The Indirect Air Cooling Towers Optimization Of Shape Under Crosswind Condition

The heat transfer characteristics and flow characteristics of air cooling towers under cross-wind conditions are of great significance in practical projects(heat transfer characteristics are the main process indicators of most air cooling towers,and the flue gas flow characteristics of flue gas exhaust towers for desulfurization processes are also extremely important.Large research value),the shape of tower has a more significant impact on both.In recent years,the development of new skin-type external towers has been rapid.Due to the great differences in tower wall materials and shapes from traditional concrete towers,their heat transfer characteristics and flow characteristics have not been fully and accurately studied.This study summarized the differences between the new tower and the traditional concrete tower(such as tower wall materials,tower shape,etc.)through preliminary research.Based on the actual engineering situation and relevant specifications,the traditional research methods have been improved.According to the size of the actual engineering tower,combined with specifications,12 shapes of tower are designed with a total of two schemes,and the new tower under crosswind is numerically calculated by CFD software.The numerical simulation results were compared with the wind pressure curve of the throat of the hyperbolic tower to verify the accuracy of the flow characteristics.By numerically simulating towers with different column height ratios under five wind speed conditions,it was found that the tower with a column height ratio of 0.4 had better overall performance under crosswinds,and the heat exchange volume and outlet flow rate showed a first decrease Increasing trend after small with the rise of wind speed.By introducing Archimedes number and Froude number as the analysis criteria,it was found that the tower wall structure at the outlet,the vertical height range is 20 m,can affect the flow characteristics of the tower.The second scheme takes the conclusion of the first scheme as the starting point,combined with the research results of the flared tower,and changes the 20 m height of the outlet wall of the straight cylinder into a 9.6 ° flared shape.The numerical simulation results show that the heat transfer characteristics of the straight cylinder outlet tower at the same volume are slightly inferior to the flared tower,and the difference in total heat exchange between the two does not exceed 2% at different wind speeds.Further analysis of the cloud image of Option 2 reveals that the flared tower has an airflow backflow phenomenon at the leeward side of the tower mouth at a high wind speed of 20 m / s,while the straight tower tower is prone to backflow at low wind speed and is on the windward side.The interference intensity of the flared tower to the flow field around the tower is strong and of small range,while the impact intensity of the straight outlet tower to the flow field is weak but has a wide range.