Energiaa säästävä uusi viemäriveden pumppausteknologia

Pumppaaminen kuluttaa teollisuudessa huomattavan osan energiasta, joten siellä on myös merkittäviä säästömahdollisuuksia. Maailmanlaajuisesti pumppaus kuluttaa noin viidenneksen sähkömoottorien energiantarpeesta, ja tietyillä teollisuudentoimialoilla jopa yli 50%. Jätevedenpumppaus perustuu edelleenkin pääosin 50- ja 60- luvuilla kehitettyyn tekniikkaan, merkittäviä energiansäästöjä on mahdollista saavuttaa suhteellisen pienillä investoinneilla. Työn teoriaosassa käsitellään perusteet jätevedenkäsittelystä, ja viemäriputkiston rakenteesta. Pumppuja, sähkömoottoreita ja taajuusmuuttajia käsitellään laajemmin keskittyen niiden toimintaan ja toimintaa ohjaaviin teorioihin. Empiirisessä osassa tutkitaan uuden teknologian energiansäästöpotentiaalia erilaisilla mittauksilla, sekä mittausten pohjalta tehdyillä case-analyyseillä. Näitä analyysejä varten työn aikana kehiteltiin laskin, jolla voidaan arvioida energian kulutusta tunnetulle pumpulle, kun tiedetään haluttu toimintapiste. Työssä käsitelty uusi teknologia on mahdollisesti merkittävin uudistus viemäriveden pumppausteknologiaan taajuusmuuttajien käyttöönoton jälkeen. Teknologialla päästään eroon imukaivoista liki täysin, ja sitä kautta saadaan paremmin hallittua monia ongelmia kuten hajuhaittoja. Teknologian merkittävin hyöty on kuitenkin energiansäästö. Perinteisessä teknologiassa taajuusmuuttajat ovat olleet kannattavia, mikäli geodeettisen nostokorkeuden osuus on mahdollisimman pieni. Tyypillisessä uuden teknologian sovelluskohteissa geodeettinen nostokorkeus tulee yleensä olemaan pieni, joten uuden teknologian käyttöönoton kannattavuus on näissä kohteissa erityisen hyvä.

Efficiency and reliability enhancement of silicon nanocrystal field-effect luminescence from nitride-oxide gate stacks

We report on a field-effect light emitting device based on silicon nanocrystals in silicon oxide deposited by plasma-enhanced chemical vapor deposition. The device shows high power efficiency and long lifetime. The power efficiency is enhanced up to 0.1 %25 by the presence of a silicon nitride control layer. The leakage current reduction induced by this nitride buffer effectively increases the power efficiency two orders of magnitude with regard to similarly processed devices with solely oxide. In addition, the nitride cools down the electrons that reach the polycrystalline silicon gate lowering the formation of defects, which significantly reduces the device degradation.

CHARACTERISING THE EOS SLOT-SCANNING SYSTEM WITH THE EFFECTIVE DETECTIVE QUANTUM EFFICIENCY.

NlmCategory="UNASSIGNED">As opposed to the standard detective quantum efficiency (DQE), effective DQE (eDQE) is a figure of merit that allows comparing the performances of imaging systems in the presence of scatter rejection devices. The geometry of the EOS™ slot-scanning system is such that the detector is self-collimated and rejects scattered radiation. In this study, the EOS system was characterised using the eDQE in imaging conditions similar to those used in clinical practice: with phantoms of different widths placed in the X-ray beam, for various incident air kerma and tube voltages corresponding to the phantom thickness. Scatter fractions in EOS images were extremely low, around 2 % for all configurations. Maximum eDQE values spanned 9-14.8 % for a large range of air kerma at the detector plane from 0.01 to 1.34 µGy. These figures were obtained with non-optimised EOS setting but still over-performed most of the maximum eDQEs recently assessed for various computed radiology and digital radiology systems with antiscatter grids.

Analyzing the temporal regulation of translation efficiency in mouse liver.

