Mechanical compression type multi-effect distillation seawater desalination system coupled with water source heat pumps

Abstract

The invention relates to a mechanical compression type multi-effect distillation seawater desalination system coupled with water source heat pumps. The system comprises a first-effect evaporator and a second-effect evaporator; a primary heat pump system is communicated with an industrial circulation water source; a secondary heat pump system is used for supplying saturated steam and high-temperature raw material seawater for the first-effect evaporator; one branch of concentrated seawater generated by the first-effect evaporator and the second-effect evaporator is used for heating the raw material seawater and is subsequently discharged; the other branch of the concentrated seawater is back supplemented into the unevaporated raw material seawater; a non-condensable gas extracting pump is mounted at the tail end of a fresh water condenser; the first-effect evaporator is connected with the second-effect evaporator in series; the non-condensable gas extracting pump is used for generating negative pressure in evaporator shell steam passages; the steam generated by the evaporators is condensed into fresh water; then the steam is used for heating the raw material seawater and is subsequently discharged. The mechanical compression type multi-effect distillation seawater desalination system coupled with water source heat pumps is capable of effectively absorbing heat energy in the industrial circulation water and reducing the pollution of industrial heat sources; the evaporators adopt spraying flash evaporation and falling-film evaporation techniques; through multiple manners of back supplementing the concentrated seawater and heating the raw material seawater by using the discharged heat energy, the heat energy efficiency of desalination of the seawater is greatly improved; the desalination cost of the seawater is reduced.

Description

technical field

[0001] The invention belongs to the technical field of seawater desalination and water treatment, in particular to a mechanical compression multi-effect distillation seawater desalination system coupled with a water source heat pump. Background technique

[0002] Multi-effect distillation technology can use various low-grade heat energy to distill seawater to produce high-quality freshwater, which has low requirements on seawater quality, high heat energy utilization rate, high heat transfer efficiency, large operating flexibility (40%-110%), and high water quality (Total dissolved solids TDS<10PPM) and long service life of the device have become an important seawater desalination technology. In this technology, the multi-effect horizontal tube falling film evaporator has been widely used. However, in the multi-effect horizontal tube falling film evaporator, due to the certain heat loss in the evaporation process, it is necessary to use electric Heating th...

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