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  • 551.
    Tran, Ha-Vu
    et al.
    Univ Quebec, ETS Engn Sch, LACIME Lab, Montreal, PQ H3C 1K3, Canada..
    Kaddoum, Georges
    Univ Quebec, ETS Engn Sch, LACIME Lab, Montreal, PQ H3C 1K3, Canada..
    Tran, Hung Vinh
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hong, Een-Kee
    Kyung Hee Univ, Sch Elect & Informat, Yongin 449701, South Korea..
    Downlink Power Optimization for Heterogeneous Networks with Time Reversal-based Transmission under Backhaul Limitation2017Ingår i: IEEE Access, E-ISSN 2169-3536, ISSN 21693536, Vol. 5, s. 755-770Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we investigate an application of two different beamforming techniques and propose a novel downlink power minimization scheme for a two-tier heterogeneous network (HetNet) model. In this context, we employ time reversal (TR) technique to a femtocell base station (FBS) whereas we assume that a macrocell base station (MBS) uses a zero-forcing-based algorithm and the communication channels are subject to frequency selective fading. Additionally, HetNet's backhaul connection is unable to support a sufficient throughput for signaling information exchange between two tiers. Given the considered HetNet model, a downlink power minimization scheme is proposed, and closed-form expressions concerning the optimal solution are provided, taking this constraint into account. Furthermore, considering imperfect channel estimation at TR-employed femtocell, a worst-case robust power minimization problem is formulated. By devising TR worst-case analysis, this robust problem is transformed into an equivalent formulation that is tractable to solve. The results presented in our paper show that the TR technique outperforms the zero-forcing one in the perspective of beamforming methods for femtocell working environments. Finally, we validate the proposed power loading strategy for both cases of perfect and imperfect channel estimations .

  • 552.
    Tran, Hung Vinh
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Kaddoum, G.
    University of Québec, France.
    Gagnon, F.
    University of Québec, France.
    Sibomana, L.
    Blekinge Institute of Technology, Karlskrona, Sweden.
    Cognitive radio network with secrecy and interference constraints2017Ingår i: Physical Communication, ISSN 1874-4907, E-ISSN 1876-3219, Vol. 22, s. 32-41Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we investigate the physical-layer security of a secure communication in single-input multiple-output (SIMO) cognitive radio networks (CRNs) in the presence of two eavesdroppers. In particular, both primary user (PU) and secondary user (SU) share the same spectrum, but they face with different eavesdroppers who are equipped with multiple antennas. In order to protect the PU communication from the interference of the SU and the risks of eavesdropping, the SU must have a reasonable adaptive transmission power which is set on the basis of channel state information, interference and security constraints of the PU. Accordingly, an upper bound and lower bound for the SU transmission power are derived. Furthermore, a power allocation policy, which is calculated on the convex combination of the upper and lower bound of the SU transmission power, is proposed. On this basis, we investigate the impact of the PU transmission power and channel mean gains on the security and system performance of the SU. Closed-form expressions for the outage probability, probability of non-zero secrecy capacity, and secrecy outage probability are obtained. Interestingly, our results show that the strong channel mean gain of the PU transmitter to the PU's eavesdropper in the primary network can enhance the SU performance. 

  • 553.
    Varini, Maria
    et al.
    KTH Royal Inst Technol, Stockholm, Sweden..
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH Royal Inst Technol, Sweden..
    Lindbergh, Goran
    KTH Royal Inst Technol, Stockholm, Sweden..
    A semi-empirical, electrochemistry-based model for Li-ion battery performance prediction over lifetime2019Ingår i: Journal of Energy Storage, E-ISSN 2352-152X, Vol. 25, artikel-id UNSP 100819Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Predicting the performance of Li-ion batteries over lifetime is necessary for design and optimal operation of integrated energy systems, as electric vehicles and energy grids. For prediction purposes, several models have been suggested in the literature, with different levels of complexity and predictability. In particular, electrochemical models suffer of high computational costs, while empirical models are deprived of physical meaning. In the present work, a semi-empirical model is suggested, holding the computational efficiency of empirical approaches (low number of fitting parameters, low-order algebraic equations), while providing insights on the processes occurring in the battery during operation. The proposed model is successfully validated on experimental battery cycles: specifically, in conditions of capacity fade > 20%, and dynamic cycling at different temperatures. A comparable performance to up-to-date empirical models is achieved both in terms of computational time, and correlation coefficient R-2. In addition, analyzing the evolution of fitting parameters as a function of cycle number allows to identify the limiting processes in the overall battery degradation for all the protocols considered. The model suggested is thus suitable for implementation in system modelling, and it can be employed as an informative tool for improved design and operational strategies.

  • 554.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Bartusch, Cajsa
    Dahlquist, Erik
    Differences in electricity and hot water consumption in apartments of different sizes2008Konferensbidrag (Refereegranskat)
  • 555.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Bartusch, Cajsa
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    A simulation model of the interactions between power producers and customers2008Ingår i: Conference proceedings SIMS 2008 in Oslo, October 7-8, 2008 / [ed] Bernt Lie, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    We have had a strong mechanism for interaction between power production companies and the power trading/supplier companies for a number of years by now. In the future we can expect new types of more interactive communications between single customers and groups of customers towards the energy market companies. We can expect a stronger request side from customers to buy only green energy, only nuclear etc.

    Power (kW) will be a part aside of energy (kWh) and there will be new possibilities to buy energy when it is as cheap as possible. This may include new applications like charging batteries for your car when the electricity price is low. Differentiation of price may be not only as a direct function of time, but also energy availability like when it is windy, as wind power becomes a major part of many energy systems. Energy storage will be more important and perhaps we will get new possibilities to buy shares in central energy storages like you buy space at servers for your web-pages etc.

    Other type of functions may develop as a result of the introduction of individual metering of first electricity and later on hot water and temperature. By metering the individual consumption and invoicing just what has been spent, you will have a driving force also to do actions like shutting of high demand functions like “infra-heating”, “large screen TV” and similar, when other usages are on, and the price is high. We expect displays with interaction possibilities in all homes, where you can see your consumption and pricing information.

    These new type of systems will put new demands on both hardware for supply and software to handle the services/functions. As part of developing this, mathematical modelling of the systems and tests with simulators will be an important tool. Also new soft ware functions will be developed to support the actual services, like simulators giving information on how different actions you make as a user will influence your energy consumption in the future, both short term and more long term. For the more long term case, new investments in new hardware and software may be proposed and evaluated for you in both technical and economic terms.

    In this paper the system aspects including the costs is analysed through a simulation model. This includes the physical system as well as the user behaviour and possible effects of different price models, like a combination of kW and kWh. The effect on the users, the distributors and the power producers are evaluated.

  • 556.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Campillo, Javier
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tecnol Bolivar Univ, Fac Engn, Cartagena 130001, Colombia..
    Adoption barriers for electric vehicles: Experiences from early adopters in Sweden2017Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 120, s. 632-641Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electric vehicles are considered as one of the most effective technologies for reducing current greenhouse gas emissions from the transport sector. Although in many countries, local and national governments have introduced incentives and subsidies to facilitate the electric vehicle market penetration, in Sweden, such benefits have been limited. Results from a survey carried out among private owners of electric vehicles are presented in this paper, including the analysis of the respondents socio-demographic characteristics, reasons for choosing an electric vehicle, charging locations and driving preferences, among others. The main results characterize current electric vehicle drivers as male, well-educated, with medium-high income; electric vehicles are used mainly for private purposes and charged at home during night time. Furthermore, the paper presents an analysis of the impact of large-scale penetration of electric vehicles on existing power distribution systems. The findings presented in this paper provide important insights for assuring a sustainable large-scale penetration of electric vehicles by learning from the experiences of early adopters of the technology and by analyzing the impact of different EV penetration scenarios on the power distribution grid.

