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| 293. |
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| 294. |
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| 295. |
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| 296. |
- Salomón Popa, Marianne, 1976-
(författare)
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On the optimal use of industrial-generated biomass residues for polygeneration
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Increasing energy demand as well as climate change concerns call for an analysis and optimization of energy services. Efficient use of energy resources, mitigation of environmental effects and supply an increasing demand are just some of the issues that are relevant nowadays in the energy system. In this regard, worldwide efforts are being made to increase the use of renewable energy and to promote energy efficiency measures in order to reduce the emission of greenhouse gases.Thus, sustainable solutions that take a holistic approach on covering the demands of the society are needed. The work presented herein addresses the use of industrial derived biomass residues for energy purposes in different contexts. The analysis was focused on: a) different alternatives to use solid palm oil residues in the Colombian mills for energy purposes including services b) the possibilities of implementing biomass-based heat and power plants in the Swedish energy system and their integration with already established biomass processing industries for polygeneration purposes.The assessment of the palm oil residues consisted on a technical analysis of the possible alternatives for electricity, heat, and biofuels production. For that, a thermodynamic approach was used to evaluate different alternatives. The assessment of biomass power plant integrated with the Swedish industry considered the thermodynamic, economic and environmental factors associated with certain energy conversion technologies. In this case a multiobjective optimization methodology was used to perform the thermoeconomic analysis. This allowed the evaluation of two contrasting scenarios were polygeneration at industrial level could be suggested: a less economically developed country where environmental policies are limited and industrial energy efficiency has not been implemented and a high income country with energy and environmental policies well established and energy efficiency measures being encouraged.Results show that the palm oil industry in Colombia has the capacity of being self-sufficient to cover of all their energy needs using the solid residues available. In the case of the thermoeconomic assessment of biomass-based integrated polygeneration plants in Sweden the results indicate that it is feasible to produce power while supplying the process steam required by nearby industries and district heating.
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| 297. |
- Salomon Popa, Marianne, 1976-, et al.
(författare)
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Small-scale biomass CHP plants in Sweden and Finland
- 2011
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 15:9, s. 4451-4465
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Tidskriftsartikel (refereegranskat)abstract
- Biomass continues to attract much interest as a renewable, low-CO2, and increasingly cost competitive alternative to traditional fossil fuels for heat and/or electric power generation. At the same time, deregulation of electricity markets offer new opportunities for small-scale decentralized power plants (<20 MWe) in an area where traditional centralized technologies mostly dominate. These factors represent a strong driving force for the development of innovative small-scale combined heat and power (CHP) plants based on biofuels. This paper provides an overview of small-scale CHP with biomass as a fuel. A survey of existing plants in Sweden and Finland is presented, along with an overview of major energy conversion technologies under development. Information is provided related to energy taxation along with an outlook on future prospects.
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| 298. |
- Sandoz, Raphael, et al.
(författare)
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Air-Based Bottoming-Cycles for Water-Free Hybrid Solar Gas-Turbine Power Plants
- 2013
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Ingår i: Journal of engineering for gas turbines and power. - : ASME International. - 0742-4795 .- 1528-8919. ; 135:10, s. 101701-
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Tidskriftsartikel (refereegranskat)abstract
- A thermoeconomic model of a novel hybrid solar gas-turbine power plant with an air-based bottoming cycle has been developed, allowing its thermodynamic, economic, and environmental performance to be analyzed. Multi-objective optimization has been performed to identify the trade-offs between two conflicting objectives: minimum capital cost and minimum specific CO2 emissions. In-depth thermoeconomic analysis reveals that the additional bottoming cycle significantly reduces both the levelized cost of electricity and the environmental impact of the power plant (in terms of CO2 emissions and water consumption) when compared to a simple gas-turbine power plant without bottoming cycle. Overall, the novel concept appears to be a promising solution for sustainable power generation, especially in water-scarce areas.
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| 299. |
- Sandoz, Raphael, et al.
(författare)
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Air-Based Bottoming-Cycles for Water-Free Hybrid Solar Gas-Turbine Power Plants
- 2013
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Ingår i: Proceedings of the ASME TurboExpo 2013. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- A thermoeconomic model of a novel hybrid solar gas- turbine power plant with an air-based bottoming cycle has been developed, allowing its thermodynamic, economic, and environmental performance to be analyzed. Multi-objective optimization has been performed to identify the trade-off between two conflicting objectives: minimum capital cost and minimum specific CO2 emissions. In-depth thermoeconomic analysis reveals that the additional bottoming cycle significantly reduces both the levelized cost of electricity and the environmental impact of the power plant (in terms of CO2 emissions and water consumption) when compared to a simple gas-turbine power plant without bottoming cycle. Overall, the novel concept appears to be a promising solution for sustainable power generation, especially in water-scarce areas.
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| 300. |
- Sanz Luengo, Antonio, 1986-
(författare)
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Experimental Investigation of the Influence of Local Flow Features on the Aerodynamic Damping of an Oscillating Blade Row
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The general trend of efficiency increase, weight and noise reduction has derived in the design of more slender, loaded, and 3D shaped blades. This has a significant impact on the stability of fan, and low pressure turbine blades, which are more prone to aeroelastic phenomena such as flutter. The flutter phenomenon is a self-excited, self-sustained unstable vibration produced by the interaction of flow and structure. These working conditions will induce either blade overload, or High Cycle Fatigue (HCF) produced by Limited Cycle Oscillation (LCO).The main objectives of the present work are on the investigation of the aeroelastic properties of a high-lift low-pressure in the light of the local flow features present in such profiles, in nominal and extreme off-design conditions both in high and low subsonic Mach number, for three dif-ferent rigid body modes. In addition, the validity of the linearity assump-tion of the influence coefficient technique has also been investigated, in order to expand the understanding of the physical limits of this assumption.This work has been designed as experimental investigation in the influence coefficient domain focused on a high-lift low-pressure turbine designed by ITP within the framework of the European FP7 project FU-TURE. These experiments have been carried out in the Aeroelastic test rig (AETR), at KTH Stockholm, which consist of an instrumented annular sector cascade with a single oscillating blade. The results acquired have been supported by numerical results provided by a non-propietary commercial software package (ANSYS CFX).The results suggest that the typical three-dimensional effects associated secondary flow features and tip leakage flows have a significant influence on the aeroelastic performance and the cascade stability. However the major influence appears as a consequence of the separation surface on the pressure side which appears at extreme off-design operating conditions. The contribution to stability of this local feature depend on the oscillation mode showing for the axial and torsion mode a neutral stability contribution, which is directly associated with the geometrical properties of the cascade. However, on the circumferential mode this separation surface has a stabilizing effect much more independent of the blade geometry.The study of the linearity assumption of the influence coefficient domain has revealed, that an apparent linear relation between the integrated unsteady response and the vibrational amplitude, does not necessary imply that the local unsteady response is linear with respect to the oscillation amplitude. The results also suggest that the validity of the linearity as-sumption is more sensitive to high oscillation amplitudes at high Mach conditions.
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