Adopting inclined channel to decline the salinity mixing for rotary energy recovery device: Simulation and optimization

[Display omitted] After years of research, the energy efficiency of energy recovery device has been raised to a high level, but the salinity mixing has not been effectively improved. Mixing will lead to a rise of high-pressure seawater salinity, which will increase the operating cost. In this paper, the computational fluid dynamics (CFD) simulation of the rotary energy recovery device (RERD) is carried out. It is found that the unstable flow caused by the non-parallel between the channel and the flow direction of fluid is an important reason for mixing. After the inclined channel structure is adopted, the non-parallel problem is improved. The formation of unstable flow is effectively controlled. Under the commercial product operating conditions, the volumetric mixing of the optimized device is reduced from 3.34% to 1.29%, showing the effectiveness of the structure.