  • 557.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Campillo, Javier
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Technology assessment of the two most relevant aspects for improving urban energy efficiency identified in six mid-sized European cities from case studies in Sweden2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 94, s. 808-818Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increasing population living in cities is leading to higher resource utilization, which strains the cities’ability to focus on sustainability. Adoption of different technologies can transform cities into ‘‘smartcities” that utilize energy in a more efficiently.This paper presents results from a technology assessment tool developed together with six mid-sizedEuropean cities. The main areas of focus have been evaluated based on the cities’ priorities: transportation(both public and private) and consumers’ perspectives on the use of smart electricity meters. The useof electric vehicles in Sweden, and a techno-economic evaluation of biogas-derived biomethane and electricityuse in public transportation have been analyzed. The main conclusions show an overall higher efficiencyfor biogas-derived electricity use in electric buses; a need for higher consumer engagementthrough more detailed information provision for both increasing EV market penetration and electricitysavings; and a need to establish detailed technology assessments for successful technology adoption incities.

  • 558.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Campillo, Javier
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    The citizens' role in energy smart city development2016Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 88, s. 200-204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of the paper was to investigate citizens' experiences and feedback related to strategies and products targeting energy savings and emission reduction in Sweden. Survey results presented in this paper showed that consumers did not make use of the advantages of the smart meters and that tailored feedback is necessary to help them save electricity. Moreover, despite the high satisfaction levels among electric vehicles owners, additional improvements (e.g. reliable charging infrastructure) and information are needed to attract potential owners. Effective information dissemination is thus a crucial part of increasing urban sustainability. 

  • 559.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    The impact of consumers' feedback preferences on domestic electricity consumption2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 93, nr SI, s. 575-582Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite all initiatives introduced for maximizing energy savings domestic energy consumption is in constant increase. However, very little investigation has been carried out on the integration of household' consumption trends, the parameters influencing them and the characteristics of the provided feedback. 2000 Swedish households were included in this study. Electricity consumption data for apartments and houses has been analyzed for a 4 year period as well as possible household socio-economic factors affecting it. The data has been further compared to other households located in different cities in Sweden. The effects of the different ways of presenting feedback used for the different households groups have also been evaluated. From the results obtained from the questionnaire used, several households' characteristics were proposed together with consumers' preferences to be considered during the development of feedback. Web based feedback resulted in being the most effective (when compared to display and bills), achieving electricity savings of approximately 15% within households that visited the web-site. The monthly income is amongst the most influential factors determining electricity consumption although only in high and low income groups

  • 560.
    Vassileva, Iana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Analytical comparison between electricity consumption and behavior characteristics of Swedish households in rented apartments2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 90, nr SI, s. 182-188Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sufficient data of electricity consumption during large periods of time are accumulated and analyzed in order to develop appropriate electricity-saving measures. An important first step is to analyze and identify buildings/households that have an energy saving potential. In this work an evaluation of monthly electricity consumption data was conducted in identical buildings in the city of Vasteras in Sweden. Different behavioral consumption profiles have been analyzed using information from two sources: technical data of electricity consumption and behavioral parameters for each household obtained from a questionnaire survey. The questionnaire was formed by three groups of questions which concerned residents' characteristics, type and usage of electrical appliances, and attitudes towards energy consumption. The results show that electricity consumption profile of individual household can be mostly related to a given parameter. For example, the total household's income resulted one of the important factors determining the consumer behavior and as a rule is related to higher electricity consumption. Another important conclusion of our questionnaire-based analysis is the necessity for more detailed information about household/tenants behavior specifying the technical features of appliances for a given household.

  • 561.
    Vedde, Jan
    et al.
    SiCon.
    Richter, Mauricio
    Tjendgdrawira, Caroline
    KU Leuven.
    Herteleer, Bert
    KU Leuven och CAT Projects.
    Herz, Magnus
    TÜV Rheinland Energie und Umwelt GmbH.
    Jahn, Ulrike
    TÜV Rheinland Energie und Umwelt GmbH.
    Stridh, Bengt
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB Corporate Research.
    Frearson, Lyndon
    CAT Projects.
    Green, Mike
    M.G. Lightning ltd.
    Technical Parameters Used in PV Financial Models: Review and Analysis2016Ingår i: 32nd European Photovoltaic Solar Energy Conference and Exhibition, 2016, s. 2897-2902, artikel-id 7DO.14.4Konferensbidrag (Refereegranskat)
    Abstract [en]

    When photovoltaic (PV) projects are developed and constructed for investment purposes, financing from professional investors and banks are required, and financial models are developed that describe the expected cash-flow generated by the PV plant over the economic lifetime of the project. The calculation is based on models that require both technical and financial inputs. In this paper we will review and analyse the technical assumptions in these models and discuss how the technical assumptions are typically used and to what extent the uncertainty related to the input parameters are appropriately addressed. Finally, a calculation and visualisation method is presented that highlights the nature and effect of this uncertainty.

  • 562.
    Wahlberg, Tobias
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Modeling of Heat Transfer2011Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Modeling of heat transfer using Dymola. In this report a evaporator, economizer and superheater where modeled. The report describes how the models where modeled and what input was most suitable for a accurate model.

  • 563.
    Walde, Fredrik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Metod för analys av elförbrukning i hushåll2009Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 564.
    Wallenbert, Henrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Energiprisstrukturens inverkan på val av energieffektiviseringsåtgärder: En analys av trender inom el- och fjärrvärmeprissättning och dess inverkan på effektiviseringsåtgärder i bostadsbeståndet2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I detta arbete har syftet varit att hitta de vanligaste energieffektiviseringsåtgärderna som görs idag i det svenska bostadsbeståndet. Energieffektiviseringsåtgärderna påverkar effekttoppar i flerbostadshus och har undersökts. Om det antas att energiprisstrukturen går mot en mer effektbaserad taxa kan åtgärderna få större påverkan på energipriset i framtiden. I arbetet har varmvattnets andel av timeffekttoppar undersökts, med stöd av energianvändningsdata från 15 anonymiserade flerbostadshus med fjärrvärme.

    Energianvändningen i bostadsbeståndet står för ca 40 % av Sveriges energianvändning. Det ställs då krav på de lågenergihus som byggs idag och vid renovering av hus att möta Sveriges som såväl EU 2020 målet att minska energianvändningen i bostäder genom att implementera energieffektiviseringsåtgärder.

    De vanligaste energieffektiviseringsåtgärderna i flerbostadshus har varit isolering av väggar och vind, installation av energiglas och frånluftssystem med värmeåtervinning. En sänkt inomhus temperatur har även medtagits. För fastighetsägare av flerbostadshus, där energianvändning för uppvärmning och varmvatten domineras av fjärrvärme är prisutvecklingen viktig. Om i framtiden ett antagande görs att el och fjärrvärmepriset övergår från en energibaserad taxa kr/kWh till en mer effektbaserad taxa kr/kW där kunden betalar för de högsta effekttopparna under ett år. I denna studie redovisas det när effekttoppar uppstår och vilka energieffektiviseringsåtgärder som påverkar effekttopparna i flerbostadshus. De högsta effekttopparna uppstår oftast under vinterårstiden då uppvärmningsbehovet är störst.

    I ett framtaget typbostadshus där de valda energiåtgärderna beräknades, det visade sig att energiglas minskar effektbehovet och effektpriset mest, därefter väggisolering med mineralull. Emellertid ger energiglas och väggisolerings åtgärderna ger förluster i lönsamhetsberäkningen. Det skiljer sig från tilläggsisolering med mineralull av vinden och sänkt inomhus temperatur som har en investerings vinst över en 40 års period. I beräkningarna användes temperaturdata från år 2012 både på typhuset innan och efter implementerad åtgärd.En viktig parameter vid minskning av uppvärmningsbehovet är U-värdet. Tilläggsisolering av vind samt sänkt temperatur är de åtgärder som rekommenderas då båda påverkar effektbehovet och ger en lönsam investering. Åtgärd vid fönster och väggar minskar dock uppvärmningsbehovet mest men ger en olönsam ekonomisk investering.

