Conference Proceeding published 2008 by ASHRAE
Written By Richard C. Cavestri, PhD; Donna Seeger-Clevenger
This paper is based on findings resulting from ASHRAE Research Project RP-1303.
The distribution of the noncondensable gases (NCGs) nitrogen and dry air in refrigerant liquid and vapor is determined at temperatures in the range of 3°F, 65°F, and 130°F (â16°C, 18.3°C, and 54.4°C) at five different partial pressures (5, 15, 30, 45, and 60 psi) in each of eight refrigerants (R-22, 123, 124, 134a, 404A, 407C, 410A, and 507). R-123 is equilibrated at 109°F, 120°F, and 130°F (43°C, 49°C, and 54°C) with the same partial pressures, due to its high normal boiling point. The distribution is determined by measuring the concentration of the NCG in the liquid and in the vapor phases after equilibrium is achieved.
Equilibrium is achieved by introducing the NCGs into the thermostatically controlled and highly agitated liquid refrigerant and circulating them until a constant pressure is achieved. The entire circulating and sampling mechanism, with NIST traceable pressure transducers, is held at constant temperatures. Samples of the liquid and vapor phases of the refrigerant mixture are expanded into smaller cells contained in a temperaturecontrolled oven held at 140°F (60°C) prior to gas chromatograph (GC) analysis. Sampling and analysis are accomplished without air exposure into a GC equipped with a thermal conductivity detector and hydrogen carrier gas. Gas solubility equations for each refrigerant are developed from the resulting values.
Units: Dual
Citation: ASHRAE Transactions, vol. 114, pt. 2, Salt Lake City 2008
