RP-1303 -- Partitioning of Non-Condensable Gases in Refrigerant Liquid and Vapor Phases

Date on document is 2007.

The distribution of non-condensable gases (NCGs) nitrogen and dry air in refrigerant liquid and vapor is determined at temperatures in the range of 3°F (-16°C), 65°F (18.3°C) and 130°F (54.4°C) at five different partial pressures (5, 15, 30, 45, and 60 psi) in each eight refrigerants (R-22, 123, 124, 134a, 404A, 407C, 410A and 507). R-123 is equilibrated at 109°F (43°C), 120°F (49°C), 130°F (54°C) with the same partial pressures.

The NCGs are introduced into the thermostatically controlled, highly agitated liquid refrigerant via a gas tube immersed in the liquid contained in a vertical cell that has an approximate 0.25 liter volume normally filled to 70-80% full. Liquid refrigerant is circulated through the cell until pressure equilibrium is achieved with either air or nitrogen. The entire circulating and sampling mechanism, with NIST traceable pressure transducers, is held at constant temperatures. Samples of the refrigerant mixture are loaded into smaller cells contained in a temperature controlled chamber at 140°F (60°C) prior to GC analysis. Values for NCGs and vapor are determined by sampling from the top of the cell through a 6 port assembly directly 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