scholarly journals Inverse determination of the heat transfer coefficient distribution on a steel plate cooled by a water spray nozzle

2012 ◽  
Author(s):  
A. Cebo-Rudnicka ◽  
Z. Malinowski ◽  
T. Telejko ◽  
J. Gielzecki
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Steel Plate ◽  
Spray Nozzle ◽  
Water Spray ◽  
Coefficient Distribution ◽  
The Heat Transfer Coefficient

Implementation of the Axially Symmetrical and Three Dimensional Finite Element Models to the Determination of the Heat Transfer Coefficient Distribution on the Hot Plate Surface Cooled by the Water Spray Nozzle

2012 ◽  
Vol 504-506 ◽  
pp. 1055-1060 ◽  
Author(s):  
Zbigniew Malinowski ◽  
Tadeusz Telejko ◽  
Beata Hadala ◽  
Agnieszka Cebo-Rudnicka
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Three Dimensional ◽  
Spray Nozzle ◽  
Water Spray ◽  
Coefficient Distribution ◽  
The Heat Transfer Coefficient ◽  
Material Temperature

Plate and strip hot rolling lines are equipped with water cooling systems used to control the deformed material temperature. This system has a great importance in the case of thermal - mechanical deformation of steel which is focused on formation a proper microstructure and mechanical properties. The desired rate of cooling is achieved by water spray or laminar cooling applied to the hot surface of a strip. The water flow rate and pressure can be changed in a wide range and it will result in a very different heat transfer from the cooled material to the cooling water. The suitable cooling rate and the deformed material temperature can be determined based on numerical simulations. In this case thermal boundary conditions have to be specified on the cooled surface. The determination of the heat transfer coefficient distribution in the area of the water spray nozzle would improve numerical simulations significantly. In the paper an attempt is made to determine the heat transfer coefficient distribution on the hot plate surface cooled by the water spray nozzle. In the inverse method direct axially symmetrical and three dimensional solutions to the plate temperature field have been implemented. The computation time and the achieved accuracy have been compared for five cases. The studied cases differed in the maximum value of the heat transfer coefficient in nozzle spray axis and its distribution in the cooling time.

Determination of the heat transfer coefficient of PV panels

Energy ◽  
2019 ◽  
Vol 175 ◽  
pp. 978-985 ◽  
Author(s):  
İlhan Ceylan ◽  
Sezayi Yilmaz ◽  
Özgür İnanç ◽  
Alper Ergün ◽  
Ali Etem Gürel ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
The Heat Transfer Coefficient

Analytical and numerical determination of the heat transfer coefficient between scrap and hot metal based on small-scale experiments

2019 ◽  
Vol 138 ◽  
pp. 640-646 ◽  
Author(s):  
Florian Markus Penz ◽  
Roberto Parreiras Tavares ◽  
Christian Weiss ◽  
Johannes Schenk ◽  
Rainer Ammer ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Small Scale ◽  
Numerical Determination ◽  
Hot Metal ◽  
The Heat Transfer Coefficient

Inverse BEM Method to Identify Surface Temperatures and Heat Transfer Coefficient Distributions at Inaccessible Surfaces

2005 ◽  
Author(s):  
Alain J. Kassab ◽  
Eduardo A. Divo ◽  
Minking K. Chyu ◽  
Frank J. Cunha
Keyword(s):  
Heat Transfer ◽  
Inverse Problem ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Field Variable ◽  
Quadratic Functional ◽  
Two Dimensional ◽  
Additional Information ◽  
Coefficient Distribution ◽  
The Heat Transfer Coefficient

The purpose of the inverse problem considered in this study is to resolve heat transfer coefficient distributions by solving a steady-state inverse problem. Temperature measurements at interior locations supply the additional information that renders the inverse problem solvable. A regularized quadratic functional is defined to measure the deviation of computed temperatures from the values under current estimates of the heat transfer coefficient distribution at the surface exposed to convective heat transfer. The inverse problem is solved by minimizing this functional using a parallelized genetic algorithm (PGA) as the minimization algorithm and a two-dimensional multi-region boundary element method (BEM) heat conduction code as the field variable solver. Results are presented for a regular rectangular geometry and an irregular geometry representative of a blade trailing edge and demonstrate the success of the approach in retrieving accurate heat transfer coefficient distributions.

