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  • 101.
    Mayorca, María Angélica
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Vogt, Damian M.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Andersson, C.
    Mårtensson, Hans
    VOLVO Aero Corporation.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Uncertainty of forced response numerical predictions of an industrial blisk - Comparison with experiments2012Ingår i: Proceedings of the ASME Turbo Expo 2012: Volume 7, Issue PARTS A AND B, 2012, ASME Press, 2012, s. 1537-1548Konferensbidrag (Refereegranskat)
    Abstract [en]

    Numerical methods, both Computational Fluid Dynamics (CFD) as well as Finite Elements (FE) methods, are widely used in industry with the purpose of predicting potential fatigue problems early in the design process. However, the uncertainty of such predictions is not clearly identified. The present paper presents the prediction of the vibration response of a rotor blisk part of 1 1/2 transonic compressor stage with comparison with experiments. Different uncertainty sources along the numerical aeromechanical chain are then identified. CFD solvers are employed for the prediction of both blade row interaction forces as well as the aerodynamic damping determination. Mistuning is assessed by the use of Reduced Order Modeling analyses and results compared with tip timing data. The peak amplitude response of a resonance mode of interest is determined for two different inlet conditions and thus the accuracy dependence on the excitation level is discussed. Results show that the largest uncertainties come from the unsteady aerodynamics, in which both aerodynamic damping and forcing estimations are critical. The structural dynamic models seem to capture the vibration response and mistuning effects well. Additionally, the challenges of tip timing data processing for detailed one-to-one validation of the tools are highlighted.

  • 102.
    Mayorca, María Angélica
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Vogt, Damian
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Mårtensson, Hans
    VOLVO Aero Corporation, Trollhättan, Sweden.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Numerical tool for prediction of aeromechanical phenomena in gas turbines2009Ingår i: 19th ISABE Conference / [ed] ISABE, Montreal: American Institute of Aeronautics and Astronautics Inc. , 2009, s. 1-11Konferensbidrag (Refereegranskat)
    Abstract [en]

    A numerical tool for aeromechanic design is presented. The output of the tool is the fatigue risk of the critical blade obtained by the Haigh diagram, and stability curves for the stability analyses. The tool integrates results from commercial Computational Fluid Dynamics (CFD) and Finite Element (FE) solvers. It uses a Reduced Order Modeling (ROM) technique in order to account for mistuning effects in an efficient way. The description of the numerical tool and an overview of typical results are presented in this paper. The applicability of the tool in the industrial design process is discussed as well as the outlook of the targeted capabilities.

  • 103.
    Monaco, Lucio
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Vogt, Damian
    Bergmans, J.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi. KIC InnoEnergy S.E.,, Netherlands .
    A remotely operated aeroelastically unstable LPT cascade for turbomachinery aeromechanics education and training: Remote flutter lab2014Ingår i: Proceedings of the ASME Turbo Expo, 2014, Vol. 6Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The use of advanced pedagogical methodologies in connection with advanced use of modern information technology (ICT) for delivery enables new ways of communicating, of exchanging knowledge, and of learning that are gaining increasing relevance in our society. Remote laboratory exercises offer the possibility to enhance learning for students in different technical areas, especially to the ones not having physical access to laboratory facilities and thus spreading knowledge in a world-wide perspective. A new "Remote Flutter Laboratory" has been developed to introduce aeromechanics engineering students and professionals to aeroelastic phenomena in turbomachinery. The laboratory is world-wide unique in the sense that it allows global access for learners anywhere and anytime to a facility dedicated to what is both a complex and relevant area for gas turbine design and operation. The core of the system consists of an aeroelastically unstable turbine blade row that exhibits self-excited and self-sustained flutter at specific operating conditions. Steady and unsteady blade loading and motion data are simultaneously acquired on five neighboring suspended blades and the whole system allows for a distant-based operation and monitoring of the rig as well as for automatic data-retrieval. This paper focuses on the development of the "Remote Flutter Laboratory" exercise as a hands-on learning platform for online and distant-based education and training in turbomachinery aeromechanics enabling familiarization with the concept of critical reduced frequency and of flutter phenomena. This laboratory set-up can easily be used "as is" directly by any turbomachinery teacher in the world, free of charge and independent upon time and location with the intended learning outcomes as specified in the lab, but it can also very easily be adapted to other intended learning outcomes that a teacher might want to highlight in a specific course. As such it is also a base for a turbomachinery repository of advanced remote laboratories of global uniqueness and access. The present work documents also the pioneer implementation of the LabSocket System for the remote operation of a wind tunnel test facility from any Internet-enabled computer, tablet or smartphone with no end-user software or plug-in installation.

  • 104.
    Monaco, Lucio
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Vogt, Damian
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    A new linear cascade test facility for use in engineering education2012Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A new low-speed air-operated linear cascade testfacility has been developed at the Heat and PowerTechnology Division at KTH, Sweden. The rig has fullyremote operability and is used as an educational tool forthe students in engineering courses on turbomachinery.Both on campus and distant students are involved inexperimental activities with the rig in the form oflaboratory exercises. The current setup allowsdetermination of profile losses through a low pressureturbine blade row at low subsonic flow conditions.The present paper contains a description of test rigdesign and its commissioning and introduces theconcepts for future applications of the facility ininvestigation of additional flow phenomena inturbomachinery. Findings of the first field experiencewith the linear cascade are here reported.

  • 105.
    Monaco, Lucio
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Vogt, Damian
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Implementation of a remote pump laboratory exercise in the training of engineering students2012Ingår i: Proceedings of ASME Turbo Expo 2012 GT2012: Volume 3, 2012, ASME Press, 2012, s. 479-487Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of laboratory exercises in the training of engineering students is of paramount importance to give the students the possibility to gain practical experience on real hardware and on real test data. Recent trends in the education of engineers at the Department of Energy Technology at KTH go towards an increasing share of distant-based education, which is put in place to educate students at different geographic locations, not only locally (such as for example with engineers in industry) but also internationally (i.e. with students in different countries). In order to provide the possibility to follow a course at a distance without compromising on learning objectives and learning quality, a number of remotely operated laboratory exercises have been developed and implemented in the engineering curriculum at the department. Among these, to mention the work carried out by Navarathna et al. [11] on a remotely operated linear cascade test facility. The present laboratory exercise is integrated in a course on turbomachinery and gives the students the possibility to interactively learn about the operation of pumps at various speeds, various mass flow rates, parallel operation and serial operation. Students access the laboratory exercise using a web-based interface, perform measurements and finally have test data sent to an initially specified email address for further analysis.

  • 106. Moyroud, F.
    et al.
    Fransson, Torsten H.
    KTH, Tidigare Institutioner                               , Energiteknik.
    Jacquet-Richardet, G.
    A comparison of two finite element reduction techniques for mistuned bladed disks2002Ingår i: Journal of engineering for gas turbines and power, ISSN 0742-4795, E-ISSN 1528-8919, Vol. 124, nr 4, s. 942-952Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The high performance bladed disks used in today's turbomachines must meet strict standards in terms of aeroelastic stability and resonant response level. One structural characteristic that can significantly impact on both these areas is that of bladed disk mistuning. To predict the effects of mistuning, computational efficient methods are much needed to make free-vibration and forced-response analyses of full assembly finite element (FE) models feasible in both research and industrial environments. Due to the size and complexity of typical industrial bladed disk models, one must resort to robust and systematic reduction techniques to produce reduced-order models of sufficient accuracy. The objective of this paper is to compare two prevalent reduction methods on representative test rotors, including a modern design industrial shrouded bladed disk, in terms of accuracy (for frequencies and mode shapes), reduction order computational efficiency, sensitivity to intersector elastic coupling, and ability to capture the phenomenon of mode localization. The first reduction technique employs a modal reduction approach with a modal basis consisting of mode shapes of the tuned bladed disk which can be obtained from a classical cyclic symmetric modal analysis. The second reduction technique uses Craig and Bampton substructure modes. The results show a perfect agreement between the two reduced-order models and the nonreduced finite element model. It is found that the phenomena of mode localization is equally well predicted by the two reduction models. In terms of computational cost, reductions from one to two orders of magnitude are obtained for the industrial bladed disk, with the modal reduction method being the most computationally efficient approach.

