Analysis of Temperature Field in an Oil-Shale Retorting Furnace with Gas Heat Carrier Based on CFD

2014 ◽  
Vol 672-674 ◽  
pp. 597-600
Author(s):  
Jing Ru Bai ◽  
Si Yu Xin ◽  
Qing Wang ◽  
Hong Qin

Taking the physical model of a small oil-shale retorting furnace with gas heat carrier as research object, a quasi homogeneous mathematical model was established to simulate the process of heating the pebbles in the porous zone and was solved by Fluent, a commercial CFD software. We compared the calculated results of temperature with the measured data, and analyzes the cause of the deviation between them.The result showed that the calculated value is relatively close to the measured data(the relative error is 6.85%) and the model can predict accurately the actual temperature field. The research results can provide support for the process of structural design of the large oil-shale retorting furnace with gas heat carrier.

Vestnik IGEU ◽  
2019 ◽  
pp. 22-30
Author(s):  
G.A. Perevezentsev ◽  
V.A. Gorbunov ◽  
O.B. Kolibaba

The main element of metalworking, engineering and other industries is heating and heat-treating furnaces. An array of workpieces that are loaded into the furnace includes bulk tanks with different parameters. The existing designs of heating furnaces have a number of disadvantages, one of which is the lack of heat carrier filtration in the vertical direction. However, this feature can be found in the developed design of the batch furnace with sole flues. The aim of the work is to develop and study the parameters of a mathematical model of the heating process of a bulk tank in a heat-treating furnace with sole flues. The paper describes and studies a mathematical model of a heat-treating furnace equipped with special sole flues. The bulk tank model is built based on a fractal structure, in particular the Menger sponge. To solve the problem of deter-mining the temperature field of the bulk tank, we used a numerical calculation of heat exchange based on the finite-difference method, also called the grid method. For this purpose, a new design of the batch furnace with hearth chambers has been proposed. As a result of mathematical modeling of the heating process, we have obtained a graph reflecting the temperature field of the bulk tank on the surface and in the heating center. We have also compared the temperature regime of bulk tank heating under normal conditions and in conditions of additional heat carrier filtration through the flues from the hearth chambers to the furnace hearth. The reliability of the results is confirmed by comparing the numerical simulation results and the results of the physical experiment. The error is not more than 10 %. The efficiency of the heat-treating furnace is improved by additional heat carrier filtration through special channels in the furnace sole. The obtained mathematical model can be used to calculate different heating modes in heat-treating furnaces and to develop technological maps of heating bulk tanks with different porosity values.


1988 ◽  
Vol 25 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Mu Shen

The objective of this paper is to present a numerical analysis by finite elements of a two-dimensional nonlinear mathematical model for heat conduction with phase change in a thawing embankment in permafrost. The calculated results are compared with actual measured data, and good agreement is obtained. All calculations were carried out on a personal computer. Key words: permafrost, thawing, embankment, temperature field, numerical analysis.


Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 2023
Author(s):  
Ruixin Li ◽  
Yiwan Zhao ◽  
Gaochong Lv ◽  
Weilin Li ◽  
Jiayin Zhu ◽  
...  

Near-wall microenvironment of a building refers to parameters such as wind speed, temperature, relative humidity, solar radiation near the building’s façade, etc. The distribution of these parameters on the building façade shows a certain variation based on changes in height. As a technology of passive heating and ventilation, the effectiveness of this application on heat collection wall is significantly affected by the near-wall microclimate, which is manifested by the differences, and rules of the thermal process of the components present at different elevations. To explore the feasibility and specificity of this application of heat collection wall in high-rise buildings, this study uses three typical high-rise buildings from Zhengzhou, China, as research buildings. Periodic measurements of the near-wall microclimate during winter and summer were carried out, and the changing rules of vertical and horizontal microclimate were discussed in detail. Later, by combining these measured data with numerical method, thermal process and performance of heat collection wall based on increasing altitude were quantitatively analyzed through numerical calculations, and the optimum scheme for heat collection wall components was summarized to provide a theoretical basis for the structural design of heat-collecting wall in high-rise buildings.


