NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Compressed liquid density and speed of sound measurements and correlation of the binary mixture carbon dioxide (CO2) + 1,1-difluoroethene (R1132a)} at temperatures from 220 K to 350 K
Published
Author(s)
Davide Menegazzo, Aaron Rowane, Giulia Lombardo, Sergio Bobbo, Laura Fedele, Mark McLinden
Abstract
The combination of carbon dioxide (CO2) and R1132a has been proposed as a viable substitute for R23 in low-temperature applications. This study provides new experimental data on the compressed-liquid density, vapor density, and compressed-liquid speed of sound for the CO2 + R1132a binary system. These measurements were obtained using a two-sinker densimeter and a pulse-echo-type instrument. The density measurements span a temperature range of 220 K to 350 K and pressures up to 30 MPa, while the speed of sound measurements cover temperatures from 230 K to 350 K and pressures up to 65 MPa. For both properties, two different mixture compositions were tested. Additionally, we present an Equation of State (EoS) correlation for the experimental data, derived from a Helmholtz free energy model, which demonstrates a good fit with the measurements. Due to the mixture's strong absorption of the sound pulse, the standard dual-path analysis could not be employed. Therefore, a method utilizing only the short-path signal was developed.
Menegazzo, D.
, Rowane, A.
, Lombardo, G.
, Bobbo, S.
, Fedele, L.
and McLinden, M.
(2025),
Compressed liquid density and speed of sound measurements and correlation of the binary mixture {carbon dioxide (CO2) + 1,1-difluoroethene (R1132a)} at temperatures from 220 K to 350 K, International Journal of Refrigeration, [online], https://doi.org/10.1016/j.ijrefrig.2025.01.014, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958500
(Accessed October 2, 2025)