Performance fluctuations and evaluation of a piston type integrated high pressure pump-energy recovery device

The development of energy recovery device (ERD) is a decisive factor for the recent prevalence of reverse osmosis (RO) technology in the seawater desalination field. Unlike broadly studied large scale ERDs, the investigations of small scale ERDs are scarcely reported, especially on the performance fluctuations under variable operating conditions. Based on an authors’ exploratory research on a piston type integrated high pressure pump-energy recovery device (HPP-ERD), further performance exploitation of the HPP-ERD is conducted. With a constructed experiment platform, the influences of inlet seawater temperature, inlet seawater salinity, as well as the operating frequency on the performance of the HPP-ERD coupled with seawater reverse osmosis (SWRO) desalination system are investigated. The temperature and salinity of the inlet seawater are numerically correlated with the specific energy consumption (SEC) of the HPP-ERD. With the correlated equation, the marine hydrological data of two observatories acquired from a national authoritative database, and the annualized life cycle cost approach incorporated, annual performance assessment is proposed for an SWRO desalination system equipped with the HPP-ERD in the light of energy and economic indices. The study results indicate that the proposed HPP-ERD is competent under various operating conditions for SWRO desalination systems.