The History of NIST's Refrigerants Program: 1. Zeotropic Mixture Cycles and Heat Transfer
The NIST Refrigerants Program was initiated in 1981 under the sponsorship of the Electric Power Research Institute with the intent to determine if a zeotropic mixture, operating in a Lorentz Cycle, could be found that would give superior performance to the traditional R-22 Vapor Compression Cycle. From the very beginning it was necessary to establish a method for predicting both refrigerant thermophysical properties of new refrigerants as well as the properties of the refrigerant mixtures for incorporation into the existing NIST performance models. These models would then be used as the primary screening for promising mixtures. At the time the heat pump facilities, both the breadboard apparatus and the production units, that were available from the energy conservation program of the 1970s, were adapted for the counter-flow heat exchange between the refrigerant and the secondary heat transfer fluid. In addition, the existing evaporative heat transfer rig was dedicated to mixture measurements. All of these projects were fully under way when the ozone crisis was officially announced in 1987 and when the NIST program goal was shifted to one of determining and evaluating alternatives to the CFCs that were in current use. Some of the more significant technical reports and journal papers are listed in this paper's references as are the three database computer programs that were developed for public use.
American Society of Heating, Refrigerating and Air-Conditioning Enginners | | | ASHRAE
The History of NIST's Refrigerants Program: 1. Zeotropic Mixture Cycles and Heat Transfer, American Society of Heating, Refrigerating and Air-Conditioning Enginners | | | ASHRAE
(Accessed June 10, 2023)