Development of a burnett PVT apparatus for low-gwp refrigerants at high temperatures up to 473 K

A Burnett apparatus for the PVT property measurement of new refrigerants with low global warming potential (GWP) was developed. In the Burnett method, the PVT properties of a sample fluid filled in the sample cell are evaluated by repeatedly expanding the sample to the evacuated expansion cell isothermally and measuring the equilibrium pressure of the sample after the expansions. This method does not require the sample mass measurements, and are very useful in the vapor phase. The present apparatus has a constant temperature bath using silicone oil as a heating medium, and is available at temperatures up to 473 K. In this paper, the PVT properties of R134a at 353 K and at pressures up to 0.6 MPa were measured, and they are in good agreement with a reliable equation of state (EOS) within 0.1 %. Then, the PVT properties of R1234ze(Z) have been measured at 353 K and at pressures up to 0.3 MPa, and the obtained data are compared with the latest EOS.