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  • 151.
    Daraei, Mahsa
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dotzauer, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Potentials for increased application of renewables in the transportation system: A case study for Södermanland County, Sweden2019In: Energy Procedia, Elsevier Ltd , 2019, p. 267-273Conference paper (Refereed)
    Abstract [en]

    In this study, possible alternations in a regional transport sector are assessed to increase the use of renewable resources. Three scenarios are developed aimed to investigate different alternatives including potential straw-based bioethanol supply to fuel regional cars with combustion engines, more use of Electrical Vehicles (EVs) with use of potential power from solar energy, and the feasibility of application of hybrid cars fueled with electricity and bioethanol. The evaluation considers the reduction in CO 2 emissions and increased balance in energy demand and supply. Results of the study indicate that application of hybrid vehicles with bioethanol-fueled engines and electrical motors could potentially reduce the CO 2 emissions compared with other proposed approaches in the studied scenarios. At the same time, there would be a balance in the system, so that, the bioethanol production from the available cereal straw in the region can meet the energy demand of suggested hybrid cars in wintertime. While, the energy supply from solar cells installed on the rooftop of the buildings can cover the electricity need of the motor during summer. This approach will also result in increased use of renewables in the transportation system.

  • 152.
    Davidsson, H.
    et al.
    Lund University, Sweden.
    Bernardo, R.
    Lund University, Sweden.
    Gomes, J.
    Solarus AB, Älvkarleby, Sweden.
    Gentile, N.
    Lund University, Sweden.
    Gruffmanc, C.
    ÅF AB, Gävle, Sweden .
    Chea, L.
    Universidade Eduardo Mondlane, Maputo, Mozambique .
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Construction of laboratories for solar energy research in developing countries2014In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 57, p. 982-988Article in journal (Refereed)
    Abstract [en]

    A large number of photovoltaic systems have been installed in developing countries around the world during numerous projects. The goal is often to improve the quality of life in rural areas often lacking electricity. Many of these installations provide important services such as lighting and charging of various devices. However, when the projects are finished, there is a large risk that maintenance is not carried out properly and that malfunctions are never repaired. This situation can leave an otherwise well- functioning system unusable. A key problem is that there are not enough trained technicians that can maintain and repair the system locally. One reason for this is the lack of practical education in many developing countries. Furthermore, the availability of spare parts is essential for long term effectiveness. During 2011 a group of researchers from Lund University in Sweden built a small scale laboratory in Maputo, Mozambique, with local researchers. The project was successful and today the laboratory functions both as a teaching facility and as a measurement station for solar energy research for licentiates, masters and Ph.D. students. The main goal now is to widen the project in order to incorporate more universities in developing countries. We are now looking for new interested partners in developing countries who believe that such a laboratory could strengthen their ability to teach practical work and to perform research at a local university. Partners for planning and executing the project are also needed.

  • 153.
    Desideri, U.
    et al.
    Università di Perugia.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Analysis and comparison between a concentrating solar and a photovoltaic power plant2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 113, p. 422-433Article in journal (Refereed)
    Abstract [en]

    Solar energy is a source, which can be exploited in two main ways to generate power: direct conversion into electric energy using photovoltaic panels and by means of a thermodynamic cycle. In both cases the amount of energy, which can be converted, is changing daily and seasonally, causing a discontinuous electricity production. In order to limit this drawback, concentrated solar power plants (CSP) and photovoltaic plants (PV) can be equipped with a storage system that can be configured not only for covering peak-loads but also for the base-load after the sunset or before the sunrise. In CSP plants it is the sun's thermal energy to be stored, whereas in PV applications it is the electrical energy to be stored in batteries, although this is not economically and environmentally feasible in large-scale power plants.The main aim of this paper is to study the performance of concentrated solar power plants equipped with molten salts thermal storage to cover a base load of 3MWel. In order to verify the possibility of storing effectively the thermal energy and to design a plant for base load operation, two locations were chosen for the study: Gela in southern Italy, and Luxor in Egypt. The electricity production of the CSP facilities has been analyzed and then compared with the electricity production of PV plants. Two different comparisons were done, one by sizing the PV plant to provide the same peak power and one using the same collectors surface. This paper has also highlighted some important issues in site selection and in design criteria for CSP plants used for base load operation.The high variability of the direct normal radiation during the year in southern Italy may cause several problems in CSP facilities, mainly related to the wide range of energy input from the sun. The more uniform and higher values of the solar radiation in the Egyptian location mitigates this problem and allows achieving higher efficiencies than in southern Italy. In most cases the electricity produced by the CSP plant is higher than that produced by a similar PV plant, because the presence of the storage system guarantees the continuity of electricity production even without solar radiation. An economic analysis based on the estimation of the levelized electricity cost (LEC) for both CSP and PV power plants located both in south of Italy and Egypt was carried out in order to investigate which is the most cost effective solution. In all the cases considered, the CSP facilities resulted the best option in terms of cost of electricity produced due to the continuity of energy production during the night hours.

  • 154.
    Dibdiakova, Janka
    et al.
    Norwegian Institute of Bioeconomy Research, Ås, Norway..
    Liang, Wang
    Sintef Energy Research, , Norway.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Heating Value and Ash Content of Downy Birch Forest Biomass2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 1302-1308Article in journal (Refereed)
    Abstract [en]

    Biomass from forestry sector provides an important contribution to meet the government's targets for increasing bioenergy production and utilization. Characterization of forest residues is critical for exploiting and utilizing them for energy production purpose. In present work, stem wood, stem bark, branches, top of trees from downy birch forest were sampled from different sites in South Norway and subjected to heating value and ash content measurement. Properties of different parts of trees vertically along the tree trunk and radially along the branch and crown level were assessed via the statistical model. The heating value of stem wood was in range 18.14-18.57 MJ/kg, of stem bark 18.50-18.72 MJ/kg and of branch wood 18.21-18.50 MJ/kg. The vertical dependence of heating value of downy birch stem wood was similar to that of stem bark. Regular decreasing of heating value towards the tree top was observed. Significantly higher heating value at level p<0.05∗of stem bark than the one of stem wood was observed. The ash content of downy birch branch wood did vary axially along the branch whereas there are only slight differences of ash content of branch within the crown. The stem bark has the highest ash content in range 2.0-2.5%, followed by branch wood in range of 1.0-1.6% and the lowest for stem wood in range of 0.3-0.5%.

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  • 155.
    Dibdiakova, Janka
    et al.
    Norwegian Forest & Landscape Inst, Norway.
    Wang, Liang
    Sintef Energy Res, Trondheim, Norway.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Characterization of ashes from Pinus Sylvestris forest biomass2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, p. 186-191Article in journal (Refereed)
    Abstract [en]

    Efficient and profitable biomass combustion is often limited by ash related operational problems. Knowledge of the ash melting and sintering is of important, in terms of predict and reduce ash-related problems in biomass-fired boilers. In this study, chemical composition and melting behaviors of ashes from the four parts of P. sylvestris trees were investigated. The four parts from Pinus sylvestris trees are stem wood, bark, branch base and twigs. A simultaneous thermal analyzer (STA) was used to characterize the melting behavior of selected biomass fuels in oxidizing atmosphere. Ash melting process was identified as the distinctive endothermic peaks on recorded DSC curves. The results showed that the stem wood of pine contains higher contents of most of the ash forming matters than other tree parts. Chemical composition of ashes from four parts of the pine tree is dominated by element Ca, K, Mg, Mn, P and Si. The K, Na and P contents in the twigs are significantly higher than that of stem wood, bark, and branch base indicating high tendency of ash melting and slagging. STA experiments indicated that the melting process of the studied fuel ashes start in the temperature range of 930-965 degrees C. Scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometry (EDX). Analyses results showed that the stem wood ash remains loose structure even after 1000 degrees C sintering treatment. But the ashes originated from top branch show sign of sintering at 1000 degrees C. The obtained results of present work can be considered as useful information within an industry interest for a prediction of the forest biomass ash melting behavior. 

  • 156.
    Diehl, Stefan
    et al.
    Lund Univ, Ctr Math Sci, POB 118,Lund, Sweden..
    Zambrano, Jesus
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Carlsson, Bengt
    Uppsala Univ, Dept Informat Technol, POB 337, Uppsala, Sweden..
    Analysis of photobioreactors in series2018In: Mathematical Biosciences, ISSN 0025-5564, E-ISSN 1879-3134, Vol. 306, p. 107-118Article in journal (Refereed)
    Abstract [en]

    A photobioreactor (PBR) contains microalgae which under illumination consume carbon dioxide and substrate dissolved in water, and produce oxygen. The process is used in water recovery resource facilities with a continuous flow of wastewaster through the PBR. With several PBRs in series the reduction of substrate can be improved. This paper contains a thorough analysis of a model of PBRs in series, where each PBR is modelled with a system of three ordinary differential equations for the concentrations of dissolved substrate and biomass (algae), and the internal cell quota of substrate to biomass. Each PBR has a certain volume and irradiation. The absorption rate of substrate into the cells is modelled with Monod kinetics, whereas the biomass growth rate is modelled with Droop kinetics, in which both a minimum and a maximum internal cell quota are assumed. The main result is that the model has a unique stable steady-state solution with algae in all PBRs. Another stable steady-state solution is the wash-out solution with no algae in the system. Other steady-state solutions are combinations of these two with no algae in some of the first PBRs and algae in the rest of the PBRs in the series. Conditions on the illumination, volumetric flow and volumes of the PBRs are given for the respective solution. Numerical solutions illustrate the theoretical results and indicate further properties.

