▎ 摘　　要

NOVELTY - A supercritical carbon dioxide-graphene nanofluid comprises supercritical carbon dioxide and nano graphene uniformly dispersed in carbon dioxide, and is at a pressure of 8-22 MPa and a temperature of 40-800 degrees C. The concentration of nano graphene is 0.1-2 wt.% and the average grain diameter is 1-10 nm. USE - Supercritical carbon dioxide-graphene nanofluid is useful as working medium in Brayton cycle system in nuclear power generators and distributed power generators (all claimed). ADVANTAGE - The nanofluid has uniform dispersion, and excellent thermal conductivity, chemical inertness, and safety. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of nanofluid, which involves adding nano graphene powder to a mixing container, vacuumizing, mixing through an emulsifier to form high-pressure carbon dioxide-nano graphene powder mixed gas, and compressing the mixed gas; and (2) Brayton cycle system.