On the thermal conductivity of R32 in critical region

UDC 561.22

On the thermal conductivity of R32 in critical region

Tsvetkov O. B., Laptev Yu.A. , Rykov S.V. , Galachova N.A. , Ismagilov N.G.

The thermal conductivity of R32 at temperatures from 294,72 to 356,68 K and at densities up to 1000 kg·m-3 has been measured. The data were obtained applying the coaxial cylinder cell. Experiments were conducted with sample of R32 certified to be 99,84 %. The apparatus was checked with four kinds of liquids and gases. The thermal conductivity measured for liquid phase was compared to data reported in the literature with satisfactory agreement. The enhancement of the thermal conductivity was observed at states close to the critical point. The representations for the critical thermal conductivity are developed for the thermal diffusivity and the Maxwell factor of R32. Densities, isobaric and isochoric specific heats were calculated from the equation of state proposed for R32 which a has critical pressure pcr of 5,7847 MPa, a critical temperature Tcr of 351,255 K and a critical density ρcrof 424 kg·m-3.

Keywords: thermal conductivity, R32, singularity, thermal diffusivity, Maxwell factor.

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