Abstract Preheating seawater before it flows into the evaporators in multi-effect distillation (MED) system could improve the system performance. The number and position of the preheaters play an important role in the thermal performance. A comparison of systems with different numbers and positions of preheaters was performed. On the premise of the constant distillate production, taking the 10-effect evaporation desalination system as an example, the effects of preheater arrangement on the gained output ratio (GOR) of the system and the total heat transfer area of the evaporators (Atotal) were analyzed. By adopting the equal temperature difference design method, a mathematical model was developed for the system performance analysis under different preheater arrangements. The results indicated that the GOR and Atotal are changed obeying some rules when the position of the preheater changes in one evaporator group or in different evaporator groups. In addition, with the increase in the number of preheaters, the mean GOR rises, the mean Atotal grows and the promotion space of system performance improves. The research provides a certain guiding direction for the optimization of desalination devices.

中文翻译：

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预热器布置对MED脱盐系统性能的影响

摘要 在海水进入多效蒸馏（MED）系统的蒸发器之前对其进行预热可以提高系统性能。预热器的数量和位置对热性能起着重要作用。对具有不同数量和位置的预热器的系统进行了比较。在馏出物产量恒定的前提下，以10效蒸发淡化系统为例，预热器布置对系统增产比（GOR）和蒸发器总传热面积（Atotal）的影响为分析了。采用等温差设计方法，建立了不同预热器布置下系统性能分析的数学模型。结果表明，在一组或不同的蒸发器组中，当预热器的位置发生变化时，GOR和Atotal的变化遵循一定的规律。此外，随着预热器数量的增加，平均GOR上升，平均Atotal增大，系统性能提升空间增大。该研究为海水淡化装置的优化提供了一定的指导方向。