Belt conveyor energy efficiency analysis and energy model development

An energy model of a belt conveyor was designed. Operation of a belt conveyor was researched. Operational indexes were calculated. Energy optimization process and recommendations were presented.

Ensimmäisen ja toisen sukupolven nestemäisten liikennebiopolttoaineiden kasvihuonekaasupäästöjenvertailu

Elinkaariarviointia voidaan käyttää ensimmäisen ja toisensukupolven nestemäisten liikennebiopolttoaineiden kasvihuonekaasupäästöjen ja primäärienergian kulutuksen vertailuun. Elinkaariarviointia käyttämällä pyritään tuottamaan luotettavaa tietoa koko elinkaaren ajalta. Nestemäisiä liikennebiopolttoaineita käsittelevissä tutkimuksissa elinkaari jaetaan yleensä kahteen osaan,joista suurempi painoarvo on elinkaaren alkuosalla. Tässä diplomityössä tehdään yksinkertaistettu elinkaariarviointi selluloosaetanolin ja Fischer-Tropsch-dieselin elinkaaren alkuosalle ja verrataan niitä sitten ohraetanoliin ja rypsimetyyliesteriin. Tässä työssä keskitytään primäärienergian kulutukseen sekä hiilidioksidi-, metaani- ja dityppioksidipäästöihin. Selluloosaetanolin raaka-aineena tarkasteltiin ruokohelpeä, Fischer-Tropsch-dieselin raaka-aineena metsätähdettä. Diplomityö osoitti, että toisen sukupolven nestemäisten liikennebiopolttoaineiden tuotannossa kuluu vähemmän primäärienergiaa ja syntyy vähemmän kasvihuonekaasupäästöjä kuin ensimmäisen sukupolven nestemäisten liikennebiopolttoaineiden tuotannossa. Sama tulos on saatu myös muissa aihetta käsittelevissä tutkimuksissa.

Energiansäästäminen, sen toteutus ja vaikutukset lannoitteita valmistavalla tehtaalla

Suomen täytyy vähentää kasvihuonekaasupäästöt vuoden 1990 tasolle vuosien 2008–2012 velvoitekauden aikana. Suomen kansallisen ilmasto-ohjelman mukaan noin puolet vaadittavasta vähennystavoitteesta voidaan saavuttaa lisäämällä biopolttoaineiden käyttöä ja säästämällä energiaa. Kemira Agro Oy:n Uudenkaupungin tehtaiden energiansäästäminen on alkanut sen liityttyä teollisuuden vapaaehtoiseen energiansäästösopimukseen vuonna 1999. Sopimus velvoittaa vähentämään energian ja veden kulutusta sekä raportoimaan vuosittaisista kulutuksista. Työssä on esitelty energiansäästämisen eteneminen yrityksessä sopimuksen hyväksymisestä energiansäästöanalyysin toteutukseen asti. Työssä on etsitty energiaa säästäviä ratkaisuja lannoitetehtaan käyttöön tehtaan tuotantoprosesseissa. Tuotanto-osastoille on laskettu energiataseet, joiden avulla on piirretty energiavirtoja kuvaavat sankey – diagrammit. Työssä on esitetty perusidea energiansäästön toteuttamiseksi ja alustavat kustannusarviot. Löydetyillä kohteilla voidaan säästää tehtaan sähkönkulutusta yhteensä 19 GWh/a ja lisätä tuotantoa. Ionivaihdettua vettä voidaan säästää noin 6000 m3/a. Laskelmat on esitetty cd-romilla liitteessä 31.

Knowledge Map of Research on Biofuels

This work highlights and analyzes the citations and co-citations by different authors, countries and institutions in series of researches on biofuel. These relations represent a knowledge map which shows the areas of research by different countries and authors. The contributions of different institutions were also shown. With this knowledge map developed, areas of research that still need more attention as well as the most important studies were highlighted. The software used for this analysis is Citespace which is developed by Chaomei Chen. Sources of information are articles retrieved from ISI Web of Science. Biofuel as a renewable form of energy is discussed. Its sources, types, methods of production, effects, market, and producers were discussed. Also plans and strategies that aim at boosting world biofuel market were listed as well as recent researches on it. Knowledge mapping, its types and methods as well as the method and software used for the analysis were also discussed.

