scholarly journals The Modeling of Chemical Technological Process in the Fire Chambers

2017 ◽  
Vol 4 (3) ◽  
pp. 147
Author(s):  
A.S. Askarova ◽  
S.A. Bolegenova ◽  
E.I. Lavrishcheva ◽  
I.V. Loktionova
Keyword(s):  
Mass Transfer ◽  
Numerical Modeling ◽  
Temperature Distribution ◽  
Numerical Experiment ◽  
Chemical Reactions ◽  
Three Dimensional ◽  
Hydroelectric Station ◽  
Heat Propagation ◽  
Heat Radiation ◽  
Radiation Chemical

<p>In this paper the results obtained by the method of numerical modeling of Ekibastuz coal burning in furnace on the example of fire chamber fixed on Aksy hydroelectric station are represented. Numerical experiment was carried out on the basis of three-dimensional equations of convective heat and mass transfer, taking into account the heat propagation, heat radiation, chemical reactions and multiphase structure of the medium. After the numerical experiment, the pictures of temperature distribution on the height of the chamber and concentration of CO, CO<sub>2</sub>, ash and coke distribution along the chamber were obtained. The results are represented graphically.</p>

Numerical Modeling and Design of an Inspection Device with Thermoelectric Coolers for the Coke Oven

2009 ◽  
Vol 419-420 ◽  
pp. 29-32 ◽  
Author(s):  
Tung-Hsin Yeh ◽  
Jiin Yuh Jang ◽  
Yu Bin Chen ◽  
Der Her Wang
Keyword(s):  
Numerical Modeling ◽  
High Temperature ◽  
Temperature Distribution ◽  
Necessary Conditions ◽  
Three Dimensional ◽  
Coke Oven ◽  
Thermoelectric Coolers ◽  
Thermal Insulator ◽  
Wall Condition ◽  
Cooling Element

In order to inspect on wall condition inside the coke oven, an inspection device has been developed to protect a camera inside and sustains high temperature long enough so that it can be permanently-installed on the pusher ram beam. The temperature of the coking chamber during operation is about 1200 °C while the maximum tolerable temperature of a camera is less than 40 °C. The device has to function as a good thermal insulator with cooling element for the camera at the pusher head and for signal cables along the beam. In this paper, the necessary conditions of the inspective device were found out by building a three-dimensional numerical model of the device to simulate the temperature distribution inside the device with CFD commercial software.

The Temperature Distribution of Oil-Immersed Transformer Starting with Heavy Load in Cold Regions

2014 ◽  
Vol 1079-1080 ◽  
pp. 553-557
Author(s):  
Tao Wan
Keyword(s):  
Temperature Distribution ◽  
Low Temperatures ◽  
Three Dimensional ◽  
Transformer Oil ◽  
Heat Radiation ◽  
Heavy Load ◽  
Cold Regions ◽  
Early Start ◽  
Local Overheating ◽  
Short Period

When the large oil-immersed transformer start with heavy load in cold regions, due to the high viscosity of the oil at low temperatures, the flow of the oil is extremely slow in the early start of heavy load, resulting in a negative heat radiation. At the same time, the winding and the core are rapidly increasing heat in the early start of heavy load. Rapid increase in heat and the lack of heat dissipation caused a series of problems. In this paper, we study the process of heating and cooling when the large oil-immersed transformer start with heavy load in cold region and takes a transformer of 31.5MVA as example to build a three-dimensional model ,the model is based on the actual size of the transformer. We use the finite volume method to calculate three-dimensional temperature field distribution changing with time when the oil-immersed transformer startup with heavy load in - 35 °C,-30 °C and-25 °C three cases. The results show that the viscosity coefficient of transformer oil is very high at low temperatures. In the early start of the transformer, because of the poor fluidity of the oil, the heat cannot be dissipated in time and the transformer local overheating near the winding. Then we analyzes the damage of local overheating for a short period of time in the transformer, especially the damage of the oiled paper's insulation At last ,we analysis of the causes of transformer internal local overheating and give some measures to avoid local overheating when oil-immersed transformer start with heavy load in cold regions.KEYWORDS: oil-immersed transformer, cold regions, start with heavy load, FVM, three-dimensional temperature distribution

scholarly journals Hot Spots Drift in Synchronous and Asynchronous Polars: Results of Three-Dimensional Numerical Simulation

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 110
Author(s):  
Dmitry Bisikalo ◽  
Andrey Sobolev ◽  
Andrey Zhilkin
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Temperature Distribution ◽  
Hot Spots ◽  
Transfer Rate ◽  
Hot Spot ◽  
Mass Transfer Rate ◽  
Three Dimensional ◽  
Jet Trajectory ◽  
Dominant Influence

In this paper, the characteristics of hot spots on an accretor surface are investigated for two types of polars: the eclipsing synchronous polar V808 Aur and the non-eclipsing asynchronous polar CD Ind in configuration of an offset and non-offset magnetic dipole. The drift of hot spots is analyzed based on the results of numerical calculations and maps of the temperature distribution over the accretor surface. It is shown that a noticeable displacement of the spots is determined by the ratio of ballistic and magnetic parts of the jet trajectory. In the synchronous polar, the dominant influence on the drift of hot spots is exerted by variations in the mass transfer rate, which entail a change in the ballistic part of the trajectory. It was found that when the mass transfer rate changes within the range of 10−10M⊙/year to 10−7M⊙/year, the displacement of the hot spot in latitude and longitude can reach 30∘. In the asynchronous polar, a change in the position of hot spots is mainly defined by the properties of the white dwarf magnetosphere, and the displacement of hot spots in latitude and longitude can reach 20∘.

scholarly journals Numerical Analysis on Characteristics of Reduction Process within a Pre-Reduction Rotary Kiln

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1180
Author(s):  
Chenghong Liu ◽  
Xueyong Ding ◽  
Hegong Liu ◽  
Xinlin Yan ◽  
Chao Dong ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Chemical Reactions ◽  
Rotary Kiln ◽  
Reduction Potential ◽  
Three Dimensional ◽  
Measurement Data ◽  
Reduction Process ◽  
Physical Parameters ◽  
C Language ◽  
Bed Temperature

The reduction process inside the ore pre-reduction rotary kiln involves a series of physicochemical reactions, and in-depth understanding of the reduction behavior is helpful to improve the product quality and productivity. This paper reports a three-dimensional steady state mathematical model based on computational fluid dynamics, which considers heat transfer, mass transfer and chemical reactions inside the rotary kiln. A user-defined functions (UDFs) program in C language is developed to define physical parameters and chemical reactions, and calculate the heat and mass transfer between freeboard and bed regions. The model is validated by measurement data and is then used to investigate the detailed information inside the rotary kiln. The results show that there is a temperature gradient in the bed, which is maximal near the kiln tail and decreases gradually as the reduction process progresses. The result also confirms that the reduction of FeO to Fe is the limiting step of the whole reduction process because this reaction requires a higher reduction potential. Furthermore, the influence of C/O mole ratio and fill degree are analyzed by comparing the average bed temperature, reduction potential and metallization ratio.

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