scholarly journals Determination for Thickness of the Multilayer Thermal Insulation Clothing Based on the Inverse Problems

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Bo Yu ◽  
Qiao Chang ◽  
Tingting Zhao ◽  
Linlin Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Inverse Problems ◽  
Surface Temperature ◽  
Thermal Insulation ◽  
Transfer Model ◽  
Optimal Thickness ◽  
Fire Area ◽  
In Fire ◽  
High Temperature Operation

In this paper, the optimal thickness of multilayer special clothing material under the high temperature operation based on the inverse problems is studied. We analyze the parameters of the thickness of thermal insulation clothing material and the surface temperature of the dummy. Using the least-squares fitting, the function with the distribution of the dummy surface temperature is established. Then the heat transfer model and optimization model to obtain the optimal thickness of different clothing layers are built, respectively. Taking the true data as an example, we give the application of thermal insulation clothing in fire area, and the results show that the models are feasible.

scholarly journals Heat Transfer Model of Multilayer Thermal Protective Clothing for High-Temperature Operation

2019 ◽  
Vol 13 (11) ◽  
pp. 21
Author(s):  
Man-Jing Li ◽  
Mao Zhu ◽  
Jia-Xu Han ◽  
Yuan-Biao Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Steady State ◽  
High Temperature ◽  
Protective Clothing ◽  
Heat Transfer Model ◽  
Heat Radiation ◽  
Transfer Model ◽  
Thermal Protective Clothing ◽  
High Temperature Operation

The thermal protective clothing for high-temperature operation usually consists of three-layer fabrics and a gap called the air layer or Layer IV between Layer III and skin. In order to design more effective thermal protective clothing at less cost, based on the heat transfer principles, we establish heat transfer models of fabrics and air layer, which are one-dimensional nonlinear partial differential equations with constant coefficients. In the three-layer fabrics, we consider the effects of heat conduction and heat radiation in Layer I but only consider heat conduction in Layer II and Layer III. Furthermore, the heat transfer model of Layer IV is decoupled and simplified to steady-state heat conduction in Layer IV and radiation heat transfer on surface of Layer IV. According to the explicit difference schemes for the models, we use the parameters in an experiment which puts a thermal manikin in high-temperature environment for some time and measures the temperature of lateral skin at regular time, to solve the models and calculate the temperature of each layer. With MATLAB, the visual interface of three-dimensional temperature distribution is provided, which is reference for functional design of thermal protective clothing. We also compare the simulation result of skin surface with the experimental data. The results show that at the same position, the temperature rises over time but with decreasing rate and finally reaches the steady state. Moreover, at one moment after reaching the steady state, the temperature has a gradual decrease with the increase of distance from the external environment.

Analysis and Modelling of Temperature at Lake’s Water – Atmosphere Interface

2021 ◽  
Author(s):  
Vassilis Z. Antonopoulos ◽  
Soultana K. Gianniou
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Surface Temperature ◽  
Water Surface ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Net Radiation ◽  
Water Surface Temperature ◽  
Simulation Results ◽  
Input Variables

Abstract The knowledge of micrometeorological conditions on water surface of impoundments is crucial for the better modeling of the temperature and water quality parameters distribution in the water body and against the climatic changes. Water temperature distribution is an important factor that affects most physical, chemical and biological processes and reactions occurring in lakes. In this work, different processes of water surface temperature of lake’s estimation based on the energy balance method are considered. The daily meteorological data and the simulation results of energy balance components from an integrated heat transfer model for two complete years as well as the lake’s characteristics for Vegoritis lake in northern Greece were used is this analysis.The simulation results of energy balance components from a heat transfer model are considered as the reference and more accurate procedure to estimate water surface temperature. These results are used to compare the other processes. The examined processes include a) models of heat storage changes in relationship to net radiation (Qt(Rn) values, b) net radiation estimation with different approaches, as the process of Slob’s equation with adjusted coefficients to lake data, and c) ANNs models with different architecture and input variables. The results show that the model of heat balance describes the water surface temperature with high accuracy (r2=0.916, RMSE=2.422oC). The ANN(5,6,1) model in which Tsw(i-1) is incorporated in the input variables was considered the better of all other ANN structures (r2=0.995, RMSE=0.490oC). The use of different approaches for simulating net radiation (Rn) and Qt(Rn) in the equation of water surface temperature gives results with lower accuracy.

