Combustion and flammability chemistry for the refrigerant HFO-1234yf (2,3,3,3-tetrafluroropropene)

Needham, Craig D.; Westmoreland, Phillip R.

doi:10.1016/j.combustflame.2017.06.004

Cited by 44 publications

(7 citation statements)

References 20 publications

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“…Table 2 lists the fluorine-containing hydrocarbon and oxidized-hydrocarbon species considered in the kinetic model with their standard enthalpies of formation ΔfH o , standard entropies So, and heat capacities at constant pressure Cp, o (all at 298.15 K). Thermochemical data for the species CF3CCF, CF=CHCF3, CHF=CCF3 and CH=CFCF3 were estimated using group additivity approaches, using several sources [7,[25][26][27][28][29][30][31]. Data for the other species were taken from the literature [27][28][29]32].…”

Section: Hfc Refrigerant Cas Numbermentioning

confidence: 99%

“…Thermochemical data for the species CF3CCF, CF=CHCF3, CHF=CCF3 and CH=CFCF3 were estimated using group additivity approaches, using several sources [7,[25][26][27][28][29][30][31]. Data for the other species were taken from the literature [27][28][29]32]. Note that the thermodynamic data for fluorine-containing species were updated from a previous set of data [33] using two main sources [32,34].…”

Section: Hfc Refrigerant Cas Numbermentioning

confidence: 99%

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Modeling of combustion of fluorine-containing refrigerants

Babushok¹,

Burgess²,

Kim³

et al. 2021

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A gas-phase chemical kinetic model for the combustion of C1-C3 fluorine-containing refrigerants is presented, including a list of relevant species, their thermodynamic and transport properties, and the Arrhenius parameters for their reactions. Also included are tables of available experimental data in the literature for the laminar burning velocities for these HFC refrigerants and their mixtures. A comparison is made between the experimental data and predicted burning velocities as a function of the fuel-air equivalence ratio for the refrigerants. The model has been developed for the refrigerants: R-32, R-125, R-134a, R-152a, R-143, R-143a, R-1234yf, R-1234ze(E), R-1243zf and their mixtures. Agreement between predicted and measured burning velocity is very good for most of the refrigerant mixtures, and reasonably good agreement for a few.

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Section: Hfc Refrigerant Cas Numbermentioning

confidence: 99%

Section: Hfc Refrigerant Cas Numbermentioning

confidence: 99%

Modeling of combustion of fluorine-containing refrigerants

Babushok¹,

Burgess²,

Kim³

et al. 2021

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“…The transport properties (see the Supporting Information) were taken from a number of sources, augmented with our estimations by analogy. [16][17][18][19][20] In our spherically expanding flame experiments that were used to validate the kinetics model, the gas is ignited with a spark in the center of the vessel. The kinetic model here should work adequately for all cases for burning R-32.…”

Section: Overview Of Chemical Kinetic Mechanismmentioning

confidence: 99%

“…To this relatively well-known C/H/O chemistry, it is necessary to add a fluorocarbon submechanism that describes the breakdown of the fluorinated components. Fortunately, considerable previous work 16, on the combustion of fluorinated hydrocarbon systems has established the most relevant chemistry at the qualitative level. For instance, one expects unimolecular decomposition of the fuel to be important, as well as radical reactions involving the fuel and major active flame radicals such as H, OH, O, and F. 7 The intermediate fluorocarbon species created (J/mol/K) to those of the starting fuel, as well as recombination, disproportionation, and reaction with O 2 .…”

Section: Overview Of Chemical Kinetic Mechanismmentioning

confidence: 99%

A chemical kinetic mechanism for combustion and flame propagation of CH₂F₂/O₂/N₂ mixtures

Burgess

Babushok

Manion

2021

Int J of Chemical Kinetics

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In this work, we compiled and evaluated rate expressions for reactions relevant to the decomposition and combustion of CH 2 F 2 (difluoromethane, refrigerant R-32) in CH 2 F 2 /O 2 /N 2 flames. The recommended values have been used in premixed flame calculations, reported elsewhere, to model experimentally derived burning velocities determined using a constant volume spherical flame method. In this work, we also provide a detailed description of the reaction pathways for decomposition and combustion of CH 2 F 2 . This work is part of a larger effort at NIST to characterize and predict the flammability of new refrigerant working fluids and their blends for consideration as replacements of current refrigerants with high global warming potentials.

