2级分段膜法海水淡化系统设计参数的数模计算

Numerical Computation of Design Parameters for Two-pass SWRO Desalination System with Two Stages

提出了1种膜法海水淡化系统的数模分析方法,利用这种方法计算研究了2级分段膜法海水淡化系统。结果表明,系统比能耗的洼值区为一级一段、一级二段膜回收率的低值区(低于50%)及二级膜回收率的高值区(大于50%);系统回收率随一级一段、一级二段、二级反渗透回收率的增加而增加,但增加的幅度不同,系统回收率随一级二段膜回收率的增加增幅较大,随一级一段膜和二级膜回收率的增加增幅较小;2级分段膜工况参数的优化工况点为系统比能耗等值面与系统回收率等值面的切点。在工程设计实践中,当需要保证较高的系统回收率时(如70%),2级分段膜法较常规的2级不分段膜法系统比能耗更低(如低34.35%)。可为工程设计实践提供借鉴。

A mathematical model for SWRO desalination system was established in this study, and it was carried out the computational analysis of the mathematical model for two-pass SWRO desalination system. The results indicated that, the lower general specific energy consumption could be obtained located on the lower water recovery（less than 50%） of the first pass reverse osmosis with all two stages and the higher water recovery（larger than 50%）of the second pass reverse osmosis. The general water recovery was increased with the increase of reverse osmosis recovery of the first pass with all two stages and the second pass. But the first pass reverse osmosis with the second stage presented more powerful effect to the general water recovery. The optimal operating parameters of reverse osmosis membranes could be estimated by the point of tangency between the contour planes of the general specific energy consumption and general water recovery. When the higher general water recovery was required, 70% for example, the two-pass SWRO desalination system with two stages presented 34.35% lower general specific energy consumption than conventional two-pass SWRO desalination system without stages. This mathematical method provided a reference for engineering design of SWRO system.