  • 107.
    Munajat, Nur Farizan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Erlich, Catharina
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fakhrai, Reza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten H.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Influence of water vapour and tar compound on laminar flame speed of gasified biomass gas2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 98, s. 114-121Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biomass can be converted to a gaseous fuel through gasification in order to be used in higher efficiency conversion equipment. Combustion of a gaseous fuel generally allows for higher combustion temperatures than that of a solid fuel leading to the higher efficiency. However, the gasified biomass gas (GBG) contains condensable compounds, such as water vapour and tars, which both will affect the subsequent combustion process with respect to emission levels and flame stability. Cleaning of the GBG prior to combustion is very costly and therefore further research is needed on direct combustion of GBG containing these condensable compounds, in order to develop stable combustion techniques for GBG. The laminar flame speed is a main parameter that relates to other important flame properties such as stability, extinction limit and flashback. Each of GBG components have different chemical and transport properties, which then influences the laminar flame speed of GBG. In this study, the individual effect of water vapour (H2O) and tar compound addition in simulated GBG on laminar flame speed is investigated at atmospheric pressure. The tar compound used is benzene (C6H6) and simulated GBG used is CO/H-2/CH4/CO2/N-2 mixture. Experiments were carried out with conical burner stabilized flame and a Schlieren photography system. The volume fraction of additives in the fuel mixture was varied: for H2O from 0% to 5% and for C6H6 from 0% to 10%. The unburned fuel air mixture was preheated and the temperature was maintained at T-i = 398 K to avoid condensation of the liquid. It was found that measured laminar flame speed of GBG-air mixture decreases with addition of H2O in the fuel mixture. While, non-monotonic behaviour is shown with addition of C6H6. Initially, as the volume fraction of C6H6 incremented, the laminar flame speed decreases, reaching a minimum value, and then increase.

  • 108. Mårtensson, H.
    et al.
    Vogt, Damian
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Assessment of a 3D Linear Flutter Prediction Tool using Sector Cascade Test Data2005Ingår i: Proceedings of the ASME Turbo Expo 2005, Vol 4, ASME Press, 2005, s. 613-623Konferensbidrag (Refereegranskat)
    Abstract [en]

    An assessment and validation of a numerical prediction tool for flutter are made using new experimental data from experiments on turbine blades in a sector cascade. The 3D geometry is that of a low-pressure (LP) turbine blade with twist and a profile that changes along span in an annular sector cascade. The numerical model is a linear harmonic Euler equation solver. Rig results are obtained for the blade by oscillating I blade out of 7 in the annular sector cascade. The blade is oscillated in the rig using a mechanical type of actuator to control the mode. The mode shapes in the rig consist of torsion and bending modes around a pivot mechanism fixed inside the hub end wall. The frequencies obtained in the rig are in the range up to 219 Hz, or reduced frequency based on full chord k=0.5, which covers the range of useful reduced frequencies typically found in turbine designs. Under reference running conditions the unsteady pressure responses are found qualitatively in line with the experiment. The test case is shown to be challenging to the numerical tool in terms of effects of tip clearance as well as off-design effects. In order to improve results tip clearance modeling and inclusion of viscous terms are identified as key factors.

  • 109.
    Navarathna, Nalin
    et al.
    KTH, Tidigare Institutioner                               , Energiteknik.
    Fedulov, Vitali
    KTH, Tidigare Institutioner                               , Energiteknik.
    Martin, Andrew
    KTH, Tidigare Institutioner                               , Energiteknik.
    Fransson, Torsten
    KTH, Tidigare Institutioner                               , Energiteknik.
    Web-based, interactive laboratory experiment in turbomachine aerodynamics2004Ingår i: Proceedings of the ASME Turbo Expo 2004, Vienna, 2004, Vol. 1, s. 885-891Konferensbidrag (Refereegranskat)
    Abstract [en]

    Remote laboratory exercises are gaining popularity due to advances in communication technologies along with the need to provide realistic yet flexible educational tools for tomorrow's engineers. Laboratory exercises in turbomachinery aerodynamics generally involve substantial equipment in both size and power, so the development of remotely controlled facilities has perhaps not occurred as quickly as in other fields. This paper presents an overview of a new interactive laboratory exercise involving aerodynamics in a linear cascade of stator blades. The laboratory facility consists of a high-speed fan that delivers a maximum of 2.5 kg/s of air to the cascade. Traversing pneumatic probes are used to determine pressure profiles at upstream and downstream locations, and loss coefficients are later computed. Newly added equipment includes cameras, stepper motors, and a data acquisition and control system for remote operation. This paper presents the laboratory facility in more detail and includes discussions related to user interface issues, the development of a virtual laboratory exercise as a complement to experiments, and comparative evaluation of Virtual, Remote and Local laboratory exercises.

  • 110.
    Navarathna, Nalin
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fedulov, Vitali
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Martin, Andrew
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Web-Based, Interactive Laboratory Experiment in Turbomachine Aerodynamics2010Ingår i: Journal of turbomachinery, ISSN 0889-504X, E-ISSN 1528-8900, Vol. 132, nr 1, s. 011015-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Remote laboratory exercises are gaining popularity due to advances in communication technologies along with the need to provide realistic yet flexible educational tools for tomorrow's engineers. Laboratory exercises in turbomachinery aerodynamics generally involve substantial equipment in both size and power, so the development of remotely controlled facilities has perhaps not occurred as quickly as in other fields. This paper presents an overview of a new interactive laboratory exercise involving aerodynamics in a linear cascade of stator blades. The laboratory facility consists of a high-speed fan that delivers a maximum of 2.5 kg/s of air to the cascade. Traversing pneumatic probes are used to determine pressure profiles at upstream and downstream locations, and loss coefficients are later computed. Newly added equipment includes cameras, stepper motors, and a data acquisition and control system for remote operation. This paper presents the laboratory facility in more detail and includes discussions related to user interface issues, the development of a virtual laboratory exercise as a complement to experiments, and comparative evaluation of virtual, remote, and local laboratory exercises.

