Long Term Performance Analysis of an Experimental Sliding Vane Energy Recovery Device for Village Scale Reverse Osmosis

Abstract Many communities globally experience a combination of brackish groundwater, low coverage of piped water, and poor access to an electricity grid. Community-scale solar powered reverse osmosis systems can improve water access, but community adoption is hindered because the high specific energy costs of these systems require large expensive solar systems. Prior art identified a novel architecture for an energy recovery device using off-the-shelf sliding vane pumps that could recover up to 62% of the energy lost in the system thereby reducing the specific energy costs. This study assesses the feasibility of the energy recovery concept for resource constrained regions by measuring the power consumption and maintenance requirements of the system over time. Two long-term tests were completed using a prototype reverse osmosis system. One test measured power consumption over time during continuous water desalination. The second test evaluated system reliability and maintenance requirements in a run-to-fail test. This work demonstrated that a coupled sliding vane pump could reduce power consumption during desalination, however the results of the testing revealed a potential catastrophic failure mode that may be caused by pressure pulsing of the vane pumps as they interact with the hydraulic system. Future work should focus on improving system reliability for this configuration.