Experimental results on a chiller using a CO2-DME mixture

CO₂-DME (Carbon Dioxide-Dimethyl Ether) mixtures raised our interest in the last year as they promise to increase the COP with respect to pure CO₂ while maintaining GWP = 1. The mixture can be non-flammable, as far as the percentage of DME is low. This study presents experimental findings obtained from a chiller system utilizing CO₂-DME mixtures as the working fluid. The experimental investigation aims to analyse the performance and behaviour of the chiller under varying operating conditions. Key parameters, such as coefficient of performance, cooling capacity, and thermodynamic behaviour are examined to assess the suitability and efficacy of the CO₂-DME mixture in chiller applications. The experimental results shed light on the thermodynamic characteristics and operational considerations of the chiller system, providing valuable insights into the potential of CO₂-DME mixtures for environmentally friendly, safe and energy-efficient cooling technologies. The experimental findings indicate a maximum increase in COP of 15 % for a mixture comprising 10 % DME, with a condensation temperature of 35 °C. Furthermore, the cooling capacity is reduced only by 7 % in the worst case.