Contribution to Load-Frequency Regulation of a Hydropower Plant with Long Tail-Race Tunnel

In this paper, a hydroelectric power plant with long tail-race tunnel has been modelled for assessing its contribution to secondary regulation reserve. Cavitation problems, caused by the discharge conduit length, are expected downstream the turbine where low pressure appears during regulation manoeuvres. Therefore, governor's gains should be selected taking into account these phenomena. On the other hand, regulation services bidden by the plant operator should fulfil TSO (Transmission System Operator) quality requirements. A methodology for tuning governor PI gains is proposed and applied to a Hydro power plant in pre-design phase in northwest area of Spain. The PI gains adjustment proposed provides a proper plant response, according to some established indexes, while avoiding cavitation phenomena.

Coletores de distribuição e sua otimização hidráulica, aplicados a uma instalação de produção de água arrefecida em sistemas de AVAC ( Fórum Picoas)

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Monipolttoainekattilan päästöjen tarkkailu ja raportointi

Suurten polttolaitosten päästöjen tarkkailu- ja raportointivaatimukset ovat uudistuneet viime vuosina paljon. Suurimpia muutosten aiheuttajia ovat Valtioneuvoston asetus 1017/2002 ja standardi EN-14181. Tässä työssä kuvataan uudet vaatimukset täyttävän päästöjen tarkkailu- ja raportointijärjestelmän rakentaminen monipolttoainekattilalle. Aluksi esitellään mitä uusia vaatimuksia päästöjen tarkkailulle ja raportoinnille on tullut viime aikoina. Lisäksi selvitetään vaatimusten mahdolliset ristiriidat ja ristiriitatilanteiden ratkaisutavat. Seuraavaksi esitellään vaatimukset täyttävän järjestelmän määritelmät. Erityisestiselvitetään kattilan erityispiirteiden vaatimia ratkaisuja. Lopuksi esitellään päästöjen tarkkailu- ja raportointijärjestelmän käyttökokemuksia ja parantamismahdollisuuksia. Kaikki tarkastelut tehdään ensisijaisesti toiminnanharjoittajan näkökulmasta. Järjestelmä toteutettiin Stora Enso Oyj:n Heinolan Flutingtehtaan voimalaitoksen pääkattilalle, jossa käytetään laajaa polttoainevalikoimaa. Toteutuspaikan valinta tehtiin sillä perusteella, että uudet päästöjen tarkkailu- ja raportointivaatimukset ovat erityisen haasteellisia monipolttoainekattiloiden tapauksessa. Työssä selvitetään järjestelmän soveltamismahdollisuuksia myös kahdella muulla Stora Enson tehtaalla. Käyttöönottovaiheen johtopäätöksenä todettiin päästöjen tarkkailu- ja raportointijärjestelmän täyttävän sille asetetut vaatimukset. Lisäksi havaittiin, että toiminnanharjoittajan kannattaa panostaa erityisesti järjestelmän joustavuuteen, luotettavuuteen, helppokäyttöisyyteen ja vikasietoisuuteen. Toiminnanharjoittaja pystyy määrittelyvaiheessa vaikuttamaan järjestelmän ominaisuuksiin helpommin ja edullisemmin kuin käyttöönoton jälkeen. Toiminnanharjoittajalta vaadittu työtuntimäärä arvioitiin Heinolan Flutingtehtaan tapauksen perusteella. Lopuksi selvitettiin mahdollisia tulevaisuuden kehityskohteita vastaavissa järjestelmissä.

EDF and the Brazilian Power Sector

Electricité de France (EDF) is a leading player in the European energy market by being both the first electricity producer in Europe and the world’s leading nuclear plant operator. EDF is also the first electricity producer and supplier in France. However, Europe, EDF’s core market, is currently underperforming: the European sovereign debt crisis is lowering significantly the growth perspective of an energy market that has already reached its maturity. As a consequence, European energy companies are now looking at international markets and especially BRIC economies where economic growth potential remains high. Among them, Brazil is expected to keep its strong economic and electricity demand growth perspectives for the coming decades. Though Brazil has not been considered as a strategic priority for EDF after the Light reversal in 2006, the current economic situation has led the Group to reconsider its position toward the country. EDF’s current presence in Brazil is limited to its stake in UTE Norte Fluminense, a thermal plant, located in the state of Rio de Janeiro. This report investigates the possibility and the feasibility of EDF’s activities expansion in Brazil and what added value it could bring for the Brazilian power market. Considering that the status quo would not allow EDF to take full advantage of Brazil’s future growth, this work is identifying the various options that are currently opened to EDF: market exit, status quo, EDF alone, local partner. For that purpose, this study collects and analyses the latest energy market data as well as generation companies’ information which are necessary to give a relevant overview of the current brazilian power sector and to present EDF strategic options for the country.

