Seawater desalination method implemented by solar membrane distillation

Abstract

The invention discloses a seawater desalination method implemented by solar membrane distillation, which belongs to a water desalination technology. A membrane distillation assembly, a pretreatment unit, a solar heat-collected circulating water inlet unit, an internal phase change heat recovery unit and an external condensing heat recovery unit are included, wherein a hollow fiber membrane and a hollow fiber condenser pipe are filled in the membrane distillation assembly in a staggered weaved mode, and the pretreatment unit, the solar heat-collected circulating water inlet unit, the internal phase change heat recovery unit and the external condensing heat recovery unit are assorted. A material liquid to be treated, alternately as a hot material liquid and a cold material liquid, is fed into a hot cavity of the hollow fiber membrane of the membrane distillation assembly and a cold cavity of the hollow fiber condenser pipe, so that the membrane distillation assembly can be flexibly amplified for multi-group and multi-level arrangement, therefore, the membrane distillation assembly both can be implemented in a small-scale arrangement mode, and also facilitates wide-range integrated seawater desalination applications; and the design of the novel membrane distillation assembly ensures the high-yield water efficiency, and the multi-level arrangement mode and external condensing heat recovery process of the membrane distillation assembly improve the utilization rate of heat energy. A cheap solar heat collecting device is taken as a driving heat source, and a liquor condensate cooling device is not required to be separately introduced, so that the investment, operation cost and energy consumption of the device are greatly reduced.

Description

technical field [0001] The invention relates to a seawater desalination method, in particular to a method for preparing fresh water by using solar membrane distillation to desalinate seawater, which belongs to the water desalination technology. Background technique [0002] The shortage of water resources is one of the major challenges facing mankind in the 21st century. China's per capita water resources are only a quarter of the world's, and nearly 70% of the country's urban water supply cannot be effectively guaranteed. At the same time, my country has a long coastline and abundant brackish water resources in the central and western regions. Under the reality of difficulties in obtaining groundwater and regional water transfer, using seawater desalination technology to open up new freshwater resources will undoubtedly effectively alleviate the water resource crisis. [0003] Membrane distillation technology (MD) is a new type of water desalination and desalination techno...

AI Technical Summary

Problems solved by technology

However, this system adds an additional electric-driven condensate outlet cooling device, which increases the investment cost and also increases the energy consumption of the system

[0007] Most of the solar membrane distillation systems that have been reported so far only focus on the operation design of the system, and pay less attention to the configuration optimization and thermal energy utilization of the membrane modules at the core of the system, and low energy consumption, low cost and high water production efficiency cannot be achieved at the same time , so the potential for scale-up and practical application is insufficient

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