Low GWP halocarbon refrigerants: A review of thermophysical properties

In the present work, a large number of compounds described in the publicly available literature have been reviewed with the aim to identify possible substitutes for high-GWP HFCs in HVAC&R and organic Rank- ine cycle (ORC) applications. Taking into account various criteria (particularly low toxicity, low flamma- bility, low GWP, and high energy efficiency), only a few single-component compounds are suitable for many of the relevant applications. In particular, in addition to natural fluids, studies have shown that there are only a few HFCs and a dozen or so HFOs, i.e. halogenated olefins characterized by the presence of a C = C double bond in the molecule, that are potentially suitable for a number of relevant applications. Here, a review of the present state-of-the-art of experimentally-determined thermophysical properties of a number of HFOs working fluids and their mixtures also with other categories of refrigerants is pre- sented, with particular emphasis placed on saturation and critical properties, vapor phase PVT data, liquid density, specific heat capacity, thermal conductivity, viscosity, and surface tension.