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Evaporation Reduction Test of Premium Unleaded Fuel by the Smart Floating Roof Method in a Horizontal Cylindrical Tank
Bagui Emmanuel,
Gbaha Prosper,
N. Guessan Kotchi Rémi
Issue:
Volume 5, Issue 2, December 2021
Pages:
15-28
Received:
21 June 2021
Accepted:
26 July 2021
Published:
9 August 2021
Abstract: The floating roof is originally the device that is easily used in a vertical cylindrical storage tank for volatile products. It covers the evaporative surface which remains constantly circular, regardless of the level of the fluid in the tank. However, in a horizontal cylindrical tank, the extent and shape of the free surface of the fluid, the seat of evaporation, varies according to the residual stock. To this end, the concept of the intelligent or flexible floating roof arises from the problem of pollution and energy losses resulting from the excessive evaporation of unleaded premium fuel (SPb) in the Ivory Coast, in the city of Korhogo, which has a hot and dry climate. Therefore, the objective of this study was to design a floating roof suitable for horizontal cylindrical tanks with a fairly competitive evaporation reduction performance. This study was carried out on an experimental station where two identical tanks were tested in comparative trials. One with a floating polypropylene ball roof and the other without a roof. The respective residual volumes of the fluid in each tank were monitored regularly and concomitantly according to evaporation factors such as temperature and pressure. At the end of these tests, it was found that the flexible floating roof absorbed more losses, with an estimated non-evaporation rate of 88% compared to the tank without the flexible floating roof, whose rate was estimated at 80%, i.e. an added value of 08%. Thus, the layers of beads placed at the gas-liquid interface reduced the heat, mass and pressure transfer between the two fuel phases.
Abstract: The floating roof is originally the device that is easily used in a vertical cylindrical storage tank for volatile products. It covers the evaporative surface which remains constantly circular, regardless of the level of the fluid in the tank. However, in a horizontal cylindrical tank, the extent and shape of the free surface of the fluid, the seat...
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Principles of Wheelset Hunting and Construction of Total Solution to Hunting
Issue:
Volume 5, Issue 2, December 2021
Pages:
29-39
Received:
20 July 2021
Accepted:
2 August 2021
Published:
12 August 2021
Abstract: Wheelset hunting is a motion with two degrees of freedom. The second degree of freedom of hunting is investigated in this paper. Rolling radius difference is commonly understood as the root cause of wheelset hunting. Normally, hunting will begin as soon as the truck begins to move. Rolling radius difference will initiate the hunting and can only be used to determine the configuration of the first quarter of a hunting cycle. Then a mechanism will come into exist to determine the configuration of the second quarter of the hunting cycle, which is exactly the same as the one of first quarter but in the opposite direction. The second half of the hunting cycle is a mirror of the first half. The information from wheelset hunting is too large and too complicated for people to understand and analyze. However, the radius of curvature of wheelset circular motion can be calculated exactly, especially at some special configurations, even though the radius of curvature of wheelset circular motion keeps changing in both magnitude and direction. Furthermore, comparison of the radii of curvature between hunting curve and a cosine curve shows that the curve for the wheelset in hunting motion is sinusoidal. This is proven mathematically in the paper. The limits in Klingel’s results were discussed. Due to the fact that Klingel’s results are unable to provide a strong theoretical base for further understanding the complicated dynamic characteristics caused by hunting, misleading in hunting is overwhelmed. After understanding the principles of wheelset hunting, three critical speeds in hunting and dynamic loading for truck design in three directions were calculated; wheelset hunting curve while curving was generated; wheelset dynamic interaction was analyzed and the question “Why trains stay on tracks” was answered correctly, just to name a few. Thus, a total solution to the hunting problems can be expected and was discussed in the paper.
Abstract: Wheelset hunting is a motion with two degrees of freedom. The second degree of freedom of hunting is investigated in this paper. Rolling radius difference is commonly understood as the root cause of wheelset hunting. Normally, hunting will begin as soon as the truck begins to move. Rolling radius difference will initiate the hunting and can only be...
