Analysis Of Flow Field And Reflux Rate Of Mechanical Draft Cooling Tower

The research object of this thesis is mechanical draft cooling tower.Cooling tower is a kind of circulating water and atmosphere to exchange heat and mass to achieve the temperature of water flow down,is the most widely used,the most economical cooling equipment,in the industrial circulating water system occupies an increasingly important position.In the actual use of cooling tower,different water density will cause the change of flow field in the tower,and the cooling efficiency will also be affected.In addition,mechanical draft cooling tower in most cases is multi-cooling tower group arrangement,tower and tower will produce mutual interference,especially in the case of strong wind such a phenomenon.Therefore,the reflux and interference between single and double towers should also be studied.The main contents of the thesis include:(1)The finite element analysis of the tower structure of the cooling tower is carried out,includes static analysis and modal analysis of tower structure.The total deformation,strain distribution and stress distribution of the tower structure under the action of various forces are obtained.Finally,the performance of the tower structure is judged to meet the needs according to the results.(2)The heat and mass transfer process of the cooling tower in different water-leaching density was numerically simulated.The air is continuously subjected to phase treatment,the water is added into the calculation in the state of the discrete phase,the initial state of the water drops is added on the spraying surface.A porous medium model is used in the filler region.The flow of air and water droplets in the packing area is simulated by a drop-like flow in place of the film-like flow and by adding a resistance.(3)The flow of the air in the tower outlet of the cooling tower at the side wind is simulated,and the change of the return flow rate at different wind speeds is calculated.Pre-process the model,divide the unstructured mesh,and then simulate the following parts:using Fluent to calculate the change of the return flow rate of a single cooling tower under different environmental wind speeds;calculating the change of the return flow rate of the two cooling towers at the fixed tower spacing,different environmental wind speed and the wind direction;and calculating the distance between the two cooling towers at different towers.The change of the return flow rate at different ambient wind speeds.After the above simulation,CFD-Post and Tecplot are used to post-process the results,and the corresponding deformation diagram,stress diagram,velocity distribution and temperature distribution of air and water droplets are obtained.After sorting out the relevant simulation data,draw a chart and summarize the relevant laws.