scholarly journals Melting/Solidification Processes of PEG 1500 in Vertical and Horizontal Annular Enclosure

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
F. A. Hamad ◽  
◽  
E. Egelle ◽  
Abbas Mohammed ◽  
S. Gooneratne ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Surface Temperature ◽  
Hydrate Formation ◽  
Heating Surface ◽  
Melting Time ◽  
Insulation Material ◽  
Wax Deposition ◽  
Solidification Processes ◽  
Polyethylene Glycol 1500 ◽  
Vertical Case

In this paper, the primary aim is to look at the fundamental melting/solidification processes of polyethylene glycol 1500 (PEG 1500) for energy storage – insulation to prolong the cooling time of pipelines in unexpected shut-down conditions, prevent/minimize the wax deposition, and hydrate formation. Polyethylene glycol 1500 was selected because its melting temperature is >317 K making it a suitable candidate as lagging material to prevent wax deposition and hydrate formation in subsea oil pipelines. Experimental apparatus was designed with the Perspex to give an insight into the melting process. Vertical and horizontal annular geometries were used to consider the real-life cases. The vertical annular enclosure length is 950 mm and 34 mm width (Height/Width=27.94). The horizontal annular enclosure length is 300mm and 15.9 mm width (Height/Width=18.87). The thermocouples and camera are used to collect the data for three cases of inner wall temperature of 333 K,343 K and 353 K where is the heat added to the phase change material (PCM) for both cases. The main conclusions are: i) the horizontal annular case melt faster than the vertical case, in particular, at higher heating surface temperature of 353 K, ii)The temperature of the inner region was remained hot for long time which provide a good evidence that support the concept of using the PCM as heat storage–insulation material; iii) the melting percentage for horizontal case is 100% higher from the melting percentage of vertical case at 333 K which reduced to about 20% for 343 K, iv) increasing the heating surface temperature substantially reduces the total melting time for both orientations.

scholarly journals Study on the Application Possibility of Uninsulated Duct Firestop System using Simulation

2020 ◽  
Vol 20 (2) ◽  
pp. 119-126
Author(s):  
Heewon Seo ◽  
Myungo Yoon ◽  
Dongho Choi ◽  
Daehoi Kim ◽  
Hyungdo Lee
Keyword(s):  
Surface Temperature ◽  
Ambient Air ◽  
Radiant Heat ◽  
Radiant Heat Transfer ◽  
Insulation Material ◽  
Structure Surface ◽  
Important Input ◽  
Verification Test ◽  
Radiant Temperature ◽  
Fire Spreading

A simulation of the uninsulated duct firestop system was performed to review its application possibility to the building by analyzing the radiant heat transfer and its impact to the surrounding structures in the event of a fire. The simulation targets were divided by the presence or absence of an insulation material (1 m long) as floor and wall duct firestop systems, and the surface temperature, which is an important input data, was based on the existing verification test data. Then, the ambient air temperature, surrounding structure surface temperature, and radiant temperature at some distance from the duct were analyzed through simulations in the modeled virtual spaces. As a result of simulation, it is judged that the application of the uninsulated duct firestop system wrapped by the insulation material can significantly reduce the possibility of fire spreading due to the radiant heat.

scholarly journals Peculiarities in Leidenfrost water droplet evaporation

2020 ◽  
Author(s):  
Tadeusz Orzechowski
Keyword(s):  
Surface Temperature ◽  
Orthogonal Projection ◽  
Water Droplet ◽  
Linear Time ◽  
Heating Surface ◽  
Droplet Evaporation ◽  
Measuring System ◽  
Main Element ◽  
Bottom Surface ◽  
Good Representation

Abstract The investigations involved a large water droplet deposited on the heating surface, the temperature of which was higher than the Leidenfrost point. The main element of the experimental setup was the heating cylinder with K-type shielded thermocouple located in its centre just below the surface. The measuring system was located on highly sensitive scales. The analysis of the droplet behaviour in time was conducted based on measured droplet mass changes over time and also photographic data recorded with high resolution digital camera. The energy balance equation is given for the assumption that evaporation from the droplet upper surface is small compared with the amount of heat dissipated from the bottom surface. The formula for the heat transfer coefficient depends on two slope values and an orthogonal projection of the drop onto the heating surface. The slopes are estimated based on the droplet diameter linear time dependence and mass versus the contact zone relationship. The solution provides a good representation of droplet evaporation under Leidenfrost conditions. The investigations, reported in the study, which concern water droplet at atmospheric pressure deposited on a hot surface with the temperature higher than the Leidenfrost point, indicate the following regularities: droplet orthogonal projection onto the heating surface changes linearly with the droplet mass, evaporation of the same amount of mass decreases linearly with an increase in the heating surface temperature, slope of the graph showing mass loss versus the heating surface temperature successively decreases.