  • 157.
    Diehl, Stefan
    et al.
    Lund University, Sweden.
    Zambrano, Jesús
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Carlsson, Bengt
    Uppsala University, Sweden.
    Steady-State Analyses of Activated Sludge Processes with Plug-Flow Reactor2017In: Journal of Environmental Chemical Engineering, ISSN 2160-6544, E-ISSN 2213-3437, Vol. 5, no 1, p. 795-809Article in journal (Refereed)
    Abstract [en]

    Activated sludge processes (ASPs) consisting of a plug-flow reactor (PFR) and a settler are analyzed in steady-state operation using a reduced model consisting of one soluble substrate and one particulate biomass component modelling the dominating biological process. Monod biomass growth rate is assumed. Two settler models are studied. One is the commonly used ideal settler, or point settler, which is assumed to never be overloaded and to have unlimited flux capacity. The other recently published steady-state settler model includes hindered and compressive settling, and models a realistic limiting flux capacity. Generally, the steady-state concentration profiles within the PFR and the settler are governed by nonlinear ordinary differential equations. It is shown that the steady-state behaviour of the ASP can, however, be captured by equations without derivatives. New theoretical results are given, such as conditions by means of inequalities on input variables and parameters for a steady-state solution to exist. Another novel finding is that, if the incoming substrate concentration is increased from a low or moderate stationary value and the solids residence time is kept fixed, then this results in a lower effluent concentration in the new steady state. The steady-state equations are solved numerically for different operating conditions. For common parameter values, numerical solutions reveal that an ASP having a PFR, instead of a continuously stirred tank reactor, is far more efficient in reducing the effluent substrate concentration and this can be obtained for much lower recycle ratios, which reduces the pumping energy considerably.

  • 158.
    Ding, J.
    et al.
    Sun Yat-Sen University, Guangzhou, China.
    Pan, G.
    Sun Yat-Sen University, Guangzhou, China.
    Du, L.
    Sun Yat-Sen University, Guangzhou, China.
    Lu, J.
    Sun Yat-Sen University, Guangzhou, China.
    Wei, X.
    South China University of Technology, Guangzhou, China.
    Li, J.
    National Supercomputer Center in Guangzhou, Guangzhou, China.
    Wang, W.
    Sun Yat-Sen University, Guangzhou, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Institute of Technology, Stockholm, Sweden.
    Theoretical prediction of the local structures and transport properties of binary alkali chloride salts for concentrating solar power2017In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 39, p. 380-389Article in journal (Refereed)
    Abstract [en]

    Comprehensive molecular simulations have been carried out to compute local structures and transport properties of different components of binary NaCl-KCl over a wide operating temperature range. The partial radial distribution functions, coordination number curves and angular distribution functions were calculated to analyze the influence of temperature and component on local structures of molten Alkali Chlorides. Transport properties were calculated by using reverse non-equilibrium molecular dynamics (RNEMD) simulations including densities, shear viscosity and thermal conductivity. The results show that ion clusters are considered to be formed and the distance of ion clusters become larger with increasing temperature which has great influence on macro-properties. The calculated properties have a good agreement with the experimental data, and similar method could be used to computationally calculate the properties of various molten salts and their mixtures.

  • 159.
    Ding, Jing
    et al.
    Sun Yat Sen Univ, Sch Engn, Guangzhou 510006, Guangdong, Peoples R China..
    Du, Lichan
    Sun Yat Sen Univ, Sch Engn, Guangzhou 510006, Guangdong, Peoples R China..
    Pan, Gechuanqi
    Sun Yat Sen Univ, Sch Engn, Guangzhou 510006, Guangdong, Peoples R China..
    Lu, Jianfeng
    Sun Yat Sen Univ, Sch Engn, Guangzhou 510006, Guangdong, Peoples R China..
    Wei, Xiaolan
    South China Univ Technol, Sch Chem & Chem Engn, Guangzhou 510640, Guangdong, Peoples R China..
    Li, Jiang
    Natl Supercomp Ctr Guangzhou, Guangzhou 510006, Guangdong, Peoples R China..
    Wang, Weilong
    Sun Yat Sen Univ, Sch Engn, Guangzhou 510006, Guangdong, Peoples R China..
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Inst Technol, Energy Proc Div, Stockholm, Sweden..
    Molecular dynamics simulations of the local structures and thermodynamic properties on molten alkali carbonate K2CO32018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 220, p. 536-544Article in journal (Refereed)
    Abstract [en]

    Molten carbonate salts have received particular attention for high-temperature thermal energy storage and heat Molecular dynamics simulation transfer applications due to desirable thermal characteristics, such as wide operating temperature range, low Molten alkali carbonates causticity and excellent thermal stability. In this study, molecular dynamics (MD) simulations were performed Local structures on molten alkali carbonate K2CO3 based on an effective pair potential model, a Born-Mayer type combined with Thermodynamic properties a Coulomb term. The radial distribution functions (RDF) and coordination number curves of the molten salt were characterized to explore the temperature dependences of macroscopic properties from microscopic view. The results suggest that the distance between K2CO3 particles is getting larger with temperature increasing, resulting in the increase of molar volume and the diminished ability of resistance to shear deformation and heat transfer by vibration between ions. Besides, it can be concluded that the structure of CO32- is inferred reasonably to be ortho-triangular pyramid from the comprehensive analysis of local structures including the angular distribution functions (ADF). Moreover, the thermodynamic properties were simulated in detail from 1200 to 1600 K including the density, thermal expansion coefficient, specific heat capacity, sheer viscosity, thermal conductivity and ion self-diffusion coefficient, which was hard to be measured from experiments under high-temperature extreme conditions, All the simulation results are in satisfactory agreement with available experimental data with high accuracy, and the minimum simulation error is as low as 1.42%.

  • 160.
    Ding, Y.
    et al.
    College of Electrical Engineering, Zhejiang University, Hangzhou, ChinaCollege of Electrical Engineering, Zhejiang University, Hangzhou, ChinaCollege of Electrical Engineering, Zhejiang University, Hangzhou, ChinaCollege of Electrical Engineering, Zhejiang University, Hangzhou, ChinaCollege of Electrical Engineering, Zhejiang University, Hangzhou, ChinaCollege of Electrical Engineering, Zhejiang University, Hangzhou, China.
    Shao, C.
    College of Electrical Engineering, Zhejiang University, Hangzhou, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Division of Energy Processes, KTH-Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
    Song, Y.
    College of Electrical Engineering, Zhejiang University, Hangzhou, China.
    Zhang, C.
    Division of Energy Processes, KTH-Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
    Guo, C.
    College of Electrical Engineering, Zhejiang University, Hangzhou, China.
    Economical flexibility options for integrating fluctuating wind energy in power systems: The case of China2018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 228, p. 426-436Article in journal (Refereed)
    Abstract [en]

    The inherent stochastic nature of wind power requires additional flexibility during power system operation. Traditionally, conventional generation is the only option to provide the required flexibility. However, the provision of the flexibility from the conventional generation such as coal-fired generating units comes at the cost of significantly additional fuel consumption and carbon emissions. Fortunately, with the development of the technologies, energy storage and customer demand response would be able to compete with the conventional generation in providing the flexibility. Give that power systems should deploy the most economic resources for provision of the required operational flexibility, this paper presents a detailed analysis of the economic characteristics of these key flexibility options. The concept of “balancing cost” is proposed to represent the cost of utilizing the flexible resources to integrate the variable wind power. The key indicators are proposed respectively for the different flexible resources to measure the balancing cost. Moreover, the optimization models are developed to evaluate the indicators to find out the balancing costs when utilizing different flexible resources. The results illustrate that exploiting the potential of flexibility from demand side management is the preferred option for integrating variable wind power when the penetration level is below 10%, preventing additional fuel consumption and carbon emissions. However, it may require 8% of the customer demand to be flexible and available. Moreover, although energy storage is currently relatively expensive, it is likely to prevail over conventional generation by 2025 to 2030, when the capital cost of energy storage is projected to drop to approximately $ 400/kWh or lower.

  • 161.
    Ditaranto, M.
    et al.
    SINTEF Energy Research, Trondheim, Norway.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hu, Y.
    University of South Wales, United Kingdom.
    Evaluation of a pre-combustion capture cycle based on hydrogen fired gas turbine with exhaust gas recirculation (EGR)2014In: Energy Procedia, 2014, p. 1972-1975Conference paper (Refereed)
    Abstract [en]

    Pre-combustion capture technology is a promising route to power generation with CO2 free emissions, by transforming the fossil hydrocarbon fuel into a hydrogen rich fuel with near zero Carbon containing species. This gaseous fuel also allows to use a high efficiency gas turbine into a coal based power plant. The gas turbine combustor however has to meet the challenge of high temperature flame responsible for unacceptable NOx emissions, and a highly reacting fuel impeding the use of conventional dry low NOx combustion technologies. The actual solution to this problem is to dilute the hydrogen fuel with up to 50% Nitrogen. This paper presents a concept where the exhaust gas of the gas turbine is recirculated (EGR) such as to deplete the air of oxygen to produce a low temperature combustion with undiluted hydrogen fuel while flame stability is still ensured by the highly reactive properties of hydrogen. The study compares the concept with a cycle using Selective Catalytic Reduction for NOx control.

  • 162.
    Ditaranto, M.
    et al.
    SINTEF Energy Research, Trondheim, Norway .
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Løvås, T.
    Norwegian University of Science and Technology, Trondheim, Norway .
    Concept of hydrogen fired gas turbine cycle with exhaust gas recirculation: Assessment of combustion and emissions performance2015In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 37, p. 377-383Article in journal (Refereed)
    Abstract [en]

    A novel gas turbine cycle concept applicable to power plants with pre-combustion CO<inf>2</inf> capture or integrated gasification combined cycle (IGCC) is presented. These power plants use a hydrogen rich fuel with high reactive combustion properties which makes fuel dilution necessary to achieve low NOx emissions. The proposed novel gas turbine arrangement is set up as to avoid both fuel dilution and its consequent efficiency penalty, and breakthrough in low NOx combustion technology. In this concept, a high exhaust gas recirculation (EGR) rate is applied in order to generate an oxygen depleted working fluid entering the combustor, enough to reduce the high reactivity of hydrogen rich fuels. As a result, the combustion temperature in this environment is inherently limited, thus, keeping NOx formation rate low. A first order assessment of the combustion characteristics under such gas turbine operating conditions is made in the light of a numerical analysis of stability and NOx emissions potential. Both diffusion and premixed types combustor are considered according to the selected EGR rate. It is first shown that the flame stability could be maintained at EGR rates well above the maximum EGR limit found in conventional natural gas fired gas turbines. The study further shows that at these high EGR rates, considerable reductions in NOx emissions can be expected. The conclusion of this first order analysis is that there is a true potential in reducing the efficiency penalty induced by diluting the fuel in power plants with pre-combustion CO<inf>2</inf> capture. 