Mammalian physiology and behavior follow daily rhythms that are orchestrated by endogenous timekeepers known as circadian clocks. Rhythms in transcription are considered the main mechanism to engender rhythmic gene expression, but important roles for posttranscriptional mechanisms have recently emerged as well (reviewed in Lim and Allada (2013) [1]). We have recently reported on the use of ribosome profiling (RPF-seq), a method based on the high-throughput sequencing of ribosome protected mRNA fragments, to explore the temporal regulation of translation efficiency (Janich et al., 2015 [2]). Through the comparison of around-the-clock RPF-seq and matching RNA-seq data we were able to identify 150 genes, involved in ribosome biogenesis, iron metabolism and other pathways, whose rhythmicity is generated entirely at the level of protein synthesis. The temporal transcriptome and translatome data sets from this study have been deposited in NCBI's Gene Expression Omnibus under the accession number GSE67305. Here we provide additional information on the experimental setup and on important optimization steps pertaining to the ribosome profiling technique in mouse liver and to data analysis.

Taajuusmuuttajaohjatun pumppukäytön simulointimallin kehittäminen ja testaus

Pumppukäytöt vastaavat noin neljänneksestä Euroopan sähkömoottoreissa kulutettavasta sähkötehosta. Energian kallistumisen vuoksi energian säästämisestä ja energiatehokkuudesta on tullut yhä tärkeämpää. Taajuusmuuttajat ovat tuoneet yksinkertaisen säätötavan, jolla suurimmassa osassa pumppukäyttöjä voidaan saada huomattavia energiasäästöjä. Koko energiansäästöpotentiaalin hyödyntämiseksi täytyy kuitenkin pumppujen toimintaa tarkkailla. Tarkkailu voidaan toteuttaa käyttämällä taajuusmuuttajan sisäisiä mittauksia pumpun toimintapisteen määrittämiseen. Tässä työssä muodostetaan kaksi simulointimallia, joilla voidaan tutkia pumppukäytön toimintapistettä ja energiatehokkuutta. Pumpattavan nesteen ominaisuuksien vaikutusta malleihin tutkitaan ja tapoja korjata virhettä selvitetään. Mallien tuottamia estimaatteja verrataan laboratorio ja pilot-kohteiden mittauksiin. Pilot-kohteiden avulla tutkitaan voidaanko simulointimalleja käyttää teollisuuden energiansäästöpotentiaalia omaavien pumppukäyttöjen havaitsemiseen.

Energy efficiency parameters in variable speed drives

The main purpose of this thesis is to measure and evaluate how accurately the current energy saving calculation in ABB’s new variable speed drive ACS850 works. The main topic of this thesis is energy-efficiency parameters. At the beginning of this thesis centrifugal pump, squirrel cage motor and variable speed drive, including some equations related to them, are being introduced. Also methods of throttling control and variable speed drive control of centrifugal pumps are being introduced. These subjects are introduced because the energy saving calculation in ACS850 is related to the centrifugal pumps usually driven by squirrel cage motors. The theory also includes short section about specific energy of pumping. Before measurements the current energy saving calculation of ACS850 is being introduced and analyzed. The measurements part includes introduction of measuring equipment, measurement results, summary and analysis of the measurements. At the end of this thesis a proposal for an improvement to the current energy saving calculation is being introduced and few proposals are made for new energy-efficiency parameters, which could be added to variable speed drives. At the end are also thoughts

Enhancing the efficiency of freight transport by using simulation

The role of transport in the economy is twofold. As a sector of economic activity it contributes to a share of national income. On the other hand, improvements in transport infrastructure create room for accelerated economic growth. As a means to support railways as a safe and environmentally friendly transportation mode, the EU legislation has required the opening of domestic railway freight for competition from beginning of year 2007. The importance of railways as a mode of transport has been great in Finland, as a larger share of freight has been carried on rails than in Europe on average. In this thesis it is claimed that the efficiency of goods transport can be enhanced by service specific investments. Furthermore, it is stressed that simulation can and should be used to evaluate the cost-efficiency of transport systems on operational level, as well as to assess transportation infrastructure investments. In all the studied cases notable efficiency improvements were found. For example in distribution, home delivery of groceries can be almost twice as cost efficient as the current practice of visiting the store. The majority of the cases concentrated on railway freight. In timber transportation, the item with the largest annual transport volume in domestic railway freight in Finland, the transportation cost could be reduced most substantially. Also in international timber procurement, the utilization of railway wagons could be improved by combining complementary flows. The efficiency improvements also have positive environmental effects; a large part of road transit could be moved to rails annually. If impacts of freight transport are included in cost-benefit analysis of railway investments, up to 50 % increase in the net benefits of the evaluated alternatives can be experienced, avoiding a possible inbuilt bias in the assessment framework, and thus increasing the efficiency of national investments in transportation infrastructure. Transportation systems are a typical example of complex real world systems that cannot be analysed realistically by analytical methods, whereas simulation allows inclusion of dynamics and the level of detail required. Regarding simulation as a viable tool for assessing the efficiency of transportation systems finds support also in the international survey conducted for railway freight operators; operators use operations research methods widely for planning purposes, while simulation is applied only by the larger operators.

