Supercritical CO2

Supercritical CO₂ shows great potential as a future working fluid in power plants, refrigeration units plants and heat pumps. In comparison to application using sub-critical fluids heat transfer, it has advantageous physical properties, such as high density and high specific heat capacity. Furthermore, close to its critical point (T_cr = 31 °C, p_cr = 7.4 MPa) there are anomalies in the physical properties that can significantly affect the heat transfer within a heat exchanger (so-called Enhanced or Detoriated Heat Transfer). Thus, the use of supercritical CO₂ as working fluid allows relatively high system efficiencies at moderate investment costs. For this reason, there are already a lot of applications for supercritical CO₂, e.g. refrigerant R744 in stationary air-conditioning systems.
Different experimental and numerical activities form the basis of this research area:

SCARLETT-Setup

• Heat transfer in single channels and pipes
• Heat exchanger analyses

Numerical Simulations

• Direct numerical simulation of heated pipe flows

System analyses

• Feasibility study of a joule cycle with supercritical CO₂ as working fluid to be used as self-propelling heat removal system in a boiling water reactor
• Experimental investigation of a printed compact heat exchanger (PCHE)