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  • 251.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Daneryd, Anders
    ABB AB, Corporate Research, Västerås, Sweden.
    Heat transfer by liquid jets impinging on a hot flat surface2016Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 164, nr 15, s. 934-943Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Runout Table (ROT) cooling is one of the most important factors for controlling quality of hot rolled steel. ROT cooling uses large quantities of water to cool the steel plate. Optimizing heat transfer in the ROT would reduce the amount of water used, which will lower the amount of energy needed for pumping, filtering, storage and use of water. Optimization will therefore result in a direct energy saving as well as increasing the product quality.

    This study investigates heat transfer by turbulent water jets impinging on a hot flat steel plate at temperatures below the boiling point in order to understand convection heat transfer phenomena. This is an important stage that precedes the boiling and addresses the applicability of the heat transfer correlations available in the literature.

    A single axisymmetric jet and a pair of interacting jets are simulated using Computational Fluid Dynamics (CFD). The Reynolds Averaged Navier Stokes (RANS) model under steady and transient conditions and the kɛ turbulence model are used in both 2D axisymmetric and 3D simulations. We investigate the influence of the water flow rate on the jet cooling characteristics and develop a correlation for the radial position of the maximum Nusselt number based on numerical results.

    Two sets of boundary conditions – constant temperature and constant heat flux – are applied at the surface of the steel plate and evaluated. The single jet numerical results compare favourably with published data based on measurements and analytical models. The thermal performance of a two-jet system was found to be no better than a single jet because the jets were too far from each other to generate any additional thermal interaction.

  • 252.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Daneryd, Anders
    ABB, Sweden.
    Multi-Jet Impingement Cooling of a Hot Flat Steel Plate2014Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, s. 1835-1839Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the most important steps to control the quality in steel hot rolling is the Runout Table (ROT) Cooling. In this investigation, the heat transfer of water jets impinging on a hot flat steel plate was studied under temperatures below the boiling point to understand the convection heat transfer phenomena which is a major step preceding the boiling. Single axisymmetric jet and a pair of interacting jets are simulated using Computational Fluid Dynamics (CFD). The RANS model under steady and transient conditions as well as the k-Ɛ turbulence model are used for both 2D axisymmetric and 3D simulations. The water flow rate influence on the jets cooling characteristics is investigated.Two sets of boundary conditions, constant temperature and constant heat flux were applied at the surface of the steel plate and evaluated. The single jet numerical results are successfully compared to published data based on measurements and analytical models. The two jets thermal performance was found to be unaffected because the jets are too far from each other to generate any additional thermal interaction.

  • 253.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kristian, Rönnberg
    ABB AB, Corporate Research, Sweden.
    Taylor-Couette flow and transient heat transfer inside the annulus air-gap of rotating electrical machines2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 207, s. 624-633Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Losses in an electric motor amount to between 4–24% of the total electrical power, and are converted to heat. The maximum hot spot temperature is one of the design constraints of thermal and electrical performance. Several studies have explored flow and thermal characteristics inside the air-gap between two concentric rotating cylinders such as those found in electric motors, however the transient flow and thermal effects still remain a challenge. This study uses Computational Fluid Dynamics to predict the thermal behaviour of a machine rotating at the kind of speed usually encountered in motors. The Reynolds Averaged Navier-Stokes model together with the realizable k-ε turbulence model are used to perform transient simulations. Velocity profiles and temperature distribution inside the air-gap are obtained and validated. The transient flow features and their impact on thermal performance are discussed. The numerical results show turbulent Taylor vortices inside the air-gap that lead to a periodic temperature distribution. When compared to correlations from published literature, the simulated average heat transfer coefficient at the rotor surface shows overall good agreement. The transient effects introduce local impacts like oscillations to the Taylor-Couette vortices. These flow oscillations result in oscillations of the hotspots. However, this transient oscillatory behaviour does not show any additional impact on the global thermal performance.

  • 254.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Simulation and validation of flow and heat transfer in an infinite mini-channel using Smoothed Particle Hydrodynamics2018Ingår i: Energy Procedia, Elsevier, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Fluid flow and heat transfer in small channels have a wide range of engineering and medical applications. It has always been a topic of numerous theoretical, numerical and experimental studies. Several numerical methods have been used to simulate such flows. The most common approaches are the finite volume method (FVM) and the direct numerical simulation (DNS), which are numerically expensive to solve cases involving complex engineering problems. The main purpose of this work is to investigate the usability of the mesh-free particle based Smoothed Particle Hydrodynamics (SPH) method to simulate convective heat transfer. To validate our approach, as a starting point, we choose to solve a simple well-established problem which is the laminar flow and heat transfer through an infinitely long mini-channel. The solution obtained from SPH method has been compared to the solution from FVM method and analytical solution with good accuracy. The results presented in this paper show that SPH is capable to solve laminar forced convection heat transfer, however, turbulent flow cases need to be considered to be able to utilize the SPH method for engineering thermal applications.

  • 255.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Sweden.
    Domínguez, J. M.
    EPHYSLAB Environmental Physics Laboratory, Universidade de Vigo, Spain.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Smoothed particle hydrodynamics modeling of industrial processes involving heat transfer2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 252, artikel-id 113441Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Smoothed Particle Hydrodynamics (SPH) is a mesh-free particle method that has been widely used over the past decade to model complex flows. The method has mainly been used to investigate problems related to hydrodynamics and maritime engineering, in which heat transfer does not play a key role. In this article, the heat-conduction equation is implemented in the open-source code DualSPHysics, based on the SPH technique, and applied to different study cases, including conduction in still water in a cavity, laminar water flow between two infinite parallel plates and tube bank heat exchanger. The thermal solutions obtained from SPH are benchmarked with the solutions from Finite Volume Method (FVM) and validated using available analytical solutions. DualSPHysics results are in good agreement with FVM and analytical models, and demonstrate the potential of the meshless approach for industrial applications involving heat transfer.

  • 256.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Domínguez, José
    University of VIGO, Spain.
    Crespo, Alejandro
    University of VIGO, Spain.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Smoothed Particle Hydrodynamics modeling of transient conduction and convection heat transferManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Smoothed Particle Hydrodynamics (SPH) is a mesh-free particle method that has been widely used in the last years to model some complex flows. SPH was mainly used to investigate problems related to hydrodynamics and maritime engineering where heat transfer is of no importance. Thermal problems have seldom been addressed due to the limitation of the main commercial and open-source SPH codes.

    In this article, the energy equation is implemented in the SPH based open-source code DualSPHysics to solve conduction and forced convection heat transfer problems. Laminar flow cases are simulated as the first validation cases of the implemented model. The studied cases include conduction in an aluminum block, conduction in still water in a cavity, laminar water flow between two infinite parallel plates and tube bank heat exchanger. The thermal solutions obtained from SPH are benchmarked with the solutions from Finite Volume Method (FVM) and also validated using available analytical solutions. The obtained results are in good agreement with FVM and available analytical models, which combined with the advantages of the meshless approach, show the high potential for industrial heat transfer applications.

    This development is an important step towards thermal optimization of several industrial applications that can’t benefit from the conventional FVM approach due to geometry or process complexities. The demonstrated SPH simulation and visualization capabilities contribute to build the future reliable energy-saving solutions.

  • 257.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB Corp Res, Sweden.
    Fdhila, Rebei Bel
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB Corp Res, Sweden.
    Literature Review of accelerated CFD Simulation Methods towards Online Application2015Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, s. 3307-3314Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Engineering advanced methods for example Computational Fluid Dynamics (CFD) are heavily used to solve, design and model complex industrial applications. They provide high accuracy however, the simulation time is too long and this limit its generalized use dramatically as for control purposes. CFD tools and methods are often used to analyze the energy distribution and management in different industrial processes like hot rolling industries, furnaces and boilers as well as a number of areas where mixing and thermal management are of importance. Huge amounts of energy are often fed into such processes. A small amount of optimization can provide a very large energy saving. It is now an urgent need to have a tool like real-time CFD to analyze, control and optimize on-line various industrial processes. This tool or method can contribute to build efficient and sustainable energy systems. The scope of this work is to find alternative simulation techniques that can also address industrial applications and provide solutions within a decent accuracy and resolution. In this paper we provide a literature review of those methods that can be categorized as mesh based, mesh free and hybrid that are capable of providing appropriate results in some key areas of interest. As a next step one of these methods will be implemented and coupled to CFD simulation of cooling impinging jets used to control the heat transfer and temperature behavior of a hot flat surface in a hot rolling process where thermal energy and cooling water are used with excess. (C) 2015 The Authors. Published by Elsevier Ltd.