Energy efficiency determinants: An empirical analysis of Spanish innovative firms

This paper examines the extent to which innovative Spanish firms pursue improvements in energy efficiency (EE) as an objective of innovation. The increase in energy consumption and its impact on greenhouse gas emissions justifies the greater attention being paid to energy efficiency and especially to industrial EE. The ability of manufacturing companies to innovate and improve their EE has a substantial influence on attaining objectives regarding climate change mitigation. Despite the effort to design more efficient energy policies, the EE determinants in manufacturing firms have been little studied in the empirical literature. From an exhaustive sample of Spanish manufacturing firms and using a logit model, we examine the energy efficiency determinants for those firms that have innovated. To carry out the econometric analysis, we use panel data from the Community Innovation Survey for the period 2008‐2011. Our empirical results underline the role of size among the characteristics of firms that facilitate energy efficiency innovation. Regarding company behaviour, firms that consider the reduction of environmental impacts to be an important objective of innovation and that have introduced organisational innovations are more likely to innovate with the objective of increasing energy efficiency. Keywords: energy efficiency, corporate targets, innovation, Community Innovation Survey. JEL Classification: Q40, Q55, O31

Efficiency and Equity in Learning Communities and schools

Traditionally, school efficiency has been measured as a function of educational production. In the last two decades, however, studies in the economics of education have indicated that more is required to improve school efficiency: researchers must explore how significant changes in school organization affect the performance of at-risk students. In this paper we introduce Henry Levin’s adoption of the X-efficiency approach to education and we describe the efficient and cost-effective characteristics of one Learning Communities Project School that significantly improved its student outcomes and enrollment numbersand reduced its absenteeism rate to zero. The organizational change that facilitatedthese improvements defined specific issues to address. Students’ school success became the focus of the school project, which also offered specific incentives, selected teachers, involved parents and community members in decisions, and used the most efficient technologies and methods. This case analysis reveals new two elements—family training and community involvement—that were not explicit parts of Levin’s adaptation. The case of the Antonio Machado Public School should attract the attention of both social scientists and policy makers

Converter Supply Transformer For LVDC Distribution System

This master’s thesis is focused on optimizing the parameters of a distribution transformer with respect to low voltage direct current (LVDC) distribution system. One of the main parts of low voltage direct current (LVDC) distribution system is transformer. It is studied from several viewpoints like filtering capabilities of harmonics caused by rectifier, losses and short circuit current limiting Determining available short circuit currents is one of the most important aspects of designing power distribution systems. Short circuits and their effects must be considered in selecting electrical equipment, circuit protection and other devices.

Position sensorless electrically excited synchronous motor drive for industrial use based on direct flux linkage and torque control

