The path for water molecules transported across a membrane in real porous membranes has been considered to be a constant factor in the membrane distillation (MD) process (i.e., constant tortuosity); as such, its effect on membrane performance at various operating conditions has been ignored by researchers. Therefore, a simultaneous heat and mass transfer model throughout the direct contact membrane distillation (DCMD) module was developed in this study by taking into account the hypothetical path across the membrane as a variable factor within the operating conditions because it exhibits the changes to the mass transfer resistance across the membrane under the DCMD run. The DCMD process was described by the developed model using a system of nonlinear equations and solved numerically by MATLAB software. The performance of the poly-tetra-fluoroethylene (PTFE) membrane was examined to treat 200 g/L NaCl saline at various operating conditions. The simulation results in the present work showed that the hypothetical proposed path across the membrane has a variable value and was affected by changing the feed temperature and feed concentration. The results estimated by the developed model showed an excellent conformity with the experimental results. The salt rejection remained high (greater than 99.9%) in all cases. The temperature polarization coefficient for the DCMD ranged between 0.88 and 0.967, and the gain output ratio (GOR) was 0.893. The maximum thermal efficiency of the system was 84.5%.

中文翻译：

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使用直接接触膜蒸馏 (DCMD) 的高盐水淡化：实验和模拟研究

在真正的多孔膜中，水分子穿过膜的路径被认为是膜蒸馏 (MD) 过程中的一个恒定因素（即恒定的曲折度）；因此，研究人员忽略了它在各种操作条件下对膜性能的影响。因此，在本研究中开发了贯穿直接接触膜蒸馏 (DCMD) 模块的同时传热和传质模型，将穿过膜的假设路径作为操作条件内的可变因素，因为它表现出质量的变化在DCMD运行下跨膜的转移阻力。DCMD 过程由使用非线性方程组的开发模型描述，并通过 MATLAB 软件进行数值求解。检查了聚四氟乙烯 (PTFE) 膜在各种操作条件下处理 200 g/L NaCl 盐水的性能。目前工作中的模拟结果表明，假设的建议穿过膜的路径具有可变值，并且受到进料温度和进料浓度变化的影响。开发的模型估计的结果与实验结果非常吻合。在所有情况下，脱盐率仍然很高（大于 99.9%）。DCMD 的温度极化系数介于 0.88 和 0.967 之间，增益输出比 (GOR) 为 0.893。该系统的最大热效率为84.5%。目前工作中的模拟结果表明，假设的建议穿过膜的路径具有可变值，并且受到进料温度和进料浓度变化的影响。开发的模型估计的结果与实验结果非常吻合。在所有情况下，脱盐率仍然很高（大于 99.9%）。DCMD 的温度极化系数介于 0.88 和 0.967 之间，增益输出比 (GOR) 为 0.893。该系统的最大热效率为84.5%。目前工作中的模拟结果表明，假设的建议穿过膜的路径具有可变值，并且受到进料温度和进料浓度变化的影响。开发的模型估计的结果与实验结果非常吻合。在所有情况下，脱盐率仍然很高（大于 99.9%）。DCMD 的温度极化系数介于 0.88 和 0.967 之间，增益输出比 (GOR) 为 0.893。该系统的最大热效率为84.5%。9%) 在所有情况下。DCMD 的温度极化系数介于 0.88 和 0.967 之间，增益输出比 (GOR) 为 0.893。该系统的最大热效率为84.5%。9%) 在所有情况下。DCMD 的温度极化系数介于 0.88 和 0.967 之间，增益输出比 (GOR) 为 0.893。该系统的最大热效率为84.5%。