Inverse Thermal Analysis of a Coke Drum Using a Bayesian Probabilistic Approach

2015 ◽  
Author(s):  
Edrissa Gassama ◽  
Charles Panzarella ◽  
Jeffrey Cochran
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Temperature Distribution ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Heat Conduction Problem ◽  
Probabilistic Approach ◽  
Operating Conditions ◽  
Heat Flux Distribution ◽  
Posterior Probability Distribution

There is much interest in predicting the optimal operating conditions of a coke drum in order to extend its life and optimize both maintenance and repair. Typically, only temperature measurements on the outer surface of the wall are available from monitoring. In order to predict damage due to thermal stresses and other mechanisms, the temperature distribution through the wall is required. This could be determined if the heat flux on the inner surface of the wall were known, but this is difficult to obtain directly. In this paper, the heat flux distribution on the inner wall is determined solely from thermocouple measurements taken on the outside of the wall by solving a stochastic inverse heat conduction problem (IHCP). A finite element analysis is used to solve the forward thermal problem, and a Bayesian inference approach is used to model the posterior probability distribution of the heat flux. A newly developed probabilistic sampling technique known as the Particle Raking Algorithm (PRA) is found to be quite effective at solving this inverse problem. Once determined, the heat flux distribution is then applied as a boundary condition for the finite element model to determine the through-wall temperature distribution.

Heat Flux Distribution Over a Solar Central Receiver Using an Aiming Strategy Based on a Conventional Closed Control Loop

2017 ◽  
Author(s):  
Jesús García ◽  
Yen Chean Soo Too ◽  
Ricardo Vasquez Padilla ◽  
Rodrigo Barraza Vicencio ◽  
Andrew Beath ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Control Strategies ◽  
Multiple Input Multiple Output ◽  
Control Loop ◽  
Heat Flux Distribution ◽  
Input Multiple Output ◽  
Solar Receiver ◽  
Solar Field

Solar thermal towers are a maturing technology that have the potential to supply a significant part of energy requirements of the future. One of the issues that needs careful attention is the heat flux distribution over the central receiver’s surface. It is imperative to maintain receiver’s thermal stresses below the material limits. Therefore, an adequate aiming strategy for each mirror is crucial. Due to the large number of mirrors present in a solar field, most aiming strategies work using a data base that establishes an aiming point for each mirror depending on the relative position of the sun and heat flux models. This paper proposes a multiple-input multiple-output (MIMO) closed control loop based on a methodology that allows using conventional control strategies such as those based on Proportional Integral Derivative (PID) controllers. Results indicate that even this basic control loop can successfully distribute heat flux on the solar receiver.

The Temperature Field Around a Spherical Ridge or Trough in a Plane

1992 ◽  
Vol 114 (2) ◽  
pp. 317-325 ◽  
Author(s):  
J. Fransaer ◽  
J. R. Roos
Keyword(s):  
Heat Flux ◽  
Contact Angle ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Flux Distribution ◽  
Spherical Particles ◽  
Heat Flux Distribution ◽  
Conducting Plane ◽  
Temperature Distributions ◽  
Random Array

An analytical solution, which describes the temperature field around a single spherical particle partly embedded in a plane or around a trough making an arbitrary contact angle with a plane, is presented here. The temperature distributions for three cases are studied: the temperature distribution around a conducting bowl or trough, the temperature distribution around a non-conducting bowl or trough present in a conducting plane, and the temperature profile around a conducting bowl or trough conducting heat toward a sink at infinity. The normalized heat flux distribution on the plane and particle is presented. The various incremental resistances caused by a single and a dilute planar random array of truncated spherical particles are also derived.

scholarly journals Integrated study of flue gas flow and superheating process in a recovery boiler using computational fluid dynamics and 1D-process modeling

TAPPI Journal ◽  
2020 ◽  
Vol 19 (6) ◽  
pp. 303-316
Author(s):  
KUNAL KUMAR ◽  
VILJAMI MAAKALA ◽  
VILLE VUORINEN
Keyword(s):  
Fluid Dynamics ◽  
Heat Flux ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Flue Gas ◽  
Gas Flow ◽  
Flux Distribution ◽  
Heat Flux Distribution ◽  
Recovery Boilers ◽  
Material Temperature

Superheaters are the last heat exchangers on the steam side in recovery boilers. They are typically made of expensive materials due to the high steam temperature and risks associated with ash-induced corrosion. Therefore, detailed knowledge about the steam properties and material temperature distribution is essential for improving the energy efficiency, cost efficiency, and safety of recovery boilers. In this work, for the first time, a comprehensive one-dimensional (1D) process model (1D-PM) for a superheated steam cycle is developed and linked with a full-scale three-dimensional (3D) computational fluid dynamics (CFD) model of the superheater region flue gas flow. The results indicate that: (1) the geometries of headers and superheater platens affect platen-wise steam mass flow rate distribution (3%–7%); and (2) the CFD solution of the 3D flue gas flow field and platen heat flux distribution coupled with the 1D-PM affect the platen-wise steam superheating temperature (45%–122%) and material temperature distribution (1%–6%). Moreover, it is also found that the commonly-used uniform heat flux distribution approach for the superheating process is not accurate, as it does not consider the effect of flue gas flow field in the superheater region. These new observations clearly demonstrate the value of the present integrated CFD/1D-PM modeling approach.

Temperature Distributions and Thermal Stresses in Asymmetrically Heat Radiated Tubes

1986 ◽  
Vol 53 (1) ◽  
pp. 116-120 ◽  
Author(s):  
T. Fett
Keyword(s):  
Heat Flux ◽  
Half Space ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Tube Wall ◽  
Stress Distributions ◽  
Heat Flux Distribution ◽  
Temperature Distributions

The transient and stationary temperature distributions in a tube wall caused by an asymmetrical heat flux distribution are evaluated. The results are represented for the case of a heat radiating half-space. In addition, the accompanying stress distributions are computed.

A New Grinding Heat Flux Distribution Developed by Theoretical Derivation

2013 ◽  
Vol 774-776 ◽  
pp. 1160-1163
Author(s):  
Yan Jing ◽  
Qang Han Fang
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Thermal Field ◽  
Flux Distribution ◽  
Distribution Model ◽  
Grinding Process ◽  
Finite Element Models ◽  
Heat Flux Distribution ◽  
Theoretical Derivation ◽  
Made In

Heat flux distribution has an important influence on grinding thermal field, therefore an accurate heat flux distribution model must be established in order to precisely simulate the grinding process. A new heat flux distribution model was developed by theoretical derivation in this paper. In order to simulate the transient grinding thermal field, finite element models were created, applied with the new, uniform and triangular heat flux models respectively. Comparisons between the distributions of temperatures and temperature histories calculated from numerical simulations using the three different models were also made in this paper.

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