Focusing on the steam flow distribution and flow resistance problem of the exhaust pipe in a 1000 MW direct air-cooled system

the flow characteristics for the different piping layouts

including the scatter type

the conventional Y-type and high position-type were simulated and compared by using the computational fluid dynamics(CFD)method.The results show that

the scatter type piping layout scheme II improves the uniformity of flow distribution

minimizes the flow distribution difference between each cooling unit

reduces the consumption of large diameter pipes

and significantly decreases the material cost.However

the disadvantage of the scatter type piping structure(scheme II)is to create a high flow resistance

the pressure drop increases about 20 Pa compared with that of the Y-type and high position-type piping layouts under the same flow conditions.Therefore

during the actual engineering design

the scatter type piping layout scheme II can be selected as the arrangement scheme for exhaust pipes.