  • 111.
    Noor, Hina
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Genrup, Magnus
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Selection of one-dimensional design parameter 'reaction degree' for 1 st stage of a cooled gas turbine2012Ingår i: Proc. ASME Turbo Expo, 2012, nr PARTS A, B, AND C, s. 2345-2354Konferensbidrag (Refereegranskat)
    Abstract [en]

    The recommendations available today in open literature for the choice of design parameter such as flow coefficient, stage loading and reaction degree incorporates mainly the influence of aerodynamics loss on efficiency. However, it is difficult to find the recommendation relating the influence of not only the aerodynamics loss but also cooling mass flow and cooling losses on varying most influential design parameters. In this paper, preliminary design and performance guidelines are presented for a cooled turbine stage using the 1D design tool LUAXT. The intention is to provide recommendations on the selection of design parameters, mainly reaction degree, which is found to be highly influenced by not only the aerodynamics loss but also the cooling mass flow and cooling loss such as in 1st stage of a High Pressure Turbines (HPT). The One-Dimensional (1D) design methods used to perform this task are verified and validated against experimental test data. A comparison of different loss models has been performed to provide most accurate outcomes for certain tested ranges. Based on the outcomes of this study, 'Craig & Cox' loss model has been considered to perform subsequent investigations for HPT design and performance estimation while formulating a parametric study. From this study, the design recommendations for the selection of performance parameter reaction degree are developed for cooled turbines. The results shows that for a HPT 1st stage, the recommended reaction degree range of 0.20 to 0.37 seems to provide the optimum stage design when chosen for stage loading in between 1.40 to 1.80 along with the stator exit flow angle in range of 74° to 78°.

  • 112.
    Noor, Hina
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Genrup, Magnus
    Lund Univ, Dept Energy Sci, S-22100 Lund, Sweden..
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    INVESTIGATION OF ONE-DIMENSIONAL TURBINE DESIGN PARAMETERS WITH RELATION TO COOLING PARAMETERS FOR A HIGH PRESSURE INDUSTRIAL GAS TURBINE STAGE2011Ingår i: 9TH EUROPEAN CONFERENCE ON TURBOMACHINERY: FLUID DYNAMICS AND THERMODYNAMICS, VOLS I AND II / [ed] Sen, M Bois, G Manna, M Arts, T, EUROPEAN TURBOMACHINERY SOC-EUROTURBO , 2011, s. 557-568Konferensbidrag (Refereegranskat)
    Abstract [en]

    This parametric study describes the effects of design parameters on coolant consumption and performance loss of the first stage of a high pressure industrial gas turbine. The Lund University Axial Turbine (LUAX-T) tool is employed to develop a better coupling between design parameters, cooling air and aerodynamic losses. From the performed design study; a lower stage reaction degree decreases the rotor coolant requirement, mainly due to a resulting decrease in rotor inlet temperature. However, a low reaction degree increases the cooling losses for the vane, which is because of a direct proportion between the mixing losses and the local Mach number. Based on the performed calculations and loss predictions, a range of design parameters is recommended for first stage of a gas turbine, while considering the influence of this choice on the next stage. The loss calculated for the stator blade has been calibrated against existing experimental data.

  • 113.
    Noor, Hina
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Genrup, Magnus
    Department of Energy Sciences, Lund University, Sweden.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Investigation of one-dimensional turbine design parameters with relation to cooling parameters for high pressure industrial gas turbine stage2011Ingår i: The 9th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics, 2011Konferensbidrag (Refereegranskat)
  • 114. Ortiz-Marcos, I.
    et al.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Hagström, Peter
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mazorra, J.
    Project Based Learning in an International Context in Sustainability and the Global Economy. TIME European Summer School: A Truly European Learning Experience2016Ingår i: International Journal of Engineering ,Science and Innovative Technology, ISSN 0949-149X, E-ISSN 2277-3754, Vol. 32, nr 5, s. 2284-2293Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper an innovative experience developed by seven Universities (six European and one non-European) to teach a two weeks summer course in a non-conventional, remotely way is presented. The course is developed using a Project Based teaching-learning methodology and it is also designed to have a deeper knowledge of the relationship between sustainable development and the economic and financial conditions. The experience is innovative because the technology used, allowed students to share knowledge and participate from countries all over the world. Competences of students in this context are measured and strengthened. The most interesting issues, challenges and difficulties are presented here. Conclusions help professors to propose actions to improve the methodology in order to strengthen students' competences.

  • 115.
    Ortiz-Marcos, Isabel
    et al.
    Universidad Politécnica de Madrid, ETSII.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Hagström, Peter
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Lhermitte, Claude
    Ecole Supérieure d’ Electricité (SUPÉLEC).
    TIME European Summer School: An Innovative International Educational Experience2011Ingår i: International journal of engineering education, ISSN 0949-149X, Vol. 27, nr 5, s. 924-932Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents an innovative experience that was developed by six European universities to teach a common course in an unconventional, remote way, to geographically-separate groups of students. The course is especially designed to enable engineering students to learn the basics of how the European social and sustainable model works, to acquire some basic cultural and religious awareness, and to stimulate transnational group discussions on such intercultural affairs. One overarching goal of this T.I.M.E. (Top International Managers for Europe) European Summer School (TESS) course is to identify some of the challenges that an academic collaboration organization like T.I.M.E. faces for future education, especially considering that the computer literate and highly web-based children who are born today will, with their expectations of ‘virtual 3D encounters’, be entering university by 2030. This web-based, social interaction experience has been developed over the last four years. This paper gives the results.

  • 116.
    Persson, Katarina
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Ersson, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Manrique Carrera, Arturo
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Jayasuriya, Jeevan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fakhrai, Reza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Järås, Sven
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Supported palladium-platinum catalyst for methane combustion at high pressure2005Ingår i: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 100, s. 479-483Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Catalytic combustion of methane over a supported bimetallic Pd-Pt catalyst and a monometallic Pd catalyst has been investigated experimentally. Two different reactor configurations were used in the study, i.e. a tubular lab-scale reactor working at atmospheric pressure and a high-pressure reactor working at up to 15 bar. The results showed that the bimetallic catalyst has a clearly more stable activity during steady-state operation compare to the palladium only catalyst. The activity of the bimetallic catalyst was slightly higher than for the palladium catalyst. These results were established in both test facilities. Further, the impact of pressure on the combustion activity has been studied experimentally. The tests showed that the methane conversion decreases with increasing pressure. However, the impact of pressure is more prominent at lower pressures and levels out for pressures above 10 bar

  • 117.
    Petrov, Miroslav
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten H.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    DESIGN AND STRUCTURE OF AUTOMATICALLY-CORRECTED DIGITAL EXERCISES IN A GRADUATE ENGINEERING COURSE2013Ingår i: INTED2013, IATED , 2013, s. 505-512Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A conceptual analysis of automatically-corrected digitalized calculation exercises and their plausible practical construction and implementation in graduate energy engineering education is presented and discussed herein. The target course focuses on sustainable power generation, taught to MSc-level students of various nationalities both on campus and off-campus, at the Department of Energy Technology, Royal Swedish Institute of Technology (KTH) in Stockholm, Sweden.

    Computerized teaching and training tools are becoming important and widely applied to all types and levels of education. Often, classes on campus are being taught in parallel with distance groups, which require commonly applicable and interactive educational tools and online platforms. Moreover, the digitalization of study material and the home-learning approach offers the students a chance to retain a high level of activity throughout the course regardless of if they attend classes or not. On the other hand, it is comparatively difficult to apply online tools and computerized educational methods to calculation exercises, as the direct contact to an instructor and the ability to train or grade the solution approach rather than just the final answers is crucial for the proper follow-up on learning outcomes.

    The authors assess the advantages and drawbacks of digital calculation exercises and suggest a specific method for designing such, where understanding the solution procedure and the self-learning approach are optimized. The practical implementation of such exercises in the field of energy engineering and power technology, and their impact on effective learning is examined by observations on student performance and by analyzing feedback from students, through comparison with traditional paper-based exercise tests both among different student batches and within a certain student group.