Synchronous machines with an AC converter are used mainly in large drives, for example in ship propulsion drives as well as in rolling mill drives in steel industry. These motors are used because of their high efficiency, high overload capacity and good performance in the field weakening area. Present day drives for electrically excited synchronous motors are equipped with position sensors. Most drives for electrically excited synchronous motors will be equipped with position sensors also in future. This kind of drives with good dynamics are mainly used in metal industry. Drives without a position sensor can be used e.g. in ship propulsion and in large pump and blower drives. Nowadays, these drives are equipped with a position sensor, too. The tendency is to avoid a position sensor if possible, since a sensor reduces the reliability of the drive and increases costs (latter is not very significant for large drives). A new control technique for a synchronous motor drive is a combination of the Direct Flux Linkage Control (DFLC) based on a voltage model and a supervising method (e.g. current model). This combination is called Direct Torque Control method (DTC). In the case of the position sensorless drive, the DTC can be implemented by using other supervising methods that keep the stator flux linkage origin centered. In this thesis, a method for the observation of the drift of the real stator flux linkage in the DTC drive is introduced. It is also shown how this method can be used as a supervising method that keeps the stator flux linkage origin centered in the case of the DTC. In the position sensorless case, a synchronous motor can be started up with the DTC control, when a method for the determination of the initial rotor position presented in this thesis is used. The load characteristics of such a drive are not very good at low rotational speeds. Furthermore, continuous operation at a zero speed and at a low rotational speed is not possible, which is partly due to the problems related to the flux linkage estimate. For operation in a low speed area, a stator current control method based on the DFLC modulator (DMCQ is presented. With the DMCC, it is possible to start up and operate a synchronous motor at a zero speed and at low rotational speeds in general. The DMCC is necessary in situations where high torque (e.g. nominal torque) is required at the starting moment, or if the motor runs several seconds at a zero speed or at a low speed range (up to 2 Hz). The behaviour of the described methods is shown with test results. The test results are presented for the direct flux linkage and torque controlled test drive system with a 14.5 kVA, four pole salient pole synchronous motor with a damper winding and electric excitation. The static accuracy of the drive is verified by measuring the torque in a static load operation, and the dynamics of the drive is proven in load transient tests. The performance of the drive concept presented in this work is sufficient e.g. for ship propulsion and for large pump drives. Furthermore, the developed methods are almost independent of the machine parameters.

Analyzing the cost-efficiency and performance of a payroll department by benchmarking

Tämän diplomityön tavoitteena oli analysoida Stora Enson palkkakeskuksen ja sen henkilöstöhallinnon järjestelmän, SAP HR:n, kustannustehokkuutta ja suorituskykyä. Tutkimuksessa käytettiin apuna benchmarkingia. Viisi suurta suomalaisyritystä osallistui benchmarkingiin. Benchmarkingin pääkohteena oli yritysten välinen kustannusvertailu. Kyselyssä perehdyttiin myös yritysten järjestelmien suorituskykyyn. Tuloksien perusteella Stora Enson palkkakeskus tarjoaa kustannustehokkaan ja kilpailukykyisen ratkaisun, joka menestyy hyvin vertailussa muihin suomalaisiin yrityksiin.

Hybrid LC Filter for Power Electronic Drives: Theory and Implementation

Power electronic converter drives use, for the sake of high efficiency, pulse-width modulation that results in sequences of high-voltage high-frequency steep-edged pulses. Such a signal contains a set of high harmonics not required for control purposes. Harmonics cause reflections in the cable between the motor and the inverter leading to faster winding insulation ageing. Bearing failures and problems with electromagnetic compatibility may also result. Electrical du/dt filters provide an effective solution to problems caused by pulse-width modulation, thereby increasing the performance and service life of the electrical machines. It is shown that RLC filters effectively decrease the reflection phenomena in the cable. Improved (simple, but effective) solutions are found for both differential- and common-mode signals; these solutions use a galvanic connection between the RLC filter star point and the converter DC link. Foil chokes and film capacitors are among the most widely used components in high-power applications. In actual applications they can be placed in different parts of the cabinet. This fact complicates the arrangement of the cabinet and decreases the reliability of the system. In addition, the inductances of connection wires may prevent filtration at high frequencies. This thesis introduces a new hybrid LC filter that uses a natural capacitance between the turns of the foil choke based on integration of an auxiliary layer into it. The main idea of the hybrid LC filter results from the fact that both the foil choke and the film capacitors have the same roll structure. Moreover, the capacitance between the turns (“intra capacitance”) of the foil inductors is the reason for the deterioration of their properties at high frequencies. It is shown that the proposed filter has a natural cancellation of the intra capacitance. A hybrid LC filter may contain two or more foil layers isolated from each other and coiled on a core. The core material can be iron or even air as in the filter considered in this work. One of the foils, called the main foil, can be placed between the inverter and the motor cable. Other ones, called auxiliary foils, may be connected in star to create differential-mode noise paths, and then coupled to the DC link midpoint to guarantee a traveling path, especially for the common-mode currents. This way, there is a remarkable capacitance between the main foil and the auxiliary foil. Investigations showed that such a system can be described by a simple equivalent LC filter in a wide range of frequencies. Because of its simple hybrid construction, the proposed LC filter can be a cost-effective and competitive solution for modern power drives. In the thesis, the application field of the proposed filter is considered and determined. The basics of hybrid LC filter design are developed further. High-frequency behaviour of the proposed filter is analysed by simulations. Finally, the thesis presents experimental data proving that the hybrid LC filter can be used for du/dt of PWM pulses and reduction of common-mode currents.

