Influence Of Annular Guide Plate And Despin-type Device On The Performance Of Indirect Air-cooled Tower

The situation of water shortage is becoming more and more severe.With distinct superiority in water saving and energy saving,the indirect air-cooled technology has developed rapidly and been widely used in northern China,characterized as abundance in coal and lacking in water.The indirect air-cooled technology is a typical transfer process between the ambient air and the radiators.Air flow rate have significant influences on the air flow field characteristics and heat transfer performance.Therefore,it is of great significance to study the flow field characteristics and heat transfer performance of air-cooled system under ambient wind conditions,and then to optimize the design of air-cooled system.Take indirect air-cooled tower in a 660 MW unit as an example,the effects of environmental wind on the air flow field characteristics and heat transfer performance of air-cooled system were investigated by using a numerical method.Then three kinds of annular guide plates with different size parameters and three kinds of despin-type devices with different structures were designed.They were respectively installed on the top of the air-cooled radiator and inside the air-cooled tower.The air flow field characteristics as well as heat transfer performance of indirect air-cooled tower were obtained considering the flow guiding devices.The annular guide plate and despin-type device with better effect are selected and installed at the same time.As a result,the installation of the annular guide plate can effectively reduce the pressure at the inlet of cooling air,weaken the vortex behind the air cooling tower,narrow the high temperature area behind the radiator on the leeward side,and improve the the cooling air flow rate and heat transfer performance of the air-cooled tower.Among them,annular guide plate of h=3.8m has better effect.The installation of the annular guide device can effectively reduce the fluid pressure around it,prevent the phenomenon of hot air passing through the air-cooled tower,and weaken the vortex in the tower.The internal flow field of air-cooled tower is obviously optimized.The installation of the swirling guide plate can guide the cooling air flowing up in a rotating way.The flow field inside the tower has not been obviously optimized.The installation of the shunting guide plate can effectively reduce the internal pressure on the leeward side of air-cooled tower,prevent the phenomenon of hot air passing through the cooling tower,and weaken the vortex in the tower.The cooling air flow rate and heat transfer performance of the air-cooled radiator are improved effectively.Among them,shunting guide plate has better effect.In addition,the effect of installing annular guide plate of h=3.8m and shunting guide plate at the same time is better than that of single arrangement.