  • 118.
    Petrov, Miroslav
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Göransson, Åke
    Siemens Industrial Turbomachinery AB, Finspång.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    High-speed Steam Turbine Systems for Distributed Generation Applications2012Ingår i: Proceedings of the ASME 2012 Power Conference. Power 2012, ASME Press, 2012, s. 7-Konferensbidrag (Refereegranskat)
    Abstract [en]

    The efficiency of utilization of low-grade solid fuels of either renewable or fossil origin such as biomass, municipal or agricultural wastes, peat, lignite, etc. for distributed generation applications and combined heat and power (CHP) production at small scales can be improved by a simple technology shift. This study evaluates the technical feasibility of a compact power generation package comprising a small steam turbine directly coupled to a high-speed alternator delivering around 2 MW of electricity. Existing high-speed electrical generators at MW-scale are presented and reviewed, and a basic thermodynamic design and flow-path analysis of a steam turbine able to drive such a generator is attempted. Most importantly, the speed-controlled turbogenerator arrangement promises improved electrical efficiency especially at part-load (in off-design mode), compared to the typically low off-design performance of small-scale steam cycles using state-of-art fixed speed turbines. High-speed alternators with related power electronics are nowadays becoming increasingly available for the MW-size market. One such product – a commercial 2 MW permanent-magnet alternator running at 22,500 rpm – has been used as a reference for evaluating the behavior of a speed-controlled steam turbine as a prime mover. The specific turbine losses due to its comparatively small size remain serious. However, a low steam parameter approach suits well for converting, for example, heat-only boilers into CHP units, adding value by local electricity production at affordable costs. Steam superheat temperatures of around or less than 350 C (660 F) would keep the steam volumetric flow sufficiently high in order to restrain the turbine losses and allow for a cost-effective electricity production for enhanced utilization of locally-available solid fuels via steam cycles. Such a steam turbine is possible to manufacture and would deliver a promising performance despite its small size. The possibility for the turbine to be speed-controlled and its characteristics thereof have been evaluated by computer simulations using the in-house code AXIAL by courtesy of the Swedish branch of Siemens Industrial Turbomachinery, steam turbine division. Simulation results show that a reasonable improvement in part-load performance can be achieved for the high-rpm turbine-generator drivetrain: up to 30% better in the load spectrum down to 50% of nominal output, if compared with a fixed-speed arrangement of similar size and parameters.

  • 119.
    Petrov, Miroslav
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Göransson, Åke
    Fransson, Torsten H.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    High-Speed Steam Turbine Systems For Small-Scale Power Generation Applications2012Ingår i: Proceedings of the 20th International Conference on Nuclear Engineering collocated with the ASME 2012 Power Conference: ICONE20-POWER2012, American Society of Mechanical Engineers ASME, ASME Press, 2012, s. 651-657Konferensbidrag (Refereegranskat)
    Abstract [en]

    Energy utilization from low-grade fuels of either fossil or renewable origin, or from medium-temperature heat sources such as solar, industrial waste heat, or small nuclear reactors, for small-scale power generation via steam cycles, can be reasonably enhanced by a simple technology shift. This study evaluates the technical feasibility of a compact power generation package comprising a steam turbine directly coupled to a high-speed alternator delivering around 8 - 12 MW of electrical power. Commercial or research-phase high-speed electrical generators at MW-scale are reviewed, and a basic thermodynamic design and flow-path analysis of a steam turbine able to drive such a generator is attempted. High-speed direct drives are winning new grounds due to their abilities to be speed-controlled and to avoid the gearbox otherwise typical for small system drivetrains. These two features may offer a reasonable advantage to conventional drives in terms of higher reliability and better economy. High-speed alternators with related power electronics are nowadays becoming increasingly available for the MW-size market. A generic 8 to 12 MW synchronous alternator running respectively at 15,000 to 10,000 rpm, have been used as a reference for evaluating the fundamental design of a directly coupled steam turbine prime mover. The moderate steam parameter concept suits well for converting mid-temperature thermal energy into electrical power with the help of low-tech steam cycles, allowing for distributed electricity production at reasonable costs and efficiency. Steam superheat temperatures below 350 degrees C (660 degrees F) at pressures of maximum 20 bar would keep the steam volumetric flow sufficiently high in order to restrain the turbine losses typical for small-scale turbines, while helping also with simpler certification and safety procedures and using primarily established technology and standard components. The proposed steam turbines designs and their characteristics thereof have been evaluated by computer simulations using the in-house code ProSteam and its sub-procedures AXIAL and VaxCalc, by courtesy of Siemens Industrial Turbomachinery and its steam turbine division located in Finspong, Sweden. The first results from this study show that high-speed steam turbines of the proposed size and type are possible to design and manufacture based on conventional components, and can be expected to deliver a very satisfactory performance at variable power output.

  • 120.
    Petrov, Miroslav
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Martin, Andrew
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Salomón, Marianne
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Master Program in Distant Sustainable Energy Engineering: Self-assessment of the intake autumn 20062008Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The present report summarizes the experiences obtained in running the DSEE MasterProgram at the Department of Energy Technology, KTH, and in particular the performanceand results of distance students who started in autumn 2006 along the 1.5 year program.This is a review from the DSEE Program Coordinators’ side.

  • 121.
    Petrov, Miroslav P.
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Salomon Popa, Marianne
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten H.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Solar augmentation of conventional steam plants: From system studies to reality2012Ingår i: World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference, American Solar Energy Society , 2012, s. 2682-2689Konferensbidrag (Refereegranskat)
    Abstract [en]

    Solar energy is often available in abundant quantities in the vicinity of conventional steam power plants close to large energy-consumption centers, where also the need for clean add-on power is substantial. Fossil-fuel based power units (coal fired steam plants or natural gas fired combined cycles) can be augmented with solar thermal power for feedwater preheating or parallel steam generation. Especially relevant is if the solar field in such developments is designed to deliver lower temperatures when compared to solar-only steam units, therefore decreasing the costs for the solar hardware and its maintenance. Employing solar energy either for upgrade of existing large-scale utility plants or in new constructions avails also of their intrinsically high efficiency of energy conversion and established infrastructure. The potential benefits of solar-fossil hybrid steam cycles have already been widely recognized and various feasibility studies carried out. A more systematic approach for proper evaluation of efficiency gain is necessary, for several representative types and sizes of conventional utility steam plants. More straightforward optimization studies are also required for finding the optimum penetration of solar power in the fossil-fired steam cycle, taking into account both technological and economy values. The present work attempts to provide an exhaustive review of previous efforts in this field, summarize the potential for practical deployment, and primarily build up the basis for a normalized systematic approach upon which various broad optimization studies can be performed with the ultimate goal of examining the technical and economical feasibility of any solar-fossil integrated concept and ultimately proposing a viable practical application for any specific location.

  • 122.
    Petrov, Miroslav
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Salomon Popa, Marianne
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Educating the Energy Engineers of Tomorrow: challenges of internationalisation and knowledge interchange2012Ingår i: INTED2012 Proceedings CD, IATED , 2012, s. Paper ID: 2026-Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper summarises the authors’ own teaching experiences from two large MSc-level courses taught as part of several international Master programmes related to Sustainable Energy Engineering, organized by the Department of Energy Technology at the Royal Institute of Technology (KTH) in Stockholm, Sweden.  

