is believed that proper daylighting schemes can help reduce the electrical demand and contribute to achieving environmentally sustainable building developments. This paper presents a simple method for estimating the likely energy savings in electric lighting due to daylighting and the possible cooling penalty. Vertical solar radiation and illuminance data measurements are described. Cumulative frequency distributions of daylight availability are reported. The likely energy savings in office buildings are determined based on on–off and top-up controls, and the energy and environmental implications are discussed.     

不同安装方式太阳电池板倾斜面上辐射量分析计算

根据红寺堡2009年7～10月观测数据,分析计算在不同倾角和最佳倾角时,固定式、单轴跟踪及双轴跟踪三种安装方式下的太阳辐射量。     

Modeling and calculation of energy characteristics of the solar radiation linear concentrators

An algorithm and program are developed for calculating and studying the characteristics of the concentration of linear cylindrical parabolic concentrators as a function of the time of day. The possibility of generalizing the concentration and flow curves at the receiver as a function of time is demonstrated.     

On the calculation of solar radiation in hazy atmospheres and on turbidity in Ibadan

A previous model is examined in greater detail for the harmattan haze periods (November to January) of 1975–1980 at Ibadan, when the atmosphere is often heavily overcast with dust. It is shown that for air mass (m) and turbidity (β) product values of mβ > 4.05 the scattering transmittance τ_scat, for the instantaneous direct solar radiation becomes negative, while for mβ < 0.22 τ_scat changes too rapidly, thus failing to give acceptable values of irradiation for such periods. This problem is overcome by employing the limits 0.22 mβ 3.07 in the calculations, which corresponds to β of 0.40 and 0.22 for “very hazy” and “hazy-hot clear” atmospheres, respectively. The resulting daily and monthly average total insolation are mainly within ± 15% and ± 10%, respectively, of the experimental data provided by the International Institute of Tropical Agriculture (I.I.T.A.), Ibadan.The variation of the turbidity in the city is also studied for all days of the six years. Daily average values 0.10 β 0.175 occur on about 60% of the days, while “clear” (β < 0.125) and “very hazy” (β 0.40) weather days have about 16% and 12.37%, respectively. Some 74.4% of the very hazy days fall within the harmattan period during which the monthly average turbidity is often higher than 0.35.     

Theoretical aspects for optimization of solar radiation concentrators with plane facets

The experience of the 25 years operation of two concentrators of solar energy (CSE) of 2.8 and 5.0 m diameter manufactured by gluing plane facets of thin glass onto metal radio antennae convincingly demonstrates their technical and economic efficiency. Besides (or in addition to) simplicity of manufacturing and the possibility to achieve temperatures up to 2000 K and more, there is one more undoubted advantage of such concentrators: it is possible to get a focal spot with rather uniform distribution of the irradiance. The problem of determining the plane facets’ optimum configuration and the structure of their arrangement on the CSE surface which guarantees forming a focal spot of the given dimension is solved by this work. Perfect geometric configuration of the facets and paraboloid is assumed. The working zone of the facets reflecting the incident solar radiation at the circular focal spot is approximately an ellipse. Trapezoid is an optimum configuration for the facets taking up a minimum area and ensuring the maximum use of CSE surface. A system of equations is obtained for calculation of a CSE structure with annular packing of the facets. The results of calculations for the 1.8 m and 15 m diameter concentrators are presented.     

Test reference year generation from meteorological and simulated solar radiation data

In this paper, a new method for generating test reference year (TRY) from the measured meteorological variables is proposed. Hourly recorded data of air temperature, relative humidity and wind velocity for two stations, Valladolid and Madrid (Spain) were selected to develop the method and a TRY was obtained. Monthly average solar radiation values were calculated taking into account the temperature and solar radiation correlations. Four different methodologies were used to evaluate hourly global solar radiation from hourly weather data of temperature and, as a consequence, four different TRYs with common data sets of temperature, relative humidity and wind velocity were generated for Valladolid and Madrid (Spain) stations. In order to evaluate the four different methodologies, TRYs data were compared with long-term measured data series using statistical estimators such as average, standard deviation, root mean square error (rmse) and mean bias error (mbe). Festa and Ratto and the TAG model, from Aguiar and Collares-Pereira, respectively, turned out to be the best methods for generating hourly solar irradiation data. The best performance was shown by the TRY0 year which was based on the solar radiation models mentioned above. The results show that the best reference year for each site varies with the season and the characteristics of the station.     

呼和浩特地区太阳辐射模型分析

依据太阳辐射相关理论,针对多种太阳辐射计算模型,运用MATLAB计算平台,分析计算了不同工况下,水平面上和任意朝向倾斜面上的太阳辐射量,并与呼和浩特地区太阳辐射实测值进行了比较.HOTTEL模型的计算值与实测值符合较好,可预测计算本地区太阳辐射量,并能为相近地区太阳辐射量计算提供参考.