  • 258.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Fdhila, Rebei Bel
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Rönnberg, Kristian
    ABB AB, Corporate Research.
    Air-Gap Flow and Thermal Analysis of Rotating Machines using CFD2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 5153-5159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thermal management of the rotating electrical machines is a very challenging area which needs appropriate solutions for each machine and operating condition. The heat is generated by the electromagnetic losses and the mechanical friction during the rotation. Computational Fluid Dynamics (CFD) is used in this study to predict and analyze the thermal performance of a rotating electrical machine where high speed rotation is coupled with small flow gaps. The investigation presented in this paper is based on a geometry used for model assessment and verification purposes. However, the approach outlined and the observations made are transferrable to other geometries. ANSYS Fluent has been used to perform CFD simulation where both the air velocity field and the temperature distribution are obtained. The results are qualitatively highly interesting to understand the thermal behavior within an electrical machine operations. The results show a periodic temperature distribution on the stator surface with similar periodic pattern for the heat transfer coefficient on the rotor surface. The simulated average heat transfer coefficient at the rotor surface is compared with the correlations from published literature with an overall good agreement.

  • 259.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Rönnberg, Kristian
    ABB AB, Corporate Research.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Air Flow inside Rotating Electrical Machines: A Comparison between Finite Volume and SPH Method2017Ingår i: Conference Proceedings of NAFEMS World Congress 2017 (NWC17), 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    A general, sufficiently accurate, applicable and reasonably fast approach to thermal analysis of rotating electrical machines is of high interest for motor and generator developers and manufacturers. The thermal performance and the lifetime of a machine is limited by the temperature distribution and the hot spot temperature. The most commonly encountered cooling medium is air and the temperature distribution is driven by the air flow pattern inside the machine. Two different Computational Fluid Dynamics methods, the mesh based Finite Volume Method (FVM) and the mesh free particle based Smoothed Particle Hydrodynamics (SPH) method are employed in this paper to model the airflow inside a rotating machine. Mesh based methods are quite robust, however, they are very expensive in terms of meshing effort and CPU time to be used extensively in R&D. Analysing and optimizing products with complex geometrical shapes need mesh generation for every specific design change and this may be the major part of the modelling process. This challenging task is not necessary for the SPH method. SPH method can also provide high quality 3D visualization that can improve the design process.

    This work investigates the usability of the SPH method when applied to rotating machinery for rotor speeds normally encountered in motors and generators. A comparison with an FVM based approach is also performed. Both the FVM and the SPH solvers show good agreement for the overall flow pattern inside the machine with some disagreement for the airflow inside the air-gap between the rotor and the stator. The FVM solver successfully captures the Taylor vortex flow inside the annulus air-gap which is in general a great modelling challenge. The SPH solver on the other hand shows great capability to couple rotation of the rotor and well represent the overall flow pattern inside the machine. However, the 3D SPH solver could not capture the complex Taylor vortices inside the air-gap which may be due to the limited number of particles used for the simulation. An increase in the number of particles would certainly improve the accuracy of the results as confirmed by the 2D SPH simulation. The present study shows that the SPH solver can be used to predict the air flow pattern inside rotating machines within an acceptable accuracy.

  • 260.
    Hosain, Md Lokman
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Sweden.
    Sand, U.
    ABB AB, Corporate Research, Sweden.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Sweden.
    Numerical Investigation of Liquid Sloshing in Carrier Ship Fuel Tanks2018Ingår i: IFAC-PapersOnLine, ISSN 2405-8963, Vol. 51, nr 2, s. 583-588Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Liquid sloshing inside a partially filled tank has a great impact on the fragile internal tank coating and also on the stability of carrier ships. Several studies highlighted the challenges encountered due to the sloshing and proposed anti-sloshing tank structures. However, sloshing of liquefied natural gas fuel in high pressure vessels during transportation still remain a challenge. In the present numerical study we consider a downscaled 2D geometry to investigate the sloshing. Non-dimensional numbers are used to downscale the geometry. The purpose is to understand the flow structures and validate the downscaling approach based on the similarity scale laws. In the present work, Computational Fluid Dynamics (CFD) based on the Reynolds Averaged Navier-Stokes equations (RANS) with the Volume of Fluid (VOF) method in one hand and the Smooth Particle Hydrodynamics (SPH) method in the other hand, are used to simulate the downscaled model. The results from both methods are compared and validated using experimental data. A full scale model have also been simulated using SPH to verify the applicability of the scaling laws. The SPH model shows the capability to efficiently capture the sloshing phenomena. The VOF and SPH provide similar results in terms of flow dynamics, pressure and forces. The overall numerical results agree with the measurements and show that SPH can be an efficient tool to be used in modelling sloshing phenomena, compared to the RANS-VOF approach which is expensive in terms of CPU time. However, features like turbulence need to be further investigated. 

  • 261.
    Hu, Y.
    et al.
    Royal Institute of Technology, Sweden.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Sweden.
    Numerical investigation of heat transfer characteristics in utility boilers of oxy-coal combustion2014Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 130, nr 1, s. 543-551Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Oxy-coal combustion has different flue gas composition from the conventional air-coal combustion. The different composition further results in different properties, such as the absorption coefficient, emissivity, and density, which can directly affect the heat transfer in both radiation and convection zones of utility boilers. This paper numerically studied a utility boiler of oxy-coal combustion and compares with air-coal combustion in terms of flame profile and heat transferred through boiler side walls in order to understand the effects of different operating conditions on oxy-coal boiler retrofitting and design. Based on the results, it was found that around 33vol% of effective O2 concentration ([O2]effective) the highest flame temperature and total heat transferred through boiler side walls in the oxy-coal combustion case match to those in the air-coal combustion case most; therefore, the 33vol% of [O2]effective could result in the minimal change for the oxy-coal combustion retrofitting of the existing boiler. In addition, the increase of the moisture content in the flue gas has little impact on the flame temperature, but results in a higher surface incident radiation on boiler side walls. The area of heat exchangers in the boiler was also investigated regarding retrofitting. If boiler operates under a higher [O2]effective, to rebalance the load of each heat exchanger in the boiler, the feed water temperature after economizer can be reduced or part of superheating surfaces can be moved into the radiation zone to replace part of the evaporators

  • 262.
    Hu, Y.
    et al.
    Cranfield University, Bedford, United Kingdom.
    Tewari, A.
    Cranfield University, Bedford, United Kingdom.
    Varga, L.
    Cranfield University, Bedford, United Kingdom.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    System dynamics of oxyfuel power plants with liquid oxygen energy storage2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 3727-3733Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Traditional energy storage systems have a common feature: the generating of secondary energy (e.g. electricity) and regenerating of stored energy (e.g. gravitational potential, and mechanical energy) are separate rather than deeply integrated. Such systems have to tolerate the energy loss caused by the second conversion from primary energy to secondary energy. This paper is concerned with the system dynamics of oxyfuel power plants with liquid oxygen energy storage, which integrates the generation of secondary energy (electricity) and regeneration of stored energy into one process and therefore avoids the energy loss caused by the independent process of regeneration of stored energy. The liquid oxygen storage and the power load of the air separation unit are self-adaptively controlled based on current-day power demand, day-ahead electricity price and real-time oxygen storage information. Such an oxyfuel power plant cannot only bid in the day-ahead market with base load power but also has potential to provide peak load power through reducing the load of the air separation unit in peak time. By introducing reasoning rules with fuzzy control, the oxygen storage system has potential to be further extended by integrating renewable energy resources into the system to create a cryogenic energy storage hub. 

  • 263.
    Huang, C.
    et al.
    Tongji University, Shanghai, China.
    Li, Y.
    Tongji University, Shanghai, China.
    Li, X.
    Tongji University, Shanghai, China.
    Wang, H.
    Tongji University, Shanghai, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology (KTH), Sweden.
    Wang, X.
    Tongji University, Shanghai, China.
    Wu, J.
    Tongji University, Shanghai, China.
    Li, F.
    Tongji University, Shanghai, China.
    Understanding the water-energy nexus in urban water supply systems with city features2018Ingår i: Energy Procedia, Elsevier Ltd , 2018, s. 265-270Konferensbidrag (Refereegranskat)
    Abstract [en]

    The water-energy nexus has been introduced into urban water supply systems (WSSs) to improve the current plight of scarce resources and greenhouse effect in recent years. Urban water-energy integrated management is limited by the characteristics and reality of each city. In this paper, we characterize the comprehensive influence factors of energy use in China urban WSSs including geographic differences and city forms. The results indicate that the pressure of pipeline network and plain area ratio restricted by geomorphology would significantly impact the energy consumption during conveyance and distribution stage. For the city form aspect, the total volume of urban water supply and the leakage rate of pipeline networks play important roles in energy consumption of urban WSSs in China. In this study, the specific electricity consumption in WSSs was quantified, and several factors affected by city features which show strong correlation with energy use were determined. The results are of great significance to the energy saving in water supply systems in urban areas.