  • 163.
    Djuric Ilic, D.
    et al.
    Linköping University.
    Dotzauer, Erik
    Mälardalen University, School of Business, Society and Engineering. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Trygg, L.
    Linköping University.
    Broman, G.
    Blekinge Institute of Technology,.
    Integration of biofuel production into district heating - Part I: An evaluation of biofuel production costs using four types of biofuel production plants as case studies2014In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 69, p. 176-187Article in journal (Refereed)
    Abstract [en]

    This paper evaluates the effects on profitability of biofuel production if biofuel producers would sell the waste heat from the production to a local district heating system. All analyses have been performed considering four different technology cases for biofuel production. Two technology cases include ethanol production which is followed by by-production of raw biogas. This biogas can be upgraded and sold as biofuel (the first technology case) or directly used for combined heat and power production (the second technology case). The third and the fourth technology cases are Fischer-Tropsch diesel and dimethyl ether production plants based on biomass gasification. Two different district heating price levels and two different future energy market scenarios were considered. The sensitivity analyses of the discount rate were performed as well. In the case of energy market conditions, the profitability depends above all on the price ratio between biomass (used as the feedstock for biofuel production) and crude oil (used as the feedstock for fossil diesel and gasoline production). The reason for this is that the gate biofuel prices (the prices on which the biofuel would be sold) were calculated assuming that the final prices at the filling stations are the same as the prices of the replaced fossil fuel. The price ratios between biomass and district heating, and between biomass and electricity, also have an influence on the profitability, since higher district heating and electricity prices lead to higher revenues from the heat/electricity by-produced. Due to high biofuel (ethanol + biogas) efficiency, the ethanol production plant which produces upgraded biogas has the lowest biofuel production costs. Those costs would be lower than the biofuel gate prices even if the support for transportation fuel produced from renewable energy sources were not included. If the raw biogas that is by-produced would instead be used directly for combined heat and power production, the revenues from the electricity and heat would increase, but at the same time the biofuel efficiency would be lower, which would lead to higher production costs. On the other hand, due to the fact that it has the highest heat efficiency compared to the other technologies, the ethanol production in this plant shows a high sensitivity to the district heating price level, and the economic benefit from introducing such a plant into a district heating system is most obvious. Assuming a low discount rate (6%), the introduction of such a plant into a district heating system would lead to between 28% and 52% (depending on the district heating price level and energy market scenario) lower biofuel production costs. Due to the lower revenues from the heat and electricity co-produced, and higher capital investments compared to the ethanol production plants, Fischer-Tropsch diesel and dimethyl ether productions are shown to be profitable only if high support for transportation fuel produced from renewable energy sources is included. The results also show that an increase of the discount rate from 6% to 10% does not have a significant influence on the biofuel production costs. Depending on the biofuel production plant, and on the energy market and district heating conditions, when the discount rate increases from 6% to 10%, the biofuel production costs increase within a range from 2.2% to 6.8%. 

  • 164.
    Djuric Ilic, D.
    et al.
    Linköping University.
    Dotzauer, Erik
    Mälardalen University, School of Business, Society and Engineering. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Trygg, L.
    Linköping University.
    Broman, G.
    Blekinge Institute of Technology.
    Integration of biofuel production into district heating - Part II: An evaluation of the district heating production costs using Stockholm as a case study2014In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 69, p. 188-198Article in journal (Refereed)
    Abstract [en]

    Biofuel production through polygeneration with heat as one of the by-products implies a possibility for cooperation between transport and district heating sectors by introducing large-scale biofuel production into district heating systems. The cooperation may have effects on both the biofuel production costs and the district heating production costs. This paper is the second part of the study that investigates those effects. The biofuel production costs evaluation, considering heat and electricity as by-products, was performed in the first part of the study. In this second part of the study, an evaluation of how such cooperation would influence the district heating production costs using Stockholm's district heating system as a case study was performed. The plants introduced in the district heating system were chosen depending on the future development of the transport sector. In order to perform sensitivity analyses of different energy market conditions, two energy market scenarios were applied. Despite the higher revenues from the sale of by-products, due to the capital intense investments required, the introduction of large-scale biofuel production into the district heating system does not guarantee economic benefits. Profitability is highly dependent on the types of biofuel production plants and energy market scenarios. The results show that large-scale biogas and ethanol production may lead to a significant reduction in the district heating production costs in both energy market scenarios, especially if support for transportation fuel produced from renewable energy sources is included. If the total biomass capacity of the biofuel production plants introduced into the district heating system is 900 MW, the district heating production costs would be negative and the whole public transport sector and more than 50% of the private cars in the region could be run on the ethanol and biogas produced. The profitability is shown to be lower if the raw biogas that is by-produced in the biofuel production plants is used for combined and power production instead of being sold as transportation fuel; however, this strategy may still result in profitability if the support for transportation fuel produced from renewable energy sources is included. Investments in Fischer-Tropsch diesel and dimethyl ether production are competitive to the investments in combined and power production only if high support for transportation fuel produced from renewable energy sources is included. 

  • 165.
    Djuric Ilic, D.
    et al.
    Linköping University.
    Dotzauer, Erik
    Mälardalen University, School of Business, Society and Engineering. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Trygg, L.
    Linköping University.
    Broman, G.
    Blekinge Institute of Technology, Karlskrona, Sweden .
    Introduction of large-scale biofuel production in a district heating system - An opportunity for reduction of global greenhouse gas emissions2014In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 64, no 1, p. 552-561Article in journal (Refereed)
    Abstract [en]

    In this study, cooperation between Stockholm's transport and district heating sectors is analysed. The cooperation concerns the integration of biofuel polygeneration production. A MODEST optimisation model framework is used, assuming various energy market and transport sector scenarios for the year 2030. The scenarios with biofuel production and increased biofuel use in the region are compared with reference scenarios where all new plants introduced into the district heating sector are combined heat and power plants, and the share of biofuel used in the transport sector is the same as today. The results show that the cooperation implies an opportunity to reduce fossil fuel consumption in the sectors by between 20% and 65%, depending on energy market conditions and assumed transport sector scenarios. If we consider biomass an unlimited resource, the potential for greenhouse gas emissions reduction is significant. However, considering that biomass is a limited resource, the increase of biomass use in the district heating system may lead to a decrease of biomass use in other energy systems. The potential for reduction of global greenhouse gas emissions is thus highly dependent on the alternative use of biomass. If this alternative is used for co-firing in coal condensing power plants, biomass use in combined heat and power plants would be more desirable than biofuel production through polygeneration. On the other hand, if this alternative is used for traditional biofuel production (without co-production of heat and electricity), the benefits of biofuel production through polygeneration from a greenhouse gas emissions perspective is superior. However, if carbon capture and storage technology is applied on the biofuel polygeneration plants, the introduction of large-scale biofuel production into the district heating system would result in a reduction of global greenhouse gas emissions independent of the assumed alternative use of biomass. 

  • 166.
    Dong, Beibei
    et al.
    Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China.
    Zhu, Kai
    Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China.
    PVTxy Properties of CO2 Mixtures for CCS: An Update of Experimental Data and Models Since 20092018In: JOINT INTERNATIONAL CONFERENCE ON ENERGY, ECOLOGY AND ENVIRONMENT ICEEE 2018 AND ELECTRIC AND INTELLIGENT VEHICLES ICEIV 2018, DESTECH PUBLICATIONS, INC , 2018Conference paper (Refereed)
    Abstract [en]

    The latest progress on the experimental data and theoretical models regarding PVTxy properties of CO2 mixtures has been updated. This review shows that more experimental data are available, such as the vapor liquid equilibrium (VLE) of CO2/NO and the density of CO2/O-2. But there are still some clear deficiencies: for example, there have been no data on VLE of CO2/COS and density of CO2/NH3; there are only few points on VLE of CO2/NH3 and CO2/N2O, and density of binary mixtures containing CO, N2O4, COS and H2S. Several new models exhibit advantages for calculating PVTxy properties of CO2 mixtures. For example, Equation of State for Combustion Gases and Combustion Gas-like Mixtures (EOS-CG) shows better accuracy on both phase equilibrium and density than GERG-2008 except for the critical region. Peng-Robinson+ residual Helmholtz energy-based model (PR + EOS/(E,Wilson)(ares)) displays significant improvement in the representation of high-pressure critical region (deviation decreasing from 12.6% to 1% for CO2/O-2/N-2) and wider application of polar and non-polar mixtures for VLE.

  • 167.
    Dong, Shuaili
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. China Univ Petr, Beijing, Peoples R China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Zhang, Qi
    China Univ Petr, Beijing, Peoples R China..
    Yu, Zhixin
    Univ Stavanger, Dept Energy & Petr Engn, Stavanger, Norway..
    Volatility of electricity price in Denmark and Sweden2019In: INNOVATIVE SOLUTIONS FOR ENERGY TRANSITIONS / [ed] Yan, J Yang, HX Li, H Chen, X, ELSEVIER SCIENCE BV , 2019, p. 4331-4337Conference paper (Refereed)
    Abstract [en]

    Under the pressure of global environmental climate change, all countries in the world are developing renewable energy such as hydropower, wind energy, and solar energy As a result, the electricity price varies in different patterns depending on the penetration of renewable energy. In this paper, a non-parametric model is employed to analyze the historical data of electricity spot price from Danish price areas of the Nord Pool (with high percentage of wind power), Swedish price areas of the Nord Pool (with high percentage of hydropower) and PJM market (with little renewable energy penetrated). The objective is to deeply understand the influence of renewable energies on electricity price volatility. It is found that electricity prices are more stable in Swedish price areas as hydropower is a more stable energy source. The electricity price in PJM market is also comparatively stable, only more volatile than Swedish market, as fossil fuels are dominant energy resources. For Danish price areas, the volatility of electricity prices is clearly affected by wind power, which is a highly intermittent energy resource.

