Page 86 - Design of Solar Thermal Power Plants

2.5 DISTRIBUTION OF THE SOLAR RESOURCE IN SEVERAL 75

Mountain, and is in the center of the Turpan Basin. With an eastewest
width of 90 km and northesouth length of 262 km, the terrain is higher in
the south and north than it is in the middle. Turpan’s geographic co-
o
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o
ordinates are 88 29 28 e89 54 33 00 E and 42 15 10 e43 35 N with
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0
0
0
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elevation in the range of 154 to 4000 m and total land area of 13,589 km .
The area is adjacent to Hami in the east and adjoins Hejing, Heshuo, Weili,
and Ruoqiang Counties of the Bayingolin Mongol Autonomous Prefec-
ture in the west and south; it is also separated by Tian Shan Mountain in
the north and connected to Urumqi City as well as Qitai, Jimsar, and Mori
Counties in the Changji Hui Autonomous Prefecture. The prefectural
administrative office of the Turpan area is located in Turpan city, 183 km
from Urumqi City, the capital of the Xinjiang Uygur Autonomous Region,
which governs Turpan City, Shanshan County, and Toksun County. The
area has sufficient sunshine, abundant thermal energy, a long frost-free
period, great daily temperature variation, low precipitation, and inten-
sive evaporation; it features a typical continental warm-temperate-desert
climate [10].
2.5.5.1 Weather Conditions in Turpan
The Turpan Basin has a typical continental warm temperate zone arid
desert climate. As Turpan is located in the basin and surrounded by high
mountains,its temperature rises fast and radiates slowly, which has resulted
in the formation of five major characteristics for the area, namely long
sunshine duration, high temperature, large temperature differences during
day and night, low precipitation, and strong wind. The area has sufficient
sunshine and abundant thermal energy, but it also features extreme aridity
and dry, hot weather; it has thus been given the name “Fire Continent.” As
the atmospheric pressure in the basin is low, airflow can be attracted; added
to the scarce precipitation and frequent strong wind, it has become a
well-known “Wind Storehouse” in China. More than 100 days of the year
have an force 8 (fresh gale) or greater wind, sometimes exceeding force 12.
The annual mean temperature is 13.5 C with more than 100 days of the

year having a temperature over 35 C and 28 days having an average

temperature over 40 C. During JuneeAugust, the mean maximum tem-

perature is always above 38 C; at noon, the sand surface temperature can

reach 82.3 C. During summer, the mean temperature is around 30 C; the
extreme maximum temperature in summer is 49.6 C, and the ground

surface temperature is over 70 C most of the time. The extreme minimum

temperature in winter is 28.7 C; both daily and annual temperature
differences are great, effective accumulated temperature over 10 C for the

year exceeds 5300 C, and the frost-free period lasts 224 days. Due to the
hot and dry weather, Turpan is arid and scarcely experiences rain, with
annual mean precipitation of merely 16.7 mm but evaporation as high as
3000 mm (refer to Table 2.10).