    Varmvattenandelen av den högsta timeffekttoppen över året togs fram genom att jämföra baslasten och effekttoppen under dagen då effektbehovet är som högst. Resultatet visade att varmvattenandelen av effekttoppen tycks variera mellan ca 10- 50 %. Varmvattenandelen av effekttoppen varierar stort och därför föreslås användningen av metoden i detta examensarbete istället för ett schablonvärde på 20 % vid undersökning av varmvattenandelen av timeffekttoppen.

  • 565.
    Wallin, Fredrik
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Torstensson, Daniel
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kovala, Tommy
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sandberg, Alexander
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Using an Energy Intervention Framework to Evaluate End-User Willingness to Participate in Demand-Response Activities2016Ingår i: IEEE Power and Energy Society General Meeting, Vol 2016, 2016, artikel-id 7741517Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes the results from implementing an energy intervention framework, a novel method to evaluate consumers' willingness to participate in demand-response actions. An energy intervention scenario encouraged consumers to change consumption behaviour during peak hours in December. Consumers' participation was measured through a web-based survey as well as using smart meter data. The study included 528 consumers divided into three groups: i) participation with economic compensation; ii) participation without economic compensation; and iii) control group. In total 106 households responded to the survey, 53 stated that they actively took part in the energy intervention. When analysing smart meter data it was evident that the groups that had received the intervention and confirmed their participation had lowered the load compared to the control group by 19%. The monetary incentive did not have a positive effect on either participation rate or reduced consumption. None of the participants claimed the economic compensation

  • 566.
    Wang, B
    et al.
    Mälardalens högskola. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Tianjin, Peoples R China..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Tianjin, Peoples R China..
    Yan, Jinying
    KTH Royal Inst Technol, Chem Engn, Stockholm, Sweden.;Vattenfall AB, R&D, Stockholm, Sweden..
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zhu, Kai
    Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Tianjin, Peoples R China..
    Modelling the Quench Tower in Flue Gas Cleaning of a Waste Fueled Power Plant2018Ingår i: JOINT INTERNATIONAL CONFERENCE ON ENERGY, ECOLOGY AND ENVIRONMENT ICEEE 2018 AND ELECTRIC AND INTELLIGENT VEHICLES ICEIV 2018, DESTECH PUBLICATIONS, INC , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    To control the emission of pollutants in the flue gas, a separated flue gas quench was added after flue gas desulfurization and before flue gas condensation. A mathematic model was developed to simulate the heat and mass transfer in the flue gas quench. The model was validated through the comparison with measured data. Based on this model, the impacts of inlet flue gas condition and injected recycling water flow rate on the water consumption of the quench and the temperature of exit flue gas (FG) were studied. The results show that the temperature of exit FG and water consumption increased with the increase of flow rate and moisture content of FG. The temperature of exit FG increased and the water consumption decreased with the increase of droplet water diameter. The temperature of exit FG decreased and the water consumption increased with the increase of water flow rate. In order to cooled and humidified the flue gas sufficiently, the droplet diameter should be limited to 1.2 mm and the water to FG flow rate ratio (L/G) higher than 2.

  • 567.
    Wang, Bin
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China..
    Yan, Jinying
    KTH Royal Inst Technol, Stockholm, Sweden..
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zhu, Kai
    Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China..
    Modelling the Quench Tower in Flue Gas Cleaning of a Waste Fueled Power Plant2018Ingår i: JOINT INTERNATIONAL CONFERENCE ON ENERGY, ECOLOGY AND ENVIRONMENT ICEEE 2018 AND ELECTRIC AND INTELLIGENT VEHICLES ICEIV 2018, DESTECH PUBLICATIONS, INC , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    To control the emission of pollutants in the flue gas, a separated flue gas quench was added after flue gas desulfurization and before flue gas condensation. A mathematic model was developed to simulate the heat and mass transfer in the flue gas quench. The model was validated through the comparison with measured data. Based on this model, the impacts of inlet flue gas condition and injected recycling water flow rate on the water consumption of the quench and the temperature of exit flue gas (FG) were studied. The results show that the temperature of exit FG and water consumption increased with the increase of flow rate and moisture content of FG. The temperature of exit FG increased and the water consumption decreased with the increase of droplet water diameter. The temperature of exit FG decreased and the water consumption increased with the increase of water flow rate. In order to cooled and humidified the flue gas sufficiently, the droplet diameter should be limited to 1.2 mm and the water to FG flow rate ratio (L/G) higher than 2.

  • 568.
    Wang, C.
    et al.
    Tongji University, Shanghai, China.
    Du, Y.
    Tongji University, Shanghai, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Min, G.
    University of Exeter, Exeter, United Kingdom.
    New methods for clustering district heating users based on consumption patterns2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 251, artikel-id 113373Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Understanding energy users’ consumption patterns benefits both utility companies and consumers as it can support improving energy management and usage strategies. The rapid deployment of smart metering facilities has enabled the analysis of consumption patterns based on high-precision real usage data. This paper investigates data-driven unsupervised learning techniques to partition district heating users into separate clusters such that users in the same cluster possess similar consumption pattern. Taking into account the characteristics of heat usage, three new approaches of extracting pattern features from consumption data are proposed. Clustering algorithms with these features are executed on a real-world district heating consumption dataset. The results can reveal typical daily consumption patterns when the consumption linearly related to ambient temperature is removed. Users with heat usages that are highly imbalanced within a certain period of time or are highly consistent with the utility heat production load can also be grouped together. Our methods can facilitate gaining better knowledge regarding the behaviors of district heating users and hence can potentially be used to formulate new pricing and energy reduction solutions.

  • 569.
    Wang, C.
    et al.
    Shandong University, China.
    He, Z.
    Shandong University, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wennerstern, R.
    Shandong University, China.
    Sun, Q.
    Shandong University, China.
    Evaluation on Performance of a Phase Change Material Based Cold Storage House2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 3947-3952Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Technology of phase change materials used in cold storage house has great potential in energy storage and cost saving under the background of peak and valley price of electricity. A kind of cold storage house based on water/ice as phase change material was set up and studied. Performance of this cold storage house was experimentally tested and numerical simulated. The results showed that water/ice is a promising material for its high latent heat density. Cold storage house with water/ice PCM shifts electricity load to off-peak load and then increase operating cost due to peak load power pricing. In addition, water/ice PCM increases the insulation effect and then reduces the cold energy needed. The payback period of water/ice PCM in a laboratory scale is about 4.1 years in this study. 

  • 570.
    Wang, C.
    et al.
    Tianjin University, Tianjin, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH, Stockholm, Sweden.
    Marnay, C.
    Lawrence Berkeley National Laboratory, CA, United States.
    Djilali, N.
    University of Victoria, Victoria, Canada.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Wu, J.
    Cardiff University, Cardiff, United Kingdom.
    Jia, H.
    Tianjin University, Tianjin, China.
    Distributed Energy and Microgrids (DEM)2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 210, s. 685-689Artikel i tidskrift (Refereegranskat)
  • 571. Wang, C.
    et al.
    Zeng, L.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Lundgren, J.
    Potential Carbon Dioxide Emission Reduction in China by Using Swedish Bioenergy Technologies2006Ingår i: GHGT-8 Conference, 2006Konferensbidrag (Refereegranskat)
  • 572.
    Wang, F.
    et al.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Deng, S.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Zhao, J.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Wang, J.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Sun, T.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin University, Ministry of Education of China, Tianjin, China; Royal Institute of Technology, Stockholm, Sweden.
    Performance and economic assessments of integrating geothermal energy into coal-fired power plant with CO2 capture2017Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 119, s. 278-287Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel carbon capture and storage system integrated with geothermal energy was proposed to reduce energy consumption in the post-combustion CO2 capture (PCC) process. Geothermal energy at medium temperature was used to provide the heat required for solvent regeneration. A technical and economic assessment was conducted based on a 300 MWe coal-fired power plant. Additionally, the integrated system was also compared with a stand-alone geothermal power (GP) plant to evaluate individual advantages. Both an enhanced geothermal system (EGS) and a hot sedimentary aquifer (HSA) reservoir were selected to identify the effect of geological properties and heat characteristics on system performance. The results indicated that the geothermal-assisted post-combustion CO2 capture (GPCC) plant exhibited better performance than the PCC plant. The net plant average efficiency increased 5.56% and 4.42% in the EGS scenario and HSA scenario, respectively. Furthermore, the net incremental geothermal efficiency obtained corresponded to 21.34% and 20.35% in the EGS scenario and HSA scenario, respectively. The economic assessment indicated that the GPCC systems in both the EGS scenario and HSA scenario had lower marginal cost of electricity (70.84 $/MWh and 101.06 $/MWh) when compared with that of the stand-alone GP systems (151.09 $/MWh and 101.95 $/MWh). 