  • 168.
    Du, F.
    et al.
    Department of Electronic and Electric Engineering, University of Strathclyde, Glasgow, United Kingdom.
    Zhang, J.
    Department of Electronic and Electric Engineering, University of Strathclyde, Glasgow, United Kingdom.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Galloway, S.
    Department of Electronic and Electric Engineering, University of Strathclyde, Glasgow, United Kingdom.
    Lo, K. L.
    Department of Electronic and Electric Engineering, University of Strathclyde, Glasgow, United Kingdom.
    Modelling the impact of social network on energy savings2016In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 178, p. 56-65Article in journal (Refereed)
    Abstract [en]

    It is noted that human behaviour changes can have a significant impact on energy consumption, however, qualitative study on such an impact is still very limited, and it is necessary to develop the corresponding mathematical models to describe how much energy savings can be achieved through human engagement. In this paper a mathematical model of human behavioural dynamic interactions on a social network is derived to calculate energy savings. This model consists of a weighted directed network with time evolving information on each node. Energy savings from the whole network is expressed as mathematical expectation from probability theory. This expected energy savings model includes both direct and indirect energy savings of individuals in the network. The savings model is obtained by network weights and modified by the decay of information. Expected energy savings are calculated for cases where individuals in the social network are treated as a single information source or multiple sources. This model is tested on a social network consisting of 40 people. The results show that the strength of relations between individuals is more important to information diffusion than the number of connections individuals have. The expected energy savings of optimally chosen node can be 25.32% more than randomly chosen nodes at the end of the second month for the case of single information source in the network, and 16.96% more than random nodes for the case of multiple information sources. This illustrates that the model presented in this paper can be used to determine which individuals will have the most influence on the social network, which in turn provides a useful guide to identify targeted customers in energy efficiency technology rollout programmes.

  • 169.
    Du, Y.
    et al.
    College of Electronics and Information Engineering, Tongji University, Shanghai, China.
    Wang, C.
    College of Electronics and Information Engineering, Tongji University, Shanghai, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Song, Jingjing
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, B.
    School of Mechanical Engineering, Hubei University of Arts and Science, Hubei Province, China.
    Clustering heat users based on consumption data2019In: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, p. 3196-3201Conference paper (Refereed)
    Abstract [en]

    In today's district heating (DH) energy market, it is common to use user functional categories in price models to determine the heat price. However, users in the same category do not necessarily have the same energy consumption patterns, which potentially leads to unfair prices and many other practical issues. Taking into account heat usage characteristics, this work proposes two data-driven methods to cluster DH users to identify similar usage patterns, using practical energy consumption data. Efforts are focused on extracting representative features of users from their daily usage profiles and duration curves, respectively. Employing clustering based on these features, the resulting typical usage patterns and user category distributions are discussed. Our results can serve as potential inputs for future energy price models, demand-side management, and load reshaping strategies.

  • 170.
    Efstathiadis, T.
    et al.
    Aristotle Univ Thessaloniki, Greece.
    Kalfas, A. I.
    Aristotle Univ Thessaloniki, Greece.
    Seferlis, P.
    Aristotle Univ Thessaloniki, Greece.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Rivarolo, M.
    Univ Genoa, Italy.
    Geometry Optimization of Power Production Turbine For A Low Enthalpy (<= 100 degrees C) ORC System2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, p. 1624-1630Article in journal (Refereed)
    Abstract [en]

    The present paper is examining the geometry optimization of a power production turbine, in the range of 100kW(el), for a low enthalpy Organic Rankine cycle system (<= 100 degrees C). In the last years, accelerated consumption of fossil fuels has caused many serious environmental problems such as global warming, ozone layer destruction and atmospheric pollution. It is this reason that a growing trend towards exploiting low-enthalpy content energy sources has commenced and led to a renewed interest in small-scale turbines for Organic Rankine Cycle applications. The design concept for such turbines can be quite different from either standard gas or steam turbine designs. The limited enthalpic content of many energy sources imposes the use of organic working media, with unusual properties for the turbine. A versatile cycle design and optimization requires the parameterization of the main turbine design. There are many potential applications of this power-generating turbine, including geothermal and concentrate solar thermal fields or waste heat of steam turbine exhausts. An integrated model of equations has been developed, thus creating a model to assess the performance of an organic cycle for various working fluids such as R134a and isobutane-isopentane mixture. The most appropriate working fluid has been chosen, taking its influence on both cycle efficiency and the specific volume ratio into consideration. This choice is of particular importance at turbine extreme operating conditions, which are strongly related to the turbine size. In order to assess the influence of various design parameters, a turbine design tool has been developed and applied to define the geometry of blades in a preliminary stage. Finally, as far as the working fluid is concerned, the mixture of 85% isopentane-15% isobutane has been chosen as the most suitable fluid for the low enthalpy ORC system, since its output net power is 10% higher compared to the output net power of R134a. 

  • 171.
    Ekman, Peter
    et al.
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Röndell, Jimmie
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Yang, Ying
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Exploring smart cities and market transformations from a service-dominant logic perspective2019In: Sustainable cities and society, ISSN 2210-6707, Vol. 51, article id 101731Article in journal (Refereed)
    Abstract [en]

    This study addresses the emergence of new actors and their roles in the transformation of smart cities. By building on a Service-Dominant logic perspective, the study capture how smart city transformation is closely related to a smart market transformation. While prior conceptualizations of markets have followed a linear supply-demand structure, the new market conceptualization can be described as a service ecosystem. The study empirically follows the increased use of renewable energy, such as photovoltaic (PV) systems and their related services, as they are incorporated into smart cities. The results reveal that the overall interaction level among the involved actors increases as the energy market changes from a linear to a networked logic. This transition impacts the market's information quality and, subsequently, the actors’ level of required knowledge. The study shows that even if the prevailing actors become more informed, information needs to be ‘translated’ into ‘knowledge-in-context’ to become a valuable resource. Thus, the resulting service ecosystem demands a complementary actor that requires the role of a knowledge broker to function. The paper describes the mechanisms behind this smart city transformation and clarifies the broker functions.

  • 172.
    Epple, B.
    et al.
    Technische Universität Darmstadt.
    Lyngfelt, A.
    Chalmers University of Technology.
    Adanez, J.
    Department of Energy and Environment, Miguel Luesma Castán .
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    The 2nd International Conference on Chemical Looping 20122014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 113, p. 1827-1829Article in journal (Refereed)
  • 173.
    Farahmand Ghaffarpour, Mehdi
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Ros, Henrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Integration of thermochemical heat storage with a municipal district heating system: In future scenario with large variations in electricity price2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates the feasibility and benefits of integrating Thermochemical heat Storage (THS) into a CHP (Combined Heat and Power) plant. A case study is done for the CHP-plant in Sala, Sweden, with a maximum heat output of 20.9 MW and maximum electricity output of 9.6 MW. The THS type considered is calcium oxide in a hydroxide system. The fluctuations in electricity price for years 2020, 2030 and 2040 are considered and low-price electricity is used as a charging source for THS. During charging the superheated steam (endothermic reaction) is used to cover some of the district heating demand. The high temperature discharge from the THS is used as reheat in the Rankine cycle. The operations are modeled in Ebsilon and optimization is done in MATLAB using genetic algorithm with the objective to achieve maximum annual revenue. The results suggest that it is not feasible to introduce THS with electricity as a charging source in year 2020, but in 2030 and 2040 THS shows promising potential. The biggest increase in revenue comes from reduced fuel consumption, and, to a lesser extent, increased income from electricity. It is concluded that Calcium hydroxide is a promising candidate for integration into CHP during large electricity price fluctuation. The main drivers for the feasibility of this combination are high fuel price and large fluctuations of electricity price.

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    Integration of thermochemical heat storage with a municipal district heating system
  • 174.
    Farooq, U.
    et al.
    East China University of Science and Technology, Shanghai, China.
    Danish, M.
    East China University of Science and Technology, Shanghai, China.
    Lu, S.
    East China University of Science and Technology, Shanghai, China.
    Brusseau, M. L.
    The University of Arizona,Tucson, AZ, United States.
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Fu, X.
    East China University of Science and Technology, Shanghai, China.
    Zhang, X.
    East China University of Science and Technology, Shanghai, China.
    Sui, Q.
    East China University of Science and Technology, Shanghai, China.
    Qiu, Z.
    East China University of Science and Technology, Shanghai, China.
    Efficient transformation in characteristics of cations supported-reduced graphene oxide nanocomposites for the destruction of trichloroethane2017In: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 544, p. 10-20Article in journal (Refereed)
    Abstract [en]

    Experiments were conducted to investigate the use of graphene-oxide supported metallic nanocomposites for improving the degradation of trichloroethane (TCA) by sodium percarbonate (SPC). Two methods of production, chemical reduction (CR) and solvo-thermal (ST), were tested for preparation of single (Fe) and binary (Fe-Cu) nanocomposites supported by reduced graphene oxide (rGO). A variety of analytical techniques including N2 adsorption Brunauer-Emmett-Teller (BET), x-ray diffraction (XRD), fourier-transfrom infrared spectroscopy (FTIR), and transmisison electron microscopy (TEM) were applied to characterize the physicochemical and microstructural properties of the synthesized nanocomposites. The characterization indicated that the CR method produced nanocomposites that comprised only mesoporous structure. Conversely, both micro and mesoporous structures were present for samples produced with the ST method. The synthesized single and bimetallic composites produced from the ST method showed higher surface areas, i.e. 93.6 m2/g and 119.2 m2/g as compared to the ones synthesized via the CR method, i.e. 13.8 m2/g and 38.0 m2/g respectively. The results of FTIR and XRD analyses confirmed that the ST method produced highly crystalline nanocomposites. SEM and TEM analysis validated that metallic particles with definite morphology well distributed on the surface of rGO. X-ray photoelectron spectroscopy (XPS) analysis confirmed the homogeneity nanocomposites and occurrence of variation in copper oxidation states during degradation process. EDS mapping validate the homogeneous distribution of Cu and Fe at reduced graphene oxide surface. The Fe-Cu/rGO (ST) activated SPC system effectively degraded TCA (92%) in 2.5 h at low nanocomposite dose compared to the Fe-Cu/rGO (CR) and only Fe, for which the maximum degradation efficiencies achieved were 81% and 34%. In conclusion, excellent catalytic characteristics were observed for the ST-synthesized single and bimetallic (Fe/rGO, Fe-Cu/rGO) catalysts. These catalysts were successful in improving the degradation of TCA via activated SPC. 