Calculation analysis of energy saving tools for fan and pump applications

This thesis analyses the calculation of FanSave and PumpSave energy saving tools calculation. With these programs energy consumption of variable speed drive control for fans and pumps can be compared to other control methods. With FanSave centrifugal and axial fans can be examined and PumpSave deals with centrifugal pumps. By means of these programs also suitable frequency converter can be chosen from the ABB collection. Programs need as initial values information about the appliances like amount of flow and efficiencies. Operation time is important factor when calculating the annual energy consumption and information about it are the length and profile. Basic theory related to fans and pumps is introduced without more precise instructions for dimensioning. FanSave and PumpSave contain various methods for flow control. These control methods are introduced in the thesis based on their operational principles and suitability. Also squirrel cage motor and frequency converter are introduced because of their close involvement to fans and pumps. Second part of the thesis contains comparison between results of FanSave’s and PumpSave’s calculation and performance curve based calculation. Also laboratory tests were made with centrifugal and axial fan and also with centrifugal pump. With the results from this thesis the calculation of these programs can be adjusted to be more accurate and also some new features can be added.

Strategic groups and performance: an empirical analysis of strategic groups in the wind energy industry in Europe

The strategic group theory provides an intermediate level of analysis between a single company and the whole industry for identifying issues about the company's competitive position and strategic choices. Strategic groups are companies within an industry with similar strategic characteristics or competing on similar bases. Strategic choices are aligned with the firms’ resources. The purpose of this study was to identify the strategic groups in the wind energy industry in Europe, and study, whether a certain group membership results in financial performance differences. Altogether 80 European wind energy companies were included in the study, which were clustered into four strategic groups according to their age and growth rate. Each group corresponds to a different strategy. The results show that the wind energy companies can be clustered according to the chosen strategic characteristics. Strategic decisions were investigated with characteristic variables. Performance variables were used in the analysis measuring profitability, liquidity and solvency of the groups. These strategic choices of the companies did not have a significant influence on the firms’ performance. The more mature and slower growing group proved to be the most successful. However, the differences between groups were generally not statistically significant. The only statistically significant difference found was in the solvency ratio between Mature Slow and Young Rapid groups. Measured with these variables, more mature and slower growing companies performed better. Therefore, a certain strategic group membership results in performance differences.

Strategic choices and performance – an empirical analysis of largest European and North American energy companies

Energy industry has gone through major changes globally in past two decades. Liberalization of energy markets has led companies to integrate both vertically and horizontally. Growing concern on sustainable development and aims to decrease greenhouse gases in future will increase the portion of renewable energy in total energy production. Purpose of this study was to analyze using statistical methods, what impacts different strategic choices has on biggest European and North American energy companies’ performance. Results show that vertical integration, horizontal integration and use of renewable energy in production had the most impact on profitability. Increase in level of vertical integration decreased companies’ profitability, while increase in horizontal integration improved companies’ profitability. Companies that used renewable energy in production were less profitable than companies not using renewable energy.

Induction Motor Drive Energy Efficiency - Simulation and Analysis

A coupled system simulator, based on analytical circuit equations and a finite element method (FEM) model of the motor has been developed and it is used to analyse a frequency-converterfed industrial squirrel-cage induction motor. Two control systems that emulate the behaviour of commercial direct-torque-controlled (DTC) and vector-controlled industrial frequency converters have been studied, implemented in the simulation software and verified by extensive laboratory tests. Numerous factors that affect the operation of a variable speed drive (VSD) and its energy efficiency have been investigated, and their significance in the simulation of the VSD results has been studied. The dependency of the frequency converter, induction motor and system losses on the switching frequency is investigated by simulations and measurements at different speeds for both the vector control and the DTC. Intensive laboratory measurements have been carried out to verify the simulation results.

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).

