Utilization of CO_2 and R1234ze(E) as refigerant: Determination of mixture volumetric properties at the vicinity of critical point

摘要

In recent years, binary and multi-mixture refrigerant have been developed to increase the cycleefficiency and reduce environmental effects. The most promising mixture are composed ofR1234yf or R1234ze(E) with HFC or natural refrigerants. However, the experimental data of newmixture is still in short. In this work, we present the results obtained for the temperature-densitydiagram of CO2 and R1234ze(E) at the vicinity of the mixture critical point for 4 differentcompositions. Measurements were done by an equipment whom technique is based on syntheticvisual method with observation of disappearance of liquid-vapor interface. Cubic equation of stateand Refprop model were used to correlate the data. With cubic EoS, the critical point is determinedby considering Heidemann et Michelsen method. The results obtained show a good agreementbetween experiments and proposed modelling.