论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。 The typical time between overhaul of 2-stroke main engine cylinder units has been in the range of 10,000 to 15,000 hours. This has been regarded as best practice in the shipping industry for the last 3 decades a practice that has ascertained safe and reliable operation. The development of design and material technology in this period has lead to significantly higher outputs, improved reliability, lower emissions and higher cost efficiency. Examples are improved designs of the turbocharger, combustion chamber, bearings, fuel system, lubrication system and piston rings. There may still be challenges in certain areas, but all in all the gains have been considerable.At the same time ship operators have increasingly been challenged by their business partners as well as the public at large to operate within ever larger safety margins. Amongst others, this has implied that even planned overhauls requiring disabling of the main engine when the ship is in service, becomes increasingly difficult especially for any kind of tanker vessels. For a long time, there have been restrictions in place hindering overhauls when alongside at terminals. This restraint has recently also been imposed by authorities of some of the most strategic anchorages. Disabling main engines commonly requires stand-by tugs in these areas theeby increasing costs for overhauls to a large degree, and many operators see this as shrinking opportunities to carry out planned maintenance in a cost effective way. To mitigate this situation attempts have been made to operate main engines from ’dock-to-dock’, i.e. at 5-year intervals which requires about 30.000 hours between overhauls. This would entail several advantages. Clearly, planning,lead time for acquiring spare parts, availability of assistance etc. would improve the quality of work and perhaps also reduce spare part costs to some degree. Further, the time loss would become reduced. The results from the aforementioned tests have been encouraging to the degree that one could think of main overhaul intervals of even up to 10 years which would require safe operation for up to 60.00 hours. Largely prolonged service periods as well as the trend towards higher engine outputs would call for changes to the specifications for some highly loaded key components whose service life is not always predictable. A section of this paper explains the specific challenges for piston rings. Various types of coating on the running face and on the side face are now state of the art for the high efficient two stroke engines. The design of the ring groove plays also an important role if one wants to chieve running hours of approximately 60,000 hours. The hard chromium plating used today might not always be the right choice. New coatings in the piston grooves besides on the piston rings may be a necessity. Further, as the engine designers have come up with more and more powerful engine versions, it has increased the demand on the piston rings. Besides that a more prolonged TBO together with the new SECA regulation will have an important influence on the ring design for the future. The exhaust valve spindle is another example where heavy duty material may be required to withstand the stress and fatigue imposed by such long service time. Since costs for overhauls when the ship is docked tend to increase somewhat due to yard assistance and increased costs for heavy duty components, the proposition to carry out overhauls at alternate dockings becomes much more interesting as cost efficiency would increase sharply and more than outweigh operating costs associated with current practices. The paper reports on results obtained with two MAN B&W 6 S 60 MCC engines and discuss requirements to components and operational procedures. Further and outline of a maintenance programme based on condition monitoring to achieve 10 year intervals between main overhaul .

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。 In order to fulfil the requirements of the IMO-III regulation either a combination of internal engine technologies or external measures are required.Exhaust gas aftertreatment by Selective Catalytic Reduction (SCR) is a proven technology that basically allows any engine to fulfil the IMO-III regulation. The design of compact SCR systems remains a significant challenge for the developer. Besides a high efficient NOx -conversion on the catalysts, the main issue is the efficient spray preparation including the injection of ureawater solution and the distribution of the reducing agent ammonia, generated by a thermolysis reaction. The uniformity of the ammonia at the catalyst inlet is decisive in order to achieve highest levels of NOx reduction and to avoid deposit formation.Therefore well adapted designs are mandatory to fulfil the system targets concerning emissions, durability and cost effectiveness. Due to the complex physical and chemical phenomena involved in the spray injection, CFD simulations are performed to provide valuable insight on the system behaviour. This assists the development in early phases of the development and enables an efficient optimization. Development time and costs are therefore reduced. The paper provides a survey over the physical and chemical models which have been developed for the description of all relevant phenomena involved in the spray preparation, including the spray evaporation and the thermolysis, the spray-wall interaction and the wall film formation. The developed models have been implemented into a commercial CFD code and validated by experimental investigations of the individual effects. The developed method is then applied for the investigation of the spray preparation and ammonia uniformity in SCR-systems as well as to evaluate the risk of deposit formation. The paper shows the CFD-aided development of an ultra-compact inter-turbine SCR system for a medium speed ship engine fulfilling IMO-III and describes the applied methods. The emphasis of the investigations was the optimization of the ammonia uniformity at the SCR-catalyst. Furthermore the spray behaviour and the risk of deposit formation in the exhaust pipes have been evaluated. Based on the results of the CFD-investigations and on the design of the SCR-System, engine tests will be perormed to prove the performance of the SCR systems under real life conditions.