scholarly journals Online Determining Heat Transfer Coefficient for Monitoring Transient Thermal Stresses

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 704
Author(s):  
Magdalena Jaremkiewicz ◽  
Jan Taler
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Stresses ◽  
Thermal Power ◽  
Computer Calculation ◽  
Transient Temperature ◽  
Unsteady Temperature ◽  
The Heat Transfer Coefficient

This paper proposes an effective method for determining thermal stresses in structural elements with a three-dimensional transient temperature field. This is the situation in the case of pressure elements of complex shapes. When the thermal stresses are determined by the finite element method (FEM), the temperature of the fluid and the heat transfer coefficient on the internal surface must be known. Both values are very difficult to determine under industrial conditions. In this paper, an inverse space marching method was proposed for the determination of the heat transfer coefficient on the active surface of the thick-walled plate. The temperature and heat flux on the exposed surface were obtained by measuring the unsteady temperature in a small region on the insulated external surface of a pressure component that is easily accessible. Three different procedures for the determination of the heat transfer coefficient on the water-spray surface were presented, with the division of the plate into three or four finite volumes in the normal direction to the plate surface. Calculation and experimental tests were carried out in order to validate the method. The results of the measurements and calculations agreed very well. The computer calculation time is short, so the technique can be used for online stress determination. The proposed method can be applied to monitor thermal stresses in the components of the power unit in thermal power plants, both conventional and nuclear.

Experimental Determination of the Heat Transfer Coefficient of a Plate-Fin Heat Exchanger

2005 ◽  
Vol 26 (7) ◽  
pp. 29-35 ◽  
Author(s):  
Michel De Paepe ◽  
An Willems ◽  
Alexis Zenner
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Experimental Determination ◽  
The Heat Transfer Coefficient

Inverse analysis for the determination of heat transfer coefficient

2013 ◽  
Vol 91 (12) ◽  
pp. 1034-1043 ◽  
Author(s):  
Ali Fguiri ◽  
Naouel Daouas ◽  
M-Sassi Radhouani ◽  
Habib Ben Aissia
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Source Strength ◽  
Hot Wire ◽  
Source Power ◽  
Heating Source ◽  
The Heat Transfer Coefficient

The parallel hot wire technique is considered an effective and accurate means of experimental measurement of thermal conductivity. However, the assumptions of infinite medium and ideal infinitely thin and long heat source lead to some restrictions in the applicability of this technique. To make an effective experiment design, a numerical analysis should be carried out a priori, which requires a precise specification of the heating source strength and the heat transfer coefficient on the external surface. In this work, a more accurate physical and mathematical modeling of an experimental setup based on the parallel hot wire method is considered to estimate the two above-mentioned parameters from noisy temperature histories measured inside the material. Based on a sensitivity analysis, the heating source strength is estimated first using early time measurements. With such estimated value, determination of the heat transfer coefficient using temperatures measured at later times is then considered. The Levenberg–Marquardt (LM) method is successfully applied using a single experiment for the inverse solution of the two present parameter estimation problems. Estimates of this gradient-based deterministic method are validated with a stochastic method (Kalman filter). The effects of the measurement location, the heating duration, the measurement time step, and the LM parameter on the estimates and their associated confidence bounds are investigated. Used in the traditional fitting procedure of the parallel hot wire technique, the estimated heating source power provides a reasonable agreement between fitted and exact values of the thermal conductivity and the thermal diffusivity.

scholarly journals Distributed parameter modeling and thermal analysis of a spiral water wall in a supercritical boiler

2013 ◽  
Vol 17 (5) ◽  
pp. 1337-1342 ◽  
Author(s):  
Shu Zheng ◽  
Zixue Luo ◽  
Huaichun Zhou
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Supercritical Pressure ◽  
Distributed Parameter ◽  
Water Wall ◽  
Coefficient Distribution ◽  
Distributed Parameter Model ◽  
The Heat Transfer Coefficient

In this paper, a distributed parameter model for the evaporation system of a supercritical spiral water wall boiler is developed based on a 3-D temperature field. The mathematical method is formulated for predicting the heat flux and the metal-surface temperature. The results show that the influence of the heat flux distribution is more obvious than that of the heat transfer coefficient distribution in the spiral water wall tube, and the peak of the heat transfer coefficient decreases with an increment of supercritical pressure. This distributed parameter model can be used for a 600 MW supercritical-pressure power plant.

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