  • 573.
    Wang, F.
    et al.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zhao, J.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Deng, S.
    Tianjin University, Ministry of Education of China, Tianjin, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    Technical and economic analysis of integrating low-medium temperature solar energy into power plant2016Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 112, s. 459-469Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to mitigate CO2 emission and improve the efficiency of the utilization of solar thermal energy (STE), solar thermal energy is proposed to be integrated into a power plant. In this paper, seven configurations were studied regarding the integration of STE. A 300 MWe subcritical coal-fired plant was selected as the reference, chemical absorption using monoethanolamine solvent was employed for CO2 capture, and parabolic trough collectors and evacuated tube collectors were used for STE collection. Both technical analysis and economic evaluation were conducted. Results show that integrating solar energy with post-combustion CO2 capture can effectively increase power generation and reduce the electrical efficiency penalty caused by CO2 capture. Among the different configurations, Config-2 and Config-6, which use medium temperature STE to replace high pressure feedwater without and with CO2 capture, show the highest net incremental solar efficiency. When building new plants, integrating solar energy can effectively reduce the levelized cost of electricity (LCOE). The lowest LCOE, 99.28 USD/MWh, results from Config-6, with a parabolic trough collector price of 185 USD/m2. When retrofitting existing power plants, Config-6 also shows the highest net present value (NPV), while Config-2 has the shortest payback time at a carbon tax of 50 USD/ton CO2. In addition, both LCOE and NPV/payback time are clearly affected by the relative solar load fraction, the price of solar thermal collectors and the carbon tax. Comparatively, the carbon tax can affect the configurations with CO2 capture more clearly than those without CO2 capture. 

  • 574.
    Wang, F.
    et al.
    Key Laboratory of Efficient Utilization of Low and Medium Grade Energy (Tianjin University), Ministry of Education of China, Tianjin, China.
    Zhao, J.
    Key Laboratory of Efficient Utilization of Low and Medium Grade Energy (Tianjin University), Ministry of Education of China, Tianjin, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Ningbo RX New Materials Tech. Co., Ltd., Ningbo, China.
    Deng, S.
    Key Laboratory of Efficient Utilization of Low and Medium Grade Energy (Tianjin University), Ministry of Education of China, Tianjin, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Key Laboratory of Efficient Utilization of Low and Medium Grade Energy (Tianjin University), Ministry of Education of China, Tianjin, China.
    Preliminary experimental study of post-combustion carbon capture integrated with solar thermal collectors2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 185, s. 1471-1480Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The amine-based chemical absorption for CO2 capture normally needs to extract steam from the steam turbine cycle for solvent regeneration. Integrating solar thermal energy enables the reduction of steam extraction and therefore, can reduce the energy penalty caused by CO2 capture. In this paper, a pilot system of the solar thermal energy assisted chemical absorption was built to investigate the system performance. Two types of solar thermal energy collectors, parabolic trough and linear Fresnel reflector, were tested. It was found that the values of operation parameters can meet the requirements of designed setting parameters, and the solar collectors can provide the thermal energy required by the reboiler, while its contribution was mainly determined by solar irradiation. The solvent regeneration was investigated by varying the heat input. The results show that the response time of the reboiler heat duty is longer than those of the reboiler temperature and desorber pressure. This work provides a better understanding about the overall operation and control of the system.

  • 575.
    Wang, Fu
    et al.
    Tianjin Univ, Peoples R China.
    Zhao, Jun
    Tianjin Univ, Peoples R China.
    Li, Hao
    Tianjin Univ, Peoples R China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zhao, Li
    Tianjin Univ, Peoples R China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin Univ, Peoples R China; Royal Inst Technol, Stockholm, Sweden.
    Experimental study of solar assisted post-combustion carbon capture2015Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, s. 2246-2252Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Solar-assisted post-combustion carbon capture system is studied to compensate the energy penalty of coal-fired plant due to absorbent regeneration. The system is highly integrated with the amine-based carbon capture process coupled with solar thermal sub-system. The dynamic performance is largely affected by the variations of parameters and the fluctuations in solar collectors. An experimental facility of solar-assisted chemical absorption pilot with two types of collectors (parabolic trough and linear Fresnel) was constructed in this study. The impacts on the absorbent regeneration performance were studied on the dynamic variation of the solar heat and the operating temperature of the reboiler. The results show that an optimum ration of liquid-to-gas of 2.5-3.0 was determined at the lowest of the required regeneration energy. The study suggests that a better understanding of the key parameters associated with both capture process as well as the solar assisted sub-system if of importance for the overall operation and control.

  • 576.
    Wang, G.
    et al.
    China University of Petroleum-Beijing, Changping, Beijing, China.
    Zhang, Q.
    China University of Petroleum-Beijing, Changping, Beijing, China.
    Li, Y.
    China University of Petroleum-Beijing, Changping, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin University of Commerce, Tianjin, China.
    Policy simulation for promoting residential PV considering anecdotal information exchanges based on social network modelling2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 223, s. 1-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Surveys and empirical researches have revealed that the households’ perceptions of benefits play a more important role than the benefits themselves in the decision process of adopting residential photovoltaic (PV). However, it has been overlooked in previous models about the green technology diffusion. This work developed an innovation diffusion model based on a social network, which was integrated with an anecdotal information exchange process. The contributions were to model the households’ evaluation, which changes with social influence, and analyze the impact of such dynamics on the adoption of residential PV. A case study was conducted for villages in Beijing. Different scenarios about policies have been considered concerning both the economic benefits and the information diffusion on social network. The results show that: (1) Providing insurance against the damage of PV to adopters for free can improve the adoption rate from 24% up to 62% (full insurance), and the new adopter acquisition cost is only 36% of that of providing additional subsidy; (2) The enhancement of communications (e.g. Bulletin Board System (BBS) and Social Networking Services (SNS)) creates an obstacle to the residential PV adoption when the majority of households have insufficient knowledge about the PV system; and (3) Information campaigns and information screening are both effective and necessary in mitigating the negative effect from the enhancement of communications at the initial stage of the residential PV market. 

