Multi-effect membrane distillation seawater desalination system based on mechanical compression

Abstract

The invention discloses a multi-effect membrane distillation seawater desalination system based on mechanical compression. The multi-effect membrane distillation seawater desalination system based on the mechanical compression comprises a plurality of serially-connected vacuum membrane distillation assemblies and heat exchange assemblies, a plurality of serially-connected concentrated water flash distillation tanks, a plurality of serially-connected fresh water flash distillation tanks, a mechanical steam compressor and a vacuumizing system, wherein the serially-connected vacuum membrane distillation assemblies and the heat exchange assemblies form multi-effect distillation in the conventional distillation sense; the serially-connected concentrated water flash distillation tanks receive concentrated seawater after membrane distillation and perform stage-by-stage flash distillation, and flash distillation steam is used as heating steam corresponding to each-effect material liquids; the serially-connected fresh water flash distillation tanks receive fresh water produced during the membrane distillation and perform stage-by-stage flash distillation, and flash distillation steam is used as heating steam corresponding to each-effect material liquids; the mechanical steam compressor raises the temperature and the pressure of secondary steam produced by the last-effect membrane distillation assembly through consumption of electric energy, and provides heating steam for the first-effect heat exchange assembly. The multi-effect membrane distillation seawater desalination system based on the mechanical compression couples a multi-effect membrane distillation process and a multi-stage flash distillation process, pumps the last-effect secondary steam through the mechanical steam compressor, and recycles the last-effect secondary steam after quality improvement to achieve gradient utilization of energy and two-way concentration of the material liquid, so that consumption of cooling water is not required, the heat efficiency is high, the water making ratio is high, the concentrating ratio is high, and the adaptability is high.

Description

technical field [0001] The invention belongs to the technical field of membrane separation and seawater desalination, and relates to a multi-effect membrane distillation seawater desalination system based on mechanical compression. Background technique [0002] With the development of the economy and the increase of the population, the human demand for water resources continues to increase, coupled with the unreasonable exploitation and utilization of water resources, many countries and regions have different degrees of water shortages, and the world is facing increasing serious water crisis. [0003] Seawater desalination is an open-source incremental technology to realize the utilization of water resources. It can increase the total amount of fresh water without being affected by time, space and climate, and can ensure a stable water supply such as drinking water for coastal residents and supplementary water for industrial boilers. Seawater desalination, also known as sea...

AI Technical Summary

Problems solved by technology

This invention patent needs to configure the terminal condenser to cool the secondary steam generated by the final membrane distillation component, and consume a large amount of cooling water. The heat loss of cooling water will reduce the thermal efficiency of the system

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