<p>År 2004 förbrukades 5 037 800 MWh energi i byggsektorn. Idag pratas det mycket om energieffektivisering i förvaltningsskedet. Denna rapport inriktar sig mer på hur energiförbrukningen kan minskas under bygget, närmare bestämt hur valet av uppvärmningssystem för att påskynda härdningen av betong på byggarbetsplatsen kan minska energianvändningen. Energianvändningen är något som påverkar både ekonomin och miljön, det är därför aktuellt att spara på energin där det är möjligt.</p><p> Det finns en rad olika uppvärmningsanordningar för att torka betong, att välja den mest lämpade för bygget är av stor vikt. Både ur ett tidsperspektiv och även ur energibesparingsperspektiv. Rapporten berör de idag mest använda anordningarna men fokuserar på de anordningar som torkar och härdar betongen genom att värma luften; eldrivna varmluftsfläktar, hetvattendrivna luftvärmare, dieseleldade byggtorkar samt gasoleldade byggtorkar. Anordningarna jämförs utifrån koldioxidutsläpp, kostnader samt sina för- och nackdelar för användning på arbetsplatsen. För att underlätta valet av uppvärmningsanordning har ett program tagits fram där kostnader och koldioxidutsläpp beräknas. Programmet fungerar som så att effektbehovet beräknas och utifrån detta väljer användaren de mest lämpade anordningarna för bygget i fråga. I rapporten jämförs de fyra uppvärmningsanordningarna i två olika månader, november och februari, samt med dålig isolering och obefintlig isolering i uppvärmningsskedet. Beräkningarna i rapporten är utförda på ett standard flerbostadshus för Peab.</p><p>Resultatet av de utförda beräkningarna visas i diagrammen ovan. Slutsatsen av rapporten blir att vid högre effektbehov, och om möjligheten finns, är det alltid bäst att använda sig av fjärrvärme sett till de totala kostnaderna och koldioxidutsläppen. Där effektbehovet och ett fjärrvärmesystem inte motiveras ekonomiskt bör ett gasolbaserat system användas. Ett diesel- och elbaserat system är i ett tidigt skede aldrig en bra lösning på grund av höga kostnader för energin och stora utsläpp.</p>

Agglomeration (the sticking together of particles) is often the major growth mechanism in granulation processes. The population balance equation (PBE) is a mathematical framework that is often applied to systems to describe how the particle size distribution changes as a function of time. Different kinetic terms are included in the PBE to describe the different particle growth mechanisms. In this work, a new kinetic model framework is proposed for the growth mechanism binary agglomeration. Binary agglomeration means that only two particles are involved in an agglomeration event. The generality of the new model framework is an advantage over the previous coalescence kernel framework. It is shown that an existing coalescence kernel model can be expressed by means of the new framework. The new model framework is then adapted to the special case of fluidized bed granulation (FBG) by proposing/choosing expressions for the three submodels in the model framework. An advantage of the new FBG model is that a maximum number of agglomeration events per unit time can be estimated. This means that the model is one step closer to being used predictively. At the moment, no population balance models can predict granulation processes where agglomeration is the dominant growth mechanism. It is shown that both the new FBG model and an existing model could fit experimental data well, however, the new model reflects the situation that the presence of surface liquid is rate limiting for the agglomeratio process. Experiments in a laboratory batch fluidized bed granulator were carried out. Samples of the particle size distribution were taken at intervals during an experiment. These data were used to fit the model parameters of the FBG model. The dissertation includes a discussion of the effect of certain operating conditions such as bed temperature and liquid spray rate on a model parameter.

In this thesis the evaporation from and condensation on a plane liquid surface have been studied by analysis and molecular dynamics simulations. The effect of the condensation coefficient on the inverted temperature gradient for a two-surface evaporation-condensation geometry is investigated by the moment method. The influence of the molecular exchange phenomenon on the gas-kinetic treatment of evaporation and condensation is shown to be neglible under certain assumptions. Methods to simulate half-space steady evaporation or condensation in Direct Simulation Monte Carlo simulations are adapted to Molecular Dynamics (MD). A microscopic definition of evaporation and condensation is introduced and values for the evaporation and condensation coefficients are calculated from MD. The velocity distribution functions for the evaporation and condensation modes have been calculated and compared with the standard assumptions in gas-kinetic calculations.