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。Gas engines have during the years been a derivate of the diesel engine development. The developed Diesel engine families have given a reliable and cost effective platform for developing gas engines. By adapting gas technologies to existing platforms the development time has been significantly reduced which has led to reduced lead times and cost competitive products. The first Wärtsilä gas engines were introduced to the power plant market driven by the fuel price, operational flexibility and emissions. The awareness of utility companies has increased and gas engines are considered reliable, flexible, and efficient and cost competitive energy converters. Yearly globally electricity demand grows with a speed of 10 to 15 %. Renewable fuels have gained momentum and will stand for 20% of the total production. The main challenge with the renewable energy is related to availability and predictability. Big wind mills producing 500 MW might lose there total power in a few minutes’ which needs to be compensated. Traditional coal and turbines can not cope with this rapid power demands, if starting from standstill. Shipping is facing tough emission restrictions in 2016 when the requirements on fuel quality and NOx emissions will be introduced. Gas engines will be a competitive choice as the availability of gas is improving especially in the ECA areas. The use of gas engines in the Merchant and Offshore segments is already a standard as the first installations for cruise and navy are under delivery. This paper will describe in addition to the reliability, output and lifecycle cost improvements a summary of challenges like engine loading, methane slip and how they have been tackled. The paper is shared in 2, one reviewing the diesel and one reviewing the gas in more detail. To be noted however that many technologies naturally can be applied for both. Please also read paper ’Diesel’.

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。Typical plain bearing alloy, Sn-Sb-Cu alloy is being overlaid on the carbon steel backing metal by either casting or welding method. Overlay welding type bearing is a competitive alternative to casting type in terms of higher bond strength and lower cost. Surface protrusion phenomena at the running surface of welding type bearing were occasionally observed after engine operation. Occurrence of protrusion phenomena were simulated as a function of dehydrogenizing treatment, preheating before welding and postheating after welding. It was found that the protrusion of weld overlaid bearing surface was closely related to diffusion and build-up of hydrogen from the backing steel.

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。High speed engines typically are used for multi-application operation as e.g. locomotive, marine, electric power generation, electrical drilling and other non-road usage for example mining trucks or well fracturing. The present performance and emission development of these engines implies the necessity to fulfill on the one hand the fuel consumption targets, which are usually lower than the existing series production. On the other hand limiting cost factors as hardware communality and production line capability and hardware limits as peak firing pressure or turbocharger availability have to be taken into account. Beide these facts user acceptance for the different technology routes exhaust gas recirculation, exhaust after treatment or dual fuel operation make the engine developer’s job more and more challenging. Nevertheless the optimum solution for an engine platform has to be worked out without accepting too many compromises. This article will discuss typical aspects and boundaries for a TIER 4 development of a multi-application high speed Diesel engine with exhaust gas recirculation as well as SCR technology.

