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Hebenstreit, Babette
Publications (5 of 5) Show all publications
Lichtenegger, K., Hebenstreit, B., Pointner, C., Schmidl, C. & Höftberger, E. (2015). The role of leak air in a double-wall chimney (ed.). Paper presented at . Heat and Mass Transfer, 51(6), 787-794
Open this publication in new window or tab >>The role of leak air in a double-wall chimney
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2015 (English)In: Heat and Mass Transfer, ISSN 0947-7411, E-ISSN 1432-1181, Vol. 51, no 6, p. 787-794Article in journal (Refereed) Published
Abstract [en]

In modern buildings with tight shells, often room-independent air supply is required for proper operation of biomass stoves. One possibility to arrange this supply is to use a double-wall chimney with flue gas leaving through the pipe and fresh air entering through the annular gap. A one-dimensional quasi-static model based on balance equations has been developed and compared with experimental data. Inclusion of leak air is crucial for reproduction of the experimental results.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-15428 (URN)10.1007/s00231-014-1454-6 (DOI)000354196400004 ()2-s2.0-84928994592 (Scopus ID)eeef632d-ac0d-4985-91eb-74517a65c4c7 (Local ID)eeef632d-ac0d-4985-91eb-74517a65c4c7 (Archive number)eeef632d-ac0d-4985-91eb-74517a65c4c7 (OAI)
Note
Validerad; 2015; Nivå 2; 20141111 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Hebenstreit, B., Schnetzinger, R., Ohnmacht, R., Höftberger, E., Lundgren, J., Haslinger, W. & Toffolo, A. (2014). Techno-economic study of a heat pump enhanced flue gas heat recovery for biomass boilers (ed.). Paper presented at . Biomass and Bioenergy, 71, 12-22
Open this publication in new window or tab >>Techno-economic study of a heat pump enhanced flue gas heat recovery for biomass boilers
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2014 (English)In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 71, p. 12-22Article in journal (Refereed) Published
Abstract [en]

An active condensation system for the heat recovery of biomass boilers is evaluated. The active condensation system utilizes the flue gas enthalpy exiting the boiler by combining a quench and a compression heat pump. The system is modelled by mass and energy balances. This study evaluates the operating costs, primary energy efficiency and greenhouse gas emissions on an Austrian data basis for four test cases. Two pellet boilers (10 kW and 100 kW) and two wood chip boilers (100 kW and 10 MW) are considered. The economic analysis shows a decrease in operating costs between 2% and 13%. Meanwhile the primary energy efficiency is increased by 3–21%. The greenhouse gas emissions in CO2 equivalents are calculated to 15.3–27.9 kg MWh−1 based on an Austrian electricity mix. The payback time is evaluated on a net present value (NPV) method, showing a payback time of 2–12 years for the 10 MW wood chip test case.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-7370 (URN)10.1016/j.biombioe.2014.01.048 (DOI)000345349500002 ()2-s2.0-84911913561 (Scopus ID)5bed4c8c-15b4-443b-9bf1-5f1be2f7379c (Local ID)5bed4c8c-15b4-443b-9bf1-5f1be2f7379c (Archive number)5bed4c8c-15b4-443b-9bf1-5f1be2f7379c (OAI)
Note
Validerad; 2014; 20140304 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Lichtenegger, K., Schappacher, W., Hebenstreit, B., Schmidl, C. & Höftberger, E. (2014). Towards a Stochastic Cellular Automata Model of Log Wood Combustion (ed.). Paper presented at International Conference on Mathematical Modeling in Physical Sciences : 01/09/2013 - 05/09/2013. Journal of Physics, Conference Series, 490(1), Article ID 12015.
Open this publication in new window or tab >>Towards a Stochastic Cellular Automata Model of Log Wood Combustion
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2014 (English)In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 490, no 1, article id 12015Article in journal (Refereed) Published
Abstract [en]