    Some important hinders and obstacles to effective learning are presented and discussed, addressing especially certain challenges for the students and their effect on student performance. Observations have been made throughout several years of increasing demand for energy- and sustainability-related knowledge by ever larger student groups. The growing number of international students and the fact that many students are aiming at expanding their abilities by specialising in energy engineering without having the necessary background, as well as the fact that many students following certain non-engineering programmes focusing on environmental or sustainability issues need nevertheless to study also purely engineering courses, brings many positive characteristics to the blended student team but also displays serious challenges to the practical optimisation of the learning activities, the intended learning outcomes, the speed of advancement in knowledge, and the general quality of education for such a diverse group of students.

    Possible improvements and augmentations of the learning activities with the goal of finding solutions to these challenges on both a programme level and course level are proposed and subjected to testing in recent student batches. The expected results in terms of improved student performance, and the plausible further extension of this work, are introduced and analysed.

  • 123. Philit, M.
    et al.
    Ferrand, P.
    Labit, S.
    Chassaing, J. -C
    Aubert, S.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Derivated turbulence model to predict harmonic loads in transonic separated flows over a bump2012Ingår i: 28th Congress of the International Council of the Aeronautical Sciences 2012, ICAS 2012: Volume 4, 2012, 2012, s. 2713-2723Konferensbidrag (Refereegranskat)
    Abstract [en]

    Nowadays, frequency-domain time-linearized flow solvers are widely employed for aerospace engineering applications like turbomachinery or wing aeroelacticity. Due to substantial savings in the computational costs compared to the classical time-nonlinear methods, these methods are promising in the context of industrial design process in aeronautics. Nevertheless, the timelinearized solution is often relying on the assumption of frozen turbulence which can lead to significant discrepancies in the unsteady flow prediction, especially when the steady flow exhibits strong shock-wave boundary layer interactions. In the present paper, we propose to account for effects of the turbulence on the unsteady field by linearizing the k-? turbulence closure of Wilcox. To this end, an Automatic Derivation Tool is applied to the discretized Reynolds Average Navier-Stokes solver Turb'Flow™. The resulting time-linearized LRANS solver Turb'Lin™is used to computed the unsteady response of forced shock-wave motion in a transonic nozzle due to harmonic back pressure fluctuations. The accuracy of the present methodology is assessed by comparison with time-nonlinear and harmonic-balance solutions for both weak and strong shock-wave turbulent boundary layer interactions forced by an excitation frequency equal to 500 Hz.

  • 124.
    Raza, Rizwan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Zhu, Bin
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Zn0.6 Fe0.1Cu0.3/GDC Composite anode for Low Temperature SOFC (300-600) oC2010Ingår i: Journal of Fuel Cell Science and Technology, ISSN 1550-624X, E-ISSN 1551-6989, Vol. 8, nr 3Artikel i tidskrift (Refereegranskat)
  • 125.
    Raza, Rizwan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Zhu, Bin
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten H.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Zn0.6Fe0.1Cu0.3/GDC Composite Anode for Solid Oxide Fuel Cell2011Ingår i: J FUEL CELL SCI TECHNOL, ISSN 1550-624X, Vol. 8, nr 3, s. 031010-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent research results show that homogeneity and microstructure are very important parameters for the development of low cost materials with better performance for fuel cell applications. This research effort has been contributed in the development of low temperature solid oxide fuel cell (LTSOFC) material and technology as well as applications for polygeneration. The microstructure and electrochemical analyses were conducted. We found a series of new electrode materials which can run solid oxide fuel cell at 300-600 degrees C range with high performances, e. g., a high power density output of 980 mW cm(-2) was obtained at 570 degrees C. The fuel cell electrodes were prepared from metal oxide materials through a solid state reaction and then mixed with doped ceria. The obtained results have many advantages for the development of LTSOFCs for polygeneration. The nanostructure of the anode has been studied by high-resolution electron microscopy, the crystal structure and lattice parameters have also been studied by X-ray diffraction. The electrical conductivity of the composite anode was studied by electrochemical impedance spectra.

  • 126.
    Reza, Fakhrai
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Bahram, Saadatfar
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Computational Fluid Dynamics as an Alternative Representation of Physical Phenomena for an Iterative Learning Environment2012Ingår i: EDULEARN12 Proceedings: 4th International Conference on Education and New Learning Technologies,Barcelona, Spain. 2-4 July, 2012, IATED , 2012, s. 1325-1332Konferensbidrag (Refereegranskat)
    Abstract [en]

    Computational fluid dynamic (CFD) is an alternative representation of the physical phenomenon in engineering education. The method will replace the hardware-based laboratory in education as the computation power increases and became more available. However, CFD is a cross disciplinary field with its roots in computer science, programing, fluid mechanic, and visualization. Nevertheless it is utilized in almost all disciplines, in each viewed as the exceedingly self-directed and constructivist form of learning. Currently the desired proficiency in the fundamentals and conversant is conquered through instruction followed by practice “learning by doing”. This method has been considered to be a superior pedagogic method in this field and closely woven into the fabric of demonstrative activities of the learners with honors from centuries ago. During the last decade, a variety of frameworks have been employed to enhance the ease of use of the tools in numerical prediction and data applications. However, the educational aspect of CFD, though evolving with notable precincts, has been left unaddressed. There are not effective teaching and learning methods guaranteeing the utilization of high level cognitive process by students. In addition, there is a fundamental lack of definition of terminology in this field as well as in other educational technologies as a whole. The neglect has widened the gap concerning tools and their execution environments, stifling advances in research and education. This work is dedicated to identify the project works that best exemplify the CFD regardless the discipline in which the students are trained. Numbers of problems covering all aspects of CFD were design, offered and executed by students. Students undertook the problem in groups and reported the results. The progress of the work monitored and the best exercise which cutch the student’s interests and covered cross-disciplinary nature of the CFD were identified. The important properties of these project works were mapped and will be tested once more in upcoming teaching events.

  • 127.
    Reza, Fakhrai
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Bahram, Saadatfar
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Conceptual Model for Educational Deployment of Podcast in Context of Learning Process Enhancement2013Ingår i: INTED2013 Proceedings: 7th International Technology, Education and Development Conference Valencia, Spain. 4-5 March, 2013., IATED , 2013, s. 1716-1719Konferensbidrag (Refereegranskat)
    Abstract [en]

    Research has shown that learners are progressively more emphasizing on the importance of communication platform in learning and teaching along with convenience and flexibility, to accommodate the needs of their active lifestyles. In other words, learners are looking for an educational system to deliver in a relevant manner that is technology-enhanced. New technologies, Information and Communications Technology have made sizable evolution and generated impact and improvement over the conditions for learning in education, training and Lifelong Learning (LLL).

    To deal with the issues that are created by this changing landscape, a research project created across a course to review the use, effectiveness and impact of the podcast across teaching and learning scenarios and services. It was structured around some specific items: creation, deployment and impact. The output of this study illuminates the significant potentials of using podcast in learning process, intended learning outcomes as well as describes a conceptual framework used by integrating podcast into learning process.

  • 128. Rubensdörffer, F. G.
    et al.
    Fransson, Torsten H.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Numerical investigations of geometric design parameters defining nozzle guide vane endwall heat transfer2006Ingår i: Proc. ASME Turbo Expo, 2006, s. 173-182Konferensbidrag (Refereegranskat)
    Abstract [en]

    The objective of this work is to compare the predicted flow field and the endwall heat transfer of a baseline nozzle guide vane configuration with a combustion chamber variant, a heat shield variant without and with additional cooling air, and a cavity variant without and with additional cooling air. The comparison is carried out numerically using the commercial 3D Navier-Stokes software package Fluent [1]. For the turbulence modeling the v2-f model by Durbin [2] been used. The detailed comparison of the flow field and the endwall heat transfer shows major differences between the baseline and heat shield configuration. The heat shield in front of the airfoil of the nozzle guide vane cascade influences the secondary flow field and the endwall heat transfer pattern strongly. The additional cooling air, released under the heat shield also has a distinctive influence. The cavity between the combustion chamber and the nozzle guide vane affects the secondary flow field and the endwall heat transfer pattern. Here the influence of the additional cavity cooling air is more decisive.

