Numerical analysis of the energy recovery process in a disc-type pressure exchanger with pressure-boost effect

Pressure exchanger acts as an intermediary device that transfers pressure energy between liquid streams in different pressures. This work is an exploratory study to introduce a novel disc-type pressure exchanger, which combines characteristics of both positive displacement and centrifugal type pressure exchangers. In order to properly describe the complex flow behaviors in the rotating disc channels, a three-dimensional numerical simulation was carried out to study the pressure exchange process between brine and seawater streams in the device. The pressure exchange performance including pressure recovery efficiency and mixing rate were evaluated under different operating conditions. Additionally, unbalanced operating methods were discussed for mixing control. Simulation results show that the mixing rate and pressure exchange efficiency of such device are well competent for energy recovery process. And the mixing rate can be further controlled by decreasing flow rate and increasing rotational speed and unbalanced lead flow ratio.