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- Dahlquist, Erik, et al.
(author)
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Alternative Pathways to a fossil-fuel free energy system in the Mälardalen region of Sweden
- 2006
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In: Proceedings of the Second International Green Energy Conference, 2006. ; , s. 822-830
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Conference paper (other academic/artistic)abstract
- This paper presents a study on alternative pathways to a fossil-fuel free regional energy system in the Mälardalen region of Sweden with a population of 3 million inhabitants. We describe and address how the region can be made independent of fossil fuels by integration of resource management, technology advances, and behavior change in energy use. First we investigate the consumption pattern of the inhabitants. Then we study what resources are available, and how these can be used to fulfill the different demands. If we just use the resources in a pattern of business as usual today without changing the behavior, the balance between demands and resources is difficult to reach. By combining a slightly different behavior and a change of crops it could be possible to fulfill the needs. Some advanced technological solutions have also been proposed. For example, dedicated biomass energy plants such as fodder sugar beats can be used for ethanol production. Also Salix, straw, hemp and some cereals can be used and the residues can be gasified to produce dimethylether (DME), which is good as a replacement for diesel fuel. Still the fuel demand for transport is high, and the vehicle weight could be further reduced. For example, by going back to the car size we had only ten years ago the weight would be 25-30 % less, and fuel consumption would be at least 15 % lower. With diesel engines instead of Otto-engines the fuel consumption could be reduced by 35 %, and with hybrid technology additional 20% fuel reduction could be gained. Improved public transportation will also give a positive effect especially for those commuting between the larger cities and between the cities and the suburbs. The results of our calculations show that it would be possible to accomplish a fossil-free energy system in the Mälardalen region. The results of this study are important since it shows that an energy balance without fossil fuels could be possible for an area with a population in the order of 3 million people, which would also be valuable in studies of other areas in the world.
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- Jansson, Johan, 1975-
(author)
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Digester modelling for diagnostics and control
- 2009
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Doctoral thesis (other academic/artistic)abstract
- This thesis will show the possibility for the development and use of an on-line model for application to continuous digesters for pulp production. The model is developed by using a program called Dymola (Dynamic Modeling Laboratory). What makes the Dymola software so well suited is that the program solves equations simultaneously. The model is a further development from the Purdue model [Bhartiya et al, 2003]. The main difference between this model and the Purdue model however, is the dynamics in the model. The dynamics are very important when you use the model for control purposes because the cooking process has long dead and retention times. The main purpose of this model is to use it for the advanced control of continuous digesters as well as giving the operators a better understanding of what happens in the cooking process when changes are made. The model will also be used for diagnostic purposes. Advanced control in this case is Model Predicted Control (MPC). The MPC will control the quality of the pulp “kappa” number and the chemical consumption during digestion. This thesis describes the model and results are shown for applications of on-line diagnosis in three pulp mills in South Africa. Real time process data from the pulp mills is fed into the model and a simulation is performed. Thereafter, the results from the simulation are compared to the actual measured data for a number of key variables. By comparing the simulation results to the real process data and following the trends of the deviations between the two, different types of faults and upsets can be detected in both the process and sensors.
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- Karlsson, Christer
(author)
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On the On-line Tools for Treatment of Deterioration in Industrial Processes
- 2008
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Doctoral thesis (other academic/artistic)abstract
- For industrial processes high availability and efficiency are important goals in plant operation. This thesis presents studies and development of tools for on-line treatment of process deterioration and model and sensor errors in order to achieve these goals. Deterioration of measurement devices, process components and process models has caused economical losses, plant failure and human losses. The development of on-line methods to prevent such losses is of special interest and has been conducted at The Department of Energy Technology, Mälardalen University. Important technological obstacles to implementing automatic on-line methods have been identified, such as data selection for adaptation and adaptation of data-driven models to new states.A new method has been developed for decision support by combining artificial intelligence methods and heat and mass balance models, and concepts are proposed for decision support in order to detect developing faults and to conduct appropriate maintenance actions. The methods have been implemented in simulation environment and evaluated on real process data when available. The results can be sumarised as successful development of a decision support method on a steam turbine by combining artificial neural networks and Bayesian networks, and identification of important obstacles for automation of methods for adaptation of heat and mass balance process models and data-driven models when they are subject to deterioration.
