Artificially Intelligent and Adaptive Methods for Prediction and Analysis of Superheater Fireside Corrosion in Fluidized Bed Boilers

Superheater corrosion causes vast annual losses for the power companies. With a reliable corrosion prediction method, the plants can be designed accordingly, and knowledge of fuel selection and determination of process conditions may be utilized to minimize superheater corrosion. Growing interest to use recycled fuels creates additional demands for the prediction of corrosion potential. Models depending on corrosion theories will fail, if relations between the inputs and the output are poorly known. A prediction model based on fuzzy logic and an artificial neural network is able to improve its performance as the amount of data increases. The corrosion rate of a superheater material can most reliably be detected with a test done in a test combustor or in a commercial boiler. The steel samples can be located in a special, temperature-controlled probe, and exposed to the corrosive environment for a desired time. These tests give information about the average corrosion potential in that environment. Samples may also be cut from superheaters during shutdowns. The analysis ofsamples taken from probes or superheaters after exposure to corrosive environment is a demanding task: if the corrosive contaminants can be reliably analyzed, the corrosion chemistry can be determined, and an estimate of the material lifetime can be given. In cases where the reason for corrosion is not clear, the determination of the corrosion chemistry and the lifetime estimation is more demanding. In order to provide a laboratory tool for the analysis and prediction, a newapproach was chosen. During this study, the following tools were generated: · Amodel for the prediction of superheater fireside corrosion, based on fuzzy logic and an artificial neural network, build upon a corrosion database developed offuel and bed material analyses, and measured corrosion data. The developed model predicts superheater corrosion with high accuracy at the early stages of a project. · An adaptive corrosion analysis tool based on image analysis, constructedas an expert system. This system utilizes implementation of user-defined algorithms, which allows the development of an artificially intelligent system for thetask. According to the results of the analyses, several new rules were developed for the determination of the degree and type of corrosion. By combining these two tools, a user-friendly expert system for the prediction and analyses of superheater fireside corrosion was developed. This tool may also be used for the minimization of corrosion risks by the design of fluidized bed boilers.

Error Modeling and Accuracy Analysis of a Novel Mobile Hybrid Parallel Robot

Over the last decades, calibration techniques have been widely used to improve the accuracy of robots and machine tools since they only involve software modification instead of changing the design and manufacture of the hardware. Traditionally, there are four steps are required for a calibration, i.e. error modeling, measurement, parameter identification and compensation. The objective of this thesis is to propose a method for the kinematics analysis and error modeling of a newly developed hybrid redundant robot IWR (Intersector Welding Robot), which possesses ten degrees of freedom (DOF) where 6-DOF in parallel and additional 4-DOF in serial. In this article, the problem of kinematics modeling and error modeling of the proposed IWR robot are discussed. Based on the vector arithmetic method, the kinematics model and the sensitivity model of the end-effector subject to the structure parameters is derived and analyzed. The relations between the pose (position and orientation) accuracy and manufacturing tolerances, actuation errors, and connection errors are formulated. Computer simulation is performed to examine the validity and effectiveness of the proposed method.

MCMC Analysis Of Classical Time Series Algorithms

Identification of order of an Autoregressive Moving Average Model (ARMA) by the usual graphical method is subjective. Hence, there is a need of developing a technique to identify the order without employing the graphical investigation of series autocorrelations. To avoid subjectivity, this thesis focuses on determining the order of the Autoregressive Moving Average Model using Reversible Jump Markov Chain Monte Carlo (RJMCMC). The RJMCMC selects the model from a set of the models suggested by better fitting, standard deviation errors and the frequency of accepted data. Together with deep analysis of the classical Box-Jenkins modeling methodology the integration with MCMC algorithms has been focused through parameter estimation and model fitting of ARMA models. This helps to verify how well the MCMC algorithms can treat the ARMA models, by comparing the results with graphical method. It has been seen that the MCMC produced better results than the classical time series approach.

Utilization of a Time Domain Simulator in the Technical and Economic Analysis of a Wind Turbine Electric Drive Train