  • 264.
    Huang, J.
    et al.
    East China University of Science and Technology, Shanghai, China.
    Yang, J.
    East China University of Science and Technology, Shanghai, China.
    Yu, X.
    East China University of Science and Technology, Shanghai, China.
    Tu, S. -T
    East China University of Science and Technology, Shanghai, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Energy-efficient extraction of fuel from chlorella combined with CO2 capture2014Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, s. 2805-2808Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To combine the abilities of lipids extraction and CO2 capture by algae + IL system, chlorella hydrolysis integrating CO2 removal by ILs ([bmim][BF4], [bmim]Cl and [amim]Cl) to extract lipids energy-efficiently was demonstrated in this study. The addition of CO2 to [bmim][BF4] can increase the lipids yield from 14.2% to 15.6%. The value of net energy gain increased from 10.4 to 35.9 with the CO2 addition to [bmim][BF4] because of the compensated CO2 capture energy in the algae extraction process.

  • 265.
    Hui, Hongxun
    et al.
    Zhejiang Univ, Peoples R China..
    Ding, Yi
    Zhejiang Univ, Peoples R China..
    Shi, Qingxin
    Univ Tennessee, Dept Elect Engn & Comp Sci, Knoxville, TN 37996 USA..
    Li, Fangxing
    Univ Tennessee, USA..
    Song, Yonghua
    Zhejiang Univ, Peoples R China.;Univ Macau, Peoples R China..
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH Royal Inst Technol, Stockholm, Sweden..
    5G network-based Internet of Things for demand response in smart grid: A survey on application potential2020Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 257, artikel-id UNSP 113972Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Demand response (DR) has been widely regarded as an effective way to provide regulation services for smart grids by controlling demand-side resources via new and improved information and communication technologies. Emerging 5G networks and 5G-based Internet of Things (IoTs) can doubtless provide better infrastructure for DR, owing to 5G's advantages of fast transfer speed, high reliability, robust security, low power consumption, and massive number of connections. However, nearly none of the existing studies have applied 5G technology to DR, which will be the subject surveyed in this paper. First, the concept of DR and recent practical advances are investigated, especially the application of communication technologies to DR. Then, a comprehensive review of the cyber security, consumer privacy, and reliability of DR is presented. These topics received little attention in the past, but they will be among the most crucial factors in the future. In addition, the essential features and typical application scenarios of 5G communication are investigated. On this basis, the advantages, methods, recent advances, and implementation planning of 5G on DR are studied. Finally, the future work that must urgently be conducted in order to achieve the application of 5G to DR is discussed. This paper's application survey of 5G on DR is carried out before 5G technology enters the large-scale commercial stage, so as to provide references and guidelines for developing future 5G networks in the smart grid paradigm.

  • 266.
    Huopana, Tuomas
    et al.
    University of Eastern Finland, Finland.
    Niska, Harri
    University of Eastern Finland, Finland.
    Kolehmainen, Mikko
    University of Eastern Finland, Finland.
    Jääskeläinen, Ari
    Savonia University of Applied Sciences, Finland.
    Antikainen, Eero
    Savonia University of Applied Sciences, Finland.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Klintenberg, Patrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Hakalehto, Elias
    Finnoflag, Finland.
    Ahrens, Thorsten
    Ostfalia University of Applied Sciences, Germany.
    Sustainability assessment of biorefinery and dry digestion systems: Case:Sweden2014Rapport (Övrigt vetenskapligt)
  • 267.
    Huopanaa, Tuomas
    et al.
    University of Eastern Finland.
    Niska, Harri
    University of Eastern Finland.
    Jääskeläinen, Ari
    Savonia University of Appled Sciences, Finland.
    Lõõnik, Jaan
    Estonian Regional and Local Development Agency, Estland.
    den Boer, Emilia
    Wroclaw University of Technology, Polen.
    Song, Han
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    A REGIONAL MODEL FOR SUSTAINABLE BIOGAS  PRODUCTION: Case study: North Savo, Finland. REMOWE Report, Integrated report no: O5.3.3, O5.3.6, O5.4.3, O5.4.4, O5.6.12012Rapport (Refereegranskat)
  • 268.
    Inayat, A.
    et al.
    Department of Sustainable and Renewable Energy Engineering, University of Sharjah, Sharjah, United Arab Emirates.
    Ghenai, C.
    Department of Sustainable and Renewable Energy Engineering, University of Sharjah, Sharjah, United Arab Emirates.
    Naqvi, Muhammad
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Ammar, M.
    Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak, Malaysia.
    Ayoub, M.
    Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak, Malaysia.
    Hussin, M. N. B.
    Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak, Malaysia.
    Parametric Study for Production of Dimethyl Ether (DME) As a Fuel from Palm Wastes2017Ingår i: Energy Procedia, Elsevier Ltd , 2017, s. 1242-1249Konferensbidrag (Refereegranskat)
    Abstract [en]

    Dimethyl Ether (DME) has been getting numerous attention as it's potential as the second generation bio-fuel. Traditionally DME is produced from the petroleum based stock which involves two steps of synthesis (methanol synthesis from the syngas and DME synthesis from methanol). DME synthesis via single step is one of the promising methods that has been developed. In Malaysia, due to the abundance of oil palm waste, it is a good candidate to be used as a feedstock for DME production. In this paper, single step process of DME synthesis was simulated and investigated using the Aspen HYSYS. Empty Fruit Bunch (EFB) from palm wastes has been taken as the main feed stock for DME synthesis. Four parameters (temperature, pressure, steam/biomass ratio and oxygen/biomass ratio) have been studied on the H2/CO ratio and DME yield. The results showed that optimum H2/CO ratio of 1.0 has been obtained when having an oxygen to biomass ratio (O/B) of 0.37 and steam to biomass ratio (S/B) of 0.23. The increment in the steam to biomass ratio increased the production of DME while the increment in oxygen to biomass ratio will cause reduction in DME production. © 2017 The Authors.

  • 269.
    Ingason, Haukur
    et al.
    SP Fire Research.
    Li, Ying Zhen
    SP Fire Research.
    Lönnermark, Anders
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. SP Fire Research.
    Tunnel Fire Dynamics2015Bok (Övrigt vetenskapligt)
  • 270.
    Ingason, Haukur
    et al.
    SP Sveriges Tekniska Forskningsintitut.
    Vylund, Lotta
    SP Sveriges Tekniska Forskningsintitut.
    Lönnermark, Anders
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. SP Fire Research.
    Kumm, Mia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Fridolf, Karl
    SP Fire Research.
    Frantzich, Håkan
    Lunds universitet.
    Palm, Anders
    Storstockholms Brandförsvar.
    Palmkvist, Krister
    Södra Älvsborgs Räddningstjänstförbund.
    Taktik och Metodik vid brand i Undermarksanläggningar (TMU) - Sammanfattningsrapport2015Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The report compiles the results from the TMU-project. The focus is on fire-fighting performance, capability and organization in underground constructions. The emphasis was on large-scale testing with authentic fire conditions and fire-fighting equipment, development of tools for prediction of hazardous conditions and capabilities of  fire-fighting during different conditions, organizational management and tactics, education and development  of recommendations.  The project was divided into different work packages and these are presented in this final summary report. The test fires performed in the project created severe conditions for fire-fighters who moved in smoke for over 180 m before fighting fully developed fires in a range of 18 to 33 MW. The fires consisted of wood pallets placed in a semi-open steel container, simulating a train wagon fire. The walking speed and connection time for hoses and connections were registered and documented by infra-red cameras. The most important results from these tests is that the time taken to approach the fire depends on parameters as type of equipment, preparation, possibilities for use of infra-red (IR) cameras and the capacity of the extinguishing media. The heat radiation from the fire was found to be important to overcome in order to get close enough to fight the fire. Recommendations and tactics for fighting fires in underground constructions are given. 

