CIMAC Congress - Schiff & Hafen

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<strong>CIMAC</strong> CONGRESS | BERGEN 2010 8:30 June 16th Room Peer Gynt Salen (11–1) Users’ Aspects – Marine Applications – Service Experiences Service experience of MAN B&W two-stroke diesel engines S. B. Jakobsen, MAN Diesel & Turbo SE, Denmark A very large number of MC & ME engines are entering service these years. The latest development of the most successful marine engine series ever is the ME-B series of which more than hundred engines are on order or delivered. The ME-B series are targeting the small bore end (35-40-46-50 and 60) of the MAN B&W two stroke engine range. Electronically controlled low speed diesels have been part of our engine programme for several years, actually since 2001. Today more than 500 electronically controlled engines are in service and with IMO Tier II emission rules coming into force for vessels with keellaying after 1st January 2011 increased focus on the electronically engine versions are expected. Also because of this development the optimized ME-B engine range is very important and has already grabbed a lot of attention among ship owners. This paper will deal with the latest service experience obtained until now with ME/ME-C engines in service. Also early service experience for the 6S40ME-B will be dealt with. The difference between the ME-C concept and the ME-B concept will be described from a service point of view. Advantages of recent ME-software updates focussing on onboard trouble shooting will be described and related to service experience. Furthermore update on service experience on the MC/MC-C engine series will be given focusing on the engine structure. Common for both the ME/ ME-C and the MC/MCC engine series is the well documented possibility to do Condition Based Overhaul (CBO) with average Time Between Overhauls (TBOs) of 32,000 hours and above. For tanker this opens up the possibility to do only major overhauls at dockings with five years interval. Many ship-owners do now have the experience of CBO. Also the development in relation to the cylinder condition with focus on cylinder oil consumption will be touched upon. Due to the present economic crisis (June 2009) a lot of focus have lately been devoted to optimisation of low load operation. In early 2009 MAN Diesel issued a Service Letter dealing with the possibility of operating continuously down to 10% load. Service tests with various scavenging air pressure increasing measures at low load have also been carried out. Here tests with turbocharger cut-out and Variable Turbine Area (VTA) turbochargers are the most important ones. Result of these tests will also be dealt with. Field experience with the MWH ReliaValve with sentry rotator: a 2-stroke exhaust valve with demonstrated time between overhauls (TBO) of over five years H. Fellmann, Märkisches Werk GmbH, Germany Optimizing exhaust valve service intervals has never been more critical than today. Weak global economic conditions mean that many twostroke engines are operating under low load only, as shipping companies try to reduce fuel consumption and related costs. At the so called ‘ecospeed’, the exhaust valve spindle operates under increased thermal load while under extremely harsh environmental conditions. The resulting frequent overhauls make exhaust valves cost intensive components of the engine. Hence, there is an obvious need in the market for a two-stroke exhaust valve which can achieve much extended service intervals even under very adverse operating conditions. Today, the majority of two-stroke exhaust valves have exhaust valve spindles with vane wheels. Exhaust gas flow actuates the vane wheel and rotates the valve during opening, resulting in a symmetrical distribution of isotherms in the exhaust valve spindle. The disadvantages of this approach include weak or absent polishing effects of the seat during closing, and risk of valve spindle sticking. As a result, most engines require overhaul of the exhaust valves after 6000 to 8000 running hours. In 2002, at the request of customers, MWH began development of a novel two-stroke valve rotator, with a goal of extending the TBO to a minimum of 18,000 hrs, equal to three years. Continued development lead to the first MWH ReliaValve with Sentry Rotator being brought into service in 2003, and receiving a patent in 2004. The detailed development steps and results of more than three years endurance test were reported at the 2007 <strong>CIMAC</strong> conference in Vienna. Now, after over six years running time, the first ReliaValves have been proven to reach a maintenance-free period of more than five years. As of the last inspection, carried out in 2009 without overhaul of the valve spindle, seat ring or Sentry Rotator, the MWH ReliaValve had reached nearly 32,000 running hours. The ReliaValve was installed again and is expected to reach its 40,000 th