Cooling effects at decompression of a CO₂-water system at temperatures from 273.15 K to 313.15 K and pressures up to 30 MPa.

Climate change is driven both directly by the global warming potential of refrigerants and indirectly by the rising global demand for cooling, which increases primary energy consumption and greenhouse gas emissions. While significant efforts have been made to improve existing refrigeration technologies, innovative approaches are also required. Although CO2 (R744) and water (R718) are well-investigated and widely used refrigerants, little work has been conducted so far on the refrigerating potential of these fluids combined in a vapor-compression system. In this work, the authors show and quantify the cooling effects occurring during the decompression of a CO2-water system at temperatures from 273.15 K to 313.15 K and pressures up to 30 MPa. These effects provide a significant refrigerating potential under suitable operating conditions. Promising applications include, for example, the generation of ice, ice slurry, cold water, or gas hydrate slurry.