scholarly journals The Calculation of Double Nonlinearity and Material Anisotropy Influence on the Temperature Distribution in the Cylinder Under High Temperature Heat Exchange

2021 ◽  
pp. 31-37
Author(s):  
Yevgenij Zaytsev
Keyword(s):  
High Temperature ◽  
Heat Exchange ◽  
A Priori ◽  
Temperature Fields ◽  
Engineering Practice ◽  
Thermophysical Characteristics ◽  
Relative Temperature ◽  
Upper Limit ◽  
Wide Range ◽  
Temperature Heat

At the present stage of the development of technology, it is necessary to ensure the strength, reliability and durability of the structure that successfully functions under conditions of high-temperature heat exchange as maximum as possible. In this regard, graphite structural elements are widely used, and they are also applied for parts of space and aircraft, jet and rocket engines. The transversely isotropic graphite cylinder used in this work has a unique set of qualities that make it indispensable for problems in nuclear physics and power engineering; however, in the calculation of thermal engineering practice, it has not been studied enough, since it contains a large scatter of thermophysical characteristics for various grades of graphite. The aim of the study, including the basis of the developed method for solving boundary value problems of doubly nonlinear unsteady thermal conductivity, is to consider the effect of temperature dependences of the thermophysical characteristics of the material on temperature, zonal radiative-convective heat transfer and anisotropy on the distribution of temperature fields along the length, at the center and surface of a semi-infinite solid cylinder. The essence of this method is that the Goodman’s and Kirchhoff’s transformations are applied to the problem posed converted to a dimensionless form, then the relative temperature and functions from it, are expanded in the series of sines on the a priori interval, then the superposition principle is applied, after which the original setting is converted to a set of linearized problems with reduced thermophysical characteristics. Linear problems are solved by the method of integral transformations, which are summed up. The upper limit of the priori interval is determined from the condition that the relative temperature obtained from the solution of the problem Fo ® ¥ takes the value of the upper limit of the a priori interval. A large number of numerical calculations in the Matlab environment graphically show changes in the relative temperature on the axis and surface of the cylinder in a wide range of Fourier criteria. It is found that with an increase in the Fourier criterion, the character of heating changes qualitatively from the axis to the surface of the cylinder, both in terms of nonlinearities and anisotropy. For the case of double nonlinearity, the location of the temperature fields at different anisotropies in comparison with an isotropic material is shown graphically.

A high temperature heat exchange calorimeter

1970 ◽  
Vol 3 (11) ◽  
pp. 889-891 ◽  
Author(s):  
J L Orehotsky ◽  
K Schröder
Keyword(s):  
High Temperature ◽  
Heat Exchange ◽  
Temperature Heat

High-temperature heat exchange in the flow of a gas in a slit-type quenching apparatus

1982 ◽  
Vol 43 (1) ◽  
pp. 725-729
Author(s):  
I. I. Borisov ◽  
V. V. Naumov ◽  
T. V. Mikhalevskaya ◽  
V. A. Reisig
Keyword(s):  
High Temperature ◽  
Heat Exchange ◽  
Temperature Heat ◽  
Quenching Apparatus

Thermal Performance Analysis of the Stationary Reflector/Tracking Absorber (SRTA) Solar Concentrator

1975 ◽  
Vol 97 (3) ◽  
pp. 451-456 ◽  
Author(s):  
J. F. Kreider
Keyword(s):  
Fluid Flow ◽  
High Temperature ◽  
Flow Rate ◽  
Thermal Performance ◽  
Concentration Ratio ◽  
Heat Energy ◽  
Operating Conditions ◽  
Fluid Flow Rate ◽  
Wide Range ◽  
Temperature Heat

The performance of a novel solar energy concentrating system consisting of a fixed, concave spherical mirror and a sun-tracking, cylindrical absorber is analyzed in detail. This concentrating system takes advantage of the spherical symmetry of the mirror and its linear image which, when taken together, form a tracking, solar-concentrating system in which only the small cylindrical absorber need move. The effects of mirror reflectance, concentration ratio, heat transfer fluid flow rate, radiative surface properties, incidence angle, an evacuated absorber envelope, and insolation level upon thermal performance of the concentrator are studied by means of a mathematical model. The simulation includes first order radiation and convection processes between the absorber and its concentric glass envelope and between the envelope and the environment; radiation processes are described by a dual-band, gray approximation. The energy equations are solved in finite difference form in order that heat flux and temperature distributions along the absorber may be computed accurately. The results of the study show that high-temperature heat energy can be collected efficiently over a wide range of useful operating conditions. The analysis indicates that mirror surface reflectance is the single most important of the principal governing parameters in determining system performance. Efficiency always increases with concentration ratio although the rate of increase is quite small for concentration ratios above 50. High fluid flow rate (i.e., lower operating temperature), an evacuated envelope, or a highly selective surface can enhance performance under some conditions. The conclusion of the study is that high-temperature heat energy can be generated at high efficiency by the present concentrator with present technology in sunny regions of the world.