running hour in 2010. Currently, eight two-stroke engines are completely fitted with MWH ReliaValves, while firm orders for fitting another seven engines with ReliaValves are in place. Additionally, more than a dozen test installations are in operation and MWH has begun the classification society’s acceptance procedure. This paper describes the latest service experience and provides field description and analysis of wear effects for different exhaust valves including detailed discussion of tribology, thermal evaluations, engine load and stresses. Some reliability trends and operating issues related to exhaust gas turbochargers and diesel engine crankshaft & running gear in the marine industry – a classification society view K. Banisoleiman, J. Stainsby, Lloyd´s Register EMEA, UK Lloyd’s Register, (LR), is a leading international classification society with objectives of enhancing its clients’ quality, safety, environmental and business performance. In support of these objectives LR maintains technical rules and regulations for classification of ships and installed machinery, including engines and turbochargers. LR’s rules for diesel engines and turbochargers stem from the International Association of Classification Societies’ (IACS) Unified Requirements. This paper provides the perspective of a classification society on marine exhaust gas turbochargers and marine diesel engine crankshaft and running gear. The following are addressed: • The most common recurring in-service defects and their incidence statistics over the past decade for exhaust gas turbochargers, crankshaft and running gear on the main propulsion two-stroke, four-stroke and auxiliary diesel engines. • Failure investigation case-studies related to turbochargers and marine diesel engine crankshafts and running gear are presented as examples of the above. Finally, overall conclusions are drawn based on the information presented affecting exhaust gas turbochargers, engine crankshafts and running gear. Operating experience with MaK M43 K. Vollrath, Caterpillar Motoren GmbH und Co. KG, Germany Example: Condition at 30,000 h overhaul At the scheduled 30,000 hour overhaul of the main engine of a 64 Ship & Offshore | 2010 | No. 3
Monday, 14 June Tuesday, 15 June Thursday, 17 June Wednesday, 16 June container feeder running on HFO 380, various components were dismantled and inspected. The components inspected included cylinder heads, inlet and exhaust valves, main and big end bearings, cylinder liners and landing surfaces, pistons, cams and rollers. Except for the cylinder liners, the named components are part of the manufacturer’s recommendations for a 30,000 hour overhaul.The cylinder heads were found in excellent overall condition, showing the expected light soiling in the combustion chamber. All hydraulic nuts, exhaust gas flanges/clamps and plug-in connections for cooling water could be dismantled without difficulty. All seals were in excellent condition. All measurements on the valve guides were found within tolerances. Inlet and exhaust valves were found in very good condition with slight to moderate soiling of the stems. The seat surfaces were fully intact and only a minimal material loss due to high temp. corrosion could be observed on the bottom of the exhaust valve plate. On the pistons, the combustion bowl was very clean with a clearly visible, cleanly limited injection pattern, but no measurable burn-off. The piston ring group was very clean overall and no measurable wear of the chromium layer was found. The wear of ring grooves during last 15,000 hours was measured at < 0.01mm/1,000 operating hours. Together with the piston skirts where no irregularities were found as well, the piston crowns were reinstalled in as-is condition. On the complete surface of the liner the honing ridges were still present, no other wear marks such as coke abrasion etc. found. In the upper area wear rates < 0.01mm/1,000 operating hours were measured. On one cylinder, the landing surface of the liner to the crankcase was inspected and no traces of relative movement between landing surface of cylinder liner and crankcase were found. All big end and main bearings were found with very good condition of the running surfaces with scarcely visible, even running pattern. No cavitation marks were found, no wear marks on the back of the bearings. The valve cams and rollers show the known wear patterns, but no ridges are perceptible. The running pattern is stable compared to earlier inspections. One complete rocking lever (lower valve drive) was dismantled and taken apart in the workshop. The check of roller, bush and pin revealed no irregularities. All inspected components safely reached the manufacturer’s expected lifetimes. Valves and bearings were exchanged because a safe operation until the next scheduled overhaul could not be guaranteed. All other inspected components could be refitted after cleaning. 