海水冷冻预淡化系统的试验研究

Experimental Investigation of a Seawater Freezing Pre-Desalination System

本文提出了一种基于冷冻脱盐的海水双级冷冻预淡化系统。该系统利用蒸发结晶器对海水进行冷冻,并通过振动分离与洗涤实现冰晶与卤水的分离,以此实现海水的初步脱盐,可作为反渗透淡化的预处理系统。同时,海水冷冻淡化过程中消耗的冷量可重新回收用于空调制冷,淡化成本得以有效降低。本文建立了海水双级冷冻预淡化系统的数学模型,获得了试验系统的关键设计参数,以此搭建了试验平台并完成了试验测试,并对海水双级冷冻预淡化系统进行了经济性分析。试验结果表明:经过海水冷冻预淡化系统,预淡化海水产量可维持在21~27 L/h之间;预淡化海水盐度可从35降低到约11;预淡化过程可回收总冷量7.91 kW;反渗透淡化总成本可降低约33%。

A seawater freezing pre-desalination system is proposed based on the freezing desalination principle.This system uses evaporative crystallizer to freeze seawater,and realizes the separation of ice crystal and brine through vibration separation and washing.It realizes the preliminary desalination of seawater,and can be used as a pretreatment system for RO(Reverse Osmosis)desalination.At the same time,the refrigerating capacity consumed in the process of seawater freezing desalination can be recycled for air conditioning refrigeration,which could effectively reduce the desalination cost.Herein,the mathematical model of seawater freezing pre-desalination system was established,and an experimental platform was built to verify and evaluate its performance.In addition,the economic analysis of seawater freezing pre-desalination system was carried out.The experimental results show that after the seawater freezing pre-desalination process,the production of pre-desalinated seawater is mostly kept between 21 L/h and 27 L/h;the salinity of pre-desalinated seawater can be reduced to around 11;the total recoverable refrigerating capacity in the pre-desalination process is 7.91 kW;the total cost of RO desalination can be reduced by 33%approximately.