  • 129.
    Saadatfar, Bahram
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fakhrai, Reza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Conceptual modeling of nano fluid ORC for solar thermal polygeneration2014Ingår i: 2013 ISES SOLAR WORLD CONGRESS, 2014, Vol. 57, s. 2696-2705Konferensbidrag (Refereegranskat)
    Abstract [en]

    A model has been developed for thermodynamic cycle of the solar thermal production of power, heating and cooling utilizing nano fluid as a working fluid in Organic Rankine Cycle. The proposed working fluid provides enhancement in power, heating, and cooling as useful outputs. Initial studies were performed with silver-nano pentane as a working fluid in the cycle. This work extends the application of the cycle to working fluids consisting of organic fluid mixtures. Nano Organic fluid could be used successfully in solar thermal power plants, as working fluids in Rankine cycles. An advantage of using nano fluid as a working fluid is that there are mature experiences with building components for these fluids. A commercially available modeling program has been used to model and investigate the performance of the system. The potential and advantages of using nano fluid are discussed. It is found that the thermodynamic efficiencies achievable with nano organic fluid, under optimum conditions, are higher than those obtained from the base fluid. Further, the size of heat exchangers, evaporator, and condenser are lower than those using the base fluid.

  • 130.
    Saadatfar, Bahram
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fakhrai, Reza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Exergo-environmental analysis of nano fluid ORC low-grade waste heat recovery for hybrid trigeneration system2014Ingår i: Energy Procedia: International Conference on Applied Energy, ICAE2014, Elsevier, 2014, s. 1879-1882Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this work, a thermodynamic model based on theoretical and experimental data is developed for utilizing nano fluid organic Rankine cycle (nORC) in a trigeneration hybrid system. The trigeneration hybrid system composed of a solid biomass boiler, gas turbine cycle, a nORC, cooling, and a heating system. The exergy of the system analyzed; moreover, environmental impact assessments and interrelated parametric studies are examined. The results show higher exergy efficiency for the hybrid trigeneration employed nORC, and indicate that carbon dioxide emissions for utilizing nano fluid in nORC trigeneration system are less than conventional working fluid system.

  • 131.
    Saadatfar, Bahram
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fakhrai, Reza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Nano Organic Rankine Cycle for Enhanced Heat Recovery2013Ingår i: ASME ORC 2013, 2nd International seminar on ORC power systems, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    There will be an incredible energy challenge in the future. With growing population, more and more energy needs to meet society’s demands. Fossil fuels are limited resources; hence there will be need more renewable energy as well as more efficient use of energy by recovering low-grade heat source. An organic Rankine cycle (ORC) system would be attractive and promising technology for energy conversion systems in low temperature thermal energy sources. Many actual ORC’s applications have been installed; nevertheless, one of the major challenges in the ORC technology is working fluid. The difficulties involved in the accurate thermophysical properties in addition to safety of organic fluids that are commonly found in ORC, may result in relatively low efficiency as well as heat exchanger and component size. In the organic Rankine cycle, heat exchangers, including evaporators and condensers, are the dominant components with most working fluid accumulation. Moreover, the working fluid is linked to the expansion part; therefore, selecting an organic fluid and expander should be performed at the same time. Conventional Organic Rankine Cycle uses organic fluid as a working fluid, whereas nano fluid organic Rankine cycle (nORC) uses nano material and organic compound as a working fluid and it is particularly suitable for utilizing small scale heat exchangers, due to creating better thermal match both in boiling and condensing, in low temperature applications. In this work, utilizing nano organic fluid as a working fluid for ORC for Some types of nanoparticles are studied; thermophysical properties of nano ORC candidate in the specific temperature range are measured and analyzed. Also, this study presents acceptable operating conditions and expansion machine by investigating the interaction among the expansion part and nano organic working fluid.

  • 132.
    Saadatfar, Bahram
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fakhrai, Reza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Conceptual Model of e-learning Educational Platform for Lifelong Learning2014Konferensbidrag (Refereegranskat)
  • 133.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Annerfeldt, Mats
    Aerodynamic Implication of Endwall and Profile Film Cooling in a Transonic Annular Cascade2013Ingår i: 21st ISABE Conference / [ed] ISABE, Busan, Korea, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    An experimental study is performed to observe the aerodynamic implications of endwall and profile film cooling on flow structures and aerodynamic losses. The investigated vane is a geometrically similar transonic nozzle guide vane with engine-representative cooling geometry. Furthermore, a new formulation of the cooling aerodynamic loss equation is presented and compared with the conventional methods. Results from a 5-hole pneumatic probe show that the film coolant significantly alters the secondary flow structure. The effect of different assumptions for the loss calculation is shown to significantly change the measured loss.

  • 134.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mamaev, Boris
    Annerfeldt, Mats
    Experimental studies of leading edge contouring influence on secondary losses in transonic turbines2012Ingår i: ASME Turbo Expo 2012: Turbine Technical Conference and Exposition, ASME Press, 2012, s. 1109-1119Konferensbidrag (Refereegranskat)
    Abstract [en]

    An experimental study of the hub leading edge contouring using fillets is performed in an annular sector cascade to observe the influence of secondary flows and aerodynamic losses. The investigated vane is a three dimensional gas turbine guide vane (geometrically similar) with a mid-span aspect ratio of 0.46. The measurements are carried out on the leading edge fillet and baseline cases using pneumatic probes. Significant precautions have been taken to increase the accuracy of the measurements. The investigations are performed for a wide range of operating exit Mach numbers from 0.5 to 0.9 at a design inlet flow angle of 90°. Data presented include the loading, fields of total pressures, exit flow angles, radial flow angles, as well as profile and secondary losses. The vane has a small profile loss of approximately 2.5 % and secondary loss of about 1.1%. Contour plots of vorticity distributions and velocity vectors indicate there is a small influence of the vortex-structure in endwall regions when the leading edge fillet is used. Compared to the baseline case the loss for the filleted case is lower up to 13 % of span and higher from 13% to 20 % of the span for a reference condition with Mach no. of 0.9. For the filleted case, there is a small increase of turning up to 15 % of the span and then a small decrease up to 35 % of the span. Hence, there are no significant influences on the losses and turning for the filleted case. Results lead to the conclusion that one cannot expect a noticeable effect of leading edge contouring on the aerodynamic efficiency for the investigated 1st stage vane of a modern gas turbine.