Soot and radiation play an important role when designing practical combustion devices, and great efforts have been put into developing models which describe soot formation and oxidation. The Eddy Dissipation Concept (EDC) has proven to describe turbulent combustion well, and has the flexibility to describe chemical kinetics in a detailed manner. The aim of this work is to study how the EDC handles soot models based on a detailed representation of the gas-phase chemical kinetics. Two versions of a semi-empirical soot model is used in conjunction with the EDC. Concentrations of various intermediate species are used as input to the soot models. The implementation of the new soot models is discussed in relation to the previous implementation of a less detailed soot model. To assure that the interaction between soot and the gas-phase species is represented correctly, the soot models are implemented with a two-way coupling of soot and gas-phase kinetics. Soot is a good radiator. In a sooting flame a substantial amount of energy will be transferred to the surroundings by thermal radiation. This transfer of energy will alter the temperature field of the flame and the change in temperature will affect the kinetics of soot and gas-phase chemistry. To simulate sooting flames correctly, it was therefore necessary to include a radiation model. To validate the coupled models of turbulence, combustion, soot, and radiation two different turbulent flames were simulated. One turbulent jet flame of methane and one turbulent jet flame of ethylene. For both flames the computed results were compared with measured values. Several aspects of the simulations are studied and discussed, such as the effect of the two-way coupling of soot and gas-phase kinetics on both soot yield and gas-phase composition, and the importance of a suitable radiation model. The two-way coupling of soot and gas phase kinetics is shown to have a positive effect on the computed soot volume fractions, and the results are considered to be encouraging. The work has demonstrated that the EDC has the capacity to handle different types of chemical reaction mechanisms, such as mechanisms for gas-phase combustion and soot kinetics, without modification.

The objective of this study was to develop an approach to integrate LCA of different fuels and energy conversion technologies into the energy planning tool eTransport. Course LCA's for relevant energy commodities, infrastructure and transport services was performed, and the results from these prepared for implementation in eTransport. In the choice of methodology for integration, a lot of aspects needs consideration. These are described throughout the report and emphasized in the choice of methodology. The methodology is illustrated by a case study on Trondheim municipality, followed by a description on how this would be done in eTransport. This project is a groundwork regarding implementation of LCA in eTransport, and will be followed up by further student work, testing the method in practice.

The increasing global demand for energy coupled with decreasing oil-supplies, and increasing risk of adverse climate change due to anthropogenic carbon emissions has created the need for combined economic and environmental assessment. This thesis attempt at devising such a framework based upon Life Cycle Assessment (LCA) and Life Cycle Costing (LCC). These methodologies represent two well established approaches for measuring environmental and economic performance of industrial projects and products. The LCA framework permits introduction of system expansion by interfacing with the greater economy by the hybrid-LCA. This approach also permits the assessment of life-cycle costs within the mathematical structure. The fundamental computations of LCA and LCC are introduced in this text in order to establish the combined assessment framework. This assessment method is applied to two National Renewable Energy Laboratory's studies on bio-ethanol production from lignocellulose. The studies are adapted to Norwegian economic conditions in order to assess the price and emissions of ethanol production from Norwegian wood mass. By combining these performance characteristics, a mitigation price of substituting gasoline with ethanol is established for various plant sizes as well as prices of gasoline.

