Effects of the Initial Gel Fuel Temperature on the Ignition Mechanism and Characteristics of Oil-Filled Cryogel Droplets in the High-Temperature Oxidizer Medium

Dmitrii O. Glushkov, Alexander G. Nigay, Vyacheslav A. Yanovsky, Olga S. Yashutina

Research output: Contribution to journalArticle

Abstract

The ignition mechanism was studied for a group of gel fuel compositions in a high-temperature oxidizer medium. It was determined how the initial temperature of the fuel influences the ignition characteristics. The gel fuel (oil-filled cryogel) was prepared from an oil emulsion based on the mixture of a combustible liquid and polyvinyl alcohol. The composition of primary oil emulsions was as follows: the aqueous solution of polyvinyl alcohol (5, 10 wt %) + 40-60 vol % of oil + 2 vol % of emulsifier. The initial temperature of gel fuels ranged from 188 to 293 K. Combustion was initiated in high-temperature motionless air at 873-1273 K. Using a high-speed video recording system, we established that at different initial temperatures of the gel fuel, a set of identical processes occurs during the induction period; these are different from the same physical and chemical processes during the ignition of a combustible liquid. After reaching threshold conditions, the flame spreads in the droplet's vicinity from a hot spot through the gas mixture. Hot spot is an ignited and a small-sized fragment separating and moving away from the molten fuel droplet as a result of a microexplosion. The values of the main process characteristic - ignition delay times - differ 25-95% for fuel samples with the initial temperature of 293 K and temperatures of 188-233 K because of a long heating and melting stage of the latter. This is explained by a 2.5-3.6-fold difference in the amount of energy, which is necessary to supply to a colder fuel sample for this phase transformation to occur, other things being equal.

Original languageEnglish
Pages (from-to)11812-11820
Number of pages9
JournalEnergy and Fuels
Volume33
Issue number11
DOIs
Publication statusPublished - 21 Nov 2019

Fingerprint

Cryogels
Ignition
Oils
Gels
Polyvinyl Alcohol
Polyvinyl alcohols
Temperature
Emulsions
Fuel Oils
Video recording
Liquids
Fuel oils
Chemical analysis
Gas mixtures
Molten materials
Time delay
Melting
Phase transitions
Heating

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Fuel Technology
  • Energy Engineering and Power Technology

Cite this

Effects of the Initial Gel Fuel Temperature on the Ignition Mechanism and Characteristics of Oil-Filled Cryogel Droplets in the High-Temperature Oxidizer Medium. / Glushkov, Dmitrii O.; Nigay, Alexander G.; Yanovsky, Vyacheslav A.; Yashutina, Olga S.

In: Energy and Fuels, Vol. 33, No. 11, 21.11.2019, p. 11812-11820.

Research output: Contribution to journalArticle

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