  • 577.
    Wang, Ge
    et al.
    China Univ Petr, Acad Chinese Energy Strategy, Beijing, Peoples R China..
    Zhang, Qi
    China Univ Petr, Acad Chinese Energy Strategy, Beijing, Peoples R China..
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Yan
    China Univ Petr, Acad Chinese Energy Strategy, Beijing, Peoples R China..
    Chen, Siyuan
    China Univ Petr, Acad Chinese Energy Strategy, Beijing, Peoples R China..
    The impact of social network on the adoption of real-time electricity pricing mechanism2017Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY / [ed] Yan, J Wu, J Li, H, ELSEVIER SCIENCE BV , 2017, s. 3154-3159Konferensbidrag (Refereegranskat)
    Abstract [en]

    The option menu of electricity tariffs is a compromise way for introducing real-time pricing (RTP) to consumers while remain the alternative fixed pricing (FP). Since it is difficult for a consumer to evaluate RTP and FP two tariffs because of the information asymmetry, and the acquaintances' opinions may play an important role when making a choice. This study aims to evaluate the impact of the social network on the diffusion of real-time electricity price using evolutionary game theoretical analysis. Consumers with heterogeneities in demand response capability and relationships in the social network are considered in an electricity market RTP and FP simultaneously. The consumers who adopt RTP can response to the varying price by shifting their electricity consumption to minimize their expenditures and inversely influence the price. As a case study, hundreds of scenarios of different initial conditions including social networks structures and update rules were analyzed and inter-compared using the developed model. The results show that: (i) the higher degree of the consumers social network, the slower the diffusion of RTP; (ii) increasing the proportion of consumers with high demand response capability can promote the adoption of RTP, implying the worth of promoting the utilization of smart home technology; (iii) a small exogenous probability (e.g. 1%) of the tariff choice mutation can accelerate the diffusion of RTP, indicating that the advertisement of RTP can be useful.

  • 578.
    Wang, Ge
    et al.
    China University of Petroleum, Beijing, China.
    Zhang, Qi
    China University of Petroleum, Beijing, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    McLellan, BC
    Kyoto University, Japan.
    Chen, Siyuan
    China University of Petroleum, Beijing, China.
    Li, Yan
    China University of Petroleum, Beijing, China.
    Tian, Yulu
    China University of Petroleum, Beijing, China.
    Study on the promotion impact of demand response on distributed PV penetration by using non-cooperative game theoretical analysis2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 185, nr 2, s. 1869-1878Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Promoting the penetration of distributed photovoltaic systems (PV) at the end-user side is an important and urgent task. This study aims to evaluate the promotion impact of the response capability of smart home consumers on the distributed PV penetration using non-cooperativegame theoretical analysis. In the analysis, the Nash equilibrium can be found for consumers with different levels of demand response capability in an electricity market with real-time pricing (RTP) mechanism under different PV installed capacities and battery capacities. As a case study, 5 levels of consumers' response capability, 32 combinations of PV installed capacities and battery capacities were analyzed and inter-compared using the developed model. The results show that: (i) the consumers with higher response capability are able to accept larger PV capacity because the marginal revenue of new installed PV for smart consumers decreases much more slowly compared to that of a common consumer; (ii) the consumers with higher response capability need less batteries to promote PV economic acceptability; (iii) the consumers with higher responsecapability can meet the electricity demand in real-time with least expenditure, so they get more ultimate benefit from the games.

  • 579.
    Wang, Ge
    et al.
    China University of Petroleum-Beijing, China.
    Zhang, Qi
    China University of Petroleum-Beijing, China.
    Mclellan, Benjamin C.
    Kyoto University, Japan.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Multi-region optimal deployment of renewable energy considering different interregional transmission scenarios2016Ingår i: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 108, s. 108-118Artikel i tidskrift (Refereegranskat)
  • 580.
    Wang, Ge
    et al.
    China Univ Petr, Peoples R China.
    Zhang, Qi
    China Univ Petr, Peoples R China.
    Tian, Ruijie
    China Univ Petr, Peoples R China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Combined Impacts of RTP and FIT on Optimal Management for a Residential Micro-Grid2015Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, s. 1666-1672Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Residential micro-grid can reduce the household's electricity expense as well as shift the electricity demand from peak time to valley time. Optimal management of a typical residential smart micro-grid is conducted using a proposed model in the present study. In the optimal management, the real-time pricing mechanism, feed-in-tariff for Photovoltaics (PV) power as residential electricity generators, and residential appliances are considered. Four scenarios are studied and the result shows that the real-time pricing mechanism shifts effectively the electricity consumption from time peak time to valley time, and different feed-in-tariff of Photovoltaic (PV) can shift the energy consumption of micro-grid between periods with strong solar irradiation and weak solar irradiation.

  • 581.
    Wang, Jianhui
    et al.
    Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA..
    Conejo, Antonio J.
    Univ Castilla La Mancha, Dept Elect Engn, E-13071 Ciudad Real, Spain..
    Wang, Chengshan
    Tianjin Univ, Sch Elect Engn & Automat, Tianjin 300072, Peoples R China..
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Inst Technol KTH, Dept Chem Engn & Technol Energy Proc, SE-10044 Stockholm, Sweden..
    Smart grids, renewable energy integration, and climate change mitigation - Future electric energy systems2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 96, s. 1-3Artikel i tidskrift (Övrigt vetenskapligt)
  • 582.
    Wang, L.
    et al.
    SINTEF Energy Research, Sem Saelends vei 11, Trondheim, Norway.
    Skreiberg, Ø.
    SINTEF Energy Research, Sem Saelends vei 11, Trondheim, Norway.
    Becidan, M.
    SINTEF Energy Research, Sem Saelends vei 11, Trondheim, Norway.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sintering of rye straw ash and effect of additives2014Ingår i: Energy Procedia, 2014, s. 2008-2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The effects of kaolin and calcite additives on the rye straw ash sintering behaviors were investigated. The rye straw ash has a high sintering tendency, with observation of severe fusion during combustion. The formation and melting of potassium silicates play key roles in sintering of the rye straw ash at elevated temperatures. Fusion characteristics temperatures of the rye straw ash were significantly increased upon kaolin and calcite addition. Kaolin addition led to formation of high temperature melting potassium aluminum silicates, which were revealed by XRD analyses. Due to formation of high temperature melting species due to kaolin addition, the severe sintering of the rye straw ash was significantly reduced. Addition of calcite provided CaO to react with silica in the rye straw ash, causing generation of high temperature melting calcium rich silicates. In addition, the dilution effect from calcite is a main reason for improved rye straw sintering behaviors.

  • 583.
    Wang, L.
    et al.
    SINTEF Energy Research, Trondheim, Norway.
    Skreiberg, Ø.
    SINTEF Energy Research, Trondheim, Norway.
    Khalil, R.
    SINTEF Energy Research, Trondheim, Norway.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Effect of fuel mixing on melting behavior of spruce wood ash2019Ingår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 1342-1347Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this work was to investigate effects of fuel mixing on melting behavior of spruce wood ash. Spruce bark was studied as additive fuel regarding its ability to lower the melting and flowing temperature of spruce wood ash. Standard ash fusion characterization tests were carried out on ashes from mixtures of spruce wood and bark after heating at 550 °C. The ash residues after the ash fusion tests were analyzed by using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX). High melting temperature and low sintering tendency of spruce wood ash was observed. It is mainly attributed to formation of calcium rich silicates with high melting temperatures. Upon mixing with 10 wt% bark, the melting temperature of the spruce wood ash considerably decreased, which flowed completely after the ash fusion test. Compared to spruce wood ash, SEM images showed that the ash from the mixture of spruce wood and bark passed a molten stage with formation of slag. SEM-EDX revealed that the concentration of silicon in the spruce wood ash increased as a result of mixing with spruce bark. It favors formation of low temperature melting potassium silicates.

