The Effect of Water Content Diameter on the Structure of Light Oil-Water Emulsion Spray Flame

Author(s):  
Manabu Fuchihata ◽  
Shuko Takeda ◽  
Tamio Ida

Microexplosions of light oil-water emulsified fuel droplets were successfully documented using a high-speed video camera with laser illumination. The local frequency of the explosion occurrence, temperature profile and exhaust gas emissions were measured in spray flames of water-in-oil type emulsion formed using an air-assist atomizer with a ring pilot burner. Those results indicate that the flame structure changes as the water droplet diameter in the emulsion fuel was varied, even if the fuel components and their fractions were same. When the fuel includes the water droplet, whose median diameter was about 75μm, HC and CO emission were reduced as compared to those for the fuel of smaller water droplet content. It is probable that if the water droplet diameter is uniform, avalanching microexplosions occur at certain local region in the flame, and the water content vaporizes almost at once and extinguishes the flame. It leads to HC and CO emission increase. When the water droplet diameters are large, atomizer atomizes those; therefore, emulsion droplets include various size of water droplet in the flame. Consequently, the avalanching microexplosion occurrence is avoided, and HC and CO emissions are reduced.

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
El-Sayed R. Negeed ◽  
M. Albeirutty ◽  
Sharaf F. AL-Sharif ◽  
S. Hidaka ◽  
Y. Takata

The aim of this study is to investigate the influence of the surface wettability on the dynamic behavior of a water droplet impacting onto a heated surface made of stainless steel grade 304 (Sus304). The surface wettability is controlled by exposing the surfaces to plasma irradiation for different time periods (namely, 0.0, 10, 60, and 120 s). The experimental runs were carried out by spraying water droplets on the heated surface where the droplet diameter and velocity were independently controlled. The droplet behavior during the collision with the hot surface has been recorded with a high-speed video camera. By analyzing the experimental results, the effects of surface wettability, contact angle between impacting droplet and the hot surface, droplet velocity, droplet size, and surface superheat on the dynamic behavior of the water droplet impacting on the hot surface were investigated. Empirical correlations are presented describing the hydrodynamic characteristics of an individual droplet impinging onto the heated hydrophilic surfaces and concealing the affecting parameters in such process.


Author(s):  
Л. І. Ниркова ◽  
С. О. Осадчук ◽  
Ю. В. Борисенко ◽  
Ф. М. Макатьора

Development of methodology for research and evaluation of internal corrosion of low-carbon steel pipeline along the bottom moving line in a hydrocarbon medium with different water content. Visual inspection and polarization resistance method were used. Based on the analysis of the peculiarities of internal corrosion of oil pipelines, the methodology of its research has been developed. A laboratory testing facility is proposed and manufactured, which simulates the inner surface of the pipeline. The design of the polarization resistance sensor was improved by applying a moisture-retaining layer, which allowed to determine the corrosion rate in the oil-water emulsion. To increase the sensitivity of the sensor in this environment, additives are introduced into the moisture-retaining layer, which promote the absorption and retention of moisture. The influence of various additives on the sensitivity of the sensor has been studied, the method of applying the moisture-retaining layer, which is suitable for use, has been worked out. The minimum concentration of the additive was determined, at which a solid moisture-retaining layer resistant to the action of moisture was obtained. The methodology of research of internal corrosion of the oil pipeline along the bottom moving line on the basis of modeling in laboratory conditions of a surface of a pipe is offered and substantiated. A laboratory testing facility was made and the design of the polarization resistance sensor was improved, which made it possible to perform measurements in oil-water emulsion. This allowed to expand the scope of the method of polarization resistance for oil environments with low water content (from 50% to 5%). The design of the electrochemical two-electrode sensor of polarization resistance with the cosurface arrangement of electrodes on which the moisture-retaining layer is put and its composition is defined is improved. A solid layer resistant to air moisture is obtained. The sensor with a moisture-retaining layer is suitable for use in oil-water emulsion with water content from 50% to 5%.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1733
Author(s):  
Yi Shi ◽  
Jiaqing Chen ◽  
Zehao Pan

