Trends in the Properties of Volatile Liquid Fuels

2009 ◽  
pp. 66-66-15
Author(s):  
DP Barnard ◽  
AH Fox
Keyword(s):  
Liquid Fuels ◽  
Volatile Liquid

Evaporation of Volatile Liquid Pools Under Forced Convection: Part 2—Integration of a Vaporization Model in a CFD Software

2012 ◽  
Author(s):  
Nicolas Doué ◽  
Karim Loueslati ◽  
Dominique Alonso ◽  
Ghislain Genin ◽  
Michel Molière
Keyword(s):  
Liquid Pool ◽  
Liquid Fuels ◽  
Accurate Assessment ◽  
Volatile Species ◽  
Reliable Prediction ◽  
Ansys Fluent ◽  
Volatile Liquid ◽  
Liquid Pools ◽  
Mass Transfers ◽  
Ventilation Conditions

The transfer under dynamic conditions of volatile species from a liquid pool to the surrounding air is gaining interest in the engineering community. In particular, increasingly stringent regulations and standards apply to all types of flammable substances. This is especially the case in stationary gas turbine applications, where the vaporization of accidentally occurring pools of liquid fuels attracts increasing attention. Since the flame-to-explosion transition cases are insufficiently controlled, the current, only practicable approach to assess the explosion risks arising from a fuel pool in an enclosure consists in quantifying the amount of vapor that leaves the pool and minimizing, by means of a proper dilution strategy, the potential damages entailed by the ignition of the resulting cloud. This approach requires two steps: (1) The accurate assessment of vaporization rates under given ventilation conditions, a task that calls for skills in thermal and mass transfers. (2) The reliable prediction of the transport of the vapors in the ventilation stream, a task specifically focused on fluid dynamics. The three teams involved in this paper have joined their efforts to achieve this multidisciplinary objective. As a first task, the LRGP team (Laboratoire des Reactions et Génie des Procédés) and GE Energy have experimentally validated a vaporization model initially devised for water pools. This work has been reported in a recent paper. Concurrently, EURO/CFD and GE Energy have developed a CFD approach devoted to the mixing/dilution processes in defined enclosure geometries and under specified ventilation conditions. Finally both approaches havebeen coupled by EURO/CFD to produce predictive isopleth pictures of the vapor clouds generated under given temperature and velocity conditions. The present paper covers the integration of the liquid pool vaporization model in thecommercial CFD software ANSYS Fluent and sets out the results obtained. This dual, concerted approach is a first of the kind to the authors’ knowledge and proves fruitful for the prediction of the spatial distributions of the volatile species developed when a volatile pool vaporizes in a ventilated enclosure. It fills a gap in the analysis of safety scenarios arising from spillages of liquid fuels and provides a rational tool in zone classification studies.

Microscopic Approaches to Decomposition and Burning Processes of a Micro Plastic Resin Particle

2007 ◽  
Author(s):  
Atsunori Yamamoto ◽  
Ryuji Yamakita ◽  
Yojiro Ishino ◽  
Norio Ohiwa
Keyword(s):  
High Speed ◽  
Diffusion Flames ◽  
Temporal Variations ◽  
Heating Time ◽  
Liquid Fuels ◽  
Combustion Gas ◽  
Resin Particle ◽  
Schlieren System ◽  
Volatile Liquid ◽  
Plastic Resin

From a fundamental and microscopic viewpoint to elucidate the possibility and availability of thermal recycling of wasted plastic resin, a series of heating processes of melting, thermal decomposition and burning of a spherical micro plastic resin particle having a diameter of about 200 μm are observed, when it is suddenly exposed to hot oxidizing combustion gas. Three ingenious devices are introduced; the first is a high-speed microscopic direct and schlieren system, the second is a pre-mixed mini-burner for abrupt heating, which is equipped with a pair of spark gaps at its exit and is discharged synchronously with the starting signal of high-speed camera, and the third is a single mini-puff generator, which enables to extinguish instantly all flames around the micro particle at an arbitrary assigned time after the spark ignition. Polyethylene terephthalate and polyethylene are used as two typical plastic resins. In this paper the dependency of internal and external appearances of residual plastic embers on the heating time and the initial plastic composition is optically analyzed, along with appearances of internal micro bubbling, micro jets and micro diffusion flames during abrupt heating. Based on temporal variations of the surface area of a micro plastic particle, the burning rate constant is also evaluated and compared with well-known volatile liquid fuels.

Microscopic versus process parameters in heavy-oil upgrading

1992 ◽  
Vol 50 (1) ◽  
pp. 366-367
Author(s):  
V.A. Munoz ◽  
R.J. Mikula ◽  
C. Payette ◽  
W.W. Lam
Keyword(s):  
Molecular Weight ◽  
Liquid Fuels ◽  
Chemical Components ◽  
Heavy Oils ◽  
Synthetic Fuels ◽  
High Hydrogen ◽  
Optical Texture ◽  
Polar Groups ◽  
Anisotropic Character ◽  
Planar Molecules

The transformation of high molecular weight components present in heavy oils into useable liquid fuels requires their decomposition by means of a variety of processes. The low molecular weight species produced recombine under controlled conditions to generate synthetic fuels. However, an important fraction undergo further recombination into higher molecular weight components, leading to the formation of coke. The optical texture of the coke can be related to its originating components. Those with high sulfur and oxygen content tend to produce cokes with small optical texture or fine mosaic, whereas compounds with relatively high hydrogen content are likely to produce large optical texture or domains. In addition, the structure of the parent chemical components, planar or nonplanar, determines the isotropic or anisotropic character of the coke. Planar molecules have a tendency to align in an approximately parallel arrangement to initiate the formation of the nematic mesophase leading to the formation of anisotropic coke. Nonplanar highly alkylated compounds and/or those rich in polar groups form isotropic coke. The aliphatic branches produce steric hindrance to alignment, whereas the polar groups participate in cross-linking reactions.

MECHANISM AND CHARACTERISTICS OF GEL FUEL IGNITION

2020 ◽  
Author(s):  
O. S. Gaydukova ◽  
◽  
D. O. Glushkov ◽  
A. G. Nigay ◽  
A. G. Kosintsev ◽  
...  
Keyword(s):  
Thermal Power ◽  
Aerospace Industry ◽  
Theory Development ◽  
Liquid Fuels ◽  
Ignition Characteristics ◽  
Deformable Materials ◽  
Combustion Processes ◽  
Thermal Power Engineering ◽  
Storage Processes ◽  
Emulsions And Suspensions

Recently, prospective direction of the combustion theory development is the preparation of fuel compositions and study of the composite fuels ignition characteristics, for example, in the form of emulsions and suspensions. Such fuels and their combustion processes are characterized by higher environmental, energy, economic, and operational properties. Of great interest is the use of gel fuels prepared by thickening emulsions and suspensions to the state of elastically deformable materials for the aerospace industry and thermal power engineering. Gel fuels have advantages over widespread liquid fuels in environmental and fire safety aspects of storage processes, transportation, and combustion.

Sign in / Sign up

Export Citation Format

Share Document