Low global-warming-potential refrigerant CH2F2 (R-32): Integration of a radiation heat loss correction method to accurately determine experimental flame speed metrics

Published

August 22, 2020

Author(s)

Gregory T. Linteris, Raik Hesse, Lukas Berger, Michael Hegetschweiler, Heinz Pitsch, Joachim Beeckmann

Abstract

Due to their high global warming potential (GWP), hydrofluorocarbon refrigerants (HFCs) are systematically being phased out. Replacements with low GWP exist, but give rise to safety hazards as they are found to be mildly flammable. The assessment of the safety hazards of such fluids is typically based on their laminar burning velocities. However, typical laminar burning velocities are below 10 cm/s, and hence are challenging to measure. Flames propagating at this speed are strongly affected by radiation heat loss and have to be corrected if considered for kinetic model validation. In the present study, the laminar burning velocity of the representative refrigerant difluoromethane (CH2F2, R-32) is easured experimentally in a outwardly propagating flame configuration (OPF) at elevated pressure and emperature. In order to assess radiation heat loss effects, detailed simulations using a recent kinetic model for R-32 are conducted. Flame speed reductions were found to be in the order of 15 %. Afterwards, an analytical radiation correction model, as discussed by Santner et al. [Combust. Flame, 161(1), (2014), 147-153.], is adopted and its suitability for refrigerant/air flames is demonstrated based on simulation. After subsequent correction of experimental results, the predictability of the model is evaluated, showing good agreement.

Citation

Proceedings of the Combustion Institute

Volume

38

Issue

3

Pub Type

Journals

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DOI Link

Keywords

Difluoromethane, Refrigerant Flammability, Laminar Flame Speed, Spherically Propagating Flame, Fire Safety, Radiation

Citation

Linteris, G. , Hesse, R. , Berger, L. , Hegetschweiler, M. , Pitsch, H. and Beeckmann, J. (2020), Low global-warming-potential refrigerant CH2F2 (R-32): Integration of a radiation heat loss correction method to accurately determine experimental flame speed metrics, Proceedings of the Combustion Institute, [online], https://doi.org/10.1016/j.proci.2020.05.026 (Accessed April 28, 2024)