  • 271.
    Jalilzadehazhari, Elaheh
    et al.
    Linnaeus University, Växjö, Sweden.
    Vadiee, Amir
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Johansson, Peter
    Jönköping University, Sweden.
    Achieving a trade‐off construction solution using BIM, an optimization algorithm, and a multi‐criteria decision‐making method2019Ingår i: Buildings, ISSN 2075-5309, E-ISSN 2075-5309, Vol. 9, nr 4, s. 1-14, artikel-id 81Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Energy Performance of Building Directive obligated all European countries to reduce the energy requirements of buildings while simultaneously improving indoor environment quality. Any such improvements not only enhance the health of the occupants and their productivity, but also provide further economic benefits at the national level. Accomplishing this task requires a method that allows building professionals to resolve conflicts between visual and thermal comfort, energy demands, and life-cycle costs. To overcome these conflicts, this study exploits the incorporation of building information modelling (BIM), the design of experiments as an optimization algorithm, and the analytical hierarchy process (AHP) into a multi-criteria decision-making method. Any such incorporation can (i) create constructive communication between building professionals, such as architects, engineers, and energy experts; (ii) allow the analysis of the performance of multiple construction solutions with respect to visual and thermal comfort, energy demand, and life-cycle costs; and (iii) help to select a trade-off solution, thereby making a suitable decision. Three types of energy-efficient windows, and five types of ground floors, roofs, and external wall constructions were considered as optimization variables. The incorporation of several methods allowed the analysis of the performance of 375 construction solutions based on a combination of optimization variables, and helped to select a trade-off solution. The results showed the strength of incorporation for analyzing big-data through the intelligent use of BIM and a simulation in the field of the built environment, energy, and costs. However, when applying AHP, the results are strongly contingent on pairwise comparisons.

  • 272.
    Jaradat, Omar
    Mälardalens högskola, Akademin för innovation, design och teknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Contracts-Based Maintenance of Safety Cases2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Safety critical systems are those systems whose failure could result in loss of life, significant property damage, or damage to the environment. System safety is a major property that shall be adequately assured to avoid any severe outcomes in safety critical systems. Safety assurance should provide justified confidence that all potential risks due to system failures are either eliminated or acceptably mitigated. System developers in many domains (e.g., automotive, avionics, railways) should provide convincing arguments regarding the safe performance of their systems to a national or international regulatory authority and obtain approvals before putting the system into service.  Building 'Safety cases' is a proven technique to argue about and communicate systems' safety and it has become a common practice in many safety critical system domains. System developers use safety cases to articulate claims about how systems meet their safety requirements and objectives, collect and document items of evidence, and construct a safety argument to show how the available items of evidence support the claims.

    Safety critical systems are evolutionary and constantly subject to preventive, perfective, corrective or adaptive changes during both the development and operational phases. Changes to any part of those systems can undermine the confidence in safety since changes can refute articulated claims about safety or challenge the supporting evidence on which this confidence relies. Hence, safety cases need to be built as living documents that should always be maintained to justify the safety status of the associated system and evolve as these systems evolve. However, building safety cases are costly since they require a significant amount of time and efforts to define the safety objectives, generate the required evidence and conclude the underlying logic behind the safety case arguments. Safety cases document highly dependent elements such as safety goals, assumptions and evidence. Seemingly minor changes may have a major impact. Changes to a system or its environment can necessitate a costly and painstaking impact analysis for systems and their safety cases. In addition, changes may require system developers to generate completely new items of evidence by repeating the verification activities. Therefore, changes can exacerbate the cost of producing and maintaining safety cases.  

    Safety contracts have been proposed as a means for helping to manage changes. There have been works that discuss the usefulness of contracts for reusability and maintainability. However, there has been little attention on how to derive them and how exactly they can be utilised for system or safety case maintenance.

    The main goal of this thesis is to support the change impact analysis as a key factor to enhance the maintainability of safety cases. We focus on utilising safety contracts to achieve this goal. To address this, we study how safety contracts can support essential factors for any useful change management process, such as (1) identifying the impacted  elements  and  those  that  are  not  impacted, (2) minimising the number of impacted  safety  case  elements, and (3) reducing the  work  needed  to  make  the  impacted  safety  case  elements valid again. The preliminary finding of our study reveals that using safety contracts can be promising to develop techniques and processes to facilitate safety case maintenance. The absence of safety case maintenance guidelines from safety standards and the lack of systematic and methodical maintenance techniques have motivated the work of this thesis. Our work is presented through a set of developed and assessed techniques, where these techniques utilise safety contracts to achieve the overall goal by various contributions. We begin by a framework for evaluation of the impact of change on safety critical systems and safety cases. Through this, we identify and highlight the most sensitive system components to a particular change. We propose new ways to associate system design elements with safety case arguments to enable traceability. How to identify and reduce the propagation of change impact is addressed subsequently.  Our research also uses safety contracts to enable through-life safety assurance by monitoring and detecting any potential mismatch between the design safety assumptions and the actual behaviour of the system during its operational phase. More specifically, we use safety contracts to capture thresholds of selected safety requirements and compare them with the runtime related data (i.e., operational data) to continuously assess and evolve the safety arguments.

    In summary, our proposed techniques pave the way for cost-effective maintenance of safety cases upon preventive, perfective, corrective or adaptive changes in safety critical systems thus helping better decision support for change impact analysis.

  • 273.
    Jiang, M.
    et al.
    Key Laboratory of Pressure Systems and Safety (MOE), School of Mechanical Engineering, East China University of Science and Technology, Shanghai 200237, China.
    Lv, Y.
    Applied Energy Innovation Institute, Ningbo 315201, China.
    Wang, T.
    China Energy Group, Beijing 100011, China.
    Sun, Z.
    State Key Laboratory of Clean and Efficient Coal-fired Power Generation and Pollution Control, Guodian Science and Technology Research Institute, Nanjing 210023, China.
    Liu, J.
    State Key Laboratory of Clean and Efficient Coal-fired Power Generation and Pollution Control, Guodian Science and Technology Research Institute, Nanjing 210023, China.
    Yu, X.
    Key Laboratory of Pressure Systems and Safety (MOE), School of Mechanical Engineering, East China University of Science and Technology, Shanghai 200237, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. School of Business Society and Technology, Mälardalen University, Västerås, Sweden; School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Performance analysis of a photovoltaics aided coal-fired power plant2019Ingår i: Energy Procedia, Elsevier Ltd , 2019, s. 1348-1353Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, integration of photovoltaics (PV) into a coal-fired power plant was proposed. The performance including economic analysis and environmental impact was conducted by a case study in the northwest area of China. The results show that the PV system can replace part of auxiliary power consumption using renewable electricity to reduce internal power consumption and the emissions. Due to the feature of the integration into a power plant, the curtailment of solar PV electricity does not occur compared to stand-alone PV system. The investment cost, operation and maintenance (O&M) expenditure were feasible compared with other PV power generation plants. 

  • 274.
    Jiang, Xi
    et al.
    Univ Lancaster, Dept Engn, Chair Energy Use & Transport, Lancaster LA1 4YR, England..
    Kraft, Markus
    Univ Cambridge, Cambridge CB2 1TN, England..
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Inst Technol, Stockholm, Sweden.
    Selected papers from the Twelfth International Conference on Combustion and Energy Utilisation (12th ICCEU) Preface2015Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 156, s. 747-748Artikel i tidskrift (Övrigt vetenskapligt)
  • 275. Jianguo, Li
    et al.
    Shaokai, Zhang
    Li, Hailong
    Mälardalens högskola, Akademin för innovation, design och teknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Xinhua, Ouyang
    Liulian, Huang
    Yonghao, Ni
    Lihui, Chen
    Cellulase pretreatment for enhancing cold caustic extraction-based separation of hemicelluloses and cellulose from cellulosic fibers2018Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 251, s. 1-6Artikel i tidskrift (Refereegranskat)
  • 276.
    Jin, Hongguang
    et al.
    nstitute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing, China.
    Gao, L.
    nstitute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080, China.
    Han, W.
    nstitute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    A new approach integrating CO2 capture into a coal-based polygeneration system of power and liquid fuel2007Ingår i: Proceedings of the ASME Turbo Expo, 2007, s. 311-321Konferensbidrag (Refereegranskat)
    Abstract [en]

    Reducing the energy penalty for CO2 Capture and Storage (CCS) is a challenge. Most of previous studies for CCS have been focused on power generation system. When CCS is included in the polygeneration system, a new methodology that jointly considering CCS and liquid fuel production should be introduced. In this paper, we proposed a new approach integrating CCS into a coal-based polygeneration system for power generation and methanol production: the syngas produced from the coal gasifier, without adjusting the composition (CO/H2 ratio) by shift reaction, is used to synthesis methanol directly. Moreover, the partial-recycle scheme, in which a part of unreacted gas is recycled back to the synthesis reactor, is adopted in the synthesis unit. Another part of unreacted gas is treated to remove CO2, and then is used as clean fuel for the power generation subsystem. Compared to the conventional CCS approaches adopted by the power generation systems, the new approach is mainly characterized by two features: firstly, the combination of the removal of the composition adjustment process and a partial-recycle scheme can not only reduces the energy consumption for methanol production, but also obtains a high concentration of COx (CO and CO2) in the unreacted gas; secondly, the CO2 is captured from the unreacted gas, instead of from syngas generated by the gasifier. Due to increment of CO x concentration, the new approach can reduce the energy consumption for CO2 capture compared to conventional pre-combustion CO 2 capture. In the conventional coal based IGCC systems, the thermal efficiency is around 34-36% for a case with CO2 capture and around 44% for a case without CO2 capture. However, with the innovative approach integrating CCS, the polygeneration system in this paper can achieve the equivalent thermal efficiency as high as 47% when 72% of CO2 is recovered, which provides a significant improvement for CO2 capture. It's clearly that the new approach can increase the thermal efficiency, instead of incurring an energy penalty for CO2 capture. The results achieved in this study have provided a new methodology integrating CO2 capture into the polygeneration system, which reveals the different characteristics compared to power-generation system that has been overlooked by the previous studies.

