Minimum ignition energies and laminar burning velocities of ammonia, HFO-1234yf, HFC-32 and their mixtures with carbon dioxide, HFC-125 and HFC-134a

Mirhadi S Sadaghiani; Arash Arami-Niya; Dongke Zhang; Tomoya Tsuji; Yukio Tanaka; Yoshio Seiki; Eric F May

doi:10.1016/j.jhazmat.2020.124781

Minimum ignition energies and laminar burning velocities of ammonia, HFO-1234yf, HFC-32 and their mixtures with carbon dioxide, HFC-125 and HFC-134a

J Hazard Mater. 2021 Apr 5:407:124781. doi: 10.1016/j.jhazmat.2020.124781. Epub 2020 Dec 8.

Authors

Mirhadi S Sadaghiani¹, Arash Arami-Niya², Dongke Zhang³, Tomoya Tsuji⁴, Yukio Tanaka⁵, Yoshio Seiki⁵, Eric F May⁶

Affiliations

¹ Fluid Science & Resources Division, Department of Chemical Engineering, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia.
² Fluid Science & Resources Division, Department of Chemical Engineering, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia; Discipline of Chemical Engineering, Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
³ Centre for Energy, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
⁴ Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur 54100, Malaysia.
⁵ Chemical Research Department, Research & Innovation Centre, Mitsubishi Heavy Industries, Ltd., Hiroshima 733-8553, Japan.
⁶ Fluid Science & Resources Division, Department of Chemical Engineering, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia; Centre for Energy, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. Electronic address: Eric.May@uwa.edu.au.

PMID: 33412363
DOI: 10.1016/j.jhazmat.2020.124781

Abstract

Given the safety issues associated with flammability characteristics of alternative environmentally-friendly refrigerants, it is vital to establish measurement systems to accurately analyse the flammability of these mildly flammable refrigerants. In this study, we used a customised Hartmann bomb analogue to measure the minimum ignition energy (MIE) and laminar burning velocity (BV) for refrigerant/air mixtures of pure ammonia (R717), R32, R1234yf and mixtures of R32 and R1234yf with non-flammable refrigerants of R134a, R125 and carbon dioxide (R744). The MIEs of R717, R32, and R1234yf were measured at an ambient temperature of 24 °C to be (18.0 ± 1.4), (8.0 ± 1.5) and (510 ± 130) mJ at equivalence ratios of 0.9, 1.27 and 1.33, respectively. Adding the non-flammable refrigerants R134a, R125 and R744 along with R32 at volumetric concentrations of 5% each to R1234yf reduced the latter compound's flammability and increased its MIE by one order of magnitude. The laminar burning velocities of pure R717 and R32 were measured at an equivalence ratio of 1.1 using the flat flame method and found to be 8.4 and 7.4 cm/s, respectively. Adding 5% R1234yf to R32 decreased the laminar burning velocity by 11%, while a further 5% addition of R1234yf resulted in a decrease of over 30% in the laminar burning velocity.

Keywords: Burning velocity; Flammability characteristics; Hydrofluorocarbons; Hydrofluoroolefins; Minimum ignition energy; Refrigerants.