Although vacuum membrane distillation (VMD) has a high distillate flux, its potential is limited by its high specific heat consumption (SHC). Flat sheet VMD systems recover the brine energy by employing a cascade system to improve the SHC. Hollow fiber VMD systems, however, have not yet been optimized for energy recovery. To overcome this knowledge gap, four multi-stage configurations (with and without brine energy recovery) were investigated via experimentation and through numerical simulations. The results show that having permeate flux promoting conditions, such as high feed temperature or lower vacuum pressure, improves the SHC for VMD configurations without brine recirculation, but have little impact for configurations with brine energy recovery. A Pareto multi-objective optimization showed that the optimized first-stage heating MS-VMD without brine recirculation has the highest SHC (908 $\mathit{kWh}/m^3$) but one of the lowest LCOW (2.37 $\mathit{USD}/m^3$). In contrast, the configuration with the first-stage heating with brine recirculation provided the lowest SHC (585–629 $\mathit{kWh}/m^3$) and an acceptable LCOW (2.27–8.30 $\mathit{USD}/m^3$). This study reveals that the development of MS-VMD represents a promising direction for thermal desalination technologies, particularly for high saline water applications.

尽管真空膜蒸馏（VMD）具有较高的馏出通量，但其潜力受到其高比热消耗（SHC）的限制。平板VMD系统通过采用级联系统来改善SHC来回收盐水能量。但是，中空纤维VMD系统尚未针对能量回收进行优化。为了克服这一知识差距，通过实验和数值模拟研究了四个多阶段配置（有或没有盐水能量回收）。结果表明，具有渗透通量促进条件，例如较高的进料温度或较低的真空压力，可在不进行盐水再循环的情况下改善VMD配置的SHC，但对回收盐水能量的配置几乎没有影响。$\mathit{千瓦时}/{米}^3$），但是最低LCOW（2.37）之一 $\mathit{美元}/{米}^3$）。相比之下，第一阶段加热和盐水再循环的配置提供了最低的SHC（585–629）$\mathit{千瓦时}/{米}^3$）和可接受的LCOW（2.27–8.30 $\mathit{美元}/{米}^3$）。这项研究表明，MS-VMD的发展代表了热脱盐技术的一个有希望的方向，特别是在高盐度水应用中。