  • 277.
    Jin, Ming
    et al.
    Univ Calif Berkeley, Dept Ind Engn & Operat Res, Berkeley, CA 94720 USA..
    Jain, Rishee
    Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA..
    Spanos, Costas
    Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA..
    Jia, Qingshan
    Tsinghua Univ, Dept Automat, Beijing, Peoples R China..
    Norford, Leslie K.
    MIT, Dept Architecture, Cambridge, MA 02139 USA..
    Kjaergaard, Mikkel
    Univ Southern Denmark, Maersk McKinney Moller Inst, Odense, Denmark..
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Energy-cyber-physical systems2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 256, artikel-id UNSP 113939Artikel i tidskrift (Övrigt vetenskapligt)
  • 278.
    Jiyang, Xie
    et al.
    Beijing University of Posts and Telecommunications, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zhanyu, Ma
    Beijing University of Posts and Telecommunications, China..
    Qie, Sun
    Shandong University, China.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Zhongwei, Si
    Beijing University of Posts and Telecommunications, China.
    Jun, Guo
    Beijing University of Posts and Telecommunications, China.
    Analysis of Key Factors in Heat Demand Prediction with Neural Networks2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 2965-2970Artikel i tidskrift (Refereegranskat)
    Abstract [sv]

    The development of heat metering has promoted the development of statistic models for the prediction of heat demand, due to the large amount of available data, or big data. Weather data have been commonly used as input in such statistic models. In order to understand the impacts of direct solar radiance and wind speed on the model performance comprehensively, a model based on Elman neural networks (ENN) was adopted, of which the results can help heat producers to optimize their production and thus mitigate costs. Compared with the measured heat demand, the introduction of wind speed and direct solar radiation has opposite impacts on the performance of ENN and the inclusion of wind speed can improve the prediction accuracy of ENN. However, ENN cannot benefit from the introduction of both wind speed and direct solar radiation simultaneously. 

  • 279.
    Johansson, Joakim
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Mid-Level Officials as Policy Makers: Anti-Corporatist Policy Change in the Swedish Employers’ Confederation, 1982–19852003Ingår i: Scandinavian Political Studies, ISSN 0080-6757, E-ISSN 1467-9477, Vol. 26, s. 307-325Artikel i tidskrift (Refereegranskat)
  • 280.
    Johansson Westholm, Lena
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Alderton, D.
    University of London, Surrey, United Kingdom.
    Mineral Resources2013Ingår i: Reference Module in Earth Systems and Environmental Sciences, Elsevier, 2013Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Throughout the history of planet Earth, minerals have formed through diverse geologic processes and at different locations, depending on the prevailing geologic conditions. Early civilizations mined minerals and rocks for a variety of purposes, initially for use in construction if the material had strength or for personal adornment if the mineral was attractive. Subsequently, minerals have been mined for a multitude of other purposes, where their chemical and physical properties have been of importance in a wide range of industrial processes. At the present time, large volumes of a variety of minerals are needed for society, and this demand is continuously increasing.

  • 281.
    Johansson Westholm, Lena
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Repo, E.
    Lappeenranta University of Technology, Finland.
    Sillanpää, M.
    Lappeenranta University of Technology, Finland.
    Filter materials for metal removal from mine drainage-a review2014Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 21, nr 15, s. 9109-9128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A large number of filter materials, organic and inorganic, for removal of heavy metals in mine drainage have been reviewed. Bark, chitin, chitosan, commercial ion exchangers, dairy manure compost, lignite, peat, rice husks, vegetal compost, and yeast are examples of organic materials, while bio-carbons, calcareous shale, dolomite, fly ash, limestone, olivine, steel slag materials and zeolites are examples of inorganic materials. The majority of these filter materials have been investigated in laboratory studies, based on various experimental set-ups (batch and/or column tests) and different conditions. A few materials, for instance steel slag materials, have also been subjects to field investigations under real-life conditions. The results from these investigations show that steel slag materials have the potential to remove heavy metals under different conditions. Ion exchange has been suggested as the major metal removal mechanisms not only for steel slag but also for lignite. Other suggested removal mechanisms have also been identified. Adsorption has been suggested important for activated carbon, precipitation for chitosan and sulphate reduction for olivine. General findings indicate that the results with regard to metal removal vary due to experimental set ups, composition of mine drainage and properties of filter materials and the discrepancies between studies renders normalisation of data difficult. However, the literature reveals that Fe, Zn, Pb, Hg and Al are removed to a large extent. Further investigations, especially under real-life conditions, are however necessary in order to find suitable filter materials for treatment of mine drainage. 

  • 282.
    Jonfelt, Clara
    et al.
    Uppsala University, Sweden.
    Zambrano, Jesús
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindblom, Erik
    Stockholm Vatten, Sweden.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Key parameters for modelling Anammox process with N2O emissions2017Ingår i: French Federation of Biotechnology - Bioreactors Symposium 2017: Innovative approaches in bioreactors design and operation, France, 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, a sensitivity analysis and a calibration were applied to a recent published model used to replicate N2O emissions in an Anammox process of a moving-bed biofilm reactor (MBBR). The model used in this study was designed to replicate a one-stage nitrification-Anammox system in a MBBR at Hammarby-Sjöstad pilot plant (Stockholm, Sweden), whichtreats of anaerobic digestion liquor. The aeration was intermittently (45/15 minutes - on/off). During the aeration, a 1.5 mg/L DO set-point was set. Three main measurements wereobtained: NH4 in water, N2O in both water and gas phase.The sensitivity analysis was done via the one-at-a-time method, where one parameter at a timeis changed (in our case, 10%) from its nominal value and the model output is quantified. Next,the most sensitive parameters were used in the model calibration. Results indicate that the biofilm porosity (η [-]), biofilm density (ρ [gTS/m3]), maximum biofilmthickness (Lmax [mm]) and boundary layer thickness of the biofilm (L0 [μm]) were the mostsensitive parameters of the model. These parameters performed the model calibration.

  • 283.
    Jurasz, Jakob
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Faculty of Management, Department of Engineering Management, AGH University, Cracow, Poland.
    Canales, F. A.
    Department of Civil and Environmental, Universidad de la Costa, Barranquilla, Atlántico, Colombia.
    Kies, A.
    Frankfurt Institute for Advanced Studies, Goethe University Frankfurt, Frankfurt am Main, Germany.
    Guezgouz, M.
    Department of Electrical Engineering, Mostaganem University, Mostaganem, Algeria.
    Beluco, A.
    Instituto de Pesquisas Hidráulicas, Universidade Federal do Rio Grande do Sul, Brazil.
    A review on the complementarity of renewable energy sources: Concept, metrics, application and future research directions2020Ingår i: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 195, s. 703-724Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Global and regional trends indicate that energy demand will soon be covered by a widespread deployment of renewable energy sources. However, the weather and climate driven energy sources are characterized by a significant spatial and temporal variability. One of the commonly mentioned solutions to overcome the mismatch between demand and supply provided by renewable generation is a hybridization of two or more energy sources into a single power station (like wind-solar, solar-hydro or solar-wind-hydro). The operation of hybrid energy sources is based on the complementary nature of renewable sources. Considering the growing importance of such systems and increasing number of research activities in this area this paper presents a comprehensive review of studies which investigated, analyzed, quantified and utilized the effect of temporal, spatial and spatiotemporal complementarity between renewable energy sources. The review starts with a brief overview of available research papers, formulates detailed definition of major concepts, summarizes current research directions and ends with prospective future research activities. The review provides a chronological and spatial information with regard to the studies on the complementarity concept.

