Heat transfer of supercritical carbon dioxide in a tube-in-tube heat exchanger-a CFD study

For better design and optimization of the heat exchanger (HX), forced convective transfer flow characteristics supercritical carbon dioxide (SCO2) in a water-cooled experimental counter-flow tube-in-tube HX were studied numerically with three-dimensional Reynolds-averaged Navier-Stokes equations shear stress transport (SST) turbulence model by using computational fluid dynamics method ANSYS CFX. With sole tube HX, effects SCO2 inlet pressure, mass flux, diameter wall flux on mean coefficient (MHTC) investigated. Influences models discretisation schemes advection terms SST model, temperature conservative hybrid values CFX-Post MHTC clarified, buoyancy effect horizontal was explored. The can achieve agreement MHTCs than other models. improve secondary flows tube.