Cooling tower irrigator layout with allowances for non-uniformity of the airflow velocity field

Abstract

This article covers the results of analysis of aerodynamic processes in the cooling tower irrigator and provides the approaches to optimal layout of preformed packing blocks (of the irrigator) developed based on these results. The analysis of the airflow velocity field in the cooling towers shows that the irrigation space can be broken down into the following zones: the peripheral zone of the cooling tower near the airblast windows, the zone near the cooling tower center, and the intermediate zone. Furthermore, the highest level of nonuniformity of the airflow velocity field in cooling towers is in the zone adjoining the tower's airblast windows. The proposed concept of the cooling tower irrigator's layout is made with allowances for the airflow velocity field characteristics in the cross-section of the irrigation space of the cooling tower. Based on this concept, we suggest that higher irrigator blocks should be placed in the zone of increased airflow consumption, which provides the possibility to enhance the hydraulic resistance and, respectively, decrease the gas flow velocity as well as to boost the efficiency of chilling the circulating water in the cooling tower. For this purpose, additional irrigator blocks can be of the same design as the main irrigator. As an option, it is possible to use blocks of the geometry and design other than the main irrigator block in the cooling tower. Advancement in the power generation industry, including the nuclear power industry, promotes the studies for improvement of cooling towers in recirculated water systems. The analysis of today's results of experimental and theoretical studies [1-4] allows us to conclude that a promising method of increasing the efficiency of cooling recirculated water could be an optimal layout of preformed packing blocks in the irrigation space of cooling towers, taking into account the peculiarities of real aerodynamic environment, in particular large-scale nonuniformities of the airflow velocity fields that form near the airblast windows.Work [4], completed in Vedeneev VNIIG, contains data showing that the nonuniformity of velocity fields of airflow in the cooling tower leads to nonuniform heating of air masses from the center of the cooling tower to its peripheral zone (airblast windows) and to a sharp-30 to 40%-decrease in efficiency of recirculated water cooling when compared to design data for generic cooling towers with a film-type packing.The suggested concept of layout of various types of packing blocks having different geometry parameters allows using a particular law in the cooling tower cross-section to program a more uniform velocity distribution and, thus, increasing the efficiency of the evaporative cooling process. AIRFLOW NONUNIFORMITIES IN COOLING TOWERSThe existence of large-scale nonuniformities of airflow in the cross-section of the irrigation space in cooling towers is discussed in [2, 3, 5-9]. As a result of the studies on the model of a cooling tower with the irrigation area of 6500 m 2 , done in a scale of 1 : 65, we prov...

Investigation into Heterogeneity of Cooling Temperature in Evaporative Cooling Towers

“…Hence, the researchers conclude that the draft in the cooling tower is also non-uniform, and hence the cooling efficiency of the unit decreases. Based on the research results, researchers have proposed to lay out the filler in such a way to reduce the non-uniformities [10].…”