中国西北地区环日辐射及其对太阳能热发电影响的数值模拟研究

NUMERICAL SIMULATION OF CIRCUMSOLAR NORMAL IRRADIANCE AND ITS EFFECT ON SOLAR THERMAL POWER GENERATION IN NORTHWESTERN CHINA

基于中国西北地区地面能见度观测数据及ERA5再分析数据,利用SMARTS模式模拟西北地区法向直接辐射(DNI),经过计算得到西北地区环日辐射(CSNI)和环日辐射比(CSR),并分析影响CSR的气象要素,结果发现:1)在2.5°半开敞角下,中国西北地区多年平均CSNI曝辐量处在21~33 kWh/m^(2)之间,最大值位于昆仑山及其以北地区,新疆北部、甘肃北部以及内蒙古西北部地区为全区域CSNI的低值区。春季和夏季CSNI曝辐量相对较高,秋季和冬季相对较低;2)中国西北地区多年平均CSR处于0.8%~1.8%之间,存在2个大值中心,一个位于昆仑山及以北的塔里木盆地,另一个位于西北地区东南部,CSR的低值区域主要位于高原地区,普遍处在1%以下。春季、夏季和秋季与年平均CSR空间分布相近,冬季的CSR则存在明显不同,能见度是影响其空间分布的重要因素。3)CSR的量值大小和空间分布反映了环日辐射对太阳能热发电的影响程度,在电站的资源评价、工程设计和发电量测算中,应充分考虑环日辐射的影响。

Based on the surface observed visibility data and reanalysis data of ERA5 in northwestern China,the direct normal irradiance(DNI)in northwestern China is simulated by SMARTS model.Through calculation,we get the circumsolar normal irradiance(CSNI)and circumsolar ratio(CSR)in northwestern China,and the meteorological factors that affect CSR are analyzed.The results show that:1)Under the 2.5°semi open angle,the radiance exposures of multiannual average CSNI in northwestern China are between 21 and 33 kWh/m^(2).The maximum values are located at Kunlun Mountain and areas north of it,while northern Xinjiang,northern Gansu and northwestern Inner Mongolia are low value areas of CSNI in the whole region.In spring and summer,the radiance exposure of CSNI is relatively high,while in autumn and winter,it is relatively low.2)The multiannual average CSR values in northwestern China are between 0.8%and 1.8%,and there are two big value centers,one is located at the Tarim Basin north of Kunlun Mountain,and the other is located at the southeastern part of northwestern China,and the low value areas of CSR are mainly located at plateau area,generally below 1%.The spatial distribution of CSR are similar in spring,summer,autumn,and annual average scale,but CSR in winter is significantly different because of the important factor visibility.3)The magnitude and spatial distribution of CSR reflect the influence extent of solar thermal power generation caused by CSNI.In the resource evaluation,engineering design and power generation calculation,the influence of CSNI should be fully considered.