Author(s):  
Zengmeng Zhang ◽  
Jinkai Che ◽  
Peipei Liu ◽  
Yunrui Jia ◽  
Yongjun Gong

Compared with pneumatic artificial muscles (PAMs), water hydraulic artificial muscles (WHAMs) have the advantages of high force/weight ratio, high stiffness, rapid response speed, large operating pressure range, low working noise, etc. Although the physical models of PAMs have been widely studied, the model of WHAMs still need to be researched for the different structure parameters and work conditions between PAMs and WHAMs. Therefore, the geometry and the material properties need to be considered in models, including the wall thickness of rubber tube, the geometry of ends, the elastic force of rubber tube, the elongation of fibers, and the friction among fiber strands. WHAMs with different wall thickness and fiber materials were manufactured, and static characteristic experiments were performed when the actuator is static and fixed on both ends, which reflects the relationship between contraction force and pressure under the different contraction ratio. The deviations between theoretical values and experimental results were analyzed to investigate the effect of each physical factor on the modified physical model accuracy at different operating pressures. The results show the relative error of the modified physical model was 7.1% and the relative error of the ideal model was 17.4%. When contraction ratio is below 10% and operating pressure is 4 MPa, the wall thickness of rubber tube was the strongest factor on the accuracy of modified model. When the WHAM contraction ratio from 3% to 20%, the relative error between the modified physical model and the experimental data was within ±10%. Considering the various physical factors, the accuracy of the modified physical model of WHAM is improved, which lays a foundation of non-linear control of the high-strength, tightly fiber-braided and thick-walled WHAMs.


2009 ◽  
Vol 76-78 ◽  
pp. 61-66
Author(s):  
Ya Dong Gong ◽  
Yan Guang Bai ◽  
Yue Ming Liu ◽  
Jian Qiu

With the help of the infrared camera temperature measurement technology, the systemic theoretical analysis and experimental research for temperature field and thermal error distribution in NC grinding machine is provided. Two different situations for temperature field and thermal error distribution are respectively measured while the free and loaded grinding by the new measurement method. The mathematical model of thermal error is built, and it shows that the actual error and the forecasted error from thermal error mathematical model have good comparability.


2012 ◽  
Vol 220-223 ◽  
pp. 1559-1563
Author(s):  
Rui Wu ◽  
Li Bao ◽  
Yuan Kui Xu

The relative direction for a constant speed can be determined according to the planar non-circular curve parts. To establish the mathematical model, a constant speed motion simulation system is designed. The parameters of (vH=5mm/s, δ<3") is commonly used for the simulation system to simulate the movement of drawing the error curve. The results show that by controlling the movement of the plane curve parts in mathematical model can derive the basic constant speed, the relative error of constant speed is less than 3%, it provides a reliable bias when apply to production practice.


2017 ◽  
Vol 139 (3) ◽  
Author(s):  
David Park ◽  
Francine Battaglia

A solar chimney is a natural ventilation technique that has potential to save energy consumption as well as to maintain the air quality in a building. However, studies of buildings are often challenging due to their large sizes. The objective of this study was to determine the relationships between small- and full-scale solar chimney system models. Computational fluid dynamics (CFD) was employed to model different building sizes with a wall-solar chimney utilizing a validated model. The window, which controls entrainment of ambient air for ventilation, was also studied to determine the effects of window position. A set of nondimensional parameters were identified to describe the important features of the chimney configuration, window configuration, temperature changes, and solar radiation. Regression analysis was employed to develop a mathematical model to predict velocity and air changes per hour, where the model agreed well with CFD results yielding a maximum relative error of 1.2% and with experiments for a maximum error of 3.1%. Additional wall-solar chimney data were tested using the mathematical model based on random conditions (e.g., geometry, solar intensity), and the overall relative error was less than 6%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model, and that the newly developed mathematical equation can be used to predict ventilation conditions for a wall-solar chimney.


Fuel ◽  
2015 ◽  
Vol 159 ◽  
pp. 943-951 ◽  
Author(s):  
Dengguo Lai ◽  
Zhaohui Chen ◽  
Yong Shi ◽  
Lanxin Lin ◽  
Jinhui Zhan ◽  
...  
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