  • 175.
    Farooq, U.
    et al.
    East China University of Science and Technology, Shanghai, China.
    Danish, M.
    University of Engineering and Technology Lahore, Faisalabad Campus, Pakistan.
    Lu, S.
    East China University of Science and Technology, Shanghai, China.
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Qiu, Z.
    East China University of Science and Technology, Shanghai, China.
    Sui, Q.
    Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
    A step forward towards synthesizing a stable and regeneratable nanocomposite for remediation of trichloroethene2018In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 347, p. 660-668Article in journal (Refereed)
    Abstract [en]

    Synthesizing supported heterogeneous catalysts is always considered as a persistent approach for degradation of contaminants. However, the stability of these nanocomposites and improvement of process conditions influencing target pollutants degradation are still limited. Herein, on the basis of self-adhesive nature of polydopamine (PDA) and its strong electrostatic interaction with metallic ions, we synthesized a facile, stable, magnetically separable, and environmentally benign PDA decorated, reduced graphene oxide (rGO) supported Fe nanocatalyst (PDA@Fe/rGO). The effects of process variables (pH, PDA@Fe/rGO, and persulphate (PS) dose) on the degradation performance of trichloroethene (TCE), a model chlorinated organic pollutant selected in this study, were investigated. PDA not only encapsulated the host Fe/rGO magnetic particles but also exhibited high magnetization. PDA wrapping tremendously enhanced the thermal stability of nanocatalyst with just 24.1% weight loss at elevated temperature compared to solo Fe/rGO (40.2%). Moreover, TCE degradation mechanism was interpreted by ESR and radical scavenger tests, validating OH[rad], SO4 [rad]− and O2 [rad]− radicals being responsible for TCE degradation. Considering its eminent catalytic activity, simple synthesis approach and excellent kinetics, this recyclable and improved PDA assisted Fe/rGO nanocatalyst further opens a door for practical implementation in the field of contaminated groundwater remediation. 

  • 176.
    Farooq, Usman
    et al.
    East China Univ Sci & Technol, China..
    Danish, Muhammad
    East China Univ Sci & Technol, China..
    Lu, Shuguang
    East China Univ Sci & Technol, China..
    Naqvi, Muhammad
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Gu, Xiaogang
    East China Univ Sci & Technol, China..
    Fu, Xiaro
    East China Univ Sci & Technol, China..
    Zhang, Xiang
    East China Univ Sci & Technol, China..
    Nasir, Muhammad
    COMSATS Inst Informat Technol, IRCBM, Lahore, Pakistan..
    Synthesis of nZVI@reduced graphene oxide: an efficient catalyst for degradation of 1,1,1-trichloroethane (TCA) in percarbonate system2017In: Research on chemical intermediates (Print), ISSN 0922-6168, E-ISSN 1568-5675, Vol. 43, no 5, p. 3219-3236Article in journal (Refereed)
    Abstract [en]

    Graphene-oxide-supported nano zero-valent iron (nZVI) composite (nZVI-rGO) was synthesized and tested as an efficient percarbonate activator for degradation of 1,1,1-trichloroethane (TCA). Significant dispersion of nZVI on the surface of reduced graphene oxide (rGO) was observed, with good limitation of nanoparticle agglomeration and aggregation. Good TCA degradation efficiency of 90% was achieved in 2.5 h in presence of 0.8 g/l nZVI-rGO catalyst and 30 mM sodium percarbonate (SPC) oxidant; however, excessive catalyst or oxidant concentration reduced the degradation efficiency. Investigation of reactive oxygen species using radical probe compounds as well as radical scavengers confirmed presence of hydroxyl (OH center dot) and superoxide () radicals that are responsible for the TCA degradation. The morphology and surface characteristics of the heterogeneous catalyst were analyzed by transmission electron microscopy and scanning electron microscopy. Brunauer-Emmett-Teller analysis revealed that the synthesized catalyst had large surface area and small particle size of 299.12 m(2)/g and 20.10 nm, respectively, compared with 5.33 m(2)/g and 1.12 A mu m for bare graphene oxide. X-ray diffraction analysis revealed good dispersion of nZVI on the surface of rGO. Fourier-transform infrared characteristic peaks confirmed strong attachment of Fe onto the rGO surface. Energy-dispersive spectroscopy analysis validated the stoichiometric composition of the prepared Fe/rGO material. In conclusion, use of nZVI-rGO-activated SPC could represent an alternative technique for remediation of TCA-contaminated groundwater.

  • 177.
    Farrokh, Mohammad
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mahmoudi, Jafar
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Modeling and Simulation of a DiasporeTubular Digestion Process2013In: International Journal of Simulation and Process Modelling, ISSN 1740-2123, E-ISSN 1740-2131, Vol. 33, no 2, p. 126-133Article in journal (Refereed)
    Abstract [en]

    A simulation model is developed to predict the performance of a tubular digestion process of a low alumina/silica ratio diaspore bauxite type. The electrolyte - NRTL property method is used to calculate the equilibrium and thermodynamic properties of the slurry. The Aspen Plus simulator has been employed to solve the reaction and thermodynamic submodels. The model was validated with several sets of the industrial experimental data in terms of the flash tanks temperatures and close agreement was found. The simulation model has been utilized by the R&D department to predict the digestion process behaviour at various operation conditions. One practical output of this work is suggestion for a new design to increase the vapour and thermal energy recovery in the digestion process unit. As a result, the exhaust vapour from the last flash tank was directed to a new pre-heater section. The industrial output has been confirmed by the energy department that has decreased 8% in the furnace fuel consumption and leads to an increase of water recovery in the digestion unit.

  • 178.
    Fell, Terence
    et al.
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Guziana, Bozena
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stad, rättvisa och boendesegregering: Stadsområdesutveckling i Eskilstuna och Västerås 2002–20122016Report (Other academic)
    Abstract [sv]

    Denna forskningsrapport studerar den socioekonomiska utvecklingen mellan 2002 och 2012 i sammanlagt 46 stadsområden i Eskilstuna och Västerås. Studien bidrar till en nyansering av boendesegregeringsdebatten genom att introducera en ny mellankategori (mezzo) av stadsområden. Med hänsyn tagen till välfärd och medborgarkapital kategoriseras stadsområdena som sämre ställda, mezzo och bättre ställda. Stadsområdenas kontext (sysselsättning, utanförskap och etnicitet), underliggande processer (gentrifiering och filtrering) och klassanalys lyfts fram för att förklara förändringar i stadsområdenas status.

    I Eskilstuna har antalet bättre ställda stadsområden ökat med fyra, mezzo har ökat med två medan sämre ställda områden har minskat med två. I Västerås stad har antal bättre ställda stadsområden fördubblats, medan de sämre ställda områdena har minskat med nästan hälften och antalet mezzo-områden är oförändrat. Den överlag positiva utvecklingen till trots låter tillämpningen av ett rättviseperspektiv skönja vissa brister, som exempelvis socioekonomisk polarisering och statuscementering. Idag finns det färre stadsområden med billiga hyreslägenheter än tidigare.

    Utmaningen för politiker och tjänstemän ligger i att både stödja sämre ställda stadsområden i deras utveckling mot mezzo-status och att undvika filtrering eftersom en sådan fördröjer och i värsta fall förhindrar en utveckling mot social hållbarhet. Därför bör största möjliga ekonomiska jämlikhet mellan samtliga stadsområden utgöra ytterligare ett villkor som den socialt hållbara staden måste uppfylla.

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  • 179.
    Fell, Terence
    et al.
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Guziana, Bozena
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Elander, Ingemar
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Klass, rumslig segration och livskvalitet i två svenska städer2019In: Statsvetenskaplig Tidskrift, ISSN 0039-0747, Vol. 121, no 1, p. 65-93Article in journal (Refereed)
    Abstract [en]

    Against a background of decades of spatial class segregation in Sweden and elsewhere, and with the Swedish city as our empirical base, we demonst rate how classposition effects residents’ life chances defined here as health, security, participation, and education. By comparing the circumstances of affluent neighbourhoodsin both cities with those of disadvantaged neighbourhoods we elucidate important changes in a modern city’s class hierarchy like increased social polarization.We conclude, firstly, that those neighbourhoods that change class position do soslowly and are becoming predominantly middle class. Secondly, we show that thesituation in both cities’ low income neighbourhood category varies dramatically.Finally, and in contradiction with mainstream urban theory, we infer that growingsocial inequality is not always detrimental to the lives of residents in disadvantagedneighbourhoods

  • 180.
    Fell, Terence
    et al.
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Guziana, Bozena
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Qaderi, Josef
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Stadsdelsutveckling i två kommuner (del 2): En analys av byråkraters syn på implementering av åtgärder för ökad social hållbarhet2014Report (Other academic)
    Abstract [sv]

    Föreliggande forskningsrapport är den andra rapporten om hållbar stadsdelsutveckling inom ramen för Samhällskontraktets samverkansområde hållbar samhällsutveckling (HSU). Studien bygger på intervjuer med tjänstemän och utförare som direkt eller indirekt har varit inblandade i utvecklingsprojekt i stadsdelen Bäckby i Västerås eller bostadsområdet Lagersberg i Eskilstuna. I fokus står de intervjuades uppfattning om framgångstro, kompetens, resurser, intressen och samverkansgrad. Delvis tar studien sin utgångspunkt i den första rapporten Stadsdelsutveckling i två kommuner: En analys av den socioekonomiska- och sociokulturella kontextens betydelse för social hållbarhet (MDH SiSS-rapport 2013:2), som dels presenterar en kartläggning av tidigare urbana satsningars erfarenheter och dels en analys av Bäckby och Lagersberg.

