Design And Performance Evaluations On Energy Recovery Device With Separate-chamber Type Fluid-Switcher

Energy recovery device (ERD) is of great importance for significantly reducingthe power consumption of seawater reverse osmosis desalination plants, and of whichthe piston-type ERD is one of the typital products on the market.As the core ofERD,the fluid switcher is mainly for guiding the high pressure brine anddepressurized brine to and out of ERD.In this paper, based on the previous research development of the research groupwho studied on the valve-concrolled ERD and against the problems includingleakage、compicated structure、fluctuations of the flow and pressure of the highpressre seawater and so on, an innovative separate-chamber type fluid switcher for theFS-ERD was designed and manufactured. Structure design characteristics of highpressure chamber and low pressure chamber for the fluid switcher were introducedand analyzed. Non-overlapped and overlapped of the high pressure ports of theswitcher were manufactered. Control plateform of one touch start for ERD and dataacquisition system were set up.The fluid dynamic performance of the ERD installed with new type fluidswitchers was experimentally tested when the goal flow was1.0m~3/h and2.0m~3/h.The results showed that Qbi、Qsi、Qbo、Qso of the system with non-overlappedswitcher fluctuated downwards periodically,which was due to the conversion ofworking phase. Qbi、Qso、Pbi、Pso of the system with overlapped switcher were stablebecause that the high pressure brine could continuously pressurize the feed seawaterdue to the largger opening of the high pressure ports.It is possible that the high pressure brine flow and the low pressure seawater floware mismatch when variable working or the actual operation.The fluid dynamicperformance of the ERD with these switchers was tested when the high pressure brineflow and the low pressure seawater flow were not match to test the switcher’sflexibility. The results showed that the switchers desighed,especially the overlappedswitcher were suitable for the problem of not matching flow. The flow and pressurewere more stable when the low pressure seawater was excess to the high pressurebrine.