Green Ship of the Future IDA Heldagskonference 26. oktober 2009 Propeller Retrofit Løsninger for Reduktion af Brændstofforbrug Jens Ring Nielsen Senior Manager Propulsion R&D J
Oversigt Optimering af fremdrivningsanlæg Præliminært Design globale parametre Detaljeret Design propeller blad Generelle retrofit løsninger Optimeret propeller og Costa Bulb Kappel Tip Fin propeller Nye propeller dyse typer Cases Scandlines færger Trawlere M/T Branly og M/V Jette Kristine Offshore og AHTS skibe Swire Pacific Offshore
Optimising Propeller Equipment
Optimum Propeller Diameter and Speed
Detailed Design - Post order phase Design Aspects Owner Requirements Hull Form Torsional Vibration Calculations Tank Test Design Off-Design Conditions Class Requirements Noise & vibration Requirements Engine/Gearbox Shafting
The Concept of Cavitation Boiling Cavitation
The optimum design The Balanced Design Fuel Consumption Vibration/Noise/Comfort
Blade Design Skew Angle Non skew Low skew Medium skew High skew
Comparison of Cavitation Patterns
Cavitation [%] Angular Extent of Cavitation 20 10 deg skew angle 40 deg skew angle 15 10 5 0 120 135 150 165 180 195 210 225 240 Angular position [deg]
Costa Bulb and Twisted Rudder Efficiency improvement up to 4% Costa Bulb Hub cone Twisted rudder
Propeller Retrofit Kappel Tip Fin Propeller 3-5 % efficiency gain Non Planer blade shape Comparable to winglets < 12 >
CP Propeller with Kappel Blade Design M/F Kronprins Frederik M/F URD
New AHT Nozzle Designs CFD Optimised for Bollard Pull
CFD Calculation Domain Boundary Conditions Outlet Inlet Outer wall Rotation
Computational Fluid Dynamics Streamlines Bollard Pull Condition
Cavitation Test AHT Nozzle Wool Tuft Test
New AHT Nozzle Designs 6-8% Increase in Bollard Pull Wageningen 19A New MAN Diesel AHT Design AHT nozzles have double curvature on both in and outside
Improvement in BP [%] Bollard Pull Astern Wageningen 19A Versus AHT 30,0 25,0 20,0 15,0 10,0 5,0 0,0 0 2000 4000 6000 8000 10000 12000 14000 16000 Power Pd [kw]
Retrofit Propeller Blades Typical fuel reduction 5 7 % New Design High Skew Old Design Low Skew
Scandlines CP Propeller Upgrading Projects M/F Sassnitz M/F Ask M/F Urd Passenger, Vehicle and Train Ferry Twin screw : 2 x 9,100 kw High skew design + increased diameter Improved efficiency: 12.5% measured Passenger, Ro-Ro Cargo Ferries Twin screw: 2 x 4,920 kw Kappel design + increased diameter Improved efficiency: 9% calculated Approx. 1.2 knots in speed
M/T Branly Trawler Up-grading propeller with new Blade Designs High skew Design Kaplan Design
M/V Jette Kristine Propeller upgrade Bollard Pull Measurement in Frederikshavn Technical Data M/V Jette Kristine Engine type: MAN 8L23/30-DKV-39KV11 Engine power: 1080 kw at 825 rpm Propeller: MAN Alpha VB740 / ø2600 / 214 rpm / 19A MAN Alpha VB740 / ø2650 / 214 rpm / AHT Measured Bollard Pull before upgrade: 19,1 tons Measured Bollard Pull after upgrade: 23,6 tons Improvement in Bollard Pull: 24% Old MAN Alpha propeller & nozzle New MAN Alpha propeller & AHT nozzle
Case study 120 Tons Bollard Pull AHTS Main engine: 9L27/38, 3285 kw at 800 rpm Reduction gear: AMG55EV, with integrated servo oil system CP propeller: VBS980, dia. Ø 3800 mm with AHT nozzle Controls: Alphatronic 2000 PCS SHIP CENTRE LINE
Propeller Nozzle Installation Headbox Support One single wide support Protruding into and fixed to the hull structure
Propeller Nozzle Installation Strut Support Strut Supports Airfoil sections and flow aligned
FEM Vibration Analysis of Nozzle including Support Excitations of a two-point strut support
Nozzle Tilting and Azimuthing Tilt angle Base line Azimuth angle
Model Tank Testing Test program Bollard Pull Tests Stock Propeller/Nozzle Final Propeller /AHT Nozzle Head box support Strut support 0 deg tilt Inward rotation 2 deg tilt Outward rotation 4 deg tilt W/-W/O Rudder
120 Ton Bollard Pull AHTS Model Test Results
120 Ton Bollard Pull AHTS Full Scale Test Results Vessel No Measured Bollard Pull [tons] 1 124.0 2 121.7 3 122.2 4 121.2 5 122.5 Measurements carried out under non optimum conditions Restricted water dept Current across tow direction Full scale bollard pull generally 2-3 % higher than measured in model scale
Konklusioner Potentialet for brændstofbesparelse er ofte større ved optimering af propeller og agterskib end ved andre tiltag såsom hovedmotor og gear Et optimeret design er ud over at have en høj virkningsgrad karakteriseret ved gode kavitationsegenskaber og dermed et lavt støj og vibrationsniveau til gavn for komforten ombord Virkningsgradforbedringer kan opnås ved anvendelse af Efficiency Improving Devices når disse er optimeret i forhold til resten af fremdrivningsanlægget Propellerdyser kan være attraktive for højt belastede propellere (langsomtgående skibe med små hurtiggående propellere) og hvor trækkraft ved lave hastigheder er vigtig. Typiske fartøjer: Tanker, bulker, trawler, offshore skibe, slæbebåde Retrofit af propellere har en hurtig tilbagebetalingstid især hvis det eksisterende design ikke er optimalt til nuværende driftsprofil
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