  • 584.
    Wang, Liang
    et al.
    SINTEF Energy Research, Norway.
    Skreiberg, Øyvind
    SINTEF Energy Research, Norway.
    Becidan, Michael
    SINTEF Energy Research, Norway.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Investigation of rye straw ash sintering characteristics and the effect of additives2016Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 162, s. 1195-1204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The understanding of ash sintering during combustion of agricultural residues is far from complete, because of the high heterogeneity of the content and composition of ash forming matters and the complex transformation of them. In order to make agricultural residues competitive fuels on the energy market, further research efforts are needed to investigate agricultural residues' ash sintering behavior and propose relevant anti-sintering measures. The aim of this work was to investigate the ash characteristics of rye straw and effects of additives. Three additives were studied regarding their abilities to prevent and abate rye straw ash sintering. Standard ash fusion characterization and laboratory-scale sintering tests were performed on ashes from mixtures of rye straw and additives produced at 550°C.Ash residues from sintering tests at higher temperatures were analyzed using a combination of X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX). High sintering and melting tendency of the rye straw ash at elevated temperatures was observed. Severe sintering of the rye straw ash was attributed to the formation and fusion of low temperature K-silicates and K-phosphates with high K/Ca ratios. Among the three additives, calcite served the best one to mitigate sintering of the rye straw ash. Ca from the calcite promoted formation of high temperature silicates and calcium rich K-phosphates. In addition, calcite may hinder aggregating of ash melts and further formation of large ash slag. Therefore, the chemical reactions and physical restraining effects arose by calcite addition contributed to reduction of ash melts and sintering degree. Upon addition of kaolin, compositions of rye straw ash shifted from low temperature melting K-silicates to high temperature melting K-Al-silicates. The changes of ash chemistry were favorable for reducing sintering of the rye straw ash. As the Ca-sludge was added, reduction of sintering of the ryestraw ash was less pronounced. Only K4CaSi3O9 and a small amount of KCaPO4 were identified in the rye straw ash as Ca-sludge was added.

  • 585.
    Wang, S.
    et al.
    Zhejiang University, Hangzhou, China.
    Shao, C.
    Zhejiang University, Hangzhou, China.
    Ding, Y.
    Zhejiang University, Hangzhou, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    Operational reliability of multi-energy customers considering service-based self-scheduling2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 254, artikel-id 113531Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The developments of energy storage and substitution techniques have made it possible for customers to self-schedule their energy consumption behaviors, to better satisfy their demands in response to uncertain supply conditions. The interdependency of multiple energies, the chronological characteristics, and uncertainties in the self-scheduling context bring about additional complexities to secure the reliable energy requirements of multi-energy customers. As a necessary and challenging task, the operational reliability of multi-energy customers is tackled in this paper. Considering that the consumed energies eventually come down to the energy-related services, the self-scheduling of multi-energy customers is implemented from the perspective of specific energy-related services rather than energy carriers. Firstly, an optimal self-scheduling model for multi-energy customers is developed with the consideration of chronological service curtailment, service shifting and possible failures during service shifting. In the optimal self-scheduling model, the costs of service curtailment and shifting are formulated based on the proposed evaluation method. The time-sequential Monte Carlo simulation approach is applied to model the chronological volatilities of multi-energy demands over the entire study period, embedded with a scenario reduction technique to reduce the computational efforts. Taking full account of the possible scenarios, the quantitative reliability indices of the multi-energy customers can be obtained. The results in test cases demonstrate that the expected energy not supplied of the multi-energy customer drops significantly by 56.32% with the self-scheduling strategy. It can be also concluded that, the self-scheduling and its inherent uncertainties do have significant impacts on the operational reliability of the multi-energy customer.

  • 586.
    Wang, T.
    et al.
    East China University of Science and Technology, Shanghai, China.
    Liu, T.
    East China University of Science and Technology, Shanghai, China.
    Luan, W.
    East China University of Science and Technology, Shanghai, China.
    Tu, S. -T
    East China University of Science and Technology, Shanghai, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Performance Improvement of High-temperature Silicone Oil Based Thermoelectric Generator2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 1211-1218Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The recent advances in waste heat recovery technologies have provided great opportunities for energy conversion efficiency improvement. This paper proposed a metal foam filled thermoelectric generator (TEG) for the utilization of liquid waste heat resource. A prototype was designed and constructed to study the performance enhancement due to metal foam inserts. High-temperature oil based experiment was conducted to investigate the TEG performance in higher liquid temperature. The influences of hot oil inlet temperature and cold water flow rate were proved to be key operating parameters for the TEG performance. Specially, net power output and net power enhancement ratio were presented to assess the overall net power output performance. The metal foam filled TEG was demonstrated to outperform the unfilled TEG both in power generation efficiency and net power performance. In the experiments, the maximum power generation efficiency and net power enhancement ratio of metal foam inserted TEG were 2.49% and 1.33, respectively. 

  • 587.
    Wang, T.
    et al.
    Key Laboratory of Pressure Systems and Safety (MOE), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Luan, W.
    Key Laboratory of Pressure Systems and Safety (MOE), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Liu, T.
    Key Laboratory of Pressure Systems and Safety (MOE), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Tu, S. -T
    Key Laboratory of Pressure Systems and Safety (MOE), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. School of Chemical Science, KTH Royal Institute of Technology, Stockholm, Sweden.
    Performance enhancement of thermoelectric waste heat recovery system by using metal foam inserts2016Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 124, nr September, s. 13-19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposed a type of metal foams filled thermoelectric generator (TEG) for waste heat recovery. Metal foam inserts of three kinds of pore densities (5 PPI, 10 PPI and 20 PPI) were included, considering the heat transfer enhancing features of porous metal mediums. A flow channel detachable prototype was designed to experimentally investigate the influence of metal foams on the performance of thermoelectric waste heat recovery (TWHR) system. The operating parameters were further experimented to improve the thermoelectric power generation efficiency, including hot air inlet temperature, cold water flow rate, metal foam pore density and thermoelectric module (TEM) connecting mode. Moreover, the TWHR performance of the system was evaluated on power generation efficiency, heat exchange effectiveness and waste heat recovery rate, respectively. The results showed that filling metal foams in the flow channels could effectively enhance the performance of the TWHR system. The maximum power generation efficiency was 2.05%, when the TEG was filled with 5 PPI metal foams. It was 29.75% higher than the value of unfilled TEG.

  • 588.
    Wang, W.
    et al.
    Sun Yat-sen University, Guangzhou, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Guo, S.
    Inner Mongolia University of Science and Technology, Baotou, China .
    He, S.
    Guangzhou University, Guangzhou, China.
    Ding, J.
    Sun Yat-sen University, Guangzhou, China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Sun Yat-sen University, Guangzhou, China.
    Yang, J.
    South China University of Technology, Guangzhou, China.
    Numerical simulation study on discharging process of the direct-contact phase change energy storage system2015Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 150, s. 61-68Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mobilized thermal energy storage system (M-TES) has been demonstrated as a promising technology to supply heat using waste heat in industries to distributed users, where heat discharging determines whether M-TES system can satisfy the required heating rate. The objective of this work is to investigate the solidification mechanism of phase change materials (PCM) for heat discharging in a direct-contact thermal energy storage (TES) container for M-TES. A 2-dimensional (2D) numerical simulation model of the TES tank is developed in ANSYS FLUENT, and validated with the experimental measurement. Effects of flow rate and inlet temperature of heat transfer oil (HTO) were studied. Results show that (a) the discharging process includes the formation of solidified PCM followed by the sinking of solidified PCM; (b) the discharging time of M-TES can be reduced by increasing the flow rate of heat transfer oil. When the flow rate is increased from 0.46m3/h to 0.92m3/h, the solidified PCM is increased from 25vol.% to 90vol.% within 30min; (c) the discharging time can be reduced by decreasing the inlet temperature of HTO. While the inlet temperature is reduced from 50°C to 30°C, the solidified PCM is increased from 60vol.% to 90vol.% within 30min. This work provides engineering insights for the rational design of discharging process for M-TES system. 

  • 589.
    Wang, Weilong
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Preparation and performance of energy storage materials and application for recovery of industrial waste heat2009Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Due to the rapid increase of energy consumption and the environmental concerns on climate change caused by the fossil fuel combustion, it becomes a big issue on how to use alternative renewable energy resources to replace fossil fuel and to improve energy utilization efficiency. In Sweden, there are plenty of detached buildings without connection with district heating (DH) network, which use oil to supply the hot water for space heating and tap water. One way is to extend the district heating network for supply the heat for the detached houses. However, this will need increased costs for the district heat pipeline which might not be economically variable for the area with less density of population. Another alternative is to apply so called mobilized thermal energy storage (M-TES) to transport heat from, e.g. industrial waste heat, to the end-users of the detached houses. This will enable to keep the detached houses in the same state as a distributed heat system while replacing the fossil fuels for heating demand.

