摘要
Due to advantages compared to alternative sources of flesh water,large SWRO desalination plants (production>30000 m3/d)have become a lucrative option for the solving of water carcity-demonstrated by a remarkable increased number of such plants online over the last couple of years.But desalinated water is relatively expensive because of high capital And operating costs.The process is energy intensive,making the power bill responsible for 30%to 40%of the specific costs per m3 production.This makes energy recovery systems an important component of such plants.Calder AG Switzerland is the world leader in supplying energy recovery technologies to the SWRO industry.It is the only company providing energy recovery devices based on two different technologies,the product range includes an isobaric device(work exchanger,DWEER)as well as a centrifugal device(Pelton turbine,ERT).On the basis of four examples of large scaled SWRO desalination plants,various approaches of plant-designs suitable for the different energy recovery technologies will be described and discussed regarding design-and operational aspects.It will be shown that,depending on certain circumstances,both technologies have their merits and decision·criteria for the evaluation of the most adequate energy recovery technology will be identified.Further,it will be demonstrated that a Pelton-turbine is rather a proofed than an ancient technology,and why specific energy consumption is an important but not the only criteria which has to be considered for supplying desalinated water at a reasonable and competitive price.