Performance Degradation Modelling and Techno-Economic Analysis of Lithium-Ion Battery Energy Storage Systems

Transmission system operators and distribution system operators are experiencing new challenges in terms of reliability, power quality, and cost efficiency. Although the potential of energy storages to face those challenges is recognized, the economic implications are still obscure, which introduce the risk into the business models. This thesis aims to investigate the technical and economic value indicators of lithium-ion battery energy storage systems (BESS) in grid-scale applications. In order to do that, a comprehensive performance lithium-ion BESS model with degradation effects estimation is developed. The model development process implies literature review on lifetime modelling, use, and modification of previous study progress, building the additional system parts and integrating it into a complete tool. The constructed model is capable of describing the dynamic behavior of the BESS voltage, state of charge, temperature and capacity loss. Five control strategies for BESS unit providing primary frequency regulation are implemented, in addition to the model. The questions related to BESS dimensioning and the end of life (EoL) criterion are addressed. Simulations are performed with one-month real frequency data acquired from Fingrid. The lifetime and cost-benefit analysis of the simulation results allow to compare and determine the preferable control strategy. Finally, the study performs the sensitivity analysis of economic profitability with variable size, EoL and system price. The research reports that BESS can be profitable in certain cases and presents the recommendations.

Computational and Experimental Analysis of Flow Field in the Diffusers of Centrifugal Compressors

Centrifugal compressors are widely used for example in process industry, oil and gas industry, in small gas turbines and turbochargers. In order to achieve lower consumption of energy and operation costs the efficiency of the compressor needs to be improve. In the present work different pinches and low solidity vaned diffusers were utilized in order to improve the efficiency of a medium size centrifugal compressor. In this study, pinch means the decrement of the diffuser flow passage height. First different geometries were analyzed using computational fluid dynamics. The flow solver Finflo was used to solve the flow field. Finflo is a Navier-Stokes solver. The solver is capable to solve compressible, incompressible, steady and unsteady flow fields. Chien's k-e turbulence model was used. One of the numerically investigated pinched diffuser and one low solidity vaned diffuser were studied experimentally. The overall performance of the compressor and the static pressure distribution before and after the diffuser were measured. The flow entering and leaving the diffuser was measured using a three-hole Cobra-probe and Kiel-probes. The pinch and the low solidity vaned diffuser increased the efficiency of the compressor. Highest isentropic efficiency increment obtained was 3\% of the design isentropic efficiency of the original geometry. It was noticed in the numerical results that the pinch made to the hub and the shroud wall was most beneficial to the operation of the compressor. Also the pinch made to the hub was better than the pinchmade to the shroud. The pinch did not affect the operation range of the compressor, but the low solidity vaned diffuser slightly decreased the operation range.The unsteady phenomena in the vaneless diffuser were studied experimentally andnumerically. The unsteady static pressure was measured at the diffuser inlet and outlet, and time-accurate numerical simulation was conducted. The unsteady static pressure showed that most of the pressure variations lay at the passing frequency of every second blade. The pressure variations did not vanish in the diffuser and were visible at the diffuser outlet. However, the amplitude of the pressure variations decreased in the diffuser. The time-accurate calculations showed quite a good agreement with the measured data. Agreement was very good at the design operation point, even though the computational grid was not dense enough inthe volute and in the exit cone. The time-accurate calculation over-predicted the amplitude of the pressure variations at high flow.

Performance analysis of software run-time behaviour using 3D-visualisation

Monimutkaisen tietokonejärjestelmän suorituskykyoptimointi edellyttää järjestelmän ajonaikaisen käyttäytymisen ymmärtämistä. Ohjelmiston koon ja monimutkaisuuden kasvun myötä suorituskykyoptimointi tulee yhä tärkeämmäksi osaksi tuotekehitysprosessia. Tehokkaampien prosessorien käytön myötä myös energiankulutus ja lämmöntuotto ovat nousseet yhä suuremmiksi ongelmiksi, erityisesti pienissä, kannettavissa laitteissa. Lämpö- ja energiaongelmien rajoittamiseksi on kehitetty suorituskyvyn skaalausmenetelmiä, jotka edelleen lisäävät järjestelmän kompleksisuutta ja suorituskykyoptimoinnin tarvetta. Tässä työssä kehitettiin visualisointi- ja analysointityökalu ajonaikaisen käyttäytymisen ymmärtämisen helpottamiseksi. Lisäksi kehitettiin suorituskyvyn mitta, joka mahdollistaa erilaisten skaalausmenetelmien vertailun ja arvioimisen suoritusympäristöstä riippumatta, perustuen joko suoritustallenteen tai teoreettiseen analyysiin. Työkalu esittää ajonaikaisesti kerätyn tallenteen helposti ymmärrettävällä tavalla. Se näyttää mm. prosessit, prosessorikuorman, skaalausmenetelmien toiminnan sekä energiankulutuksen kolmiulotteista grafiikkaa käyttäen. Työkalu tuottaa myös käyttäjän valitsemasta osasta suorituskuvaa numeerista tietoa, joka sisältää useita oleellisia suorituskykyarvoja ja tilastotietoa. Työkalun sovellettavuutta tarkasteltiin todellisesta laitteesta saatua suoritustallennetta sekä suorituskyvyn skaalauksen simulointia analysoimalla. Skaalausmekanismin parametrien vaikutus simuloidun laitteen suorituskykyyn analysoitiin.

