ARTICLE:

• HEAT AND MASS TRANSFER PERFORMANCES OF CLOSED-TYPE COOLING TOWERS  download article

Jiin-Yuh Jang
Department of Mechanical Engineering, National Cheng-Kung University, Tainan, Taiwan

Zen-Gee Wang
Department of Mechanical Engineering, National Cheng-Kung University, Tainan, Taiwan 701

ABSTRACT

The purpose of this paper is to numerically and experimentally analyze the heat and mass transfer performances in a closed-type cooling tower with bare tube bank for both cases of air/spray-water counter and parallel flows. The results indicate that the heat transfer rate in wet coils is eight times that of the dry coils. The sensible heats carried by the spray water and cooling air are 40 % ∼ 60 % and 5 %, respectively. Although the evaporation rate of the spray liquid film is only about 2 % ∼ 3 % , the heat dissipated by the evaporative liquid film is up to 35 % ∼ 55 %. The overall heat transfer coefficient for air/spray- water counterflow is 10 % higher than for air/spray-water parallel flow.

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269-276 pages

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