An experimental investigation of the pressure drop and friction factor of supercritical CO2 in circular tube is presented. Experimental length and inner diameter of the circular tube are 2000 mm and 10 mm. The experimental pressure ranges from 8 MPa to 16 MPa

mass flux ranges from 1000 kg·m-2·s-1 to 1525 kg·m-2·s-1

and heat flux on the inner wall ranges from 96.5 kW·m-2 to 283.2 kW·m-2. The variation of flow resistance was obtained and the effects of pressure

mass flux

heat flux and bulk fluid enthalpy on the frictional flow resistance coefficient of the circular tube were analyzed. The results showed that the frictional pressure drop increases significantly with increasing mass flux and pressure

particularly when the bulk enthalpy surpasses the pseudo-critical enthalpy

increased speed has become more intense

and meanwhile

it is found that the influence of heat flux on the friction pressure drop is not too great. The assessment of correlations demonstrated that constant-property-based correlations fail to predict the friction factor of supercritical CO2. Therefore

a new empirical correlation is proposed

and the experimental data accounts for 83.31% within the ±20% error band.