Capacity flexibility evaluation of a reciprocating-switcher energy recovery device for SWRO desalination system

The adoption of energy recovery device (ERD) in seawater reverse osmosis (SWRO) system has become a practical way for reducing the power consumption and permeating cost of the desalting system. The performance requirement of the ERD basically depends upon the configurations and operating parameters of the SWRO system. The temperature and salinity of the seawater feed are two typical parameters that should be considered, whose fluctuations may induce significant changes in the membrane separation performance and thus the flow balance of the SWRO system, which requires the ERD having a good adaptability to meet the practical demands. In this paper, a SWRO desalination platform is built to evaluate the capacity flexibility of a reciprocating-switcher energy recovery device (RS-ERD). The experimental results show that the RS-ERD can run in 66.7%-150.0% of the design capacity (30 m3/h) and maintain a relative constant efficiency above 96.50% and leakage ratio about 2.62%-3.95%, which proves the wide-range adaptability of the RS-ERD to the varying conditions of the SWRO desalination system.