Wind tunnel test on the flow resistance of U-type water collecting devices for natural draft wet cooling towers

Crosswind influence on cooling capacity in different zones for high level water collecting wet cooling towers based on field test

The efficiency of high-level water collecting cooling tower with the installation of cross wall affect by the evolution of aerodynamic field

Numerical study regarding cooling capacity for non-equidistant fillings in large-scale wet cooling towers

Critical guidelines to cope with the adverse impacts of the inner peripheral vortex in the high-level water collecting natural draft wet cooling tower

A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Considering the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 m), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics are crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.

Contrastive analysis of cooling performance between a high-level water collecting cooling tower and a typical cooling tower

The invention discloses a counter-flow type natural ventilation cooling tower air inlet guide and anti-freezing wind deflection integrated device. The device is uniformly arranged at the triangular air inlet formed between two adjacent herringbone supports outside the cooling tower air inlet circumference; the key improvements of the device refer to the arrangement distance of the air inlet guide plates, the guide plate main body and wind deflection blades which are movably connected with the guide plate main body. Every two air inlet guide plates are arranged in a circular distance of 5-50m, preferably 6-12m; 2-4 wind deflection blades which are vertically and sequentially arranged are connected to the side surface of the guide plate main body; and the wind deflection blades can be arranged on the single side or both sides of the guide plate main body. According to the device disclosed by the invention, the air inlet uniformity of the cooling tower can be obviously improved, the cooling performance of the cooling tower is improved, the temperature of a circulating water outlet tower is reduced, and the operating economy of the unit is improved; and moreover, the cooling tower can be prevented from being frozen, and the traditional wind deflector is replaced.

Miao Wang

Papers

Contrastive analysis of cooling performance between a high-level water collecting cooling tower and a typical cooling tower

Counter-flow type natural ventilation cooling tower air inlet guide and anti-freezing wind deflection integrated device