  • 284.
    Jurasz, Jakub
    et al.
    Mälardalens högskola.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    The potential of photovoltaic systems to reduce energy costs for office buildings in time-dependent and peak-load-dependent tariffs2019Ingår i: Sustainable cities and society, ISSN 2210-6707, Vol. 44, s. 871-879Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electrical power generation across the world is facing dramatic changes for a variety of reasons related to reliability, economics and environmental concerns. Over recent years a significant increase has been observed in installed capacity of photovoltaic systems. Due to their typical seasonal and diurnal energy conversion patterns their integration into power systems creates new opportunities as well as threats. This paper intends to show how photovoltaics can contribute to reducing peak load in office buildings and thereby minimise expenditure on electricity during time- and peak-load-dependent energy prices/tariffs. An additional benefit is also provided to the national power system by reducing the need for peaking power stations. The calculations are performed for energy tariffs commonly used for commercial buildings in Poland. The simulation relies on climatic and price data for 2016. The results show significant potential for photovoltaics to reduce the peak load (from almost 60 kW to slightly over 44 kW) whilst simultaneously minimising energy costs to the building (from 1.2% up to 5.8% depending on the selected tariff). This study demonstrates the economic benefits of using PV system for reducing peak loads. A sensitivity analysis with regard to photovoltaics investment costs is carried out showing that the increasing investment costs have different impact on total energy cost depending on the considered energy tariff.

  • 285.
    Jurasz, Jakub K.
    et al.
    AGH Univ Sci & Technol, Al A Mickiewicza 30, PL-30059 Krakow, Poland.;Malardalen Univ, Hgsk Plan 1, S-72220 Vasteras, Sweden..
    Dabek, Pawel B.
    Wroclaw Univ Environm & Life Sci, Ul CK Norwida 25, PL-50375 Wroclaw, Poland..
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Can a city reach energy self-sufficiency by means of rooftop photovoltaics?: Case study from Poland2020Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 245, artikel-id 118813Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The process of decarbonising economies has to take place on multiple levels. One of the objectives is to ensure renewables-based energy self-sufficiency of cities. Cities have become home to the majority of the world's population, and at the same time contribute enormously to environmental pollution. Considering the above, the purposes of this paper are threefold: to formulate a methodology for estimating rooftop photovoltaics (PV) potential in urban areas based on detailed Light Detection And Ranging (LiDAR) data; to calculate the spatial variability of load and photovoltaics energy supply, and thus to distinguish zones with various levels of energy self-sufficiency; and finally, to scrutinise the economic and environmental aspects of such a solution in given conditions. Wroclaw, the capital city of the Lower Silesia voivodeship in south-west Poland (Central Europe), was selected as a case study. The city has a population of close to 650,000 and an annual electricity consumption slightly exceeding 2.2 TWh. Industry constitutes 46% of that demand, and households 31%. The results show that up to 850 MW p of rooftop PV can be installed in the city, which has the potential to reduce the electrical energy related emissions by almost 30% and simultaneously to increase the city's energy self-sufficiency. Although energy storage, in the form of batteries, slightly improves both the autarky and environmental indices, the relation between potential PV generation and load makes them very infrequently useful (mostly in summer) and not economically justified. 

  • 286.
    Kalai, D. Y.
    et al.
    University of Stavanger, Stavanger, Norway.
    Stangeland, K.
    University of Stavanger, Stavanger, Norway.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yu, Z.
    University of Stavanger, Stavanger, Norway.
    The effect of la on the hydrotalcite derived Ni catalysts for dry reforming of methane2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 3721-3726Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of 20Ni-Mg-Al hydrotalcite-like (HT) precursors were prepared to study the influence of lanthanum (La) on the catalytic activity of the catalysts in the dry reforming of methane (DRM). The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD) and temperature-programmed reduction (TPR). All catalysts presented ordered mesoporous structures with a large specific surface area. XRD confirmed the presence of HT structure for all of the precursors while the La promotion resulted in an additional phase of Lanthanum carbonate hydroxide. TPR study showed larger reduction degree for the catalysts but also reduction peaks that are shifted to higher temperatures. DRM reactions at 600 and 750°C revealed that the DRM activity was increased by the addition of La, while the stability of the catalysts was reduced at 600°C. 

  • 287.
    Kanders, Linda
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Purac AB.
    Start-up and operational strategies for deammonification plants: - a study with one-stage moving bed biofilm reactors treating reject water2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    To limit eutrophication, wastewater treatment plants use biological methods to convert degraded nitrogen to nitrogen gas. Deammonification, or partial nitritation in combination with anammox, has been shown to be an energy efficient process. This process is currently implemented in approximately 150 full-scale plants, and mainly on reject waters, the liquid fraction after dewatering of anaerobic digestion at municipal wastewater treatment plants. Implementation has been impeded by the slow growth of anammox bacteria, and 99% of the full-scale plants using the process have been using different methods to inoculate the process with anammox bacteria from elsewhere. Separate reject water installations, however, have shown high nitrous oxide emissions, which could increase the total carbon footprint.

    The objective of this thesis was to develop and validate a start-up concept using the moving bed biofilm reactor (MBBR) technique applied to reject water, and to investigate how the operational strategies could be optimized to limit potential nitrous oxide emissions. The results show that a one-stage deammonification process based on the MBBR technology with indigenous anammox bacteria originating from the reject water can be set up within a applicable time frame (<100 days). This was validated in two laboratory reactors and in two full-scale studies. Reject water originating from both mesophilic and thermophilic digested sludge was used. Anammox growth and nitrogen reduction were detected with fluorescence in situ hybridization (FISH) and chemical analysis, respectively. The start-up time was 72 days in the laboratory and 120 days in full-scale. In laboratory scale, there was no improvement in start-up time when adding external anammox inoculum. Results from a screening study of seven reject waters and their content of anammox bacteria using qPCR indicated the presence of 104–105 genome units anammox per mL in reject water, which could be sufficient for starting up deammonification plants within an applicable time frame.

    A final case study shows the potential of decreasing nitrous oxide emissions when a full-scale plant treating reject water was modified from nitrification/denitrification using a Sequencing Batch Reactor (SBR) to a deammonification process using the MBBR technique. The nitrous oxide emissions decreased from 10% to 0.1–0.7% of total nitrogen load with the change of operation mode. Further optimization by pH set point led to lower emission values. This effect is thought to be linked to the lower aeration ratio and increase in complete denitrification of dissolved nitrous oxide at higher pH.

  • 288.
    Kanders, Linda
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Purac AB, Box 1146, Lund, SE-221 05, Sweden.
    Beier, M.
    Institute for Sanitary Engineering and Waste Management (ISAH), Leibniz Universitaet Hannover, Germany.
    Nogueira, R.
    Institute for Sanitary Engineering and Waste Management (ISAH), Leibniz Universitaet Hannover, Welfengarten 1, Hannover, 30167, Germany.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sinks and sources of anammox bacteria in a wastewater treatment plant - screening with qPCR2018Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 78, nr 2, s. 441-451Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The deammonification process, which includes nitritation and anammox bacteria, is an energyefficient nitrogen removal process. Starting up an anammox process in a wastewater treatment plant (WWTP) is still widely believed to require external seeding of anammox bacteria. To demonstrate the principle of a non-seeded anammox start-up, anammox bacteria in potential sources must be quantified. In this study, seven digesters, their substrates and reject water were sampled and quantitative polymerase chain reaction (qPCR) was used to quantify both total and viable anammox bacteria. The results show that mesophilic digesters fed with nitrifying sludge (with high sludge ages) can be classified as a reliable source of anammox bacteria. Sludge hygienization and dewatering of digestate reduce the amount of anammox bacteria by one to two orders of magnitude and can be considered as a sink. The sampled reject waters contained on average &gt;4.0 × 104 copies mL1 and the majority of these cells (&gt;87%) were viable cells. Furthermore, plants with side-stream anammox treatment appear to have higher overall quantities of anammox bacteria than those without such treatment. The present study contributes to the development of sustainable strategies for both startup of anammox reactors and the possibility of improving microbial management in WWTPs.

  • 289.
    Kanders, Linda
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Industriell ekonomi och organisation. Purac AB, Lund, Sweden.
    Ling, Daniel
    Purac AB, Lund, Sweden..
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Rapid start-up of one-stage deammonification MBBR without addition of external inoculum2016Ingår i: WATER SCIENCE AND TECHNOLOGY, ISSN 0273-1223, Vol. 74, nr 11, s. 2541-2550Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In recent years, the anammox process has emerged as a useful method for robust and efficient nitrogen removal in wastewater treatment plants (WWTPs). This paper evaluates a one-stage deammonification (nitritation and anammox) start-up using carrier material without using anammox inoculum. A continuous laboratory-scale process was followed by full-scale operation with reject water from the digesters at Bekkelaget WWTP in Oslo, Norway. A third laboratory reactor was run in operational mode to verify the suitability of reject water from thermophilic digestion for the deammonification process. The two start-ups presented were run with indigenous bacterial populations, intermittent aeration and dilution, to favour growth of the anammox bacterial branches. Evaluation was done by chemical and fluorescence in situ hybridization analyses. The results demonstrate that anammox culture can be set up in a one-stage process only using indigenous anammox bacteria and that a full-scale start-up process can be completed in less than 120 days.

