CFD Simulation of Domestic Gasification Boiler
Publication: Journal of Energy Engineering
Volume 143, Issue 2
Abstract
This paper describes the simulation of a wood gasification household boiler operation during the period that synthesis gas (syngas), which is produced after gasification, is further combusted for the production of heat that is transferred to the boiler heating surfaces. The particular boiler was designed by an Austrian company for the benefit of a Greek company based in northern Greece, which is currently manufacturing the boiler to test and further optimize it. The nominal fuel power of the boiler is approximately and its efficiency is about 90 percent (specifically 88.98 percent). The study is oriented toward the use of computational fluid dynamics (CFD) software as a supporting tool during the design phase of a gasification boiler and focuses on the combustion characteristics and the main gas emission concentrations expected at its outlet. In this study, the boiler is simulated under nominal operating conditions, assuming steady-state conditions as these have been defined by the Austrian company. Due to the highly transient and complex nature of wood log gasification, an ad-hoc thermodynamic model describing the associated characteristics of syngas under steady-state conditions has been developed and applied in the proposed CFD approach in order to overcome the highly complex modeling of syngas production. The numerical results are compared against the corresponding 0-D design data, since no available experimental data exist, to ensure the validity of the proposed model. The scope of this work is to achieve a better and deeper understanding of the expected emission characteristics at the boiler outlet and a better estimation of the heat transfer distribution among all different heat exchanging surfaces. However, in the near future, it is expected that the boiler will be tested at the premises of Thermodynamiki S.A (KOMBI) to identify possible discrepancies between the 3D CFD model results and the experimental values.
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Acknowledgments
The boiler manufacturer, Thermodynamiki S.A (KOMBI) provided useful data regarding the design and operation of the gasification boiler along with experimental data (flue gas temperature, pollutants concentration, etc.) for proper determination of the boundary conditions imposed in the simulation. The study described in this publication was financially supported by the Greek General Secretariat for Research and Technology (GSRT) within the frame of “Πρóγραμμα Aνα´πτυξης της Bιoμηχανικη´ς Eρευνας και Tεχνoλoγíας (ΠABET)” call for projects. The enumerated code of the Project is 326-BET (ΠΥPKAΛ). The basic boiler design of the gasification boiler was supplied to Thermodynamiki S.A by the Austrian company BIOENERGY2020+, subcontractor in this project.
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Published In
Journal of Energy Engineering
Volume 143 • Issue 2 • April 2017
Copyright
© 2016 American Society of Civil Engineers.
History
Received: May 10, 2016
Accepted: Jul 12, 2016
Published online: Aug 26, 2016
Discussion open until: Jan 26, 2017
Published in print: Apr 1, 2017
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