The amount of installed wind power has been growing exponentially during the past ten years. As wind turbines have become a significant source of electrical energy, the interactions between the turbines and the electric power network need to be studied more thoroughly than before. Especially, the behavior of the turbines in fault situations is of prime importance; simply disconnecting all wind turbines from the network during a voltage drop is no longer acceptable, since this would contribute to a total network collapse. These requirements have been a contributor to the increased role of simulations in the study and design of the electric drive train of a wind turbine. When planning a wind power investment, the selection of the site and the turbine are crucial for the economic feasibility of the installation. Economic feasibility, on the other hand, is the factor that determines whether or not investment in wind power will continue, contributing to green electricity production and reduction of emissions. In the selection of the installation site and the turbine (siting and site matching), the properties of the electric drive train of the planned turbine have so far been generally not been taken into account. Additionally, although the loss minimization of some of the individual components of the drive train has been studied, the drive train as a whole has received less attention. Furthermore, as a wind turbine will typically operate at a power level lower than the nominal most of the time, efficiency analysis in the nominal operating point is not sufficient. This doctoral dissertation attempts to combine the two aforementioned areas of interest by studying the applicability of time domain simulations in the analysis of the economicfeasibility of a wind turbine. The utilization of a general-purpose time domain simulator, otherwise applied to the study of network interactions and control systems, in the economic analysis of the wind energy conversion system is studied. The main benefits of the simulation-based method over traditional methods based on analytic calculation of losses include the ability to reuse and recombine existing models, the ability to analyze interactions between the components and subsystems in the electric drive train (something which is impossible when considering different subsystems as independent blocks, as is commonly done in theanalytical calculation of efficiencies), the ability to analyze in a rather straightforward manner the effect of selections other than physical components, for example control algorithms, and the ability to verify assumptions of the effects of a particular design change on the efficiency of the whole system. Based on the work, it can be concluded that differences between two configurations can be seen in the economic performance with only minor modifications to the simulation models used in the network interaction and control method study. This eliminates the need ofdeveloping analytic expressions for losses and enables the study of the system as a whole instead of modeling it as series connection of independent blocks with no lossinterdependencies. Three example cases (site matching, component selection, control principle selection) are provided to illustrate the usage of the approach and analyze its performance.

Search and Paper SKU Analysis of Recipes Meeting EUPS Standard

The theoretical research of the study concentrated on finding theoretical frameworks to optimize the amount of needed stock keeping units (SKUs) in manufacturing industry. The goal was to find ways for a company to acquire an optimal collection of stock keeping units needed for manufacturing needed amount of end products. The research follows constructive research approach leaning towards practical problem solving. In the empirical part of this study, a recipe search tool was developed to an existing database used in the target company. The purpose of the tools was to find all the recipes meeting the EUPS performance standard and put the recipes in a ranking order using the data available in the database. The ranking of the recipes was formed from the combination of the performance measures and price of the recipes. In addition, the tool researched what kind of paper SKUs were needed to manufacture the best performing recipes. The tool developed during this process meets the requirements. It eases and makes it much faster to search for all the recipes meeting the EUPS standard. Furthermore, many future development possibilities for the tool were discovered while writing the thesis.

Mechanical design and analysis of modular active magnetic bearing test rig

Tässä työssä on tutkittu modulaarisen aktiivimagneettilaakeroidun koelaitteen mekaanista suunnittelua ja analysointia. Suurnopeusroottorin suunnittelun teoria on esitelty. Lisäksi monia analyyttisiä mallinnusmenetelmiä mekaanisten kuormitusten mallintamiseksi on esitelty. Koska kyseessä on suurnopeussähkökone, roottoridynamiikka ja sen soveltuvuus suunnittelussa on esitelty. Magneettilaakerien rakenteeseen ja toimintaan on tutustuttu osana tätä työtä. Kirjallisuuskatsaus nykyisistä koelaitteista esimerkiksi komponenttien ominaisuuksien tunnistamiseen ja roottoridynamiikan tutkimuksiin on esitelty. Työn rajauksena on konseptisuunnittelu muunneltavalle magneettilaakeroidulle (AMB) koelaitteelle ja suunnitteluprosessin dokumentointi. Muunneltavuuteen päädyttiin, koska se mahdollistaa erilaisten komponenttiasetteluiden testaamisen erilaisille magneettilaakerikokoonpanoille ja roottoreille. Pääpaino tässä työssä on suurnopeus induktiokoneen roottorin suunnittelussa ja mallintamisessa. Modulaaristen toimilaitteiden kuten magneettilaakerien ja induktiosähkömoottorin rakenne on esitelty ja modulaarisen rakenteen käytettävyyden hyödyistä koelaitekäytössä on dokumentoitu. Analyyttisiä ja elementtimenetelmään perustuvia tutkimusmenetelmiä on käytetty tutkittaessa suunniteltua suurnopeusroottoria. Suunnittelun ja analysoinnin tulokset on esitelty ja verrattu keskenään eri mallinnusmenetelmien välillä. Lisäksi johtopäätökset sähkömagneettisten osien liittämisen monimutkaisuudesta ja vaatimuksista roottoriin ja toimilaitteisiin sekä mekaanisten että sähkömagneettisten ominaisuuksien optimoimiseksi on dokumentoitu.