Eficiència energètica aplicada a les instal·lacions de la Universitat de Vic

En termes generals, es pot definir l’Eficiència Energètica com la reducció del consum d’energia mantenint els mateixos serveis energètics, sense disminuir el nostre confort i qualitat de vida, protegint el medi ambient, assegurant el proveïment i fomentant un comportament Sostenible al seu ús. L’objectiu principal d’aquest treball, és reduir el consum d’energia i terme de potència contractat a la Universitat de Vic, aplicant un programa d’estalvi amb mesures correctores en el funcionament de les seves instal·lacions o espais. Per tal de poder arribar a aquest objectiu marcat, prèviament s’ha realitzat un estudi acurat, obtenint tota la informació necessària per poder aplicar les mesures correctores a la bossa més important de consum. Un cop trobada, dur a terme l’estudi de la viabilitat de la inversió de les mesures correctores més eficients, optimitzant els recursos destinats. L’espai on s’ha dut a terme l’estudi, ha estat a l’edifici F del Campus Miramarges, seguint les indicacions d’Arnau Bardolet (Cap de Manteniment de la UVIC). Aquest edifici consta d’un entresol, baixos i quatre plantes. L’equip de mesura que s’ha fet servir per realitzar l’estudi, és de la marca Circutor sèrie AR5-L, aquests equips són programables que mesuren, calculen i emmagatzemen en memòria els principals paràmetres elèctrics en xarxes trifàsiques. Els projectes futurs complementaris que es podrien realitzar a part d’aquest són: instal·lar sensors, instal·lar mòduls convertidors TCP/IP, aprofitar la xarxa intranet i crear un escada amb un sinòptic de control i gestió des d’un punt de treball. Aquest aplicatiu permet visualitzar en una pantalla d’un PC tots els estats dels elements controlats mitjançant un sinòptic (encendre/parar manualment l’enllumenat i endolls de les aules, estat d’enllumenat i endolls de les aules, consums instantanis/acumulats energètics, estat dels passadissos entre altres) i explotar les dades recollides a la base de dades. Cada espai tindria la seva lògica de funcionament automàtic específic. Entre les conclusions més rellevants obtingudes en aquest treball s’observa: · Que és pot reduir la potència contractada a la factura a l’estar per sota de la realment consumida. · Que no hi ha penalitzacions a la factura per consum de reactiva, ja que el compensador funciona correctament. · Que es pot reduir l’horari de l’inici del consum d’energia, ja que no correspon a l’activitat docent. · Els valors de la tensió i freqüència estan dintre de la normalitat. · Els harmònics estan al llindar màxim. Analitzant aquestes conclusions, voldria destacar les mesures correctores més importants que es poden dur a terme: canvi tecnològic a LED, temporitzar automàticament l’encesa i apagada dels fluorescents i equips informàtics de les aules “seguint calendari docent”, instal·lar sensors de moviment amb detecció lumínica als passadissos. Totes les conclusions extretes d’aquest treball, es poden aplicar a tots els edificis de la facultat, prèviament realitzant l’estudi individual de cadascuna, seguint els mateixos criteris per tal d’optimitzar la inversió.

The effect of pulp washing on bleaching efficiency

The main aim of this study was to inspect the influence of the ultrafiltration implementation on the washing and on bleaching efficiency. Four cases corresponding to four washing stages were observed: two with hardwood pulp and two with softwood pulp; each case had a reference and a trial experiment. The experiments with hardwood pulp were arranged in a manner to explore predominantly the possibility of bleaching performance improvement by applying for washing instead of untreated filtrate (reference case) the same treated one (trial case). Despite that the ultrafiltration reduced the COD of the wash filtrates allowing the decreasing of COD carry-over to the bleaching stage it didn’t affect the bleaching performance. Another set was used in the experiments with softwood pulp. It implied the ultrafiltration and recirculation of the filtrate to the same washing stage with the purpose to reduce the volumes and pollution of the bleaching effluents. In one case the negative result was obtained which was expressed by worse parameters of the pulp after bleaching. Another case showed the opportunity to replace hot water with the filtrate and reduce the fresh water consumption.