International Journal of Thermal Sciences 47 (2008) 935–941 www.elsevier.com/locate/ijts Experimental research of heat transfer performance on natural draft counter ﬂow wet cooling tower under cross-wind conditions Ming Gao ∗ , Feng-zhong Sun, Kai Wang, Yue-tao Shi, Yuan-bin Zhao School of Energy and Power Engineering, Shandong University, Jinan 250061, China Received 28 April 2007; received in revised form 21 July 2007; accepted 23 July 2007 Available online 30 August 2007 Abstract The experiment in terms of heat transfer performance of natural draft counter-ﬂow wet cooling is done for cases with cross-wind conditions. The variation of circulating-water temperature difference (T ) and cooling coefﬁcient of efﬁciency (η) with cross-wind velocity, circulating water inlet temperature and ﬂow rate, are shown under cross-wind conditions, compared with cases without wind. According to experimental results, it is found that T and η are inﬂuenced by the cross-wind, and T and η can decrease mostly by 6% and 5%, respectively. When the critical Fr l number is less than 0.174, T and η decrease with increasing cross-wind velocity, however, when it is greater than 0.174, T and η increase with increasing cross-wind velocity. In addition, based on the data regression analysis, the correlation between T , η and parameters, such as circulating-water inlet temperature and ﬂow rate, is derived for cases with windless conditions. Furthermore, its correspondence is given out for cases with cross-wind conditions.  2007 Elsevier Masson SAS. All rights reserved. Keywords: Cross wind; Cooling tower; Heat transfer performance; Coefﬁcient of efﬁciency; Temperature difference; Correlative equations 1. Introduction Cooling towers of interest play an important role in the cool- end system of power plant, and its cooling capacity can affect the total power generation capacity directly. In reality, there are various types of cooling towers, and among of them, nat- ural draft counter-ﬂow wet cooling towers are utilized widely in large-scale power plants. As Ding pointed out in [1], the cooling efﬁcient is highly sensitive to environmental conditions, partic- ularly for most cases under the cross-wind conditions that may reduce dry-cooling towers up to 40% of the total power gen- eration capacity. However, to my best knowledge, for the con- ventional design of cooling towers, the impact of cross-wind, which actually exists in most cases, has not been paid more at- tention. Therefore, it is really crucial to delve the inﬂuence of cross-wind regarding the heat transfer performance of cooling towers. * Corresponding author. E-mail address: gaomingjn@mail.sdu.edu.cn (M. Gao). Many literatures which are related to heat transfer perfor- mance of cooling towers under windless conditions, can be found [2–6], and works on heat transfer performance of cool- ing towers under cross-wind conditions are also done by some researchers [7–12]. In addition, Q. Wei [13], M.D. Su [14], Du Preez, Kroger [15,16] and Z. Zhai [17] et al. have researched the effect of cross-wind on heat transfer performance of dry- cooling towers, to some extent. D. Derksen and T. Bender [18– 20] studied the inﬂuence of cross-wind on the heat transfer performance of wet cooling towers by means of wind tunnel ex- periments and numerical calculation. However, these previous works mainly focused on the dry-cooling towers. Therefore, it is necessary to extend to wet-cooling towers from the practical viewpoint. Even though some researches have been done re- garding wet-cooling towers by D. Derksen and T. Bender, these works do not make an agreement with the geometry similarity and dynamic similarity, and so their experimental and calcula- tion results should be accepted doubtfully. Moreover, there are no works to put forward the quantitative relation between wind velocity and cooling efﬁciency in present researches, which is one of the motivations of this paper. 1290-0729/$ – see front matter  2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.ijthermalsci.2007.07.010