中空纤维透析器中纤维管填充密度对传质影响的数值模拟

通过数值模拟研究了纤维管填充密度（27.18%～67.11%）增加时传质系数的变化趋势，同时考察了流体速度对传质系数的影响.模拟结果表明：随着填充密度的增加，传质系数先增加后下降；流体速度不仅影响传质系数的大小（速度越大，传质系数越大），也影响最佳填充密度（传质系数最大值对应的填充密度）的大小（速度增大，最佳填充密度也增大）.模拟结果可为透析器的优化设计提供参考.

NUMERICAL SIMULATION OF EFFECT OF HOLLOW FIBER PACKING DENSITY ON MASS TRANSFER IN DIALYZERS

Packing density is one of the main factors affecting mass transfer performance of hollow fiber dialyzers. In literature,the conclusions about the effect of packing density on mass transfer coefficient are inconsistent, which probably is due to the ignored effect of module wall and hollow fiber interaction. One standpoint is that with increasing packing density, mass transfer coefficient first increases and then decreases,and another is just the contrary.In this paper, the effect of module wall and hollow fiber interaction is taken into account, and by means of numerical simulation the variation of mass transfer coefficient is studied with hollow fiber packing density increasing from 27.18% to 67.11%. At the same time the effect of flow velocity on mass transfer coefficient is investigated. The results show that with increasing packing density mass transfer coefficient first increases, and then decreases.The flow velocity affects not only mass transfer coefficient (the faster the velocity, the bigger the mass transfer coefficient), but also the optimal packing density corresponding to maximal mass transfer coefficient (the faster the velocity, the bigger the optimal packing density).The results are very significant for designers to improve dialyzers.