Analysis of hybrid Adiabatic Compressed Air Energy Storage - Reverse Osmosis desalination system with different topological structures

Abstract

Given the high energy consumption in the traditional Reverse Osmosis (RO) desalination system, it is necessary to enable energy-efficient and sustainable water production. This study proposed four hybrid systems of Adiabatic Compressed Air Energy Storage (ACAES) and RO desalination with different topological structures. By establishing mathematical models of each sub-system, the steady-state simulation of the hybrid system was carried out. Energy transfer modes of four different hybrid system topological structures were proposed and analyzed. Then, the effects of the storage pressure and ambient temperature variation on the system performance were analyzed. The results show that the hybrid system without electric power has a 10% reduction in energy consumption. In all simulated working conditions, when the End Pressure of Charge (EPC) varies from 8 to 12 MPa, an optimal value of 5 MPa exists for EPD, enabling the lowest Specific Energy Consumption (SEC) of the hybrid system. In comparison, system SEC can be reduced by about 30% at a high ambient gas temperature of 40 °C than at a lower temperature of 0 °C. In all simulated working conditions, when EPC and EPD are respectively 12 MPa and 5 MPa, SEC has a minimum value of 3.18 kWh/m3. This study is helpful to promote the application of ACAES in the field of RO desalination and provides a theoretical reference for the system design.