The hunt for refrigerant blends to replace R-134a

Published

August 1, 2019

Author(s)

Ian H. Bell, Piotr A. Domanski, Gregory T. Linteris, Mark O. McLinden

Abstract

We investigated refrigerant blends as possible low GWP (global warming potential) alternatives for R-134a in an air-conditioning application. We carried out an extensive screening of the binary, ternary, and four-component blends possible among a list of 13 pure refrigerants comprising four hydrofluoroolefins (HFOs), eight hydrofluorocarbons (HFCs), and carbon dioxide. The screening was based on a simplified cycle model, but with the inclusion of pressure drops in the evaporator and condenser. The metrics for the evaluation were nonflammability, low GWP, high COP (coefficient of performance), and a volumetric capacity similar to the R-134a baseline system. While no mixture was ideal in all regards, we identified 14 binary and ternary blends that were nonflammable (based on a new estimation method by Linteris, et al.) and with COP and capacity similar to the R-134a baseline; the tradeoff, however, was a reduction in GWP of, at most, 51% compared to R-134a. An additional eight blends that were estimated to be "marginally flammable" (ASHRAE Standard 34 classification of A2L) were identified with GWP reductions of as much as 99%. These 22 ``best" blends were then simulated in a more detailed cycle model.

Citation

International Journal of Refrigeration

Pub Type

Journals

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Citation

Bell, I. , Domanski, P. , Linteris, G. and McLinden, M. (2019), The hunt for refrigerant blends to replace R-134a, International Journal of Refrigeration, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926442 (Accessed April 18, 2024)