Energy and raw material consumption analysis of powder bed fusion: case study: CNC machining and laser additive manufacturing

Laser additive manufacturing (LAM), known also as 3D printing, is a powder bed fusion (PBF) type of additive manufacturing (AM) technology used to manufacture metal parts layer by layer by assist of laser beam. The development of the technology from building just prototype parts to functional parts is due to design flexibility. And also possibility to manufacture tailored and optimised components in terms of performance and strength to weight ratio of final parts. The study of energy and raw material consumption in LAM is essential as it might facilitate the adoption and usage of the technique in manufacturing industries. The objective this thesis was find the impact of LAM on environmental and economic aspects and to conduct life cycle inventory of CNC machining and LAM in terms of energy and raw material consumption at production phases. Literature overview in this thesis include sustainability issues in manufacturing industries with focus on environmental and economic aspects. Also life cycle assessment and its applicability in manufacturing industry were studied. UPLCI-CO2PE! Initiative was identified as mostly applied exiting methodology to conduct LCI analysis in discrete manufacturing process like LAM. Many of the reviewed literature had focused to PBF of polymeric material and only few had considered metallic materials. The studies that had included metallic materials had only measured input and output energy or materials of the process and compared to different AM systems without comparing to any competitive process. Neither did any include effect of process variation when building metallic parts with LAM. Experimental testing were carried out to make dissimilar samples with CNC machining and LAM in this thesis. Test samples were designed to include part complexity and weight reductions. PUMA 2500Y lathe machine was used in the CNC machining whereas a modified research machine representing EOSINT M-series was used for the LAM. The raw material used for making the test pieces were stainless steel 316L bar (CNC machined parts) and stainless steel 316L powder (LAM built parts). An analysis of power, time, and the energy consumed in each of the manufacturing processes on production phase showed that LAM utilises more energy than CNC machining. The high energy consumption was as result of duration of production. Energy consumption profiles in CNC machining showed fluctuations with high and low power ranges. LAM energy usage within specific mode (standby, heating, process, sawing) remained relatively constant through the production. CNC machining was limited in terms of manufacturing freedom as it was not possible to manufacture all the designed sample by machining. And the one which was possible was aided with large amount of material removed as waste. Planning phase in LAM was shorter than in CNC machining as the latter required many preparation steps. Specific energy consumption (SEC) were estimated in LAM based on the practical results and assumed platform utilisation. The estimated platform utilisation showed SEC could reduce when more parts were placed in one build than it was in with the empirical results in this thesis (six parts).

Building climate justice : an analysis of how the nexus between climate change and human rights shapes public policy agendas and alternatives

This thesis provides an analysis of how the nexus between climate change and human rights shapes public policy agendas and alternatives. It draws upon seminal work conducted by John Kingdon, whose landmark publication “Agendas, alternatives, and public policy” described how separate streams of problems, solutions, and politics converge to move an issue onto the public policy agenda toward potential government action. Building on Kingdon’s framework, this research explores how human rights contribute to surfacing the problem of climate change; developing alternative approaches to tackling climate change; and improving the political environment necessary for addressing climate change with sufficient ambition. The study reveals that climate change undermines the realization of human rights and that human rights can be effective tools in building climate resilience. This analysis was developed using a mixed methods approach and drawing upon substantial literature review, the researcher’s own participation in international climate policy design; elite interviews with thought leaders dealing with climate change and human rights; and regular inputs from focus groups comprised of practitioners drawn from the fields of climate change, development and human rights. This is a journal based thesis with a total of six articles submitted for evaluation, published in peer‐reviewed publications, over a five year period. Denna avhandling analyserar hur klimatfrågan och mänskliga rättigheter i samverkan formar den politiska agendan och det politiskt möjliga. Den bygger på banbrytande forskning av John Kingdon, vars publikation “Agendas, alternatives, and public policy” beskriver hur en fråga blir politiskt viktig och lyfts upp på den politiska agendan. Med utgångspunkt i Kingdons ramverk, utforskar avhandlingen hur mänskliga rättigheter bidrar till att blottlägga klimatfrågan som problem; utveckla alternativa metoder för att angripa och hantera klimatfrågan; samt skapa ett politiskt klimat nödvändigt för att på ett ambitiöst sätt kunna angripa klimatfrågan. Studien visar att klimatförändringar undergräver mänskliga rättigheterna men att arbete med mänskliga rättigheter kan vara ett effektivt verktyg för att stå emot och hantera effekterna av klimatförändringar. Analysen har genomförts med hjälp av en rad olika metoder vilka inkluderar litteraturstudier, författarens egna observationer under klimatförhandlingar; intervjuer med ledande tänkare inom klimatfrågan och mänskliga rättigheter; samt data insamlad genom fokusgrupper bestående av yrkesverksamma inom klimat, utveckling och mänskliga rättigheter. Avhandlingen är baserad på totalt sex artiklar som publicerats i fackgranskade tidskrifter under en femårsperiod.