8:30 June 16th Room Scene GH (2–1) Fundamental Engineering – Piston Engines HERCULES-B: The continuation of a major R&D effort towards the next generation marine diesel engines N. Kyrtatos, NTUA, Greece, L. Hellberg, Wärtsilä Corp., Finland, C. Poensgen, MAN Diesel & Turbo SE, Germany HERCULES-Beta is the second phase of the HERCULES programme, which was conceived in 2002 as a long-term strategic R&D plan. The project was initiated by Europe’s two major engine manufacturers, Wärtsilä Corporation and MAN Diesel and is jointly coordinated by ULEME EEIG. HERCULES-Beta began on September 2008 with a budget of EUR 25 million and it is planned to run for 36 months. The project consortium has 32 participants, including enginecomponent suppliers, equipment manufacturers, universities, research institutions and shipping companies from ten European countries. HERCULES-Beta comprises 56 subprojects and is funded by the European Commission’s Framework Program 7 for R&D (FP7, Theme Transport). The project’s principal aim is to reduce marine diesel engine fuel consumption by 10% and to improve the efficiency of marine diesel propulsion systems to more than 60%, significantly reducing CO 2 emissions as a result. A further aim of the project is to target ultra-low exhaust emissions by eliminating 70% of NOx and 50% of particulates from marine engines by 2020. The first phase of the HERCULES project concentrated on the development of tools (e.g., simulation software, measurement techniques, etc.) and the general investigation of potential avenues for reducing emissions and fuel consumption. Initially, the project established and operated prototypes. The results stemming from this indicate a great potential for significantly reducing fuel consumption and emissions and reaching the project’s ambitious targets. HERCULES-Beta directly builds on the findings of the first phase of the HERCULES project. The tools previously established are employed to more closely investigate, understand and ultimately optimise the engines. Both analytical investigations as well as prototypes will be refined, based on first-phase results, with the intention of achieving the ultra-low emission and fuel consumption targets. Finally, by carrying out fieldtests on the prototypes developed in the first phase, information on the important effect of real-life boundary conditions will be gathered and analysed. The paper presents the complex structure of the project, as well as some initial results. Optical and numerical investigation of the combustion process in a single cylinder medium speed diesel engine U. Waldenmaier, J. Metzger, P. Porten, G. Stiesch, MAN Diesel & Turbo SE, Germany, T. Heidenreich, U. Wagner, Institute for Reciprocating Engines (IFKM), University of Karlsruhe, Germany Strict emission regulations and the need of higher efficiency of future diesel engines require an optimized combustion process. For getting a better understanding of the combustion process optical investigations represent a powerful tool and they are already widely used within the development process of passenger car and truck engines. For medium speed diesel engines however, optical investigations are still not common due to costs of optical test engines and technical practicability. Within the IP-Hercules Β project MAN Diesel SE in cooperation with the “Institut fuer Kolbenmaschinen” (IfKM) at the Technical University of Karlsruhe realized optical in-situ investigations of the combustion process on an MAN Diesel SE 32/44 CR single cylinder medium speed diesel engine. For the optical investigations a special optical cylinder head was developed with several optical accesses for an endoscope and also laser illumination. Endoscopic investigations were chosen because an emphasis was placed on minimum modifications to the combustion chamber. The deflection of spray and combustion due to the optical instrumentation had to be minimized in order to obtain results fully representative of the standard engine as well. The first optical investigations aimed on soot luminescence. For that purpose special injectors were designed for separating a single flame plume and spray cone respectively. Pressure and temperature conditions at start of injection were adjusted by modified charge air conditions. Different marine fuels were used for the tests. The images of the combustion process were recorded with an endoscope and a high speed camera. For comparing optical images and CFD combustion simulation results, selected engine operating points were simulated with a modified version of the CFD code KIVA3V- Release2 containing additional sub-models developed both at the Engine Research Center of the University of Wisconsin - Madison (ERC) and at MAN Diesel. The purpose of the comparison was to validate the CFD models with in-situ measurements inside the No. 3 | 2010 | Ship & Offshore 65
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