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“…For accurate predictions however, additional research is necessary to understand the important effects of flame stretch (Pagliaro and Linteris, 2016), radiation heat losses (Burrell et al, 2018), and buoyancy (Takizawa et al, 2013). Also, the calculation of the laminar burning velocity of HFC compounds in air requires a detailed kinetic mechanism, and while these are in active stages of development (Babushok and Linteris, 2017;Needham and Westmoreland, 2017;Papas et al, 2017), more work is required (Linteris and Babushok, 2018). Thus, while work is proceeding to calculate burning velocity, presently it must be measured.…”

Section: Introductionmentioning

confidence: 99%

An empirical model for refrigerant flammability based on molecular structure and thermodynamics

Linteris

Bell

McLinden

2019

International Journal of Refrigeration

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Screening methods for refrigerant blend flammability using metrics that can be easily calculated are of great interest to the refrigerant industry. Existing flammability metrics such as heat of combustion are not adequate for hydrofluorocarbon blends. Alternative metrics are needed that can be used to assess the flammability of refrigerant blends without requiring time-consuming experimental measurements. In this work we study the combination of the maximum adiabatic flame temperature and the fluorine-substitution ratio as metrics for characterizing the flammability of refrigerant blends. The combination of these metrics yields an estimate of the flammability class of refrigerants (both blends and pure fluids) containing hydrofluorocarbon and hydrocarbon components. The calculations of adiabatic flame temperature are carried out with the open-source chemical kinetics software package Cantera using a mechanism available in the literature. 2. FLAMMABILITY METRICS The flammability of a refrigerant is classified by ANSI/ASHRAE Standard 34 (ASHRAE, 2016) and ISO Standard 817 (ISO, 2014) based on its heat of combustion, lower flammability limit, and laminar burning velocity. The classes range from "1" (fluids exhibiting "no flame propagation") to "3" ("higher flammability"-fluids with a heat of combustion greater than 19 MJ/kg or a lower flammability limit less than 0.10 kg/m 3). Fluids of "lower flammability" are assigned to class "2." Class 2 fluids have a heat of combustion less than 19 MJ/kg and a lower flammability limit greater than 0.10 kg/m 3. There is a further subclass "2L" for class 2 fluids that also meet the additional condition of a maximum burning velocity less than 10 cm/s. Flame propagation and the lower flammability limit are determined by the test method specified in ASTM E-681 (ASTM, 2015), with slight modifications. Although the distinct flammability classes of 1, 2L, 2, and 3 might suggest that there is a clear boundary between "flammable" and "nonflammable" refrigerants, flammability is, in fact, a continuum (Williams, 1974). While methane, for example, is clearly flammable and carbon dioxide is clearly nonflammable, many other fluids are somewhere in between. What constitutes "flammable" is a function of the test method and test conditions. The ASTM E-681 test (as modified for refrigerants) is carried out in a 12 L glass flask with premixed fuel and air, with ignition provided by an electric spark. The criteria for "flame propagation" is that the flame move upwards and outwards from the spark, extend to the walls of the flask, and subtend an angle equal to or greater than 90˚, as measured from the point of ignition. Thus, a refrigerant exhibiting a weak flame with a flame angle less than 90˚ in the E-681 test would

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Combustion and flammability chemistry for the refrigerant HFO-1234yf (2,3,3,3-tetrafluroropropene)

Cited by 44 publications

References 20 publications

Modeling of combustion of fluorine-containing refrigerants

Modeling of combustion of fluorine-containing refrigerants

A chemical kinetic mechanism for combustion and flame propagation of CH₂F₂/O₂/N₂ mixtures

An empirical model for refrigerant flammability based on molecular structure and thermodynamics

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Combustion and flammability chemistry for the refrigerant HFO-1234yf (2,3,3,3-tetrafluroropropene)

Cited by 44 publications

References 20 publications

Modeling of combustion of fluorine-containing refrigerants

Modeling of combustion of fluorine-containing refrigerants

A chemical kinetic mechanism for combustion and flame propagation of CH2F2/O2/N2 mixtures

An empirical model for refrigerant flammability based on molecular structure and thermodynamics

Contact Info

Product

Resources

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A chemical kinetic mechanism for combustion and flame propagation of CH₂F₂/O₂/N₂ mixtures