    De intervjuade respondenterna har delats in i tjänstemän och utförare eftersom de verkar i olika operativa kontexter. Tjänstemännen har ett övergripande ansvar för att genomföra policy, medan utförarna är den sista länken i policyprocessen gentemot omgivande samhälle. Begreppet byråkrater används då vi syftar på både tjänstemän och utförare.

    Den övergripande slutsatsen från studien är att tjänstemännens intresse och tillgång till resurser som pengar, tid, personal lokaler och utrustning är viktiga faktorer för framgångstro, medan utförarnas upplevda brist på resurser kan ha en negativ inverkan på kommunens förmåga att styra utvecklingen i berörda stadsområden.

    Flödet i kommunikation och samverkan mellan politiker, tjänstemän, utförare och samhällsaktörer kan förbättras. Att öka denna samverkan skulle kunna underlätta en god socioekonomisk utveckling och minska utanförskapet i de två områdena. Bron mellan stadshuset och stadsdelarna kan stärkas, bland annat genom att representanter från föreningar och lokala näringar deltar i redan etablerade workshops och arbetsgruppsträffar. Särskilt bör kulturföreningar uppmärksammas. De är viktiga ur ett demokratiperspektiv och är beroende av kommunens stöd. Ett problem kan dock utgöras av att de byråkrater som samverkar i stor omfattning också är de som i större utsträckning anser att valda åtgärder har sämre förutsättningar att lyckas.

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  • 181.
    Fell, Terence
    et al.
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Qaderi, Josef
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Lahdenperä, Jori
    Mälardalen University, School of Business, Society and Engineering. Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Guziana, Bozena
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stadsdelsutveckling i två kommuner: En analys av den socioekonomiska och sociokulturella utvecklingens betydelse för social hållbarhet2014Report (Other academic)
    Abstract [sv]

    Denna forskningsrapport är en del i ett samverkansprojekt som tar sin utgångspunkt i redan genomförda eller pågående utvecklingsprojekt i stadsdelen Lagersberg i Eskilstuna och bostadsområdet Bäckby i Västerås. Inom ramen för Samhällskontraktet – en plattform för samverkan mellan Mälardalens högskola, Eskilstuna kommun och Västerås stad – har en kartläggning av ovannämnda satsningars erfarenheter och nyvunna kunskaper slutförts och presenteras i denna rapport.

    Tidigare forskning och insikter från samverkan med berörda tjänstemän från båda kommunerna har legat till grund för en analysmodell. Modellen tar hänsyn till såväl kommunernas specifika samhällskontext som till andra faktorer som påverkar kommunernas genomförande av handlingsplaner.

    Förutom modellen utvecklas i rapporten en matris som fångar stadsdelarnas olika positioner med avseende på deras socioekonomiska och sociokulturella utveckling. Matrisen kallas för SUND (Sustainable Underprivileged Neighbourhood Development) och mäter hur hållbar den sociala utvecklingen är i utsatta bostadsområden och/eller stadsdelar. Ett samband mellan hög grad av mångetnicitet och en god ekonomisk och/eller sociokulturell utveckling förklarar delvis varför samma åtgärd får olika genomslagskraft i olika stadsdelar. Områden som kännetecknas av relativ låg grad av mångetnicitet kännetecknas, å andra sidan, av lågt socialt kapital och stagnerad socioekonomisk utveckling.

    Jämfört med andra områden som ingår i studien finns det fortfarande ett stort utrymme för Eskilstuna kommun att få till en god socioekonomisk och sociokulturell utveckling i området. Stadsdelen Bäckby bör vara mån om att bevara och på sikt förbättra en redan relativt god socioekonomisk utveckling och har utrymme för att ytterligare påverka den sociokulturella utvecklingen. Bäckbys utveckling över en tolvårsperiod (2000–2012) är relativt stabil i relation till Västerås stad, medan det socioekonomiska gapet mellan stadsdelen Lagersberg och Eskilstuna kommun växer under samma tidsperiod.

    Utvecklingen i stadsdelen Hallunda/Norsborg visar att det finns stor potential för Västerås stad och Eskilstuna kommun att ändra det nuvarande läget i både Lagersberg och Bäckby. Båda kommunerna visar att utvecklingen i mångetniska stadsdelar och bostadsområden inte alltid behöver stödjas av en ny eller förnyad lagstiftning, eller andra nationella satsningar. Genom resultaten från egna utvärderingar och tillämpbara forskningsresultat är kommunerna fullt kapabla att välja ”rätt” åtgärder och insatser.

    Den positiva socioekonomiska och sociokulturella utvecklingen i Lagersberg och Bäckby kan vara hållbar endast om stadsdelen och/eller bostadsområdet gagnas av den på lång sikt. Från ett hela-staden-perspektiv gynnas kommunen av att de boende är mer välutbildade, även om de flyttar till andra mer attraktiva områden, så länge det sker inom kommunens gränser. Från ett områdesperspektiv leder denna utflyttning däremot till en veritabel ”braindrain”, som kan minska områdets konkurrenskraft och öka områdets och de boendes utsatthet. Kommuner bör av detta skäl eftersträva att exempelvis nyutexaminerade studenter och företagare flyttar in eller bor kvar i områden som Lagersberg och Bäckby.

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  • 182.
    Feng, J. -C
    et al.
    School of Engineering, Sun Yat-Sen University, Guangzhou, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. School of Chemical Science and Engineering, Royal Institute of Technology, Teknikringen 42, Stockholm, Sweden.
    Yu, Z.
    School of Engineering, Sun Yat-Sen University, Guangzhou, China.
    Zeng, X.
    School of Engineering, Sun Yat-Sen University, Guangzhou, China.
    Xu, W.
    School of Engineering, Sun Yat-Sen University, Guangzhou, China.
    Case study of an industrial park toward zero carbon emission2018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 209, p. 65-78Article in journal (Refereed)
    Abstract [en]

    Industrial park shoulders heavy responsibilities for economic development, and in the meantime, acts the role as energy consumer and carbon emitter. Under the background of holding the average global temperature increase limited in 2 °C compared to the pre-industrial level, which was proposed in the Paris Agreement, the development of zero carbon emission at the industrial park level is of great importance. This study investigated how to realize zero carbon emission at an industrial park level. In addition, a practical case study of the Southern China Traditional Chinese Medicine Industrial Park located in the Zhongshan City, Guangdong Province of China was conducted. Scenario analyses were projected to realize zero carbon emission in this industrial park and the results show that zero carbon emission can be realized under all the three scenarios. Economic assessments found that purchasing carbon offsets get the minimum cost effectiveness under current market situation. However, purchasing carbon offset may not be the best choice from the aspect of absolute reduction. Sensitivity analyses illustrate that the cost effectiveness of carbon reduction is remarkably influenced by the carbon price and solar energy cost reduction ratio. Meanwhile, applying large-scale renewable energy and producing more carbon offset can harvest more economic and carbon reduction benefits when the current solar energy cost has been reduced by 90%. Moreover, challenges of building zero-carbon industrial park as well as the corresponding solution schemes were discussed.

  • 183.
    Fentaye, Amare D.
    et al.
    Universiti Teknologi PETRONAS, Malaysia.
    Baheta, Aklilu T.
    Universiti Teknologi PETRONAS, Malaysia.
    Gilani, Syed I.
    Universiti Teknologi PETRONAS, Malaysia.
    Kyprianidis, Konstantinos
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A Review on Gas Turbine Gas-Path Diagnostics: State-of-the-Art Methods, Challenges and Opportunities2019In: Aerospace, ISSN 2226-4310, Vol. 6, no 7, article id 83Article in journal (Refereed)
    Abstract [en]

    Gas-path diagnostics is an essential part of gas turbine (GT) condition-based maintenance (CBM). There exists extensive literature on GT gas-path diagnostics and a variety of methods have been introduced. The fundamental limitations of the conventional methods such as the inability to deal with the nonlinear engine behavior, measurement uncertainty, simultaneous faults, and the limited number of sensors available remain the driving force for exploring more advanced techniques. This review aims to provide a critical survey of the existing literature produced in the area over the past few decades. In the first section, the issue of GT degradation is addressed, aiming to identify the type of physical faults that degrade a gas turbine performance, which gas-path faults contribute more significantly to the overall performance loss, and which specific components often encounter these faults. A brief overview is then given about the inconsistencies in the literature on gas-path diagnostics followed by a discussion of the various challenges against successful gas-path diagnostics and the major desirable characteristics that an advanced fault diagnostic technique should ideally possess. At this point, the available fault diagnostic methods are thoroughly reviewed, and their strengths and weaknesses summarized. Artificial intelligence (AI) based and hybrid diagnostic methods have received a great deal of attention due to their promising potentials to address the above-mentioned limitations along with providing accurate diagnostic results. Moreover, the available validation techniques that system developers used in the past to evaluate the performance of their proposed diagnostic algorithms are discussed. Finally, concluding remarks and recommendations for further investigations are provided.

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  • 184.
    Foskolos, Georgios
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lennerhag, Oscar
    Independent Insulation Group, Ludvika, Sweden.
    Ackeby, Susanne
    DNV-GL Energy, Göteborg, Sweden.
    Evaluation of conservation voltage reduction - a comparison based method2018In: 2018 53rd International Universities Power Engineering Conference (UPEC), Proceedings, IEEE, 2018, p. 1-5, article id 474Conference paper (Refereed)
    Abstract [en]

    Conservation voltage reduction (CVR) is based onthe premise that conserving energy by reducing voltage levels of the electrical system will lead to reduced electrical energy consumption. In this work a comparison-based method has been applied for assessing CVR effects in a distribution grid. The reference voltage on the secondary side of the primary substation was manually altered according to a predefined schedule during 6 months, that is, perform CVR on a substation and apply “normal” voltage to the same substation with a 2-week interval between the changes. Measurements (1 second RMS-values for voltages, active powers and reactive powers) and analysis were made at the 11 kV side of a 130/11 kV transformer of a primary substation, on outgoing feeders and at the 400 V side of 11/0.4 kV distribution transformers downstream of the primary substation as well as on downstream single rural and industrial customers. Active power at different reference voltage levels versus 24 hours divided into 10 minute intervals for reoccurring days of the week were plotted and analysed.

