[FREMDRIVNINGS OPTIMERING] ... Jim Lindegaard Nielsen ¢â‚¬â€œ A11548 Fremdrivnings optimering Side 3 af

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  • 2015

    Aarhus Maskinmesterskole Jim Lindegaard Nielsen

    [FREMDRIVNINGS OPTIMERING]

  • Jim Lindegaard Nielsen – A11548 Fremdrivnings optimering

    Side 1 af 44

    Forfatter: Jim Lindegaard Nielsen – A11548

    Titel: Fremdrivnings optimering

    Uddannelse: Maskinmester

    Uddannelses sted: Aarhus Maskinmesterskole, Navitas

    Vejleder: Anders Parbo, Lektor Aams

    Dato for aflevering: 1. juni 2015

    Rapport art: Afsluttende Bachelor Projekt

    Antal normalsider: 60798 tegn - 25,3 normalsider af 2400

    anslag

    X Jim Lindegaard Nielsen

  • Jim Lindegaard Nielsen – A11548 Fremdrivnings optimering

    Side 2 af 44

    Abstract The passenger ship DFDS Crown Seaways is sailing a route from Copenhagen to Oslo. This

    trip takes approximately 17 hours where after it will stay in port for seven hours before

    returning again. Five of the 17 hours at sea is inside the fjord of Olso or Ørresund. These

    waterways are calm without any major waves. The objective of this report is to

    investigate the possibility of optimizing the ships efficiency.

    The ships propulsion system consists of four main engines which are coupled together via

    a reduction gear in pairs of two. Each pair is connected to a Controllable Pitch Propeller

    (CPP). The CPP is controlled by the bridge or engine control room via a propeller curve.

    This Curve interprets the signal from the bridge and converts it in to a pitch on the

    propeller and a matching speed of revolution. This propeller curve is designed with a sea

    margin of about 15 % this is to account for the fouling of hull and propeller and an

    increase of resistance due to high wind, waves and currents. One sixth of the journey is in

    calm waters with little change in resistance in the form of waves. This report will

    investigate the possibility of a more fuel efficient propeller curve for sailing in calm

    waters. This is done by reducing the sea margin to increase the load on the propeller and

    engine. This will raise the combustion pressure and this will have a positive effect on the

    engines efficiency. The rise in efficiency is at the cost of extra power at the given rate of

    revolution. This means less power for increased load by waves and less power for

    accelerations meaning acceleration will be slower.

    The report will cover all the relevant theory such as the losses and efficiencies of a

    diesel engine and friction theory. The methods of taking all the necessary data for

    the calculations are explained as well.

  • Jim Lindegaard Nielsen – A11548 Fremdrivnings optimering

    Side 3 af 44

    Resume Passagerskibet Crown Seaways fra rederiet DFDS sejler mellem København og Oslo. Turen

    varer ca. 17 timer, hvorefter den ligger i havn i syv timer. Ud af turens 17 timer foregår

    fem af dem indenskærs. Rapporten vil forsøge at belyse muligheden for at optimere

    driften af skibet. Skibets fremdrivnings system består af fire hovedmaskiner, der er koblet

    sammen af et reduktionsgear i to par. Skibet er udstyret med to CPP’er propeller med

    variable stigning. Motorerne og propellerne bliver styret af kombinater kurver. Der er tre

    propellerkurver, en propellerkurve til manøvre i havn, en propellerkurve med en motor

    på hver aksel og én med to motorer. På broen styres skibets fremdrivning på et håndtag

    med ti stillinger frem og ti stillinger bak. En stilling på håndtaget svarer til et bestemt antal

    omdrejninger og en bestemt stigning, der er styret af propellerkurverne. Dette giver en

    vis belasting på hovedmaskinerne. Kurverne er lavet sådan, at der er taget højde for

    belastnings forøgelser i form af høje bølger og modvind. Denne margin for belastnings

    ændringer kaldes en sø margin. Rapporten vil belyse mugligheden for, at reducere denne

    sø margin mens skibet er i rolige farvande. Det vil sige, at der skal laves en ny kombinater

    kurve til indenskærs brug. Fordelen ved dette er, at skibet kan opnå højere effektivitet

    ved at hæve det effektive middeltryk på hovedmaskinerne. Rapporten beskriver den

    grundlæggende teori bag mine målinger og beregninger, før selve analysen af målingerne

    og beregningerne finder sted.

  • Jim Lindegaard Nielsen – A11548 Fremdrivnings optimering

    Side 4 af 44

    Indholdsfortegnelse Abstract ...................................................................................................................................... 2

    Resume ....................................................................................................................................... 3

    Nomenklaturliste........................................................................................................................ 6

    Forord ......................................................................................................................................... 6

    Indledning .................................................................................................................................. 6

    Læsevejledning ........................................................................................................................... 7

    DFDS Crown Seaways ................................................................................................................. 7

    Nylige optimeringer ................................................................................................................... 7

    Hovedmaskine 2 ......................................................................................................................... 8

    Problemstilling ........................................................................................................................... 8

    Problemformulering ................................................................................................................... 8

    Afgrænsning ............................................................................................................................... 8

    Metode ....................................................................................................................................... 8

    Teorifelt .................................................................................................................................... 10

    Effekter og tab i fremdrivning .................................................................................................. 10

    Tilført effekt ............................................................................................................................. 10

    Varmetab.................................................................................................................................. 11

    Den indicerede effekt ............................................................................................................... 11

    Friktions tab ............................................................................................................................. 11

    Effekt leveret til skruen ............................................................................................................ 12

    Tab i skruen .............................................................................................................................. 12

    Effekt leveret til vandet ............................................................................................................ 12

    Skibets godhedsgrad ................................................................................................................ 13

    Oversigt over effekt, tab og virkningsgrader ........................................................................... 14

    Friktion ..................................................................................................................................... 15

    PI diagrammer .......................................................................................................................... 16

    Teoretisk PV diagram ............................................................................................................... 16

    Det faktiske PV diagram ........................................................................................................... 17

    PV diagrammet ......................................................................................................................... 17

    PA diagrammet ......................................................................................................................... 18

    Motor belastningsdiagram og Sø faktor .................................................................................. 19

    Målinger ................................................................................................................................... 21

  • Jim Lindegaard Nielsen – A11548 Fremdrivnings optimering

    Side 5 af 44

    Diesel Doktor ............................................................................................................................ 21

    Opsætning ................................................................................................................................ 21