  • 290.
    Kanders, Linda
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Purac AB, Sweden.
    Yang, Jing-jing
    IVL Swedish Environmental Research Institute, Sweden.
    Baresel, Christian
    IVL Swedish Environmental Research Institute, Sweden.
    Zambrano, Jesus
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Full-scale comparison of N2O emissions from SBR N/DN operation versus one-stage deammonification MBBR treating reject water: - and optimization with pHset-point2019Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 79, nr 8, s. 1616-1625Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To be able to fulfill the Paris agreement regarding anthropogenic greenhouse gases, all potential 12 emissions must be mitigated. Wastewater treatment plants should aim to eliminate emissions of the 13 most potent greenhouse gas, nitrous oxide. In this study, these emissions were measured at a full-scale 14 reject water treatment tank during two different operation modes: nitrification/denitrification (N/DN) 15 operating as a sequencing batch reactor (SBR), and deammonification (nitritation/anammox) as a moving 16 bed biofilm reactor (MBBR). Nitrous oxide was measured both in the water phase and in the off-gas. The 17 treatment process emitted significantly less nitrous oxide in deammonification mode 0.14-0.7 %, 18 compared to 10 % of Total Nitrogen in N/DN mode. The decrease can be linked to the change feeding 19 strategy, concentration in nitrite, load of ammonia oxidized, shorter aeration time, no ethanol dosage 20 and the introduction of biofilm. Further, evaluation was done how the operational pH set point 21 influenced the emissions in deammonification mode. Lower concentrations of nitrous oxide was 22 measured in water phase at higher pH (7.5-7.6) than at lower pH (6.6-7.1). This is believed to be mainly 23 because of the lower aeration ratio and increased complete denitrification at the higher pH set point.

  • 291.
    Kavvalos, Mavroudis
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Compressor Characteristics for Transient and Part-load Performance Simulation2019Ingår i: Proceedings of the ASME Turbo Expo, American Society of Mechanical Engineers (ASME), 2019, American Society of Mechanical Engineers (ASME) , 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Compressor performance tests are mainly focused on the typical range of operation, resulting in limited knowledge of compressor behavior in the low-speed region. The main target of this work comprises the generation of compressor characteristics at low part-load by giving particular insight into the physical aspect of this operating condition. It is necessary for running transient and part-load performance simulation and can be considered as the first crucial step toward an optimal engine starting schedule. Modelling the low part-load operating regime requires accurate component performance maps extended to the low-speed area, where engine starting and altitude relight occur. In this work, a robust methodology for generating compressor maps in the low part-load operating regime is developed. Compressor geometry and typical operation range compressor map are required as inputs. Two different modelling processes are incorporated within this methodology. Extrapolation based on the principle of similarity laws with modified law exponents constitutes the first modelling process, which seems inaccurate when predicting compressor performance at fixed-rotor conditions. Interpolation based on the fixed-rotor characteristic constitutes the second modelling process, which can be either linear or adaptive. The adaptive interpolation scheme was developed by the authors and generates low-speed characteristics using the same allocation trend as the one obtained from given performance data. It is observed that performance data points of each β-line follow an exponential trend in mass flow differences while increasing rotational speed, with a calculated average relativized Root Mean Square (RMS) error of less than 5%. Adapting the same trend in mass flow to the low-speed region, a compressor performance map with continuous exponential trend in all characteristics (for part- and full-load conditions) can be achieved. Implementing the developed methodology on the High Pressure Compressor (HPC) of the Energy Efficient Engine (E3) project is also presented, showcasing its applicability and the merit of it being incorporated into any conventional performance prediction tool. Furthermore, a sensitivity analysis for input variables, namely compressor exit effective area and pressure loss model coefficients is carried out, demonstrating the significant impact of the former on the shape of the low part-load characteristics. Generation of compressor characteristics at low-speeds with this methodology can be viewed as an enabler for running credible transient starting simulation and transient diagnostics, thereby defining an optimal starting schedule, applicable to both power generation and aerospace industry.

  • 292.
    Kavvalos, Mavroudis
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Xin, Zhao
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schnell, Rainer
    German Aerospace Center (DLR), Institute of Propulsion Technology, Cologne, Germany.
    Aslanidou, Ioanna
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kalfas, Anestis
    Department of Mechanical Engineering, Aristotle University of Thessaloniki, Greece.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    A Modelling Approach of Variable Geometry for Low Pressure Ratio Fans2019Ingår i: International Symposium on Air Breathing Engines, ISABE 2019, Canberra, Australia, 23 - 27 September 2019 Paper No. ISABE-2019-24382, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents the development and application of a modelling approach of variable geometry conceptsfor low pressure ratio fans; namely Variable Area Nozzle and Variable Pitch Fan. An enhanced approachfor Outlet Guide Vane pressure loss predictions and an aerothermodynamic analysis of variable pitchconcept are developed and integrated into a multi-disciplinary conceptual engine design framework. Astreamline curvature algorithm is deployed for the derivation of the off-design fan performance map,alleviating scaling issues from higher pressure ratio fan designs. Correction deltas are derived through thevariable pitch analysis for calculating the re-shaped off-design fan performance map. The aforementionedvariable geometry concepts are evaluated in terms of surge margin at engine and aircraft level for a lowpressure ratio aft-fan of a hybrid-electric configuration. Performance assessments carried out suggest thata +8° closing of fan blade cascades leads to a 33% surge margin improvement (with reference being thesurge margin without variable geometry) compared to a 25% improvement achieved by +20% opening thenozzle area at end of runway take-off conditions. Although weight and complexity implications of variablegeometry are not considered, the integrated modelling approach is shown to be able to assess and comparesuch novel engine technologies for low pressure ratio fans in terms of operability.

  • 293.
    Khanna, Yash
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Conceptual design and development of thermal management system for hybrid electric aircraft engine.: A study to develop a physical model and investigate the use of Mobil Jet Oil II as coolant for aircraft electrical propulsion under different scenarios and time horizons.2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The ever-increasing levels of greenhouse gas emissions has led to the scientific community starting to explore the viability of electrical aircraft system, with the most prominent research and product development for hybrid electric system, which forms the transition phase from combustion to fully electric aircrafts. The primary objective of this thesis is to find solutions towards thermal management of the electrical components of a hybrid electric aircraft propulsion system, which generate a significant amount of heat while operating at heavy load conditions required to propel an aircraft. In view of these objectives a micro channel cold plate liquid cooling system, has been dynamically modelled using a combination of lumped parameter and thermal resistance methods of heat transfer analysis. The study investigates the prospects of using Mobil Jet Oil II, typically used as an aircraft lubricant as a coolant for the thermal management system. The primary components of this model are lithium ion battery, DC-AC inverter, permanent magnet motor, cross flow finned micro channel heat exchanger, centrifugal pump and ducts. The electrical components have been dimensioned according to energy storage and load requirements considering their efficiencies and gravimetric power/energy. The system has been simulated and analyzed under different scenarios considering the coolant inlet temperature, air temperature across the heat exchanger and on two-time horizons. Analysis has been done to study the dynamic trends of the component temperature and the coolant at different stages of the system. The scope of the study includes an evaluation of the added weight of the thermal management system under different time horizons and their comparison with results from a reference study. From the simulation results it can be concluded that Mobil Jet Oil II is a promising option as a coolant and therefore its use as a common fluid for gas turbine lubrication and as coolant, will benefit the aircraft as now no extra coolant reservoir is required, allowing reduction in weight carried by the aircraft.

  • 294.
    Khokhotva, O. P.
    et al.
    National Technical University of Ukraine, Kiev, Ukraine.
    Westholm, Lena Johansson
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    The impact of surface properties of modified pine bark on the mechanism of sorption of heavy metals from aqueous media2017Ingår i: Journal of Water Chemistry and Technology, ISSN 1063-455X, Vol. 39, nr 3, s. 148-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The surface properties of pine bark before and after the treatment with urea solution and the adsorption of Cu(II), Ni(II) and Zn(II) from aqueous solutions at different pH values have been studied. Types of active sorption sites, their surface concentration and change after the bark treatment with urea solution were determined. The results of potentiometric titration were processed by using ProtoFit and FITEQL software programs. The data obtained make it possible to conclude that in the extraction mechanism of heavy metals from water the share of ion exchange decreases and the share of complexation increases. The impact of alkaline and alkaline earth metals in the range of their concentrations up to 3000 mg/dm3 on Cu(II) extraction from model aqueous solutions was also investigated. 