     

    The mechanism of energy storage and release is on the basis of transition of phase change materials (PCMs), which can solve the problem in time and spatial mismatch between the energy supply and consumption. Polyethylene glycol (PEG) as a type of organic PCMs is studied in this licentiate thesis due to its large heat capacity and multi-melting temperatures. As a representative of organic PCMs, PEG also has some disadvantages, like encapsulation needed for preventing leakage and low thermal conductivity. To resolve those, a type of so-called form-stable energy storage materials is prepared by blending PEG with silica gel. Modified aluminium nitride (AlN) powder is then added to enhance the thermal conductivity of materials. Meanwhile, another form-stable energy storage material is prepared by mixing the melted PEG into expanded graphite (EG). The results show that two types of composite materials can keep the form stable during the transition, and AlN powder can enhance the thermal conductivities of energy storage materials.

     

    Based on the knowledge of energy storage technology, M-TES system is designed and combined with the existing heat system in Eskilstuna. The feasibility study of M-TES is carried out through the data collected from CHP plant and end-user in this licentiate thesis. The results show that there are economic and environmental benefits by using M-TES system to supply heat for detached houses.

  • 590.
    Wang, Weilong
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thermal performance of the mobilized thermal energy storage system2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    A direct-contact mobilized thermal energy storage (M-TES) system with high heat density and heat transfer rate has been exploited to transport industrial heat for distributed users. In this paper, a lab-scale experimental setup has been built consisting of a direct-contact thermal energy storage (TES) container, oil/water tank, electrical boiler, oil/water pump and plate heat exchanger. Erythritol was chosen to work as an organic phase change material (PCM) due to its large heat density, suitable melting point (118oC) for industrial heat recovery, and non toxic and corrosive. Heat transfer oil (HTO) served as a heat transfer medium to carry and transfer heat. The theoretical heat capacity of the TES container is 13.1 kWh with 74 kg of Erythritol and 42 kg of HTO. In the charging process, electrical boiler heated HTO first, and then HTO was pumped into the bottom of the TES container to melt Erythritol directly. In the discharging process, heat was transferred to the cooling water through a plate heat exchanger. Results show that, the sub-cooling problem of Erythritol, which was found in the static experiments, was totally solved by dynamic heat exchange between Erythritol and HTO. During the whole process, the two liquid phases (oil and melted Erythritol) were separated clearly due to the big difference of their densities, and meanwhile a foam layer was also observed between the two sectors. In the charging process, the higher the flow rate of HTO, the less the charging time was needed, which resulted in the lower charging heat consumption. In the discharging process, the maximum heat of 10.6 kWh was released with the HTO flow rate of 12.5 l/min, which accounted for 80.9 % of the theoretical heat capacity of the TES container.

  • 591.
    Wang, Y.
    et al.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Nian, V.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yuan, J.
    China Institute of FTZ Supply Chain, Shanghai Maritime University, Shanghai, China.
    Life cycle analysis of integrated gasification combined cycle power generation in the context of Southeast Asia2018Ingår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 11, nr 6, artikel-id en11061587Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coal remains a major source of electricity production even under the current state of developments in climate policies due to national energy priorities. Coal remains the most attractive option, especially to the developing economies in Southeast Asia, due to its abundance and affordability in the region, despite the heavily polluting nature of this energy source. Gasification of coal running on an integration gasification combined cycle (IGCC) power generation with carbon capture and storage (CCS) represents an option to reduce the environmental impacts of power generation from coal, but the decarbonization potential and suitability of IGCC in the context of Southeast Asia remain unclear. Using Singapore as an example, this paper presents a study on the life cycle analysis (LCA) of IGCC power generation with and without CCS based on a generic process-driven analysis method. We further evaluate the suitability of IGCC with and without CCS as an option to address the energy and climate objectives for the developing economies in Southeast Asia. Findings suggest that the current IGCC technology is a much less attractive option in the context of Southeast Asia when compared to other available power generation technologies, such as solar photovoltaic systems, coal with CCS, and potentially nuclear power technologies.

  • 592.
    Wang, Y.
    et al.
    Tianjin University of Commerce, Tianjin, China.
    Wang, B.
    Tianjin University of Commerce, Tianjin, China.
    Zhu, K.
    Tianjin University of Commerce, Tianjin, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin University of Commerce, Tianjin, China.
    He, W.
    Tianjin University of Commerce, Tianjin, China.
    Liu, S.
    Tianjin University of Commerce, Tianjin, China.
    Energy saving potential of using heat pipes for CPU cooling2018Ingår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 143, s. 630-638Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Air cooling is the most common cooling solution for central processing units (CPUs). However, the heat dissipation capacity of conventional air-cooled heatsinks is limited because of non-uniform temperature distribution in the base of heatsinks. Embedded heat pipes into the heatsink is an effective method to improve the heat dissipation of the CPU and make the temperature distribution of the heatsink base more uniform. This work studied the cooling performance of the heat pipe embedded heatsinks, including the surface temperature, the average temperature of base, the thermal resistance and the power consumption. The impact of the different arrangements of heat pipes on the temperature distribution was also investigated. Results show that to obtain the same CPU temperature, a lower air velocity was needed for the heatsink with embedded heat pipe at the same heat flux. The minimum thermal resistance of the studied heat pipe embedded heatsinks was 0.15 °C/W, which is lower than that of the reference conventional heatsink, 0.22 °C/W. In addition, the heatsink with H-shape arrangement of embedded heat pipes had the best overall performance, which cooling capacity was increased by 22.5% and the weight of the heatsink was reduced by 30.1% compared with the heatsink without heat pipes. The energy saving potential was also evaluated based on the measured real operating status of CPUs. The dynamic simulation results show that the total fan power consumption can be effectively reduced when using a heat pipe embedded heatsink to replace the conventional heatsink, which can be up to 66.2%. 

  • 593.
    Weidong, Wang
    et al.
    Sun Yat-sen University, Guangzhou, China.
    Shiquan, He
    Guangzhou University, Guangzhou, China.
    Jing, Ding
    Sun Yat-sen University, Guangzhou, China.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Jianping, Yang
    South China University of Technology, Guangzhou, China.
    Numerical Evaluation on a Direct-contact Thermal Energy Storage System2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 4389-4394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study evaluates numerically various configurations of direct-contact PCM thermal energy storage devices, regarding inlet location, inlet flow directions, pre-heating and inlet tubes with straight fins. The direct-contact conjugate heat transfer between the heat transfer fluid (HTF) and PCM during melting process, is solved numerically by enthalpy-porosity formulation in the computational fluid dynamic approach. The results indicate that pre-heating could form channels in a short time, which improve heat transfer rate for charging stages. To further enhance heat transfer performance, inlet tubes embedded with straight fins. Compared to pre-heating method, the electric power can be saved. Each design are evaluated with respect to their heat transfer performance vis-à-vis heat storage ratio.

