Utilising CFD as efficient tool for improved equipment design

Utilising CFD as efficient tool for improved equipment design

Paper in proceedings (conference paper)

This paper presents a case study dealing with heat recovery system in an incinerator of waste sludge from a pulp mill. The aim of this study is to find an optimised design of additional measures to be installed in the exhaust duct of the incinerator that would help to prevent fouling in a connected heat exchanger. Computational Fluid Dynamics (CFD) approach is a natural choice for this application as no experimental evaluation of proposed solutions can be performed. Input data are obtained from the process using simpler balance-based approaches. CFD analysis is first used to find what causes the fouling and then to optimise the duct design in order to eliminate the undesirable phenomena. Several solution alternatives are proposed consisting of sets of vanes with different geometries. The finite volume model employed in the computations is described and the adopted approach, assumptions and simplifications are discussed. The studied alternatives are evaluated and the best of them is found using a flow uniformity index based on velocity distribution in a reference cross-section. It is concluded that the insight gained by CFD analysis is decisive for arriving at an improved design in this application.

This paper presents a case study dealing with heat recovery system in an incinerator of waste sludge from a pulp mill. The aim of this study is to find an optimised design of additional measures to be installed in the exhaust duct of the incinerator that would help to prevent fouling in a connected heat exchanger. Computational Fluid Dynamics (CFD) approach is a natural choice for this application as no experimental evaluation of proposed solutions can be performed. Input data are obtained from the process using simpler balance-based approaches. CFD analysis is first used to find what causes the fouling and then to optimise the duct design in order to eliminate the undesirable phenomena. Several solution alternatives are proposed consisting of sets of vanes with different geometries. The finite volume model employed in the computations is described and the adopted approach, assumptions and simplifications are discussed. The studied alternatives are evaluated and the best of them is found using a flow uniformity index based on velocity distribution in a reference cross-section. It is concluded that the insight gained by CFD analysis is decisive for arriving at an improved design in this application.

CFD, design optimisation, pulp, sludge incineration

CFD, design optimisation, pulp, sludge incineration

HÁJEK, J.; KERMES, V.; ŠIKULA, J.; STEHLÍK, P.

20.07.2005

Hamilton, Ontario, Canada

Proceedings of the 6th Conference on Process Integration, Modelling and Optimisation of Energy Saving and Pollution Reduction

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