Publication detail

Wall heat transfer in gas-fired furnaces: Effect of radiation modelling

VONDÁL, J. HÁJEK, J.

Original Title

Wall heat transfer in gas-fired furnaces: Effect of radiation modelling

Type

journal article - other

Language

English

Original Abstract

The purpose of this work is to study heat transfer to cooled walls in a MW-scale laboratory furnace with a dominating thermal radiation component. Experiment is performed in a specially designed combustion chamber with segmental water-cooled walls and profile of absorbed heat flux is measured along the flame. Non-premixed natural gas flame is stabilized by a guide-vane swirler. The unsteady governing equations of turbulent flow are solved by a finite-volume code with a two-equation k-ε realizable turbulence model, a combination of first-order and second-order upwind schemes and implicit time integration. The coupling of pressure with velocity is treated by SIMPLE (semi-implicit method for pressure-linked equations) algorithm. Radiative heat transfer as the main heat transfer method is modelled with special care by discrete ordinates method and gas absorption coefficient is calculated by two alternatives of WSGGM (weighted sum of grey gases model). The predicted total heat transfer rate is found to depend strongly on method chosen for the computation of mean beam length. The results of numerical simulations show that overall heat transfer in a process furnace can be successfully predicted, while heat flux profile along the flame is more difficult to predict accurately. Good engineering accuracy is nevertheless achievable with reasonable computational resources. The trend of deviations is reported, which is useful for the interpretation of practical predictions of process furnaces (fired heaters).

Keywords

gas combustion; wall heat flux; swirling diffusion flame; radiative heat transfer; numerical modelling

Authors

VONDÁL, J.; HÁJEK, J.

RIV year

2015

Released

1. 7. 2015

Publisher

University of West Bohemia, Univerzitní 8, Pilsen, Czech Republic

Location

Pilsen, Czech Republic

ISBN

1802-680X

Periodical

Applied andComputational Mechanics

Year of study

9

Number

1

State

Czech Republic

Pages from

67

Pages to

78

Pages count

12

URL

http://www.kme.zcu.cz/acm/acm/article/view/276

BibTex

@article{BUT115194,
  author="Jiří {Vondál} and Jiří {Hájek}",
  title="Wall heat transfer in gas-fired furnaces: Effect of radiation modelling",
  journal="Applied andComputational Mechanics",
  year="2015",
  volume="9",
  number="1",
  pages="67--78",
  issn="1802-680X",
  url="http://www.kme.zcu.cz/acm/acm/article/view/276"
}