Study On Energy-saving Integrated Facility For Sea Water Desalination In Island

There are about 3 million square kilometers of sea area and many islands in our country.Some islands are larger than 500 m2,but thousands of islands are smaller than 500 m2.The majority of these islands are severely short of fresh water.What is worse,the water quality usually can not meet the hygiene standards.Therefore,it is in great need to solve the problem of water shortage on these islands by fully making use of the abundant seawater to make fresh water.In order to decrease the high energy consumption,high cost of imported parts and complicated operation in domestic small scale seawater desalination plants,an island energy-saving integrated seawater desalination device was developed,which was suit for the local environment.Firstly,the energy consumption of seawater desalination system was calculated.An energy-saving integrated desalination process for seawater desalination was proposed according to the study of the effects of seawater temperature,recovery rate,water supply salinity,energy recovery efficiency and high-pressure pump efficiency on energy consumption and water quality of the seawater desalination system by using software ROSA.Secondly,a differential-pressure exchange energy recovery device which was fully considered the compactness and mobility of the device was built.The equipment in the system was highly integrated which was based on the design idea of modularization and integration.In addition,an energy-saving integrated seawater desalination device was developed,then the water consumption,produced-water quality and running noise of the device were tested.Finally,the prototype design was amplified.A set of energy-saving integrated seawater desalination device with a fresh water production of 25 m3/d was designed by amplifying the prototype design.The energy consumption of seawater desalination of the device were tested and decreased to be less than 3.0kWh/m3.The application of the device was demonstrated fully in practice.It can greatly reduce the energy consumption of the water production of the small seawater desalination system and have good economic and social benefits.The results of this paper provide an effective and promising way to alleviate the tense situation of small island fresh water shortage,and play an important role in speeding up the popularization and application of miniaturization and integrated seawater desalination plant.