Wärtsilä 31DF

The Wärtsilä 31 is the first of a new generation of medium speed engines, designed to set a new benchmark in efficiency and overall emissions performance.

The Wärtsilä 31 is available in 8 to 16 cylinder configurations and has a power output ranging from 4.2 to 9.8 MW, at 720 and 750 rpm. The launch of the Wärtsilä 31 introduces a 4-stroke engine having the best fuel economy of any engine in its class. At the same time, it maintains outstanding performance across the complete operating range. Its modular design enables a significant reduction in maintenance time and costs, thereby improving power availability and reducing the need for spare parts.

Wärtsilä 31 is recognised by Guinness World Records as the world's most efficient 4-stroke diesel engine.

    Advantages
    The Wärtsilä 31 retains its high efficiency and environmental values throughout the entire lifecycle of the vessel.
    • Lowest fuel consumption over a wide operating range.
    • Highest cylinder power in its segment, 610 kW/cylinder.
    • Available in Diesel, Dual Fuel (DF) and Pure Gas (SG) versions.
    • Meets the coming IMO Tier 3 regulations when operating on gas, and with an SCR when using diesel fuel. The SCR has a minimal effect on fuel consumption.
    • Reliability guaranteed through extensive validation and Wärtsilä’s vast manufacturing experience.
    • Supported by Wärtsilä’s extensive global service network.
    Technical data
    Wärtsilä 31DF IMO Tier III
    Cylinder bore 310 mm Fuel specification: Fuel oil
    Piston stroke 430 mm 700 cSt/50

    °C

    7200 sR1/100°F
    Cylinder output 550 kW/cyl ISO 8217, category ISO-F-RMK 700 ISO-F-DMA, ISO-F-DMB, ISO-F-DMZ ,ULSF
    Speed 750 rpm  
    Mean effective pressure 27.1 bar Gas: Methane number ³ 80
    BSEC 7205 kJ/kWh
    BSGC 7090 kJ/kWh
    Piston speed 10.75 m/s


    Rated power 
    Engine type kW
    8V31DF 4400
    10V31DF 5500
    12V31DF 6600
    14V31DF 7700
    16V31DF 8800
    Engine platform A* A B C F Weight (tons)
    Wärtsilä 8V31 6175 6114 3205 3113 1496 56.7
    Wärtsilä 10V31 6813 6754 3205 3113 1496 62.0
    Wärtsilä 12V31 7900 7840 2628 3500 1496 73.0
    Wärtsilä 14V31 8540 8480 2660 3500 1496 81.0
    Wärtsilä 16V31 9130 9070 2660 3500 1496 89.0
    W31 technical data W
    Applications

    The Wärtsilä 31 is designed to be suitable for a broad range of ship types and applications, both as a main propulsion engine and in diesel electric configurations, or as an auxiliary engine. It can be optimised for running either at constant speed or along a propeller curve. In the Offshore sector, the Wärtsilä 31 is a perfect solution for OSV´s and drilling or semi-submersible vessels, where operational flexibility, high power density, long intervals between overhauls, and high levels of safety are of paramount importance.

    Methane Number

    Wärtsilä Methane Number Calculator

    We have developed this tool for ship owners and operators to calculate the Methane Number of the fuel gas.
    The calculation result indicates whether or not the given gas quality is suitable for use in Wärtsilä dual-fuel engines.

    Methane CH4
    mol%
    EthaneC2H6
    mol%
    PropaneC3H8
    mol%
    Iso-butane (2-Methylpropane)i-C4H10
    mol%
    N-butanen-C4H10
    mol%
    Iso-pentane (2-Methylbutane)i-C5H12
    mol%
    N-pentanen-C5H12
    mol%
    EthyleneC2H4
    mol%
    PropyleneC3H6
    mol%
    Neo-pentane (2,2-Dimethylpropane) neo-C5H12
    mol%
    Mix-hexaneMix C6H14
    mol%
    Mix-heptaneMix C7H16
    mol%
    N-Octanen-C8H18
    mol%
    Carbondioxide C02
    mol%
    CarbonmonoxideC0
    mol%
    HydrogenH2
    mol%
    Nitrogen N2
    mol%
    Hydrogen sulfideH2S
    mol%
    Total mol%
    Wärtsilä Methane number (WMN)
    Propane Knock Index (PKI)
    The calculation tool is owned by Wärtsilä and is made for customer use and is for guidance only. Changes in the tool is reserved at any time.

    Press releases

    Product hologram

    Articles

    Wärtsilä 31 - the most efficient engine in the world

    Welcome to a brand-new generation of engines. The Wärtsilä 31 is setting a new standard for energy efficiency, delivering the lowest level of fuel consumption of any four-stroke engine worldwide.
    22 June 2015
    • Twentyfour7. article
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