Describing the combustion of log wood and others solid fuels with complex geometry, considerable water content and often heterogenous struture is a nontrivial task. Stochastic Cellular Automata models offer a promising approach for modelling such processes. Combustion models of this type exhibit several similarities to the well-known forest fire models, but there are also significant differences between those two types of models. These differences call for a detailed analysis and the development of supplementary modeling approaches. In this article we define a qualitative two-dimensional model of burning log wood, discuss the most important differences to classical forest fire models and present some preliminary results. © Published under licence by IOP Publishing Ltd.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-31665 (URN)10.1088/1742-6596/490/1/012015 (DOI)000335909300015 ()2-s2.0-84896985388 (Scopus ID)5e9c8dc0-695a-43ff-972a-aa397f2824ab (Local ID)5e9c8dc0-695a-43ff-972a-aa397f2824ab (Archive number)5e9c8dc0-695a-43ff-972a-aa397f2824ab (OAI)
Conference
International Conference on Mathematical Modeling in Physical Sciences : 01/09/2013 - 05/09/2013
Note
Godkänd; 2014; 20140416 (johsod); Konferensartikel i tidskriftAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Hebenstreit, B., Höftberger, E., Ohnmacht, R., Lundgren, J. & Toffolo, A. (2013). Enhanced flue gas condensation technology: Analysis of a 10 MW demonstration plant (ed.). Paper presented at European Biomass Conference and Exhibition : 03/06/2013 - 07/06/2013. Paper presented at European Biomass Conference and Exhibition : 03/06/2013 - 07/06/2013.
Open this publication in new window or tab >>Enhanced flue gas condensation technology: Analysis of a 10 MW demonstration plant
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2013 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

A study on the application of an active condensation system to a typical Austrian heating plant fed with wood chips is presented. The heating plant consists of two biomass boilers (5MW+3MW). The flue gas of both boilers is mixed and directed to a condensing heat exchanger for heat recovery. The heat gained in the heat recovery system is used for preheating the reflux. A heat pump was integrated to enhance the heat recovery. In this paper the integration of the heat pump is discussed. All parts are modeled to calculate the potential energy gain which is obtained and to assess the usefulness of the application of a heat pump from a thermodynamic point of view. In addition, an economic analysis was carried out to evaluate the payback time for the heat pump using the typical Austrian heat and electricity prices. Finally first measurement results are discussed.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-28636 (URN)2814de4c-7a7f-4d63-9064-628ed70296f3 (Local ID)2814de4c-7a7f-4d63-9064-628ed70296f3 (Archive number)2814de4c-7a7f-4d63-9064-628ed70296f3 (OAI)
Conference
European Biomass Conference and Exhibition : 03/06/2013 - 07/06/2013
Note
Godkänd; 2013; 20140416 (babheb)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Lichtenegger, K., Hebenstreit, B. & Pointner, C. (2013). Leak air in a double-wall chimney system (ed.). Paper presented at International Conference on Mathematical Modelling in Physical Sciences : 03/09/2013 - 07/09/2013. Journal of Physics, Conference Series, 410, 1-4
Open this publication in new window or tab >>Leak air in a double-wall chimney system
2013 (English)In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 410, p. 1-4Article in journal (Refereed) Published
Abstract [en]

Operating biomass stoves in modern buildings with tight shells often requires a room-independent air supply. One possibility to arrange this supply is to use a double-wall chimney with fresh air entering through the annular gap. For this setup, a mathematical model has been developed and checked with experimental data. It turned out that for commercially available chimneys, leakage is not negligible and inclusion of leak air in the calculation is crucial for reproduction of the experimental data. Even with inclusion of this effect, discrepancies remain which call for further investigations and a refinement of the model.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-28750 (URN)10.1088/1742-6596/410/1/012059 (DOI)2a4de41d-356e-436d-9301-5bab434be5de (Local ID)2a4de41d-356e-436d-9301-5bab434be5de (Archive number)2a4de41d-356e-436d-9301-5bab434be5de (OAI)
Conference
International Conference on Mathematical Modelling in Physical Sciences : 03/09/2013 - 07/09/2013
Note
Upprättat; 2014; 20140430 (babheb); Konferensartikel i tidskriftAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-30Bibliographically approved
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