64 / 2025-11-23 11:59:59

Thermophysical properties of seawater-based nanofluids in off-shore energy monopile

Shallow geothermal energy in offshore areas has great potential for development, but it has not yet been effectively utilized. Global offshore wind industry is under decommis-sioning dilemma in recent years, updating wind turbines on existing monopile reveals to be the feasible measurement. This paper proposed the offshore energy monopile to achieve the joint development of offshore wind and geothermal by installing geothermal heat exchangers in large diameter monopile during the update of wind turbines. To overcome the decrease of heat exchange efficiency by hydrodynamic environment, seawater-based nanofluids with high thermal conductivity are introduced as the circulat-ing medium. Time-varying thermophysical properties of seawater-based nanofluids with different kinds of nanoparticles and concentration under 5℃ and 30℃ were measured to develop the appropriate recipe of seawater-based nanofluid in offshore energy mono-pile. Compared to conventional nano Al2O3 and nano CuO, carbon nanotube nanofluids have higher thermal conductivity and are a more promising choice for seawater-based nanofluids.