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。 CATERPILLAR has recently announced the development of the new M46 Dual Fuel engine.This high efficient engine is equipped with an integrated CATERPILLAR electronic control system including two ECM’s for the inline engine. They also include the control logic of the FCT flex cam actuator.The safety and protection system is a CATERPILLAR new development as well and connects to the Control System with a redundant Bus Interface, providing flexible PLC logic for Start Stop Control, Slow Turn, Purge and all other functions. Besides the known data interfaces to the engine control room and alarm system, all engine data is now visible within graphical on engine displays. The engine provides an output power of 900kW/cyl at a BMEP of 21.3 bar in Diesel as well as in Gas operation. To reach the high efficiency targets while maintaining sufficient safety margins at varying gas qualities, it was decided to equip this engine with cylinder pressure sensors in each cylinder and to integrate these informations into the engine control strategy. While other known cylinder pressure based control strategies focus on Pmax only, the new M46 DF engine uses further combustion characteristics like Start,Center- and Duration-of-Combustion for monitoring, balancing and NOx control. Time to market was and is still a critical factor to the success of this new project, so it was decided to build up a partnership with an experienced supplier in the technical field of cylinder pressure sensing and processing technology. Thecompany AVAT from the german city of Tuebingen has been selected to design and develop the CATERPILLAR In-Cylinder-Pressure-Module (ICPM). AVAT is a well known supplier to CATERPILLAR as they already deliver products and services for the GCM34 and other engines. Even more important than achieving maximum control performance was to design a system with highest engine availability. The new system architecture was developed such that the system complexity was minimized. Therefore the ICPM was designed as a smart sensing device leading to a clear separation of responsibilities: sensor power supply, sensor signal processing and monitoring as well as on-line calculation of combustion characteristics and knock levels are encapsulated in the ICPM, whereas mixture control, knock control interaction and balancing strategies are realized completely in the ECM. Consequently, error handling and alarm processing are also located here, giving CATERPILLAR the maximum flexibility in designing the engine behaviour. The key combustion parameters were defined by the CATERPILLAR control and performance team. The engine control system receives these values from a high speed digital bus interface using SAE J1939 CAN protocol. Appropriate extensions to the J1939 standard have been designed and submitted to the SAE committee. This clear interface provides good flexibility of all units and a clear hierarchy of the distributed system enabling CATERPILLAR to use the ICPM on different engine platforms. During common system FMEA sessions between CATERPILLAR and AVAT safety critical functions and performance optimization could be clearly separated, which, in turn, facilitates the marine classification process. The paper ends with a presentation of test bed results showing the benefits of the new control strategy.

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。 Currently a renaissance of dual-fuel engines can be experienced in the large-bore engine markets. For a very long time this technology was in use only in stationary power generation application,where the market shares decreased clearly during the last decade due to the strong improvements on pure gas engine performance values and the extension of the pure gas engines to higher output ranges with large medium-speed engines. In addition to the previous sole land-based usage several mobile applications are now opening furthers markets for large-bore dual-fuel engines. These applications are marine main propulsion (e. g. LNG carries, cruise liners) and auxiliary usage (e. g. container vessels) as well as rail traction purposes (e. g. long-haul locomotives). The main drivers for the increased interest in DF engines are lower fuel costs in comparison to the expensive HFO or Diesel fuel and the opportunity to reduce especially the NOx emissions enabling a fulfilment of upcoming emission legislations. Further on natural gas could be a high-potential low-sulphur fuel as requested for a lot of mobile engine applications very soon. The typical secondary liquid fuel beside gas which has been disadvantageous in stationary DF applications very often enables as back-up fuel a very reliable mobile operation. In marine usage a DF engine facilitates a fulfilment of the IMO emission regulations inside and outside an ECA just by switching the mode between gas and Diesel operation. The challenges of the mobile applications are often variable speed operation, fast load response requirements, changing gas qualities and reliable engine operation even under difficult operating conditions. Due to the typical two operational modes (gas operation and Diesel operation) of DF engines several compromises must be made in engine design (e. g. compression ratio, piston bowl shape, valve timing, ) as well. This leads currently to disadvantages with respect to efficiency and power density. With regard to the before mentioned topics AVL investigated the dual-fuel engine technology by systematic medium-speed single cylinder engine testing. A wide variety of parameters were evaluated and the operational borderlines were explored. Based on the gained results an short-term outlook with todays DF engine technology will be defined. AVLs future perspective of DF engine technology will be created as well enabling the definition of required midterm developments.