In this work, a STAtic synchronous COMpensator (STATCOM) with energy storage system for wind power application has been treated. This device was proposed as a mean to improve voltage stability and power transmission by offering reactive as well as active power compensation. The work focuses on the converter topology of the STATCOM part and the control system. Further on, the energy storage system needed for this application was designed, including the choice of energy storage, its size and the interface/control system. The STATCOM, reactive part of the compensator was based on a voltage source converter (VSC), using a vector control. Its purpose was to maintain a stable grid voltage. For active compensation of wind power, a bank of super capacitors for energy storage system, SCESS, was used in this thesis. The super capacitor bank size was estimated, based upon the short term fluctuations in wind power. These fluctuations are results of contstructional factors of the turbines, variations and turbulence in the wind. The super capacitor bank was interfaced with the DC-bus of the STATCOM with a normal half-bridge buck-boost converter, to control the voltage level of the bank while maintaing a constant DC-bus voltage for good switching operation in the VSC. The control system for the active power compensation part was implented as a cascaded PI-control, compromising an inner current control loop, and an outer power control loop. The outermost loop included a dynamical power reference, based on the actual power transfer in the grid. This reference is supposed to assure that the controller is only compensating small fluctuations, while larger changes are left for other means, for instance controlled hydro power. The designed system was implemented in EMTDC/PSCAD. A small model, including one wind turbine, a weak grid and the STATCOM/SCESS was used in the simulations. With regards to the reactive- and active power compensation, the results were promising. However, the dynamical power reference could be of a better quality, as it does not take into account the losses in the STATCOM/SCESS, and thereby is inacurate regarding the amount power fed to/from the super capacitor bank. In addition, a small STATCOM model was realised in the laboratory. The results from the practical work showed the same general patterns as the simulations.

Artificial intelligence (AI) is a collective term for several computing techniques. They have in common that they use non-linear algorithms and that they are inspired from different processes in the nature, in particular how human beings make decisions. The use of AI for optimal operation of a stand-alone power plant has been investigated. This includes prediction, estimation, optimization and control. A presentation of some relevant AI techniques are given. A comparison with classical approaches such as for example PI control was made. The new techniques that were investigated proved to be very powerful and should be used more frequently than it is used today. AI techniques are especially promising for supervisorial control, but can also be used to control converters directly. A controller for a DC/DC boost converter was developed. It proved to be significantly better than a classical PI controller. Whether the computing time is shorter or faster than for classical approaches depends on the application. Compared to PI controllers the AI algorithms have a long computing time. Compared to classical wind power prediction techniques on the other hand AI techniques are very fast. A disadvantage with AI is the lack of rules for deciding the inner structure of the algorithms.

To create the ultimate wireless instrumentation unit for down-hole applications high temperature electronics with very high reliability is needed. It is possible to use ordinary bulk-CMOS devices at temperature up to 175 ⁰C, but the lifetime at these temperatures is to low for a down-hole instrumentation unit. An alternative is to use s Silicon on Insulator process under the fabrication of the semiconductors. The SOI process is a fabrication process where there is buried a oxide layer in the silicon wafer, and thus allowing higher breakdown voltage and/or lower current leakage. The low current leakage allows the semiconductors to be used at higher junction temperature. SOI devices that are commercial available off-the-shelf as a expected lifetime for at least 5 years at 225 ⁰C and thus much lower at junction temperatures below 200 ⁰C. The SOI technology can then be used together with hybrid circuits using ceramic substrate as a replacement for organic PCB and thick-film technology for the passive devices. A package like this gives a system with high reliability both toward high temperature operation and lifetime. The main limitation in the high temperature design is the availability off the larger capacitors; the limitation for high temperature stacked capacitors is 200 ⁰C. The converters designed are the standard step-up and step-down switch-mode power supplies. The converters are designed with current mode control; current mode control is used because of the advantage that comes with it. One off the advantages is the possibility to limit the inductor current; another advantage is the possibility to use constant current charging for the battery. When designing the SOI devices for high temperature operation it is difficult to achieve high enough breakdown voltage. With this in mind, the high temperature converter is designed with series coupled transistors to achieve high enough breakdown voltage for high voltage operation. The transistors have always some small perturbations in their specifications, this has to be considered when connecting transistors in series. This perturbations in for example turn-off speed makes an uneven voltage sharing; this is solved by connecting suitable capacitors in parallel with the switches to maintain an even voltage sharing.

This thesis offers a short overview of the most important stator mounted permanent magnet machines, with a closer look on the FSPM design. A FSPM machine have been built and tested as a generator, to get a better understanding of the machine concept. The focus of the work have been on the well documented 12/10 (Stator teeth/ Rotor teeth) design while the novel 12/14 pole design have also been tested, as a rotor change is the only difference between the two designs. The machine have been simulated in COMSOL, where inductances, back emf and cogging have been found and compared with the measured results.