    This work confirms the difficulties in obtaining predictable loads over time and to accurately analyse the load composition on all grid levels. Each are needed in order to quantify the effects of CVR and by extension optimising the grid operations without violating the power quality.

  • 185.
    Freidank, Tim
    et al.
    Ostfalia University of Applied Sciences, Germany.
    Drescher-Hartung, Silvia
    Ostfalia University of Applied Sciences, Germany.
    Behnsen, Andreas
    Ostfalia University of Applied Sciences, Germany.
    Lindmark, Johan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Ahrens, Thorsten
    Ostfalia University of Applied Sciences, Germany.
    MIDTERM OUTPUT REPORT – PILOT B IN SWEDEN2014Report (Other academic)
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  • 186.
    Frost, Anna. E.
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Maher, Azaza
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Patterns and temporal resolution in commercial and industrial typical load profiles2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 2684-2689Article in journal (Refereed)
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  • 187.
    Galanopoulos, Christos
    et al.
    Bremen Univ, Inst Environm Sci & Technol, D-28359 Bremen, Germany..
    Yan, Jinying
    KTH Royal Inst Technol, Chem Engn, SE-10044 Stockholm, Sweden.;Vattenfall AB, R&D, SE-16992 Stockholm, Sweden..
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Liu, Longcheng
    KTH Royal Inst Technol, Chem Engn, SE-10044 Stockholm, Sweden..
    Impacts of acidic gas components on combustion of contaminated biomass fuels2018In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 111, p. 263-277Article in journal (Refereed)
    Abstract [en]

    The formation of high concentrations of acid gases; in combustion with large variations in fuel qualities, represents a major challenge for energy production from contaminated biomass fuels. This paper provides a comprehensive evaluation of the effects of acid gas formation and retention in the combustion of recycled wood fuels. A model has been developed based on the chemical reactions involved and empirical correlations from plant monitoring and testing. The model has been used to study the behaviour of acidic gas components in critical stages of a bubbling fluidised bed boiler process. Results indicate that the variation in type of fuel contamination is the most important issue to deal with in the combustion of recycled wood fuels. Peaks in the flue gas chlorine concentrations cannot be suppressed easily by conventional flue gas cleaning measures. Upon applying ammonium sulphate dosing for the protection of chlorine induced corrosions, it is sometimes difficult to maintain the required S/Cl ratio when large variations of fuel chlorine occur. Moreover, a high level of chlorine in the fuel can also indirectly affect the emission control of sulphur dioxide because it would require an increased level of ammonium sulphate decomposition, which results in a high level of SO2 in flue gas. The study also shows a beneficial effect of the recirculation of quench water from the flue gas condenser to the boiler. It offers opportunities for the optimisation of flue gas cleaning and flue gas condensation, for improving the efficiencies of water and wastewater treatment, as well as for emission reduction with a sustainable way.

  • 188.
    Gao, X.
    et al.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Wei, P.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Xie, Y.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Zhang, S.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Niu, Z.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Lou, Y.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Yang, Xiaohu
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Institute of Technology (KTH), Stockholm, Sweden; School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Jin, L.
    School of Human Settlements and Civil Engineering, Xi'An Jiaotong University, Xi'an, China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Institute of Technology (KTH), Stockholm, Sweden.
    Experimental investigation of the cubic thermal energy storage unit with coil tubes2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, p. 3709-3714Article in journal (Refereed)
    Abstract [en]

    This study presented experimental investigations on the thermal performance of a thermal energy storage (TES) unit with coil tubes. A designed test rig was built and the melting heat transfer characteristics (melting front and temperature distribution) inside the TES unit were examined. The effects of charging flow rate on the overall phase change process were examined. The results showed that natural convection accelerated the thermal energy transport in the melt phase in the top region, but weakened the heat transfer in the bottom region; this resulted in the unmelt PCM at the bottom. The melting heat transfer was overall enhanced by the increase in inlet flow rate, indicating that the full charging time can be shortened by a larger flow rate. 

  • 189.
    Gehandler, Jonatan
    et al.
    SP Fire Research.
    Ingason, Haukur
    SP Fire Research.
    Lönnermark, Anders
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. SP Fire Research.
    Fratzich, Håkan
    Lunds tekniska högskola.
    Strömgren, Michael
    SP Fire Research.
    Performance-based design of road tunnel fire safety: Proposalof new Swedish framework2014In: Case Studies in Fire Safety, ISSN 2214-398X, Vol. 1, p. 18-28Article in journal (Refereed)
    Abstract [en]

    This paper contains a proposal of new Swedish framework for performance-based design ofroad tunnel fire safety derived from Swedish and European regulation. The overall purposeof the guideline is to protect life, health, property, environment, and key societal functionsfrom fire. The guideline is structured into five key groups of requirements: #1 Proper managementand organisation, #2 to limit the generation and spread of fire and smoke, #3 toprovide means for safe self-evacuation, #4 to provide means and safety for the rescue service,and #5 to ensure load-bearing capacity of the construction. Each group contains ahybrid of prescriptive requirements, performance-based requirements, and acceptablesolutions. Prescriptive requirements must be fulfilled, however, it is the choice of thedesign team to either adopt the proposed acceptable solutions, or to design alternativesolutions by verifying that performance-based requirements are satisfied. For verificationof performance-based requirements through risk analysis the operational, epistemic, andaleatory uncertainties are considerable. Therefore, a scenario-based risk analysis with severalspecified input variables and methods is recommended for verification of #3 and #5.Indispensable complements are scenario exercises, emergency exercises and similar methodsthat validate the design and highlight organisational aspects. The proposed designguide has been developed by the authors together with the advisory group establishedfor the work.

  • 190.
    Geng, Y.
    et al.
    Shanghai Jiaotong University, Shanghai, China .
    Wei, Y. -M
    Beijing Institute of Technology, Beijing, China.
    Fischedick, M.
    Wuppertal Institute for Climate, Energy and Environment, Germany.
    Chiu, A.
    De La Salle University, Philippines .
    Chen, B.
    Royal Institute of Technology (KTH), Sweden.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Recent trend of industrial emissions in developing countries2016In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 166, p. 187-190Article in journal (Refereed)
    Abstract [en]

    Greenhouse gas (GHG) emissions from industrial sectors are increasing, particularly in the developing world where pursuing industrialization has been highly addressed. This calls for further studies to learn and share experiences for developing countries. In order to fill in such a research gap, this special issue focuses on examining the recent trend of industrial emissions in developing countries. Among the manuscripts submitted to the Special Issue, twelve papers have been accepted after review, covering assessment indicators, tools and methods, and policies. Key industrial sectors, including cement, lime, aluminum, coal, mining, glass, soda ash, etc, have been investigated. Valuable policy insights have been raised, including wide scale upgrading, replacement and deployment of best available technologies, integrated information platforms, cross-cutting technologies and measures, a shift to low carbon electricity, radical product innovations, carbon dioxide capture and storage (CCS), demand on new and replacement products, systematic approaches and collaboration among different industries. These useful suggestions could be shared or learned by industrial policy makers or managers in the developing world so that the overall GHG emissions from their industrial sectors can be mitigated by considering the local realities.

  • 191.
    Ghaviha, Nima
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Energy Optimal Operation of Electric Trains: Development of a Driver Advisory System2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The electric traction system used in trains is the most energy efficient traction system in the transportation sector. Moreover, it has the least NOx and CO2 emissions in comparison to other transportation systems (e.g. busses, passenger cars, airplanes, etc.). On the other hand, they are extremely expensive, mainly due to high installation and maintenance cost of the catenary system, including e.g. overhead lines and substations. Consequently, the share of electrified lines is only slightly higher than non-electrified lines. For instance in Europe, 60% of the railway networks are electrified, and the percentage is much lower in other continents. Battery driven trains are a new generation of electric trains that can overcome such high costs while keeping CO2 emissions and energy consumption low.At the moment, there are only two battery driven electric trains developed and both of the trains are passenger electric multiple units (EMUs). An EMU is an electric train with a traction system in more than one wagon, in contrast to loco-haul electric trains which have a traction system in one wagon only. Energy management during the operation of battery driven trains is a crucial task, as energy optimal operation of trains considering the optimal use of batteries can increase both the operating time and the lifetime of batteries. Energy efficient train operation is realized using driver advisory systems (DAS) that instructs drivers on how to drive trains for minimum energy consumption. The aim of this research is to propose an algorithm for speed profile optimization of both EMUs and battery driven EMUs. The desired algorithm should be suitable as a core component for an online DAS with short response time.Several approaches are proposed in the literature for speed profile optimization of electric trains, and a few of these have been proposed for speed profile optimization of battery driven electric trains. The trains modeled in almost all of the approaches are trains using a notch system for controlling tractive effort. The proposed solution in this research project is to use discrete dynamic programming (DP) to find the optimum speed profile. The application of DP is studied for speed profile optimization of EMUs with a notch system as well as EMUs with a smooth gliding handle for controlling tractive effort. The problem is solved for both normal EMUs and battery driven EMUs.The results of this research show that DP can provide accurate results in a reasonably short time. Moreover, the proposed algorithm can be used as a base for a DAS with fast response time (real-time).

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  • 192.
    Ghaviha, Nima
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Increasing Energy Efficiency in Electric Trains Operation: Driver Advisory Systems and Energy Storage2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Electric traction is the most efficient traction system in the railway transportation. However, due to the expensive infrastructure and high power demand from the grid, the share of electric trains in the railway transportation is still lower than other trains. Two of the possible solutions to increase the share of electric trains are: optimal train operation to minimize energy consumption, the use of batteries as the energy source for driving electric trains on non-electrified lines. This thesis aims to extend the knowledge in the field of energy optimal operation of electric trains and battery-driven electric trains.