Strategic groupsin the European energy industry

Strategisten ryhmien teoria tarjoaa mahdollisuuden keskitason analyysiin yritysten ja toimialan välillä yritysten kilpailullisen aseman tarkasteluun. Strategiset ryhmät ovat samalla toimialalla toimivia yrityksiä, joilla on samanlaiset strategiset ominaisuudet, jotka kilpailevat samanlaisilla perusteilla tai jotka toteuttavat samanlaista strategiaa. Tässä tutkimuksessa strategisten ryhmien teoriaa on käytetty eurooppalaisten energiayritysten ryhmittelyyn. Tutkimuksessa oli mukana 104 energia-alan yritystä, jotka jaettiin viiteen strategiseen pääryhmään yritysten maantieteellisen toiminta-alueen ja koon mukaan. Jokainen ryhmä edustaa erilaista strategiaa. Muita strategisia ominaisuuksia, joita ovat diversifikaatioaste, tuotantoteknologia ja omistusmuoto, käytettiin muodostamaan alaryhmiä edellisistä pääryhmistä. Muodostettuja strategisia ryhmiä käytettiin seuraavaksi suoristuskykyerojen tutkimiseen ryhmien välillä. Suorituskykyä kuvaaviksi muuttujiksi valittiin liikevoitto-%, koko pääoman tuottoaste, vakavaraisuus-% ja current ratio. Tulokset osoittavat, että energiayritykset voidaan jakaa ryhmiin valittujen strategisten ominaisuuksien perusteella. Nämä yritysten strategiset valinnat eivät vaikuta merkittävästi yritysten taloudelliseen suorituskykyyn valittujen suorituskykymuuttujien osalta. Monikansalliset jättiläisyritykset ovat suorituskyvyltään heikoimpia ja eurooppalaiset suuryritykset parhaita ryhmiä, mutta erot eivät ole tilastollisesti merkittäviä. Ainut merkittävä ero suorituskykymuuttujissa oli vakavaraisuudessa monikansallisten ja eurooppalaisten suurten yritysten välillä. Muut suorituskykymuuttujat eivät eronneet ryhmien välillä tilastollisesti merkittävästi. Tilastollisesti merkittäviä eroja ei löydetty myöskään alaryhmien välillä.

Analysis of the voltage source inverter with small DC-link capacitor

IIn electric drives, frequency converters are used to generatefor the electric motor the AC voltage with variable frequency and amplitude. When considering the annual sale of drives in values of money and units sold, the use of low-performance drives appears to be in predominant. These drives have tobe very cost effective to manufacture and use, while they are also expected to fulfill the harmonic distortion standards. One of the objectives has also been to extend the lifetime of the frequency converter. In a traditional frequency converter, a relatively large electrolytic DC-link capacitor is used. Electrolytic capacitors are large, heavy and rather expensive components. In many cases, the lifetime of the electrolytic capacitor is the main factor limiting the lifetime of the frequency converter. To overcome the problem, the electrolytic capacitor is replaced with a metallized polypropylene film capacitor (MPPF). The MPPF has improved properties when compared to the electrolytic capacitor. By replacing the electrolytic capacitor with a film capacitor the energy storage of the DC-linkwill be decreased. Thus, the instantaneous power supplied to the motor correlates with the instantaneous power taken from the network. This yields a continuousDC-link current fed by the diode rectifier bridge. As a consequence, the line current harmonics clearly decrease. Because of the decreased energy storage, the DC-link voltage fluctuates. This sets additional conditions to the controllers of the frequency converter to compensate the fluctuation from the supplied motor phase voltages. In this work three-phase and single-phase frequency converters with small DC-link capacitor are analyzed. The evaluation is obtained with simulations and laboratory measurements.