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Reporting period: 2018-05-01 to 2018-10-31

The R&D Programme HERCULES is the outcome of the joint vision by the two major European engine maker Groups MAN and WARTSILA, to develop new technologies for marine engines, with general aims to 1) Increase engine efficiency, thus reduce fuel consumption and CO2 emissions, 2) Reduce gaseous & particulate emissions and 3) Increase engine reliability.
In the year 2004, the Integrated Project HERCULES-A commenced. It was the Phase I of the HERCULES R&D Programme (Fig. 1). HERCULES-B was the Phase II of the Programme, from 2008 to 2011. The HERCULES-C project (2012-2015) was the Phase III of the HERCULES Programme.
The current project HERCULES-2 with 32 partners and 25 M€ budget, partly funded by the European Union, is targeting at a future fuel-flexible large marine engine, optimally adaptive to its operating environment. The targets of HERCULES-2 build upon the achievements of the previous HERCULES projects (Fig. 2), going beyond the limits set by the regulatory authorities.
The general objectives of HERCULES-2 are summarized below:
- To improve fuel flexibility.
- To formulate new materials to support high temperature applications.
- To develop adaptive control methodologies to retain Lifetime powerplant performance.
- To achieve near-zero emissions for large marine engines.
The Project structure of work comprises 8 RTD Work Packages (WP) as well as 3 managerial Work Packages.
In WP1, work focused on engines able to switch between fuels. A fuel-flexible injection system was manufactured and tested with various fuels in a prototype injection test rig, as well as in the Spray Combustion Chamber. The ignition and combustion properties of alternative fuels were examined via simulations, at several experimental facilities, as well as at full-scale engines (Fig. 3). A novel engine control system for maximum flexibility for alternative fuels has also been developed.
In WP2, experimental and numerical tools & methods required to exploit new alternative fuels were developed along with new measurement techniques. CFD and chemical kinetic models for new gaseous fuels were developed and experimentally validated (Fig. 4). New optical techniques for studying fuel injection, ignition and flame propagation were developed and experimentally validated in a new spray chamber leading to fuel-specific engine control strategies.
In WP3, novel materials for advanced creep resistance of engine components for cruise applications were characterized, evaluated and tested. Various processing routes were identified and optimized. Rig testing of novel T/C casing coatings and engine testing of pre-chamber prototypes were performed (Fig. 5) and optimized for maximal durability.
In WP4, tests were performed to investigate materials to increase the thermomechanical fatigue (TMF) resistance of cylinder head and turbocharger inlet casing, for ferry applications. A turbine casing material has been evaluated in detail; a prototype was developed and rig-tested (Fig. 6). A specimen representing the cylinder head was designed and tested on a TMF test rig achieving 16% reduction of weight with an improved TMF resistance.
WP5 targets on retaining engine’s as-new performance using optimized engine control and parameterization methods. Control strategies of knock margin were implemented and full-scale engine tested. Α multivariable controller was designed and tested in a hybrid diesel-electric powertrain. Work also included the design, manufacturing and testing of a prototype adaptive, fully-flexible lubrication system (Fig. 7) resulting in 15% reduction of lubricant consumption.
In WP6, mathematical engine models were developed and used to setup model-based controllers. Engine operation with cylinder cut-out achieved at part load (slow steaming) a 4% engine efficiency increase and 50% decrease in NO emissions. Α High Pressure (HP) SCR model was also developed and used to optimize slow steaming operation. An adaptive model-based EGR controller to prevent smoke formation during acceleration was developed and successfully tested onboard a vessel (Fig. 8). Adaptive lubrication strategies for the piston ring pack was also studied via modelling and oil film measurements in a test rig.
WP7 targets NOx, particulate matter (PM) and hydrocarbon emission reduction via combination of different aftertreatment systems. Combined Diesel Particulate Filter (DPF) with SCR catalysts were developed and achieved NOx conversions from 87% to 100%, with particulate number (PN) reduction above 90%. Experimental evaluation of Electrostatic Precipitator technology was also performed achieving PM reduction of 75% to 95%. Further, the potential of oxidation catalysts for methane and ethane reduction was evaluated on a real engine (Fig. 9). Catalyst samples were installed onboard a vessel for several thousand hours in order to be full-scale tested (Fig. 10).
WP8 focused on integrated HP SCR, as well as on combined SCR and DPF. Experimental facilities were built to study the flow processes in the SCR reactor and a novel engine-integrated HP SCR design with the reactor inside the exhaust receiver was developed and full-scale tested (Fig 11). Experiments were done to test combined SCR and DPFs, using different SCR coatings and DPF substrates, in both laboratory and full-scale applications (Fig. 12), achieving reduction of NOx and PM emissions by 80%.
“Progress beyond State of Art” for WP2 and WP2 (Fuel flexible Engine): advanced test facilities with optical access, novel optical measurement techniques, reaction kinetics enabled CFD numeric tools, fuel-specific engine control strategies.
For WP3 and WP4 (New Materials): novel intermetallic material characterization for advanced TMF and creep resistance for turbine casings and cylinder heads, thermal spray and welding methods, new heat treatment and manufacturing processes for prototype parts for 2- and 4-stroke engines.
For WP5 and WP6 (Adaptive Powerplant for Lifetime Performance): predictive model-based engine controls with adaptive and self-learning behaviour, real time diagnostics and smart detection of engine failures, software-based evaluation of performance and component wear, un-attended (remote) engine control system updating, real-time tribo monitoring sensors, optimised cylinder lubrication systems.
For WP7 and WP8 (Near-Zero Emissions Engine): high pressure SCR systems for 2 and 4-stroke engines, vibration resistant catalysts, closed loop emission sensing and control, combined SCR and DPFs, prototype SCR catalyst coating onto DPF substrates, deactivation and regeneration of oxi-catalysts.
The major impact of HERCULES-2, is the achievement of efficiency gains and drastic emission reductions beyond the existing regulatory regimes and the current Best Available Technology (BAT). The project, through advanced combustion, novel materials and enhanced control systems, has achieved efficient engine operation at different operating regimes, enabling engine to perform more effectively all operating regimes including slow steaming, thus reducing drastically the greenhouse gas (GHG) emissions produced. Additional benefits in GHG emissions are also achieved from the minimisation of methane slip. Further, the combination of integrated after-treatment units and control, led to the achievement of the 80% target of reduction in gaseous and particulate matter emissions.
Prototype T/C inlet casing made of novel materials successful testing
Prototype equipment for methane and ethane abatement tests
Novel material prechamber prototypes and post analysis via scanning electron microscopy
Successful shipboard test of new EGR model-based controller during low engine load and reversing
CFD of diesel-ignited LNG operation. Contour of HRR coloured by temperature and CH4 mass fraction.
Flexible fuel injection system installed on engine(left).Injector positioning on the cylinder(right)
High Pressure SCR system development
Field test catalyst device inside the exhaust manifold of a large marine (L) and after the test (R).
Diesel Oxidation Catalyst (DOC) & SCR coated Diesel Particulate Filter(SDPF),installed in full-scale
Arrangement of components of a fully flexible lubrication system for full-scale engine test