Rapid Prediction of High-Temperature Properties of Furnace Tube Alloys Using Deep Learning Approaches

2020 ◽  
Author(s):  
Shulin Xiang ◽  
Tao Chen ◽  
Zhichao Fan ◽  
Xuedong Chen ◽  
Zhigang Wu ◽  
...  
Keyword(s):  
Deep Learning ◽  
High Temperature ◽  
Learning Algorithm ◽  
Engineering Practice ◽  
Good Prediction ◽  
Learning Approaches ◽  
High Temperature Properties ◽  
Heat Resistant ◽  
Wide Range ◽  
Rapid Prediction

Abstract With the development of Materials Genome Initiative (MGI) and data mining technology, machine learning (ML) has emerged as an important tool in the research of materials science. For the heat resistant alloys used in furnace tubes, the rapid prediction of the high-temperature properties is critical but difficult until now. In this work, the ML method based on the deep learning algorithm is developed to establish the direct correlation between microstructure inputs and output stress rupture properties of Fe-Cr-Ni based heat resistant alloys. Two simple convolutional neural networks (CNN) and the complex network with VGG16 architecture are implemented and evaluated. The simple CNN and VGG16 models are trained from scratch and pre-trained, respectively. Due to the relatively few training samples in the dataset, the data augmentation configuration and the improved architecture are effective to mitigate overfitting in simple CNN models. The result also shows that in the case of transfer learning, the features extracted from other datasets can be used directly to this new visual task. It is demonstrated that both the simple CNN and VGG16 models reach the high prediction accuracies (more than 90 %) of high-temperature properties with a wide range of microstructures. In addition, the good prediction performance achieved in the small dataset also reveals the deep learning approaches can be used to construct powerful vision models in engineering practice, where very limited data is the common situation.

Study on High-Temperature Heat Harm Control Technology in Deep Mine

2013 ◽  
Vol 401-403 ◽  
pp. 287-290
Author(s):  
Xin Feng Wang ◽  
Ming Zhong Gao ◽  
Qiang Wang ◽  
Yan Li
Keyword(s):  
High Temperature ◽  
Engineering Practice ◽  
Deep Mining ◽  
Deep Mine ◽  
Temperature Heat ◽  
Prediction And Control ◽  
Cooling Technology ◽  
And Control ◽  
Combined Cooling ◽  
Cooling Methods

In order to study the high temperature heat harm problem in the process of deep mining, Briefly analyzed the causes of high temperature by using the methods of theoretical analysis and field measurement. In addition, a series of high temperature control methods are put forward. Including take conventional non-artificial cooling and the artificial refrigeration cooling methods as well as new cooling methods of using geothermal energy cooling and combined cooling heating and power technology so many initiatives to solve the problems of high temperature of deep mine. The engineering practice proves the reliability of mine cooling technology,the results can provide a basis for prediction and control of high temperature of deep mine.

MoSi2-Based High-Temperature Structural Silicides

MRS Bulletin ◽  
1993 ◽  
Vol 18 (7) ◽  
pp. 35-41 ◽  
Author(s):  
John J. Petrovic
Keyword(s):  
High Temperature ◽  
Heat Exchangers ◽  
Aircraft Engine ◽  
Structural Ceramics ◽  
Turbine Engine ◽  
New Class ◽  
Aerospace Applications ◽  
Wide Range ◽  
Temperature Heat ◽  
Silicon Based

Structural materials that can withstand oxidizing and aggressive environments at temperatures above 1000°C constitute an enabling materials technology for a wide range of applications in the industrial, aerospace, and automotive arenas. A few of the industrial uses for such materials are furnace elements and components, power generation components, high-temperature heat exchangers, gas burners and igniters, and high-temperature filters. Aerospace applications include turbine aircraft engine hot-section components such as blades, vanes, combustors, nozzles, and seals. Automotive applications involve components such as turbocharger rotors, valves, glow plugs, and advanced turbine engine parts.There is increasing interest in silicide-based compounds for high-temperature structural uses under oxidizing conditions in the range of 1200–1600°C. In this temperature range, for oxidation and strength reasons, the choice of materials is limited to the silicon-based structural ceramics such as Si3N4 and SiC, and the new class of “high-temperature structural silicides.” An extensive survey of progress in the area of high-temperature structural silicides has recently been published.

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