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High-efficiency Engine R&D on Combustion with Ultra-low Emissions for Ships

The HERCULES IP will develop new technologies to drastically reduce gaseous and particulate emissions from marine engines and concurrently increase engine efficiency and reliability, hence reducing specific fuel consumption, CO2 emissions and engine lifecycle costs.

Tags: Water


Worldwide there are 80 000 ships larger than 2 000 tons, and about 900 new ships of this size are built each year (a ship’s life is about 20 years). Today, diesel engines account for 98% of ship power plants. A typical large marine engine on a merchant ship will operate during this period for more than 150 000 hours. A ship will achieve approximately 0.02 KWh/ton-km energy consumption which is ten times more efficient than using road transport for the same goods. During the same period, this typical single marine engine of assumed output 25 000 KW, with a maximum efficiency of about 50%, the highest of all thermal power plants, will consume 500 000 tons of fuel and will produce 60 000 tons of NOx, 2 000 tons of CO2 and 3 500 tons of particulates, all from the lifetime of a single power plant.

The vision of HERCULES, of drastically reducing emissions and at the same time increasing engine efficiency and thus reduction of CO2, will potentially affect the vast majority of ships (both new and, through possible technology, existing ships). It will therefore have a significant societal implication of worldwide effect.


HERCULES aims to push the limits of marine engine expertise. The focus of the project is on the development of a future generation of optimally efficient, clean and reliable marine power plants.

The specific objectives are provided below in terms of percentage changes related to current best available technology in service (BAT-IS) for shipboard prime movers, with at least one marine engine installation worldwide reference for 2003. The target of HERCULES is to obtain or surpass the following:

  1. Reduction of fuel consumption and CO2 emissions by 1%
  2. Reduction of NOx (relative to IMO 2000 standard) by 20%
  3. Reduction of other emission components (PM, HC) by 5%
  4. Improvement in engine reliability of 10%
  5. Reduction of time to market by 10%
  6. Reduction in lifecycle cost
To achieve the above objectives, the scope of the project includes all the technology interrelations needed for a holistic approach to marine engine efficiency improvement and emissions reduction. The integrated RTD work will allow the above objectives to be achieved simultaneously.

Final prototype tests with 2-stage TC on W20 - Design Studies - HP and LP turbocharger transversally
Final prototype tests with 2-stage TC on W20 - Design Studies - HP and LP turbocharger transversally
Wartsila Corporation

Description of work

The objectives of HERCULES will be attained through interrelated developments in thermodynamics and mechanics of extreme parameter engines, advanced combustion concepts, multistage intelligent turbo-charging, ‘hot’ engines with energy recovery and compounding, internal emission reduction methods and advanced after-treatment techniques, new sensors for emissions and performance monitoring, and adaptive control for intelligent engines. Advanced process models and engineering software tools will be developed to assist in component design. Prototype components will be manufactured and rig-tested. Engine experimental designs will be assessed on test-beds to validate the new technologies and confirm the achieved objectives. Full-scale shipboard tests of chosen systems will demonstrate the potential benefits of the next generation engines.

The work is structured in nine work packages, with 18 tasks and 54 subprojects. The consortium includes engine makers, component suppliers and equipment manufacturers, renowned universities and research institutions, as well as world-class shipping companies. The partners hold 80% of the world market in marine engines and thus are the keepers of today’s best available technology.


Work in all HERCULES work packages has progressed well. The initial concept studies and process simulation activities are completed in almost all tasks. Experimental rigs have been set up; the design of the ensuing prototype components is finished in most cases and a large number of new components have been manufactured. Full-scale tests have been performed in some cases.

New combustion models have been developed for use in marine engines and a large spray combustion chamber has been manufactured.

Advanced turbo-charging options have been studied and prototype PTI/PTO devices for two stroke engines have been designed and manufactured.

‘Hot’ engine, combined cycle configurations and key engine components have been tested.

Direct water injection (DWI) systems, inlet air humidification systems and fuel water emulsification (FWE) systems have been installed on test rigs or onboard ships. Exhaust gas recirculation (EGR) systems for two-stroke engines were designed, produced and laboratory tested.

Wet-scrubber systems were studied and rig-tested. A test rig for friction loss measurements was manufactured. Studies for ‘intelligent’ control and self-learning components with adaptive behaviour were integrated with the engine control system and full-scale tests will follow.

Twenty-seven deliverable reports have been produced during the first two years of the project.

Linking CFD-combustion simulation and FEM simulation for calculating thermal load of the combustion chamber
Linking CFD-combustion simulation and FEM simulation for calculating thermal load of the combustion chamber