Numerical Simulation on Influence of Windshield Boards Installed at a Regular Longitudinal Spacing on Wet Cooling Tower Thermal Performance

doi:10.3969/j.issn.1000-7229.2016.01.018

Abstract

Abstract:

In the north of China, water freezing phenomenon occurs easily during the operation of natural draft counter-flow wet cooling towers in winter. It is necessary to install windshield boards at the air inlet of cooling tower. During the actual operation of power plants, it often appears the situation that the number of windshield boards is over large in order to avoid water freezing in cooling tower, which decreases the economics of unit. In order to improve the feasibility of installing windshield boards to avoid water freezing, we propose a new installation method of spaced longitudinal windshield board, and establish a heat and mass transfer model of cooling tower in a 600 MW unit. With using Fluent, we simulate and analyze the influence of the installing area of windshield boards on the minimum water droplet temperature on different characteristic planes after windshield board installation, and find the optimal installing area of windshield boards at different ambient temperatures. The results indicate that, the lowest water droplet temperature in the tower increase with the installing area increase of windshield boards；when the ambient temperatures are 264.15 K, 261.15 K and 258.15 K respectively；the cooling tower can avoid water freezing with windshield boards installed at a regular longitudinal spacing at the first layer with 45 longitudinal air inlets, the first two layers with 72 longitudinal air inlets and the first three layers with 90 longitudinal air inlets respectively, the corresponding optimal installing area of windshield boards are 848.95 m², 1578.79 m² and 1864.16 m²respectively.

Key words: cooling tower, numerical simulation, thermodynamic performance, anti-freezing, installing area of windshield boards

CLC Number:

TM 621.7

LI Yonghua, LIU Juan,TANG Jinming. Numerical Simulation on Influence of Windshield Boards Installed at a Regular Longitudinal Spacing on Wet Cooling Tower Thermal Performance[J]. Electric Power Construction, 2016, 37(1): 119-124.

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