Heat Transfer Modeling in a Counter-Current Moving-Bed Tubular Reactor for High-Temperature Thermochemical Energy Storage

2021 ◽  
Author(s):  
Wei Huang ◽  
Eric Million ◽  
Kelvin Randhir ◽  
Joerg Petrasch ◽  
James Klausner ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Transfer Model ◽  
Reactor Performance ◽  
Low Oxygen ◽  
Moving Bed ◽  
Oxidation Reactor ◽  
Counter Current

Abstract An axisymmetric model coupling counter-current gas-solid flow, heat transfer, and thermochemical redox reactions in a moving-bed tubular reactor was developed. The counter-current flow enhances convective heat transfer and a low oxygen partial pressure environment is maintained for thermal reduction within the reaction zone by using oxygen depleted inlet gas. A similar concept can be used for the oxidation reactor which releases high-temperature heat that can be used for power generation or as process heat. The heat transfer model was validated with published results for packed bed reactors. After validation, the model was applied to simulate the moving-bed reactor performance, through which the effects of the main geometric parameters and operating conditions were studied to provide guidance for lab-scale reactor fabrication and testing.

Two-Dimensional Transient Heat Transfer Model for High-Temperature Laser-Scanning Confocal Microscopy

2021 ◽  
Author(s):  
Dasith Liyanage ◽  
Suk-Chun Moon ◽  
Ajith S. Jayasekare ◽  
Abheek Basu ◽  
Madeleine Du Toit ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Phase Transformation ◽  
High Temperature ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Transfer Model ◽  
Two Dimensional ◽  
Scanning Confocal Microscopy ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract High-temperature laser-scanning confocal microscopy (HT-LSCM) has proven to be an excellent experimental technique through in-situ observations of high temperature phase transformation to study kinetics and morphology using thin disk steel specimens. A 1.0 kW halogen lamp, within the elliptical cavity of the HT-LSCM furnace radiates heat and imposes a non-linear temperature profile across the radius of the steel sample. This local temperature profile when exposed at the solid/liquid interface determines the kinetics of solidification and phase transformation morphology. A two-dimensional numerical heat transfer model for both isothermal and transient conditions is developed for a concentrically solidifying sample. The model can accommodate solid/liquid interface velocity as an input parameter under concentric solidification with cooling rates up to 100 K/min. The model is validated against a commercial finite element analysis software package, Strand7, and optimized with experimental data obtained under near-to equilibrium conditions. The validated model can then be used to define the temperature landscape under transient heat transfer conditions.

Heat transfer model for calculation of the temperature field inside thin-walled sections in fire

2021 ◽  
Vol 169 ◽  
pp. 108416
Author(s):  
Michał Malendowski ◽  
Wojciech Szymkuć ◽  
Piotr Turkowski ◽  
Adam Glema ◽  
Wojciech Węgrzyński
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Thin Walled ◽  
In Fire

scholarly journals Optimization by means of an analytical heat transfer model of a thermal insulation for CSP applications based on radiative shields

2016 ◽  
Author(s):  
A. Gaetano ◽  
J. Roncolato ◽  
D. Montorfano ◽  
M. C. Barbato ◽  
G. Ambrosetti ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Insulation ◽  
Heat Transfer Model ◽  
Transfer Model

Forming of Porous Micro-Features Using Hot Compaction

2007 ◽  
Author(s):  
Peng Chen ◽  
Gap-Yong Kim ◽  
Jun Ni
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Mass Production ◽  
Heat Transfer Characteristics ◽  
High Productivity ◽  
Powder Consolidation ◽  
Micro Scale ◽  
Hot Compaction ◽  
Micro Features ◽  
High Temperature Operation

Porous metallic micro-scale features are becoming important in the modern industry. However, a mass production of such features is a challenge when robustness, cost-effectiveness, and high productivity requirements are considered. In this study, the fabrication of such porous micro-features using hot compaction was investigated. A hot compaction experiment setup was designed and fabricated, which was capable of high temperature operation (up to 700 °C), quick heat-up, and avoiding oxidation of workpiece and tools. A 3D thermal simulation of the experiment setup was conducted to understand the heat transfer characteristics of the system, which was used as a reference for the experiment. The effects of compression loading force and temperature on the compact quality in terms of powder consolidation strength and porosity were studied.

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