Experimental analysis of heat and mass transfer phenomena in a direct contact evaporative cooling tower
Experimental analysis of heat and mass transfer phenomena in a direct contact evaporative cooling tower
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DOI：
10.1016/j.enconman.2009.02.002
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发表时间：
2009-06-01
影响因子：
10.4
通讯作者：
Kaabi, A.
中科院分区：
文献类型：
--
作者：
Lemouari, M.;Boumaza, M.;Kaabi, A.
本文对填料冷却塔内水与空气直接接触时的传热传质现象进行了实验分析。塔上布满了“VGA。“（垂直格栅装置）型填料。填料高0.42 m，由四（04）块锯齿形镀锌板组成，其间平行放置三（03）块金属垂直网格，横截面试验面积为0.15 m x 0.148 m。本研究探讨了空气和水的流量对整体的热质传递系数以及水的蒸发速率到空气流中，对于不同的入口水温度的影响。在空气/水期间观察到两种操作状态;塔内接触，即薄膜状态（PR）和气泡和分散状态（BDR）。这两种状态可以确定促进这种装置中的传热和传质现象的最佳方式。BDR制度似乎比Pellicular制度更有效，因为它能够实现相对较高的整体传热和传质系数值以及较大的水蒸发速率。所得结果与文献中其它类型填料的结果进行了比较，结果表明该填料具有良好的传热传质特性。(C)2009爱思唯尔有限公司保留所有权利。
This paper deals with an experimental analysis of simultaneous heat and mass transfer phenomena between water and air by direct contact in a packed cooling tower. The tower is filled with a "VGA." (Vertical Grid Apparatus) type packing. The packing is 0.42 m high and consists of four (04) galvanised sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross-sectional test area of 0.15 m x 0.148 m. This study investigates the effect of the air and water flow rates on the global heat and mass transfer coefficient as well as the evaporation rate of water into the air stream, for different inlet water temperatures. Two operating regimes were observed during the air/water ;contact inside the tower, a Pellicular Regime (PR) and a Bubble and Dispersion Regime (BDR). These two regimes can determine the best way to promote the heat and mass transfer phenomena in such device. The BDR regime seems to be more efficient than the Pellicular Regime, as it enables to achieve relatively higher values of the global heat and mass transfer coefficient and larger water evaporation rates. The comparison between the obtained results and some of those available in the literature for other types of packing indicates that this type possesses good heat and mass transfer characteristics. (C) 2009 Elsevier Ltd. All rights reserved.