Autoignition delay times of propane mixtures under MILD conditions at atmospheric pressure

CO 2 and H 2 O effect on propane auto-ignition delay times under mild combustion operative conditions

“…In both cases, the ignition times are longer by almost one order of magnitude than those obtained for the mixture diluted in nitrogen. All three sets of data show an Arrhenius trend in the range of high temperature, whereas for lower temperatures, the obtained data for nitrogen show a change in activation energy of the ignition process that passes from intermediate to high inlet temperature, as widely discussed by Sabia et al [24].…”

“…Several main typologies of the axial-temperature profiles were recognized and associated with the characteristic combustion regimes. The typical temperature profiles were reported and thoroughly explained in Sabia et al [6,24]. Briefly, it was possible to recognize the following combustion regimes:…”

“…To evaluate the effect of CO 2 and H 2 O on the propane ignition process, it is useful to compare the obtained results (experimental and numerical) with those of mixtures that were diluted in inert environments, as reported by Sabia et al [24]. Figure 5 shows the auto-ignition delay times for a stoichiometric propane/oxygen mixture that was diluted up to 90% in N 2 , CO 2 and H 2 O.…”

“…The ''C 1 C 3 '' [27] mechanism was chosen after the evaluation of its performance in predicting main features of the oxidation process under MILD conditions in previous works [6,24].…”

“…Experimental tests were realized in a laboratory-scale stainlesssteel tubular flow reactor, which was 140 cm long with an inner diameter of 1 cm, as described elsewhere [6,23,24]. The main flow, which was composed of oxygen and diluent, was pre-heated to the desired temperature using electric fiber heaters and was subsequently mixed with the fuel flow using jets in a cross-flow configuration; then, the premixed charge entered the reactor.…”