    Energy optimal operation of electric trains is supervised using a driver advisory system (DAS), which instructs the driver to operate the train in an energy-efficient manner. This thesis contributes to DAS technology under two topics: the increase of energy efficiency and the design of DAS.

    This thesis presents a complete procedure of designing a DAS from the mathematical formulation to application on the train. The designed DAS is in the form of an Android application and is based on a dynamic programming approach. The computational performance of the approach is enhanced using heuristic state reducing rules based on the physical constraints of the system. The application of the DAS shows a potential reduction of 28% in energy consumption.

    This thesis considers the detailed energy losses in the whole propulsion system using a regression model that is generated from validated physical models. The application of the regression model instead of a previous constant efficiency factor model results in 2.3% reduction in energy consumption of the optimum speed profiles.

    Based on the solution for the normal electric trains, a solution is also offered for the optimal operation of battery-driven electric trains, in which the characteristics of the battery as one of the main components are considered using an electrical model. The solution presented in this thesis, is to combine the popular single mass point train model with an electrical circuit battery model.

    Furthermore, this thesis evaluates the performance of the optimization approaches and validates the models against the measurements from actual drives of a real-life battery train. The results show a potential of around 30% reduction in the charge consumption of the battery.

    The results of this thesis (algorithms and the Android application) are provided as open source for further research in the field of energy efficient train control.

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  • 193.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, M.
    RISE SICS, Västerås, Sweden.
    Holmberg, C.
    Bombardier Transportation, Västerås, Swede.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Skoglund, Robert
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Jonasson, Daniel
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A driver advisory system with dynamic losses for passenger electric multiple units2017In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 85, p. 111-130Article in journal (Refereed)
    Abstract [en]

    Driver advisory systems, instructing the driver how to control the train in an energy efficient manner, is one the main tools for minimizing energy consumption in the railway sector. There are many driver advisory systems already available in the market, together with significant literature on the mathematical formulation of the problem. However, much less is published on the development of such mathematical formulations, their implementation in real systems, and on the empirical data from their deployment. Moreover, nearly all the designed driver advisory systems are designed as an additional hardware to be added in drivers’ cabin. This paper discusses the design of a mathematical formulation and optimization approach for such a system, together with its implementation into an Android-based prototype, the results from on-board practical experiments, and experiences from the implementation. The system is based on a more realistic train model where energy calculations take into account dynamic losses in different components of the propulsion system, contrary to previous approaches. The experimental evaluation shows a significant increase in accuracy, as compared to a previous approach. Tests on a double-track section of the Mälaren line in Sweden demonstrates a significant potential for energy saving.

  • 194.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Speed profile optimization of an electric train with on-board energy storage and continuous tractive effort2016In: 2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion, SPEEDAM 2016, 2016Conference paper (Refereed)
    Abstract [en]

    Electric traction system is the most energy efficient traction system in railways. Nevertheless, not all railway networks are electrified, which is due to high maintenance and setup cost of overhead lines. One solution to the problem is battery-driven trains, which can make the best use of the electric traction system while avoiding the high costs of the catenary system. Due to the high power consumption of electric trains, energy management of battery trains are crucial in order to get the best use of batteries. This paper suggests a general algorithm for speed profile optimization of an electric train with an on-board energy storage device, during catenary-free operation on a given line section. The approach is based on discrete dynamic programming, where the train model and the objective function are based on equations of motion rather than electrical equations. This makes the model compatible with all sorts of energy storage devices. Unlike previous approaches which consider trains with throttle levels for tractive effort, the new approach considers trains in which there are no throttles and tractive effort is controlled with a controller (smooth gliding handle with no discrete levels). Furthermore, unlike previous approaches, the control variable is the velocity change instead of the applied tractive effort. The accuracy and performance of the discretized approach is evaluated in comparison to the formal movement equations in a simulated experimented using train data from the Bombardier Electrostar series and track data from the UK.

  • 195.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of a Battery Train Using Dynamic Programming2015Conference paper (Other academic)
    Abstract [en]

    Electric propulsion system in trains has the highest efficiency compared to other propulsion systems (i.e. steam and diesel). Still, electric trains are not used on all the routes, due to the high setup and maintenance cost of the catenary system. Energy storage technologies and the battery driven trains however, make it possible to have the electric trains on the non-electrified routes as well. High energy consumption of the electric trains, makes the energy management of such trains crucial to get the best use of the energy storage device. This paper suggests an algorithm for the optimal control of the catenary free operation of an electric train equipped with an onboard energy storage device. The algorithm is based on the discrete dynamic programming and Bellman’s backward approach. The objective function is to minimize the energy consumption, i.e. having the maximum battery level left at the end of the trip. The constraints are the trip time, battery capacity, local speed limits and limitations on the traction motor. Time is the independent variable and distance, velocity and battery level are the state variables. All of the four variables are discretized which results in some inaccuracy in the calculations, which is discussed in the paper. The train model and the algorithm are based on the equations of motion which makes the model adjustable for all sorts of electric trains and energy storage devices. Moreover, any type of electrical constraints such as the ones regarding the voltage output of the energy storage device or the power output can be enforced easily, due to the nature of the dynamic programming. 

  • 196.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Mälardalen University.
    Bohlin, Markus
    Research Institutes of Sweden RISE SICS Västerås.
    Holmberg, Christer
    Bombardier Transportation.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Speed Profile Optimization of Catenary-free Electric Trains with Lithium-ion Batteries2019In: Journal of Modern Transportation, ISSN 2095-087X, Vol. 3, no sept, p. 153-168Article in journal (Other academic)
    Abstract [en]

    Catenary-free operated electric trains, as one of the recent technologies in railwaytransportation, has opened a new field of research: speed profile optimization and energy optimaloperation of catenary-free operated electric trains. A well-formulated solution for this problem shouldconsider the characteristics of the energy storage device using a validated model and method. This paper,discusses the consideration of the battery behavior in the problem of speed profile optimization ofcatenary-free operated electric trains. We combine the single mass point train model with an electricalbattery model and apply a dynamic programming approach to minimize the charge taken from thebattery during the catenary-free operation. The models and the method are validated and evaluatedagainst experimental data gathered from the test runs of an actual battery driven train tested in Essex,UK. The results show a significant potential in energy saving. Moreover, we show that the optimumspeed profiles generated using our approach consume less charge from the battery compared to theprevious approaches.

  • 197.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    SICS - swedish institute of computer science, Sweden.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    AN ALGORITHM FOR OPTIMAL CONTROL OF AN ELECTRIC MULTIPLE UNIT2014In: Proceedings from The 55th Conference on Simulation and Modelling (SIMS 55),21-22 October, 2014. Aalborg, Denmark, Linköping: Linköping University Electronic Press, 2014Conference paper (Refereed)
    Abstract [en]

    This paper offers a solution for the optimal EMU train (Electric Multiple Unit) operation with the aim of minimizing the energy consumption. EMU is an electric train with traction motors in more than one carriage. The algorithm is based on dynamic programming and the Hamilton-Jacobi-Bellman equation. To model the train, real data has been used, which was provided by experts from Bombardier Transportation Västerås. To evaluate the model, some experiments have been done on the energy saving in exchange for the increase in the trip time. Moreover a simple accuracy factor is introduced to evaluate the accuracy of the model. The final goal is to use this approach as a base for a driver advisory system, therefore it is important to have the amount of calculations as minimum as possible. The paper also includes the studies done on the calculation time. The solution can be used for driverless trains as well as normal trains. It should be mentioned that this paper is a part of a research which is still in progress and the final model will also be used by Bombardier Transportation Västerås as an evaluation tool for the propulsions systems and trains.

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  • 198.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    SICS Swedish ICT, Sweden.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of an EMU Using Dynamic Programming2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, p. 1913-1919Article in journal (Refereed)
    Abstract [en]

    A model is developed for minimizing the energy consumption of an electric multiple unit through optimized driving style, based on Hamilton-Jacobi-Bellman equation and Bellman's backward approach. Included are the speed limits, track profile (elevations), different driving modes and the train load. This paper includes aspects like the power loss in the auxiliary systems, time management, validation of the model regarding energy calculations and a study on discretization and the accuracy of the model. The model will be used as a base for a new driver advisory system. 

  • 199.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of an EMU Using Dynamic Programming and Tractive Effort as the Control Variable2015In: Proceedings of the 56th SIMS, Linköping University Electronic Press, Linköpings universitet, 2015, p. 377-382Conference paper (Refereed)
    Abstract [en]

    Problem of optimal train control with the aim of minimizing energy consumption is one of the old optimal control problems. During last decades different solutions have been suggested based on different optimization techniques, each including a certain number of constraints or different train configurations, one being the control on the tractive effort available from traction motor. The problem is previously solved using dynamic programming for trains with continuous tractive effort, in which velocity was assumed to be the control variable. The paper at hand presents a solution based on dynamic programming for solving the problem for trains with discrete tractive effort. In this approach, tractive effort is assumed to be the control variable. Moreover a short comparison is made between two approaches regarding accuracy and ease of application in a driver advisory system.

  • 200.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Campillo, Javier
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Review of Application of Energy Storage Devices in Railway Transportation2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 4561-4568Article in journal (Refereed)
    Abstract [en]

    Regenerative braking is one of the main reasons behind the high levels of energy efficiency achieved in railway electric traction systems. During regenerative braking, the traction motor acts as a generator and restores part of the kinetic energy into electrical energy. To use this energy, it should be either fed back to the power grid or stored on an energy storage system for later use. This paper reviews the application of energy storage devices used in railway systems for increasing the effectiveness of regenerative brakes. Three main storage devices are reviewed in this paper: batteries, supercapacitors and flywheels. Furthermore, two main challenges in application of energy storage systems are briefly discussed. 

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