As most of the light and easy oil fields have been produced or are nearing their end-life, the emulsion stability is enhanced and water cut is increasing in produced fluid which have brought challenges to oil–water separation in onshore and offshore production trains. The conventional solution to these challenges includes a combination of higher chemical dosages, larger vessels and more separation stages, which often demands increased energy consumption, higher operating costs and larger space for the production facility. It is not always feasible to address the issues by conventional means, especially for the separation process on offshore platforms. Electrostatic coalescence is an effective method to achieve demulsification and accelerate the oil–water separation process. In this paper, a novel compact electrostatic coalescer with helical electrodes was developed and its performance on treatment of water-in-oil emulsions was investigated by experiments. Focused beam reflectance measurement (FBRM) was used to make real-time online measurements of water droplet sizes in the emulsion. The average water droplet diameters and number of droplets within a certain size range are set as indicators for evaluating the effect of coalescence. We investigated the effect of electric field strength, frequency, water content and fluid velocity on the performance of coalescence. The experimental results showed that increasing the electric field strength could obviously contribute to the growth of small water droplets and coalescence. The extreme value of electric field strength achieved in the high-frequency electric field was much higher than that in the power-frequency (50 Hz) electric field, which can better promote the growth of water droplets. The initial average diameters of water droplets increase with higher water content. The rate of increment in the electric field was also increased. Its performance was compared with that of the plate electrodes to further verify the advantages of enhancing electrostatic coalescence and demulsification with helical electrodes. The research results can provide guidance for the optimization and performance improvement of a compact electrocoalescer.


Author(s):  
Kai Han ◽  
Geng Fu ◽  
Changlu Zhao ◽  
Bolan Liu ◽  
Shibo Ma

An experimental study of diesel-benzyl azides blend droplets vaporization characteristics was carried out to study the reasons of diesel-benzyl azides blend shortened combustion duration using suspended droplet device and a high-speed video camera. Experiments were performed at atmospheric pressure, ambient temperature range 480–933 K, and initial droplet diameter of 0.98, 1.42, 1.88 mm. The results show a shorten in diesel-benzyl azides blend droplet lifetime by 10% compared to diesel droplet at 1.42 mm initial droplet diameter and 933 K ambient temperature companion to puffing. The above results support the original idea of designing diesel-benzyl azides blend where the energy released by the decomposition of azides improves the vaporization and the release of nitrogen leads to the breakup of the droplet. In addition, it is observed that the blend lifetime decrease with increasing ambient temperature compared to diesel droplet lifetime. More nitrogen is released and the expansion of bubbles is more violent with increasing initial droplet diameter.


Author(s):  
G H Smith ◽  
E H Owens ◽  
I Reading

The proposal, from the International Maritime Organisation (IMO), to limit further the emissions from marine diesel engines came into effect in May 2005. This has considerable consequence for the management and operation of ship diesel plant. One method that has been shown to limit the emissions of NOx is the addition of quantities of water as an emulsion into the heavy fuel oil (HFO) before it is injected into the burners. This reduces the peak combustion temperature, improves atomization of the diesel fuel, and can reduce emissions by as much as 30 per cent. A key component for an efficient and cost-effective system is a method to monitor the water content to an accuracy sufficient to allow the mix to be adjusted to meet the needs of the varying engine loads. This paper briefly presents the environmental, legislative, and technical background. The principle aim is, however, to describe the experimental work examining the application of an in-line optical sensor. Laboratory tests on HFO, having a room temperature viscosity of 180 cSt, were undertaken at two nominal temperatures, 80 and 130°. These tests provide empirical evidence that an in-line optical monitor could determine water fraction within the emulsion to the accuracy requirement (better than 3 per cent) and over the operational water content range (15-33 per cent water to oil). A hypothesis is presented to explain the changes in the optical scattering characteristics of the oil/water emulsion with water content. Additional results are presented that demonstrate the use of two commercial viscometers to quantify the oil/water fraction. It was concluded that the measurement of emulsion viscosity can be related to water fraction but that the current instruments do not have the required resolution and have serious limitations due to their temperature sensitivity. A key requirement for further work is that the scattering properties of the emulsion be investigated in greater detail. In particular a test must be undertaken at temperatures in the region of 170°. Also, the instrument must be developed to cope with the wide variety of diesel fuels that a ship may take on at bunkering facilities around the world.


Soft Matter ◽  
2015 ◽  
Vol 11 (39) ◽  
pp. 7728-7738 ◽  
Author(s):  
Kazuyuki Ueno ◽  
Ghislain Bournival ◽  
Erica J. Wanless ◽  
Saori Nakayama ◽  
Emma C. Giakoumatos ◽  
...  

The interactions between two individual water droplets were investigated in air using a combination of coalescence rig and high speed video camera.


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