  • 135.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mamaev, Boris
    Siemens LLC Energy Oil & Gas Design Department, Russia.
    Annerfeldt, Mats
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Suction and Pressure Side Film Cooling Influence on Vane Aero Performance in a Transonic Annular Cascade2013Ingår i: Proceedings of the ASME Turbo Expo, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    An experimental study on a film cooled nozzle guide vane has been conducted in a transonic annular sector to observe the influence of suction and pressure side film cooling on aerodynamic performance. The investigated vane is a typical high pressure gas turbine vane, geometrically similar to a real engine component, operated at an exit reference Mach number of 0.89. The aerodynamic results using a five hole miniature probe are quantified and compared with the baseline case which is uncooled. Results lead to a conclusion that the aerodynamic loss is influenced substantially with the change of the cooling flow rate regardless the positions of the cooling rows. The aerodynamic loss is very sensitive to the blowing ratio and a value of blowing ratio higher than one leads to a considerable higher loss penalty. The suction side film cooling has larger influence on the aerodynamic loss compared to the pressure side film cooling. Pitch-averaged exit flow angles around midspan remain unaffected at moderate blowing ratio. The secondary loss decreases (greater decrease in the tip region compared to the hub region) with inserting cooling air for all cases compared to the uncooled case.

  • 136.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mamaev, Boris
    Annerfeldt, Mats
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Utriainen, Esa
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Shower Head and Trailing Edge Cooling Influence on Transonic Vane Aero Performance2014Ingår i: ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, ASME Press, 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    An experimental investigation on a cooled nozzle guide vane has been conducted in an annular sector to quantify aerodynamic influences of shower head and trailing edge cooling. The investigated vane is a typical high pressure gas turbine vane, geometrically similar to a real engine component, operated at a reference exit Mach number of 0.89. The investigations have been performed for various coolant-to-mainstream mass-flux ratios. New loss equations are derived and implemented regarding coolant aerodynamic losses. Results lead to a conclusion that both trailing edge cooling and shower head film cooling increase the aerodynamic loss compared to an uncooled case. In addition, the trailing edge cooling has higher aerodynamic loss compared to the shower head cooling. Secondary losses decrease with inserting shower head film cooling compared to the uncooled case. The trailing edge cooling appears to have less impact on the secondary loss compared to the shower head cooling. Area-averaged exit flow angles around midspan increase for the trailing edge cooling.

  • 137.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mamaev, Boris
    Annerfeldt, Mats
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Utriainen, Esa
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Shower Head and Trailing Edge Cooling Influence on Transonic Vane Aero Performance2014Ingår i: Journal of turbomachinery, ISSN 0889-504X, E-ISSN 1528-8900, Vol. 136, nr 11, s. 111001-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An experimental investigation on a cooled nozzle guide vane (NGV) has been conducted in an annular sector to quantify aerodynamic influences of shower head (SH) and trailing edge (TE) cooling. The investigated vane is a typical high pressure gas turbine vane, geometrically similar to a real engine component, operated at a reference exit Mach number of 0.89. The investigations have been performed for various coolant-to-mainstream mass-flux ratios. New loss equations are derived and implemented regarding coolant aerodynamic losses. Results lead to a conclusion that both TE cooling and SH film cooling increase the aerodynamic loss compared to an uncooled case. In addition, the TE cooling has higher aerodynamic loss compared to the SH cooling. Secondary losses decrease with inserting SH film cooling compared to the uncooled case. The TE cooling appears to have less impact on the secondary loss compared to the SH cooling. Area-averaged exit flow angles around midspan increase for the TE cooling.

  • 138.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mamaev, Boris
    Siemens LLC Energy Oil & Gas Design Department, Russia.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Laumert, Björn
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Influence of Prehistory and Leading Edge Contouring on Aero Performance of a Three-Dimensional Nozzle Guide Vane2014Ingår i: Journal of turbomachinery, ISSN 0889-504X, E-ISSN 1528-8900, Vol. 136, nr 7, s. 071014-1-071014-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Experiments are conducted to investigate the effect of the prehistory in the aerodynamic performance of a three-dimensional nozzle guide vane with a hub leading edge contouring. The performance is determined with two pneumatic probes (five hole and three hole) concentrating mainly on the end wall. The investigated vane is a geometrically similar gas turbine vane for the first stage with a reference exit Mach number of 0.9. Results are compared for the baseline and filleted cases for a wide range of operating exit Mach numbers from 0.5 to 0.9. The presented data includes loading distributions, loss distributions, fields of exit flow angles, velocity vector, and vorticity contour, as well as mass-averaged loss coefficients. The results show an insignificant influence of the leading edge fillet on the performance of the vane. However, the prehistory (inlet condition) affects significantly in the secondary loss. Additionally, an oil visualization technique yields information about the streamlines on the solid vane surface, which allows identifying the locations of secondary flow vortices, stagnation line, and saddle point.

  • 139.
    Saha, Ranjan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Mamaev, Boris
    Siemens LLC Energy Oil & Gas Design Department, Rusia.
    Fridh, Jens
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Laumert, Björn
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Influence of pre-history and leading edge contouring on aero-performance of a 3D nozzle guide vane2013Ingår i: Proceedings of the ASME Gas Turbine India Conference -2013- ; presented at ASME 2013 Gas Turbine India Conference, December 5-6, 2013, Bangalore, India, ASME Press, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Experiments are conducted to investigate the effect of the pre-history in the aerodynamic performance of a threedimensional nozzle guide vane with a hub leading edge contouring. The performance is determined with two pneumatic probes (5 hole and 3 hole) concentrating mainly on the endwall. The investigated vane is a geometrically similar gas turbine vane for the first stage with a reference exit Mach number of 0.9. Results are compared for the baseline and filleted cases for a wide range of operating exit Mach numbers from 0.5 to 0.9. The presented data includes loading distributions, loss distributions, fields of exit flow angles, velocity vector and vorticity contour, as well as, mass-averaged loss coefficients. The results show an insignificant influence of the leading edge fillet on the performance of the vane. However, the pre-history (inlet condition) affects significantly in the secondary loss. Additionally, an oil visualization technique yields information about the streamlines on the solid vane surface which allows identifying the locations of secondary flow vortices, stagnation line and saddle point.

  • 140.
    Salomon Popa, Marianne
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Distant Master Program in Sustainable Energy Engineering: Self-assessment of the intake autumn 20042007Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Since 1997 the Department of Energy Technology (EGI) has offered the Sustainable Energy Engineering (SEE) MSc Program to over 200 students from around 50 different countries. In June 2004, it was decided by the KTH President to offer the International Master Program on Sustainable Energy Engineering (SEE) as a distance program. Based on this, EGI offered a distance version of the Sustainable Energy Engineering Program (identified as DSEE) for the academic years (2004/2005 and 2005/2006) on a trial basis to a selected group of qualified students. This is a complete e-learning program that is held in conjunction with the regular SEE-program, offering an alternative for those students who could be accepted for the regular SEE-program but who can not afford to participate in the on-campus courses. All mandatory courses are offered on-line and lectures can be followed either synchronously or asynchronously via internet.This report contains the status of the first students that started the program in autumn 2004 and highlights the experience gained during the first year of the distance program as well as the challenges and opportunities associated with offereing a distance program in energy technology.

  • 141.
    Salomon Popa, Marianne
    et al.
    KTH, Tidigare Institutioner, Energiteknik.
    Fransson, Torsten
    KTH, Tidigare Institutioner, Energiteknik.
    Fedulov, Vitali
    KTH, Tidigare Institutioner, Energiteknik.
    Interactive teaching and learning platform in Energy Technology2004Rapport (Övrigt vetenskapligt)
  • 142.
    Salomon Popa, Marianne
    et al.
    KTH, Tidigare Institutioner, Energiteknik.
    Fridh, Jens
    KTH, Tidigare Institutioner, Energiteknik.
    Kessar, Alexandros
    KTH, Tidigare Institutioner, Energiteknik.
    Fransson, Torsten
    KTH, Tidigare Institutioner, Energiteknik.
    Gas turbine simulations in the computerized educational program CompEduHPT: Educational aspects2003Ingår i: American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) IGTI, 2003, Vol. 1, s. 733-739Konferensbidrag (Refereegranskat)
    Abstract [en]

    An overview of computerized educational program (CompEduHPT) which includes several simulations was presented. These simulations provide an alternative way to learn, based on discovery and experience. All the simulations were preceded with theory chapters, quizzes and preparatory tasks to enable fruitful exercises to be designed. Evaluations show that a computerized program including multiple ways of learning provides considerable support to the conventional student-teacher way of learning.

