Numerical Modeling of the Thermal Behavior of Subsea Hydro-Pneumatic Energy Storage Accumulators Using Air and CO2

This paper numerically models the thermal performance of offshore hydro-pneumatic energy storage (HPES) systems composed a subsea accumulator pre-charged with compressed gas. A time-marching numerical approach combining first law thermodynamics heat transfer equations is used to investigate influence replacing air within an HPES system carbon dioxide (CO2). The latter able experience phase change (gas–liquid–gas) during cycle in typical temperatures when limiting peak operating pressure below critical point. influences integrating piston and inner liner mitigate issues related gas dissolution seawater corrosion are explored. It found that capacity accumulators increases substantially CO2 as compressible fluid lieu air, irrespective set up. also noted length-to-diameter ratio has considerable on round-trip efficiency for both air- CO2-based accumulators. Another factor influencing presence liner. Moreover, yields lower over air.