The new Wärtsilä 20DF engine completes the range for fuel flexibility for all marine applications

Wärtsilä Corporation, Trade press release, 1 December 2009 at 10:00 UTC+2

Wärtsilä, the marine industry’s leading ship power system integrator, has extended its dual-fuel technology to the lower power range with the launch of the new environmentally advanced Wärtsilä 20DF engine. It offers ship owners and operators a compact unit that brings all the advantages of fuel flexibility to auxiliary applications, such as generating sets or as the prime mover in smaller vessels. The new Wärtsilä 20DF engine is a testimony to Wärtsilä’s ability to successfully utilize gas as a main fuel for marine operations. This makes gas a practical and attractive option at a time when prices for liquid fuels are uncertain, and when environmental requirements are becoming increasingly stringent.

The tightening emission regulations under the IMO Tier II & III and ECA zone implementations, and volatile fuel prices mean that ship owners and operators are facing serious challenges. Solutions for complying with new environmental rules while maintaining cost-efficient operations vary, but natural gas appears to fulfil all the requirements.

The Wärtsilä 20DF completes the dual-fuel range

With the launch of the Wärtsilä 20DF, Wärtsilä is extending the benefits of dual-fuel (DF) technology to cover the entire power range. Based on the well proven and reliable Wärtsilä 20 diesel engine introduced in the early 1990s, fuel flexibility means the engine can be optimized for constant speed generating sets, as well as variable speed mechanical drives, for main engine applications.

Installed alongside Wärtsilä 34DF or 50DF main propulsion machinery, a Wärtsilä 20DF generating set completes the multi-fuel engine room concept. Compact and light, the Wärtsilä 20DF is intended for use in those vessel types where the Wärtsilä 20 is currently installed.

As well as being an ideal mechanical-drive prime mover in smaller applications, such as small cargo vessels, ferries or tug boats, it is also an excellent choice for harbour generating set applications in a wide range of vessel types.

Main fuel flexibility

Fuel flexibility enables owners and operators to opt for the most suitable fuel, taking account local environmental restrictions, fuel price variations, and fuel bunkering availability. A unique feature of the Wärtsilä DF dual-fuel engines is their ability to run on Natural Gas, Marine Diesel Oil (MDO), Heavy Fuel Oil (HFO) and Bio Fuels, thereby providing maximum flexibility in fuel choice.

In marine applications, fuel flexibility also represents a significant safety feature. In the case of an interruption to the gas supply, Wärtsilä DF engines automatically switch to diesel operation without any loss in speed or power output. Single-fuel installations do not have this additional level of operational safety.

Keeping emissions under control

When a DF engine is running in gas mode, CO2 emissions are reduced by approximately 20% since natural gas has a lower carbon content than liquid fuels. The lean-burn combustion process employed means that NOX emissions are reduced by approximately 80%, while SOX emissions are completely eliminated as natural gas does not contain any sulphur. The production of particulates is practically non-existent as natural gas has virtually no residuals.

Lean-burn combustion technology results in extremely-low emission values and very-high engine efficiency. In this process, the combustion of a lean air-gas mixture is initiated by injecting a very small amount of MDO as pilot fuel. To obtain the best efficiency and lowest emissions, each cylinder is individually controlled to ensure operation at the correct air-fuel ratio, and with the correct amount and timing of pilot fuel injection.

Wärtsilä has further developed UNIC, a special electronic control system that copes with the demanding task of controlling the combustion in each cylinder, while ensuring optimal performance in terms of efficiency and emissions under all conditions. Stable and well-controlled combustion also contributes to less mechanical and thermal load on the engine components.

In gas mode, Wärtsilä DF engines are already compliant with the forthcoming IMO Tier III regulations without the need for any secondary exhaust gas purification systems. In liquid fuel oil mode, all Wärtsilä DF engines are fully compliant with the IMO Tier II exhaust emission regulations set out in Annex VI of the MARPOL 73/78 convention.

The Wärtsilä 34DF & 50DF

The established Wärtsilä 34DF and Wärtsilä 50DF dual-fuel engines have a strong track record. The Wärtsilä 34DF (435/450 kW per cylinder) is manufactured in configurations of from 6-cylinder in-lines to 20-cylinder engines in V-configuration. The maximum mechanical output is 9000 kW and the engine speed is 720 or 750 rpm for use with 50 or 60 Hz applications. The Wärtsilä 50DF (950/975 kW per cylinder) is manufactured in configurations from 6-cylinder in-lines up to 18-cylinder engines in V-configuration, and has a maximum mechanical output of 17,100 kW at engine speeds of 500 or 514 rpm. The Wärtsilä 50DF has a maximum thermal efficiency of 49%, which is higher than any other medium-speed engine.

Like all Wärtsilä engines, the design of the Wärtsilä 34DF and the 50DF engines is simple and straightforward. Piping and external connections are minimized, safety margins are ample, maintenance is easy and quick, and an electronic safety protection system is built in.

Wärtsilä 34DF and Wärtsilä 50DF engines represent the core of an offering that is able to fulfil both local and international environmental requirements, while maximizing the overall economic viability in both electrical and mechanical applications.

Skills and knowledge

With over 20 years of experience, and more than 1000 gas engines sold and in continuous operation, Wärtsilä is the marine sector’s market leader in natural-gas based power production, and a skilled and knowledgeable partner. To date, Wärtsilä’s DF technology has accumulated more than 1,500,000 engine running hours, and the total power installed will reach 4,000,000 kW by the end of 2010.

Wärtsilä’s extended gas product portfolio is supported by in-depth know-how, competence, and design capability. Wärtsilä is an ideal system integrator whenever there is a need to optimize propulsion-related equipment. The Wärtsilä range covers natural gas storage, processing and distribution onboard, LNG use in DF engines (both main and auxiliary), power distribution, propulsion equipment, and control and automation systems. All these elements are integrated into a comprehensive system designed and produced by Wärtsilä for each application.

Welcome to meet us at the Marintec exhibition in Shanghai, China, 1-4 December on stand number 2G41 in Hall 2!

Links to related material:

Wärtsilä 20DF

Wärtsilä 34DF

Picture 1: The Wärtsilä range covers natural gas storage, processing and distribution onboard, LNG use in DF engines (both main and auxiliary), power distribution, propulsion equipment, and control and automation systems.

Picture 2: Wärtsilä’s extensive gas product portfolio is integrated into a comprehensive system designed and produced by Wärtsilä for each application.

Media contact:
Ms Marit Holmlund-Sund
Senior Manager, PR and Marketing Communications
Wärtsilä Corporation
Direct tel: +358 10 709 1439
Direct fax: +358 10 709 1425

Wärtsilä in brief:
Wärtsilä is a global leader in complete lifecycle power solutions for the marine and energy markets. By emphasising technological innovation and total efficiency, Wärtsilä maximises the environmental and economic performance of the vessels and power plants of its customers.
In 2008, Wärtsilä’s net sales totalled EUR 4.6 billion with 19,000 employees. The company has operations in 160 locations in 70 countries around the world. Wärtsilä is listed on the NASDAQ OMX Helsinki, Finland.