  • 143.
    Salomon Popa, Marianne
    et al.
    KTH, Tidigare Institutioner, Energiteknik.
    Fridh, Jens
    KTH, Tidigare Institutioner, Energiteknik.
    Kessar, Alexandros
    KTH, Tidigare Institutioner, Energiteknik.
    Fransson, Torsten
    KTH, Tidigare Institutioner, Energiteknik.
    Gas turbine simulations in the computerized educational program CompEduHPT: Three case studies2003Ingår i: American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) IGTI, 2003, Vol. 1, s. 741-748Konferensbidrag (Refereegranskat)
    Abstract [en]

    An overview of the Computerized Educational Program (CompEduHPT) which includes different simulations was presented. These simulations give the students an outlook of the different parameters that affect the performance based on the ideal and real approach of gas turbine calculations. The simulations show the students the different aspects, effects and results when a calculation is made considering a mixture of two ideal gases. They also show the improvements in the performance of the gas turbine depending on the various options available.

  • 144.
    Salomon Popa, Marianne
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    González, Miguel
    Martin, Andrew
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Energy Potential of Coconut and Palm Oil Residues: Selected Case Studies from Latin America and Small Island Developing StatesIngår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Agricultural residues continue to attract interest for energy recovery purposes as a renewable, CO2 neutral and increasingly cost competitive alternative to traditional fossil fuels. The possibility of trigeneration in already established industries such as palm oil mills and coconut processing plants is very attractive especially when residues that otherwise represent a disposal problem can be utilized efficiently. Different technological scenarios for the production of electricity, process heat and biodiesel are analyzed using coconut and palm oil residues. Environmental aspects are also included in the analysis. Studies were conducted considering various scenarios to evaluate the feasibility of using these residues for energy purposes. The residues were considered to be combusted directly in steam boilers while steam turbines were used to generate electricity. Biodiesel is produced by transesterification of palm oil/coconut oil. The required process heat for palm oil or coconut oil processing as well as the steam required for biodiesel production is supplied by the combustion of the residues.  The results show that palm oil mills/coconut processing industries can be independent of fossil fuels.  Furthermore, they can contribute positively to the energy balance of the communities by helping reduce the dependence on fossil fuels and reducing simultaneously greenhouse gas emissions. 

  • 145.
    Salomon Popa, Marianne
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Martin, Andrew
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Master Program in Distant Sustainable Energy Engineering: Self-assessment of the intake autumn 20052008Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The present report summarizes some experiences obtained in running the DSEE masterProgram at KTH.It gives the main experience, from the DSEE Program Coordinators side, of the student intakeduring the autumn 2005. It also illustrates some of the progress the students have made tilldate

  • 146.
    Salomon Popa, Marianne
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Savola, Tuula
    Helsinki University of Technology.
    Martin, Andrew
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fogelholm, Carl-Johan
    Helsinki University of Technology.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Small-scale biomass CHP plants in Sweden and Finland2011Ingår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 15, nr 9, s. 4451-4465Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    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.

  • 147.
    Salomón Popa, Marianne
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    González, Miguel
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Leal, Ernesto
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Martin, Andrew
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Energy Potential of Coconut and Palm Oil Residues2009Ingår i: 5th Dubrovnik Conference on Sustainable Development of Energy, Water and Environment Systems / [ed] Prof. Zvonimir Guzović, Prof. Neven Duić, Marko Ban (FMENA, University of Zagreb), Dubrovnik: Faculty of Mechanical Engineering and Naval Architecture, Zagreb , 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Agricultural residues continue to attract interest for energy recovery purposes as a renewable, CO2 neutral and increasingly cost competitive alternative to traditional fossil fuels. The possibility of trigeneration in already established industries such palm oil mills and coconut processing plants is very attractive especially when residues that otherwise represent a disposal problem can be utilized efficiently.

     

    The use of these residues in rural areas or in small islands could certainly represent an advantage as the use of expensive fossil fuels represents an additional burden to foster development. Different technical scenarios for the production of electricity, process heat and biodiesel are analyzed using these residues Environmental aspects are also included in this analysis.

     

    Studies were done considering certain scenarios to evaluate the feasibility of using these residues for energy purposes. Residues were considered to be combusted directly in boilers and steam turbines were used as prime movers to generate electricity. Biodiesel is produced by transesterification of palm oil/coconut oil. The required process heat for palm oil or coconut oil processing is supplied by the residues as well as the steam required for biodiesel production.  The advantage is that biodiesel is a more flexible and easy-to-distribute fuel that can be used for power generation or for transportation. The results shown that palm oil mills/coconut processing industries can be independent of fossil fuels.  Furthermore, they can contribute positively to the energy balance of the communities by helping reduce the dependence on fossil fuels and reducing at the same time greenhouse gas emissions.

  • 148.
    Sandoz, Raphael
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Spelling, James
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Laumert, Björn
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Air-Based Bottoming-Cycles for Water-Free Hybrid Solar Gas-Turbine Power Plants2013Ingår i: Proceedings of the ASME TurboExpo 2013, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    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.

  • 149.
    Sandoz, Raphael
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Spelling, James
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Laumert, Björn
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Air-Based Bottoming-Cycles for Water-Free Hybrid Solar Gas-Turbine Power Plants2013Ingår i: Journal of engineering for gas turbines and power, ISSN 0742-4795, E-ISSN 1528-8919, Vol. 135, nr 10, s. 101701-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    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.

  • 150.
    Sanz Luengo, Antonio
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Vogt, Damian
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Schmitt, S.
    Fransson, Torsten
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Validation of linearized navier-stokes based flutter prediction tool part2: Quantification of the prediction accuracy on a turbine test case2012Ingår i: Proceedings of the ASME Turbo Expo 2012: Volume 7, Issue PARTS A AND B, 2012, ASME Press, 2012, nr PARTS A AND B, s. 1581-1592Konferensbidrag (Refereegranskat)
    Abstract [en]

    This is the second part of two papers describing the validation of a tool chain for flutter prediction. The first paper provides an overview of the numerical methods and their verification. The second paper presents the detailed validation of the tool chain on the basis of experimental data obtained from measurements of an annular cascade sector comprising 3D twisted turbine blades. Aeroelastic test data has been acquired in an isolated blade row consisting of seven free-standing low-pressure (LP) turbine blades. The middle blade has been oscillated in controlled manner in three orthogonal modes and at various frequencies while measuring the unsteady blade surface pressure on several blades. The data has been reduced to aerodynamic influence coefficients and finally recombined to travelling wave mode stability curves. By acquiring data at various spanwise positions, a basis for validating three-dimensional effects has been provided. The validation of the investigated flutter prediction tool has been performed in a detailed manner and on various levels, started from a critical reduced frequency over stability curves to local work coefficients. At the lowest level of condensation, the unsteady blade surface pressures have been compared. Correlation to test data is shown and discussed rigorously at these various levels giving a detailed assessment of the prediction accuracy of the investigated tool.

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