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- Nyström, Jenny, 1970-
(author)
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Rapid measurements of the moisture content in biofuel
- 2006
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Doctoral thesis (other academic/artistic)abstract
- An increasing number of power plants in Scandinavia are beginning to use biofuel instead of coal or oil. The material in the new fuel is a mixture of woodchips, mostly Pine, Spruce and Salix, bark, GROT (tops and branches from felling waste) and sawdust from sawmills. It is heterogeneous, having a moisture content varying from 15% up to 65%. The moisture content affects the combustion of the fuel and therefore its commercial value. The industry is now interested in obtaining a method for measuring the moisture content of biofuel, quickly and reliably; preferably on delivery at the power plant. The measuring technique presented in this thesis is the first reported in the literature capable of measuring the moisture content of a large sample of such an heterogeneous material as biofuel. The equipment is today calibrated for a sample volume of 0.1 m3. A radio frequent signal is supplied from an antenna and penetrates the biofuel. Its reflection is modeled using partial least squares. As part of the work presented in this thesis, a new type of measuring rig and an analysis method for measurement of the moisture content of large samples of heterogeneous material have been developed. A statistical model for moisture content measurements of five different biofuel materials using radio waves has been built, having a root mean square error of prediction of 2.7. The interactions between biofuels and radio frequent signals have been demonstrated, indicating a variation of the reflection with varying types of biofuel material and variation in the reflection and delay of the signal with varying moisture content.
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PROCEEDINGS FROM SCIENTIFIC CONFERENCE ON GREEN ENERGY AND IT
- 2008
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Editorial proceedings (other academic/artistic)abstract
- Scientific session on Energy saving and Green energyChairman: Erik Dahlquist, Mälardalen University1. Investigations on CO2 absorption using amine solvents in hollow fiber membrane contactors by experiments .Yuexia Lv1, Xinhai Yu1*, Shan-tung Tu1, J. Yan2, E. Dahlquist2,School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China; 2. Dept. IST, Mälardalen University, Västerås, Sweden 2. Intensification of transesterification for synthesis of biodiesel using microchannel reactors.Zhenzhong Wen1, Xinhai Yu1*, Shan-tung Tu1, J. Yan2, E. Dahlquist2 1. School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China; 2. Dept. IST, Mälardalen University, Västerås 3. Continuous bioethanol production by fermentation. Bernt Lie, Juan I. Videla.Telemark University College, Porsgrunn, Norway 4. Optimization and Economic Analysis of Marnoch Thermal Energy Conversion System,C.C. Chukwu1, G.F Naterer2, M.A. Rosen3, E. Dahlquist4 I.A Marnoch5 ,1,2,3,4 University of Ontario Institute of Technology, Oshawa. Ontario, Canada, 4 Malardalen University, Vasteras Sweden, 5 Marnoch Thermal Power Inc. Toronto, Ontario, Canada, 5. Analysis of the coal based polygeneration system of hybrid typeGuoqiang Zhang1,2, Lin GAO1, Hongguang JIN1,* 1 Institute of Engineering Thermophysics, Chinese Academy of Sciences 6. Power transformer parameters identification using extended kalman filterKourosh Mousavi Takami, TDI researcher and phd student in Malardalen University , Jafar Mahmoudi , Erik Dahlquist, Malardalen University 7. An advanced energy saving method for Aluminium - iron - copper bonding using explosive weldingScientific session on Energy savings in housesChairman: Jurek Pyrko, Lund University. Mohammad Tabatabaee. TDI institute, Teheran, Iran and Mälardalen University 8. Design of hot water user profiles for Swedish households based on time diaries.751 21 Uppsala, SwedenMagdalena Lundh, Ewa Wäckelgård, Kajsa Ellegård. Department of Engineering Sciences The Ångström Laboratory Box 534 9. Modeling Household Electricity Load from Time-Use Data. Joakim Widén, Kajsa Ellegård och Ewa Wäckelgård. Department of Engineering Sciences,Solid State Physics,Uppsala University 10. Investigation of electricity consumption in single houses with electrical heating alone and together with complementary heating systems. Cajsa Bartusch, Fredrik Wallin, Erik Dahlquist, Mälardalen University. 11. Differences in electricity and hot water consumption in apartments of different sizes.Iana Vassileva, Cajsa Bartusch, Erik Dahlquist. Mälardalen University. 12. Novel Architect Designs Energy-Saving Iranian Homes. S.M. Esmail Mousavi-Takami, TDI Technical Development Institute, Teheran, Iran 13. Inform me please! - Energy use information to households and Demand Response. Jurek Pyrko, Energy Sciencees, Lunds University 14. "Consumers, energy and IT. IT and other tools to support efficient energy consumption"I.C. MariAnne Karlsson Chalmers University of Technology, Product and Production Development 15. Influence of Residential Ventilation on Radon Mitigation with Energy Saving emphasisKeramatollah Akbari, Mälardalen University and TDI in Teheran, Iran16. Extracting alumina from bauxite ore in jajarm factory process simulation using aspen softwareMohammad Farrokh and Jafar Mahmoudi, Mälardalen University and TDI in Teheran, Iran17. Description of techniques for hot spot monitoring and detection in power transformersHassan gholinejad, Kourosh Mousavi Takami and Jafar Mahmoudi, Mälardalen University and Tanesh Company, Iran
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