  • 295.
    Kladovasilakis, Nikolaos
    et al.
    Aristotle Univ Of Thessaloniki, Greece.
    Efstathiadis, Theofilos
    Aristotle Univ Of Thessaloniki.
    Aslanidou, Ioanna
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kalfas, Anestis
    Aristotle Univ Of Thessaloniki.
    Rotor Blade Design of an Axial Turbine using Non-Ideal Gases with Low Real-Flow Effects2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 1127-1132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study aims to describe a design methodology for supersonic rotor blade geometry, depending on the working fluid, for a low enthalpy Organic Rankine Cycle (ORC) system. Thus, the working fluid is a non-ideal gas with low impact of real flow effects. An innovate algorithm was developed, in order to generate the two-dimensional geometry of the rotor blade, for various working media. A design method, based on the principle of vortex flow field, was used for the blading design and, for the design of supersonic blades, the method of characteristics was selected as the most optimum. The geometry was tested using a commercial simulation software that uses a pressure-based solving algorithm named SIMPLE (Semi-implicit Method for Pressure-Linked Equations). Key advantages of this procedure are both its simplicity and precision of the results.

    The above procedure was applied for three working fluids, indicatively isobutane (R-600a), tetrafluroethane (R134a) and a mixture of 15% isobutane – 85% isopentane. Considering the ratio of specific heat capacities as constant, which is a realistic assumption for the operating conditions of these systems, the algorithm produces three different blade geometries. Results comparison indicates that every working fluid, for the same operating conditions and for the same design options, has a significantly differentiated geometry of the two-dimensional blade. Finally, the calculated total to total isentropic efficiency, for these rotor blades, is almost 92%. 

  • 296.
    Klintenberg, Patrik
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Jamieson, M.
    Tranås Utbildningscentrum, Sweden .
    Kinyaga, V.
    Desert Research Foundation of Namibia, Namibia.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Assessing biogas potential of slaughter waste: Can biogas production solve a serious waste problem at abattoirs?2014Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, s. 2600-2603Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Management of solid waste and wastewater in Namibia is a growing concern. This study investigated the biogas potential of slaughter waste at a small stock abattoir in southern Namibia. Laboratory experiments with five different mixes of blood; stomach content and manure from sheep were tested. Preliminary findings suggest that the most optimum mixture of slaughter waste was relatively large amounts of stomach and intestine content. The blood proportion should be kept relatively low, since the high nitrogen contents in the blood may inhibit the biogas production. The substrate mixture reflecting the actual ratio of waste generated in the slaughter process resulted in the highest methane production. This suggests that it is possible to produce viable amounts of biogas only using the waste produced at the abattoir, without adding other green substrate. Findings presented here together with results from a larger biogas digester, will be elaborated in the full paper.

  • 297.
    Klintenberg, Patrik
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindmark, Johan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Eskelinen, Tuomo
    Huopana, Tuomas
    Jääskeläinen, Ari
    Savonia University of Applied Sciences, University of Eastern Finland, Finland.
    INVESTMENT MEMO ABOWE PILOT B SWEDEN2014Rapport (Refereegranskat)
    Abstract [en]

    This report is one output of ABOWE project (Implementing Advanced Concepts for Biological Utilization of Waste), which belongs to EU Baltic Sea Region Programme 2007-2013. ABOWE works with two promising technologies to unlock investments. Two mobile pilot plants have been built and will be tested in several Baltic Sea regions. These pilots are based on a novel biorefinery concept from Finnoflag Oy, Finland, known as Pilot A as well as a German dry fermentation process, known as Pilot B. The pilots form the basis for compilation of Investment Memos and organizing Investor Events. Also a regional model is used to evaluate the new processes’ economic and climatic impacts in each region. The desired outcome from ABOWE is implementer/investor driven continuation projects targeting full-scaleplant investments of the two technologies.

    The purpose of ABOWE Work Package 2 is to gather and communicate information from many aspects of technologies which are piloted with Pilot A and Pilot B to support investment decisions for full scale plants. In practice, a demo full scaleplant would be needed in order to convince the commercial investors and implementers to full scale plants. This means that ABOWE provides with profound information and a step forward regarding the two technologies. After ABOWE, the technology will need development for full-scale, and the feasibility will need further analysis. An implementer and investor should be found to conduct development further towards full-scale demo plant.

  • 298.
    Klintenberg, Patrik
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindmark, Johan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Eskelinen, Tuomo
    Lappi, Mervi
    Savonia University of Applied Sciences, University of Eastern Finland, Finland.
    Kauppinen, Marja
    Huopana, Tuomas
    Jääskeläinen, Ari
    Savonia University of Applied Sciences, University of Eastern Finland, Finland.
    Hakalehto, Elias
    INVESTMENT MEMO ABOWE PILOT A SWEDEN2015Rapport (Refereegranskat)
    Abstract [en]

    This report was compiled by the ABOWE project (Implementing Advanced Concepts for Biological Utilization of Waste) funded by the EU Baltic Sea Region Programme 2007-2013. This report presentsresults and information of relevance for the up-scaling of the Finnoflag biorefinery technology, piloted in Finland, Poland and Sweden, to support investment decisions towards full-scale implementation.

    The piloting of the technology done by the ABOWE project provides valuable information and a step forward regarding the technology. The next step, after the pilot phase, would be to construct a full-scalede monstration plant to showcase the potential of the technology to potential commercial investorsor implementers. The bioprocess will need to be further designedand optimized through longer testing with selected waste materials to produce targeted products. This will all0w for full-scaleoperationsand further feasibility analysis. This falls beyond the scope of the ABOWE project. This report forms the basis of an investment memo that provides decision support topossible implementers and investors that are interested in taking the lead in the development of the technology further to a full-scale demo plant.

  • 299.
    Klintenberg, Patrik
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Azimoh, Chukwuma Leonard
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Successful technology transfer: What does it take?2014Ingår i: Applied Energy, ISSN 0306-2619, Vol. 130, s. 807813-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Technology transfer from developed to developing countries is often problematic. Insufficient resources for operation and maintenance after project finalization are common challenges. Findings from assessments of two projects in rural Botswana and Namibia where different renewable energy technologies were introduced to improve access to electricity are presented. In Tsumkwe, a Namibian off-grid settlement with about 4000 inhabitants, a large solar-diesel hybrid system has been constructed. A smaller system using photovoltaic and biogas is piloted in the off-grid settlement Sekhutlane in Botswana. In Sekhutlane beneficiaries' ability to pay for services is addressed by supporting local entrepreneurs to establish electricity-based businesses. Functionality of installations was inspected and semi-structured interviews were held with key stakeholders. In Tsumkwe local service providers were unprepared to take charge of operations and maintenance after completion of the project and users have difficulties paying for the services. Too strong focus on technology and insufficient efforts made to involve local institutions and beneficiaries throughout the project are main causes. The promotion of local entrepreneurship in Sekhutlane has resulted in 17 local businesses being established, likely to strengthen the cash economy and improved ability to pay for services, and thereby contributing financial resources towards operation and maintenance of systems. © 2014 Elsevier Ltd.

  • 300.
    Koppejan, Japp
    et al.
    Procede Biomass BV, The Netherlands.
    Lönnermark, Anders
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. SP Technical Research Institute of Sweden.
    Persson, Henry
    SP Technical Research Institute of Sweden.
    Larsson, Ida
    SP Technical Research Institute of Sweden.
    Blomqvist, Per
    SP Technical Research Institute of Sweden.
    Arshadi, M.
    Swedish University of Agricultural Sciences, Sweden.
    Valencia-Reyes, E.
    Swedish University of Agricultural Sciences, Sweden.
    Melin, Staffan
    University of British Columbia, Canada.
    Howes, P.
    AEA Group, UK.
    Wheeler, P.
    Lend Lease, UK.
    Baxter, D.
    Joint Research Institute, European Commission, The Netherlands.
    Nikolaisen, L.
    Danish Technological Institute, Denmark.
    Health and safety Aspects of Solid Biomass Storage, Transportation and Feeding2013Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This publication focuses on the health and safety issues of the supply chain of solid biofuels with the objective to highlight commonly used mitigation methodologies to promote a better working environment when dealing with solid biofuels. It has been compiled as a joint effort by experts active in Tasks 32, 36, 37 and 40 of the IEA Bioenergy Agreement, with their own specific fields of expertise. Only through this cooperation, it was possible to touch upon the full range of issues in one publication that one may come across when developing projects in which solid biomass fuels are produced, traded or used. 

    The properties of a biomass material and the intended use determine how the material should be safely transported and stored. Self-heating, off-gassing and dust explosions are significant challenges for the industry that have already resulted in significant losses of capital investments and even tragic loss of life. Likewise, exposure to biologically active material, such as moulds and spores may form a serious hazard for the health of workers involved. With the growth of the bioenergy sector, it is important not only that opportunities for bioenergy are implemented in an efficient economic manner, but also safely.

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