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Maser-rays Based on Synchrotron Radiation-Total Reflection X-ray Fluorescence (SR-TXRF)
Issue:
Volume 5, Issue 2, December 2021
Pages:
40-53
Received:
4 October 2021
Accepted:
2 December 2021
Published:
9 December 2021
Abstract: In 2012, during the experiments performed at LNLS (Brazilian Synchrotron Light Laboratory) based on SR-TXRF measurements of Ormosil films containing phosphotungstates ([PW12O40]3-) was observed an image that could be interpreted as the result of the transition from the incident X-ray beam (packets of photons) to a continuous light beam (set of continuous waves). A hypothesis could be based on a summation of small local crystalline domains, which respond differently to the incident beam, resulting in a "continuous beam". Differently of the case of LASER beam, the excitation by synchrotron radiation could generate not only excitation but also ionization of a polyatomic/poly-molecular systems (indeed considering the whole sample), instead of monoatomic system. Thus, the presence of individual MASER (Molecular Amplification by Stimulated Emission of Radiation) beam generated by SR-TXRF could be considered. A MASER produces coherent electromagnetic waves through amplification by stimulated emission (process based on the that was proposed and argued by Albert Einstein between 1916-1917). In lower ranges of energies than the corresponding to X-rays of electromagnetic spectrum like the Ultraviolet region, the Phosphotungstates molecules (([PW12O40]-3)) exhibit very interesting phenomenon as the photocromism. This phenomenon occurs when the molecules mentioned above are irradiated with ultraviolet light, which brings these molecules to an excited electronic state. The reduced phosphotungstate obtained ([PW12O40]-4) exhibit a bluish color, being called heteropolyblue. This bluish color disappears in the presence of oxygen, the discoloration time is dependent on the time in which the sample was irradiated, or on the composition/thickness of the film. It is also possible found photoluminescence in the Phosphotungstates, which is due to the multiples multielectronic collisions. For ormosil films were shown the possible pathways of electron transfer of Phosphotungstates (could be internal and external), which are based on the presence of a high number of double chemical bonds between Tungsten and Oxygen atoms. In these mechanisms, the key aspect to consider is that the molecular structure of phosphotungstates remains intact after the preparation of these materials by Sol-Gel process. Taking as base the molecular mechanisms mentioned above, one model for the generation of maser rays has been proposed, considering the phosphotungstate molecule as a Super-atom (structure built of many atoms) due to its stability structural in these films. It would be possible the generation of Multi-Maser beams by SR-TXRF also, if it is taking in consideration the processes of ionization in the whole sample.
Abstract: In 2012, during the experiments performed at LNLS (Brazilian Synchrotron Light Laboratory) based on SR-TXRF measurements of Ormosil films containing phosphotungstates ([PW12O40]3-) was observed an image that could be interpreted as the result of the transition from the incident X-ray beam (packets of photons) to a continuous light beam (set of cont...
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Modeling and Simulation of a Parabolic Trough Solar Concentrator
Kpeusseu Angeline Kouambla Epse Yeo,
Bati Ernest Boya Bi,
Prosper Gbaha
Issue:
Volume 5, Issue 2, December 2021
Pages:
54-62
Received:
11 November 2021
Accepted:
7 December 2021
Published:
24 December 2021
Abstract: This work consisted of the mathematical modeling of a parabolic trough concentrator. To this end, a heat balance has been established for the different parts of the parabolic trough concentrator, which are the heat transfer fluid, the absorber and the glass. This allowed us to establish a system of equation whose resolution was done by the finite difference method. This digital resolution made it possible to obtain the temperatures of the different parts of our parabolic trough concentrator, namely, the heat transfer fluid, the absorber and the glass. The simulation of the heating process of the fluid is done in time steps of one hour, from six hours to eighteen hours. The results obtained show that the temperature difference between the inlet and the outlet of the solar collector is very large. A computer program has been developed to simulate the temperatures of the heat transfer fluid, the absorber tube and the glass as a function of time and space. These results were obtained for a typical day with regard to the variation of the temperatures of the heat transfer fluid, the absorber and the glass, as well as the powers and efficiency of the parabolic trough concentrator and various factors for the sake of improve the performance of our prototype.
Abstract: This work consisted of the mathematical modeling of a parabolic trough concentrator. To this end, a heat balance has been established for the different parts of the parabolic trough concentrator, which are the heat transfer fluid, the absorber and the glass. This allowed us to establish a system of equation whose resolution was done by the finite d...
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