A novel method improving the temperature uniformity of hot-plate under induction heating

2020 ◽  
pp. 095440622093630
Author(s):  
Wang Jin ◽  
Chen Xing ◽  
Yu Lu ◽  
Sun Baoshou ◽  
Dequn Li
Keyword(s):  
Temperature Distribution ◽  
Magnetic Flux ◽  
Surface Temperature ◽  
Heating Surface ◽  
Target Surface ◽  
Simulation Software ◽  
Test Method ◽  
Magnetic Flux Density ◽  
Hot Plate ◽  
Novel Method

In the paper, a novel method to improve the uniformity of the temperature distribution on the surface of the hot-plate is presented. Firstly, the effect of magnetic flux density under coupling of the electromagnetic and heat transfer on target surface temperature is studied numerically by using the commercial simulation software COMSOL Multiphysics. To evaluate the uniformity of the temperature distribution on the target surface, the temperature nonuniformity index on the target surface was firstly employed in terms of a specific designed electric coil. Secondly, the principal components analysis combined with the orthogonal test method is employed to analyze the shape parameters and obtain optimized temperature distribution at the target surface of the hot-plate. The simulated results show that the uniformity of temperature can be greatly improved by appropriately adjusting distribution of magnetic flux and the uniform temperature distribution can be achieved on a heating surface of 130 mm in length, 130 mm in width, and 30 mm in height. Finally, the optimizations of target surface temperature on hot-plate with different target temperatures were studied as well.

Secondary Electron Emission from Conductive, Liquid Polyethylene Glycol 1500

1976 ◽  
Vol 31 (1) ◽  
pp. 75-79
Author(s):  
K. Doblhofer ◽  
K. P. Charlé ◽  
D. Veltwisdi
Keyword(s):  
Polyethylene Glycol ◽  
Electron Emission ◽  
Secondary Electron ◽  
Elementary Theory ◽  
Secondary Electron Emission ◽  
Solid Polymer ◽  
Yield Curves ◽  
Conductive Liquid ◽  
Liquid Polymer ◽  
Polyethylene Glycol 1500

A thorough study of the secondary electron emission (SEE) yield from liquid Polyethylene glycol 1500 (PEG) was made. This liquid (m. p. 45 °C) has a low enough vapor pressure at a working temperature of about 50 °C. In addition, it has the advantage of being a good solvent for salts which dissociate and thus render the solutions conductive. It was found that the presence of the electrolyte salt does not affect the secondary electron yield curves.A striking result is that the yield curves obtained from the PEG solutions are very well reproducible (ca. ± 7%). By fitting the experimental data to a formula given by the elementary theory of SEE it can be clearly seen that this liquid polymer shows quite a different SEE behaviour compared with that reported for chemically similar solid polymer films. The results obtained agree well with the data for polymer silicon oils, suggesting that liquid polymers differ in their SEE behaviour from the corresponding solids.Finally, it is demonstrated that the reduced yield curves can be fitted to the physically meaningful Bethe loss formula at least as well as using the conventional approach.

scholarly journals Thiophene extraction in PEG - hexan - water based systems

2022 ◽  
Vol 1212 (1) ◽  
pp. 012025
Author(s):  
V O Solov‘ev’ ◽  
S V Solov’eva ◽  
N A Milevsky
Keyword(s):  
Polyethylene Glycol ◽  
Sodium Chloride ◽  
Organic Phase ◽  
Sodium Nitrate ◽  
Iron Chloride ◽  
Water Based ◽  
Polyethylene Glycol 1500 ◽  
Peg 8000

Abstract The effect of individual and multicomponent additives of sodium chloride, iron chloride, sodium nitrate and 1-methyl-2-pyrrolidone on the interfacial distribution of thiophene in the systems polyethylene glycol 1500 (PEG-1500) - hexane - water and polyethylene glycol 8000 (PEG-8000) - hexane - water has been studied in this investigation. It was found that in most cases, the introduction of a small amount of individual and joint additives increases the extraction of thiophene from the organic phase to the aqueous.

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