Research On Structure Optimization Of Direct Air-cooled Unit With Flow Guiding Device

The distribution of China's coal resources and water resources are Serious inequality and the gap is large,Especially in the "Three North" area that rich in coal and poor in water.So the direct air-cooled unit is necessary for the construction of water shortage area because of its excellent water saving performance and environmental protection performance.However,due to the arrangement of the direct air-cooled system is in the atmospheric environment,The changes of each factor in the environmental wind field c an significantly affect the operation of the direct air cooling system,So it is significant to research the influence of environmental air on air-cool system and put forward the improvement measures to the structure optimization of the direct air-cooled-system.In this paper,a direct air-cooled unit of a power plant in Inner Mongolia is used as the analysis object,By using the numerical simulation software FLUENT to simulate and analyze the air-cooled island and its nearby plant,And the numerical simulation was carried out by using an algorithm of simple and standard k-? turbulence model.And the fluctuation laws of the heat transfer capacity of air-cooled island with the environment wind speed are studied under the condition that the wind direction is behind the boiler or parallel to the turbine room column.Taking measures such as installing flow guiding device or stretching downward windbreak to improve the flow and heat transfer capacity of air-cooled islands,At the same time,the optimization of the flow guide plate was refined to explore a better flow guide plate layout measure.The results show that the flow and heat transfer capability of the air-cooled island decreases with the increase of wind speed under any wind direction,And compared to the wind that parallel to the turbine room column,the wind behind the boiler will cause a strong hot air recirculation and seriously affecting the heat transfer capacity of air-cooled island.So it is better that the frequency and speed of wind behind the boiler is smaller when designing and building air-cooled units.And the measures such as installing flow guiding device or stretching downward windbreak can significantly reduce the phenomenon of hot air recirculation,The mode that install the flow guiding device of 226(60°)and the lower windbreak(10m)together is the best.