  • 594. Wen, Z.
    et al.
    Yu, X.
    Tu, S-T
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Intensification of transesterification for synthesis of biodielsel using micro channel reactor2008Konferensbidrag (Refereegranskat)
  • 595.
    Wetterlund, E.
    et al.
    Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Leduc, S.
    International Institute for Applied Systems Analysis (IIASA), Austria.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kindermann, G.
    International Institute for Applied Systems Analysis (IIASA), 2361 Laxenburg, Austria.
    Optimal use of forest residues in Europe under different policies-second generation biofuels versus combined heat and power2013Ingår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, Vol. 3, nr 1, s. 3-16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The European Union has set a 10 % target for the share of renewable energy in the transportation sector for 2020. To reach this target, second generation biofuels from, for example, forest residues are expected to replace around 3 % of the transport fossil fuel consumption. However, forest residues could also be utilised in the heat and electricity sectors where large amounts of fossil fuels can be replaced, thus reducing global fossil CO2 emissions. This study investigates the use of forest residues for second generation biofuel (ethanol or methanol) or combined heat and power (CHP) production at the European level, with focus on the influence of different economic policy instruments, such as carbon cost or biofuel policy support. A techno-economic, geographically explicit optimisation model is used. The model determines the optimal locations of bioenergy conversion plants by minimising the cost of the entire supply chain. The results show that in order to reach a 3 % second generation biofuel share, a biofuel support comparable to today's tax exemptions would be needed. With a carbon cost applied, most available forest residues would be allocated to CHP production, with a substantial resulting CO2 emission reduction potential. The major potential for woody biomass and biofuel production is found in the region around the Baltic Sea, with Italy as one of the main biofuel importers.

  • 596.
    Whalen, Joann
    et al.
    McGill Univ, Dept Nat Resource Sci, Montreal, PQ, Canada..
    Xu, Charles (Chunbao)
    Western Univ, Dept Chem & Biochem Engn, London, ON, Canada..
    Shen, Fei
    Sichuan Agr Univ, Sch Environm, Yaan, Peoples R China..
    Kumar, Amit
    Univ Alberta, Dept Mech Engn, Edmonton, AB, Canada..
    Eklund, Mats
    Linkoping Univ, Dept Management & Engn, Linkoping, Sweden..
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH Royal Inst Technol, Vasteras, Sweden.
    Sustainable biofuel production from forestry, agricultural and waste biomass feedstocks2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 198, s. 281-283Artikel i tidskrift (Refereegranskat)
  • 597.
    Widarsson, Björn
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik.
    Karlsson, Christer
    Mälardalens högskola, Institutionen för samhällsteknik.
    Dahlquist, Erik
    Mälardalens högskola, Institutionen för samhällsteknik.
    Bayesian Network for Decision Support on Soot Blowing Superheaters in a Biomass Fuelled Boiler2004Ingår i: 2004 International Conference on Probabilistic Methods Applied to Power Systems, 2004, s. 212-217Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In a process for combined heat and power generation there is a need for fault detection, decision support and risk assessment to prevent operational disturbances and reduction in performance. A method to achieve decision support is to use Bayesian networks, where knowledge about the process is combined with operational experience. The network covers the convectional superheaters in the flue gas train, which is a major problem domain in biomass-fuelled boilers. The superheaters are exposed to fouling from flue gases. Fouling reduces the heat transfer and result in a decreased power plant performance. The Bayesian network is constructed to give decision support on preventive action to reduce abnormal fouling. Validation of the Bayesian network show that the prediction of hard fouling works well under uncertainty.

  • 598.
    Wilhelmsen, O.
    et al.
    Sintef Energy Research, Trondheim, Norway.
    Skaugen, G.
    Sintef Energy Research, Trondheim, Norway.
    Jørstad, O.
    tatoil ASA, Trondheim, Norway.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Evaluation of SPUNG# and other equations of state for use in carbon capture and storage modelling2012Ingår i: Energy Procedia, 2012, s. 236-245Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this work, Equations of State (EoS) relevant for carbon capture and storage modelling have been evaluated for pure CO2 and CO 2-mixtures with particular focus on the extended corresponding state approach, SPUNG/SRK. Our work continues the search of an EoS which is accurate, consistent and computationally fast for CO2-mixtures. These EoS have been evaluated: Soave-Redlich-Kwong (SRK), SRK with Peneloux shift, Peng-Robinson, Lee-Kesler, SPUNG/SRK and the multi-parameter approach GERG-2004. The EoS were compared to the accurate reference EoS by Span and Wagner for pure CO2. Only SPUNG/SRK and GERG-2004 predicted the density accurately near the critical point (< 1.5 % Absolute Average Deviation (AAD)). For binary mixtures, Lee-Kesler and SPUNG/SRK had similar accuracy in density predictions. SRK had a sufficient accuracy for the gas phase below the critical point (<2.5%), and Peng Robinson had a decent accuracy for liquid mixtures (<3%). GERG-2004 was the most accurate EoS for all the single phase density predictions. It was also the best EoS for all the VLE predictions except for mixtures containing CO2 and O2, where it had deviations in the bubble point predictions (∼20 % AAD). Even though multi-parameter EoS such as GERG-2004 are state-of-the-art for high accuracy predictions, this work shows that extended corresponding state EoS may be an excellent compromise between computational speed and accuracy. The SPUNG approach combines high accuracy with a versatile and transparent methodology. New experimental data may easily be taken into account to improve the predictive abilities in the two phase region. The approach may be improved and extended to enable applications for more difficult systems, such as polar mixtures with CO2 and H 2O.

  • 599.
    Win, Kaung Myat
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Persson, Tomas
    Högskolan i Dalarna.
    Emissions factors fromresidential wood pellet boilers characterized into start-up, steady operationand stop emissions2014Ingår i: Energy and fuels, ISSN 0887-0624, Vol. 28, nr 4, s. 2496-2505Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Gaseous and particulate emissions from three residential wood pellet boilers and a stove were characterized and quantified at start-up, steady (full, medium and low combustion power), and stop phases. The aim was to characterize the emissions during the different phases of boiler operation and to identify when the major part of the emissions occur to enable actions for emission reduction where the savings can be highest. The investigated emissions comprised carbon monoxide (CO), nitrogen oxide (NO), total organic carbon (TOC), and particulate matter (PM 2.5). In this study, particle emissions were characterized by both number and mass concentration. The emission characteristics at high combustion power were relatively similar for all tested devices while significant differences in CO and TOC were observed at lower combustion power. Highest CO and TOC emissions are produced by the bottom fed boiler at low combustion power. The accumulated start-up emissions of the tested devices varied in the ranges of 0.5–12 g CO, 0.1–0.7 g NO, 0.1–2 g TOC, 0.12–2.9 g PM2.5, and 2.4 × 1013 to 3.1 × 1014 particles PM2.5. The accumulated stop emissions varied in the ranges 4–15.5 g CO, 0.01–0.11 g NO, 0.02–1.6 g TOC, 0.1–1.3 g PM2.5, and 3.3 × 1013 to 1.4 × 1014 particles PM2.5. The bottom fed boiler B1 had higher start-up and stop emissions than the tested top fed boilers and more particle emissions were accumulated in start-up phase than in stop phases of boiler B1, B3, and stove S1. Number of particles emitted from residential wood pellet combustion is dominated by fine particles smaller than 1 μm and similar particle distribution both in number and mass were observed for the tested devices. The start-up phase generated higher accumulated particle mass than the stop phase.

  • 600.
    Winn, Olivia
    et al.
    Mälardalens högskola.
    Sivaram, Kiran Thekkemadathil
    Mälardalens högskola.
    Aslanidou, Ioanna
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Skvaril, Jan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Near-infrared spectral measurements and multivariate analysis for predicting glass contamination of refuse-derived fuel2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 943-949Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates how glass contamination in refuse-derived fuel can be quantitatively detected using near-infrared spectroscopy. Near-infrared spectral data of glass in four different background materials were collected, each material chosen to represent a main component in municipal solid waste; actual refuse-derived fuel was not tested. The resulting spectra were pre- processed and used to develop multi-variate predictive models using partial least squares regression. It was shown that predictive models for coloured glass content are reasonably accurate, while models for mixed glass or clear glass content are not; the validated model for coloured glass content had a coefficient of determination of 0.83 between the predicted and reference data, and a root- mean-square error of validation of 0.64. The methods investigated in this paper show potential in predicting coloured glass content in different types of background material, but a different approach would be needed for predicting mixed type glass contamination in refuse-derived fuel. 

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