Cauchy-Stieltjes Integral on Time Scales in Banach Spaces and Hysteresis Operators

The play operator has a fundamental importance in the theory of hysteresis. It was studied in various settings as shown by P. Krejci and Ph. Laurencot in 2002. In that work it was considered the Young integral in the frame of Hilbert spaces. Here we study the play in the frame of the regulated functions (that is: the ones having only discontinuities of the first kind) on a general time scale T (that is: with T being a nonempty closed set of real numbers) with values in a Banach space. We will be showing that the dual space in this case will be defined as the space of operators of bounded semivariation if we consider as the bilinearity pairing the Cauchy-Stieltjes integral on time scales.

An emergy-based evaluation of a reverse logistics network for steel recycling

Efficient implementation of recycling networks requires appropriate logistical structures for managing the reverse flow of materials from users to producers. The steel sheet distributor studied had established a protocol for scrap recovery with the steel plant and its customers. The company invested in producing containers, hiring a specialized labor force and in purchasing trucks for container transportation to implement the logistics network for recycling. That network interconnected the company with two kinds of customers: the ones returning scrap and the ones who preferred to continue business-as-usual. The logistical network was analyzed using emergy synthesis, and the data obtained were used to evaluate and compare the system's environmental costs and benefits from the perspective of the distributor and the steel plant operator. The use of emergy ternary diagrams provided a way to assess recycle strategies to compare the relative economic and environmental benefits of the logistical network implemented. The minimum quantity of scrap that the distributor must recover to improve environmental benefits was determined allowing decision on whether it is worth keeping the system running. The new assessment method proposed also may help policy-makers to create strategies to reward or incentive users of reverse logistics, and help to establish regulations, by decreasing taxes or stimulating innovation, for effectively implement the National Policy on Solid Waste. (C) 2013 Elsevier Ltd. All rights reserved.

Operator, organizational, direct support, and general support maintenance manual : press shelter, NSN 3610-00-987-9067, component of printing plant, special warfare, transportable, NSN 3610-00-889-3311.

Includes index.

Operator, organizational, direct support, and general support maintenance manual : editorial and photomechanical shelter, NSN 3610-00-9987-9066, component of printing plant, special warfare, transportable, NSN 3610-00-889-3311.

Includes index.

Operator, organizational, direct support, and general support maintenance manual : editorial and photomechanical shelter, NSN 3610-00-987-9066, component of printing plant, special warfare, transportable, NSN 3610-00-889-3311.

"June 1978."

Operator's manual : crusher, roll, diesel and electric driven, wheel mounted, pneumatic tires, 75 ton per hour (Eagle crusher model 5230B) FSN 3820-788-5999, component of crushing and screening plant, diesel and electric driven, wheel mounted, 75 ton per hour.

Includes index.

Operator's manual : crusher, jaw, diesel and electric driven; wheel mounted pneumatic tires; 75 ton per hour (Eagle crusher model 5157) FSN 3820-783-7311, component of crushing and screening plant; diesel and electric driven; wheel mounted; 75 ton per hour.

Includes index.

Operator's manual for crusher, roll, diesel and electric driven, wheel mounted, pneumatic tires, 75 ton per hour, Eagle crusher model 5230B and 5230C (NSN 3820-00-788-5999), Eagle crusher model 5230D (NSN 3820-00-876-7876), component of crushing and screening plant, diesel and electric driven, wheel mounted, 75 ton per hour.

"September 1991."

Operator's manual for crusher, jaw, diesel and electric driven, wheel mounted, pneumatic tires, 75 ton per hour, Eagle crusher model 5157 and 5157A (NSN 3820-00-783-7311), Eagle crusher model 5157B (NSN 3820-00-880-0540), component of crushing and screening plant, diesel and electric driven, wheel mounted, 75 ton per hour.

"September 1991."

Operator and organizational maintenance manual : crusher, jaw, diesel engine driven, semitrailer mounted, 35 ton per hour capacity (Iowa Manufacturing Company model 2A-2A), FSN 3820-851-6728, component of crushing and screening plant, diesel engine driven, FSN 3820-878-4285.

"September 1970."