不同截面形状气体分布器的数值模拟

针对100kt/a大型乙烯裂解炉布置的新型急冷废热锅炉气体分布器存在背风面焦炭蓄集严重、弯曲变形大和流场湍流强的问题,利用计算流体力学方法,比较了正方形、圆形和椭圆形截面分布器气体入口流场的气体分布不均匀性、流场湍流强度、分布器应力大小和背风面焦炭蓄集的性能指标。模拟结果表明,除正方形截面分布器弯曲正应力最小外,椭圆形截面分布器气体分布不均匀性、流场湍流强度和背风面上气体流动低速区都较圆形截面分布器的小。

Numerical Simulation of the Gas Distributors with Different Cross-Section Shapes

The non-uniformity of the gas distribution,the turbulent strength of the flow field,the stress sizes at the entrances of the gas distributors,the performance index of the coke accumulation on the leeward side of the gas distributors with square,round,and elliptical cross-section shapes were compared using computational fluid dynamics（CFD）for the problems,such as serious coke accumulation on the leeward side,evident deformation,and strong turbulent of the flow field of the gas distributors of the new type quenching waste heat boilers installed in 100kt/a big-sized ethylene quenching boilers.The simulation result shows that the non-uniformity of the gas distribution,the turbulent strength of the flow field,and the low velocity zone of the gas flow on the leeward side of the gas distributors with elliptical cross-section shapes were less than those of the gas distributors with round cross-section shapes except the least bending positive stress of the gas distributors with square cross-section shapes.