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。 The present paper describes the current development status of high speed (with nominal speeds of 1200 to 1800 rpm) and medium speed (with nominal speeds up to 1000 rpm) large gas engines as well as their future development strategies for the short to middle term. The population of natural gas engines for stationary applications such as power generation or gas compression has expanded significantly in the last few decades. Growing attention to the reduction of CO 2 emission as well as upcoming more and more stringent regulations for NO x emission will make gas engines attractive also to marine and locomotive applications. In order to boost a long term growth trend of gas engines, further improvement in power density and thermal efficiency is demanded. Gas engines today have already reached competitive BMEP levels and comparable or even higher thermal efficiency levels compared to those of diesel engines. Gas engines owe such improvements greatly to the lean burn combustion principle, the Miller valve timing and incremental combustion developments such as optimization of combustion chamber geometries, increase of compression ratio and etc. Performance development of gas engine has been a struggle against knocking combustion all the time. In order to further increase the BMEP and/or thermal efficiency, knock resistance is yet to be improved. Miller cycle in conjunction with the charge air cooling suppresses the onset of knocking by reducing the combustion temperature. However, it raises requirement for the higher intake manifold pressure. As the compressor pressure ratio of a singlestage turbocharger is limited, even more aggressive Miller timing than today requires an application of twostage turbocharging. Another important aspect is the peak firing pressure capability of the engine platform.Considering that many of the gas engines currently in the market started their history with the BMEP of 10 to 12 bar and reached 20 to 22 bar up to now, they may be already close to their peak firing pressure limit. A further increase of the BMEP would impose a massive design change or even a new engine development. Based on experiences of gas engine developments with AVL proprietary single cylinder engine as well as with AVL proprietary simulation codes,the present reports reviews key technologies of gas engines and their current development status and discusses their limitations, potentials and requirements for the future gas engines. The most important key technologies that enable future development of gas engines are the application of even more aggressive Miller timing in conjunction with two stage turbocharging as well as the peak firing pressure capability of up to 250 bar and above.

论文已在中国上海举行的2013年CIMAC大会上发表，论文的版权归CIMAC所有。With the upcoming reduction in fuel sulfur content there are concerns in the shipping industry for the future fuel quality and availability. The future fuel quality may also affect the particulate matter(PM) emissions in a negative way despite the significant reduction in PM mass that will be achieved by reducing the sulfur concentration in heavy fuel oils(HFO). The remaining PM emissions may increase if the fuel quality decreases in the future due to the reduced fuel sulfur content. The authors are looking for a method that allows simple and cheap comparison of different fuel qualities without the need for full scale testing on large marine engines. The idea is to use the FIA-100/FCA(FIA) or similar device for fuel combustion and estimating the PM emissions by measuring the particle size distribution (PSD) in the FIA exhaust. This study is looking into the possibilities and the objectives were to establish whether or not it was possible to see any effect of fuel quality on the measured PSDs and if the changes in PSDs resembled what is observed in real engines. This study shows that it is possible to observe the effect of fuel quality in the FIA PSDs although the behavior was not exactly the same as observed in a real engine. The agreement for high quality fuels such as marine gas oil, gas to liquid fuel and fish oil was good while there are improvements to be made for the HFO measurements. Further improving the method will probably require the flexibility of the Fuel tech combustion research unit (CRU) or similar equipment and improvement to both sampling and measurement methods.

论文已在中国上海举行的2013年CIMAC大会上发表，论文的版权归CIMAC所有。Mitsubishi Heavy Industries, Ltd.(MHI) developed a 1100℃ turbine inlet temperature D-type gas turbine in the 1980s and constructed the world's first successful large-scale combined cycle power plant. Since then, MHI has developed the F and Gtype gas turbines with higher turbine inlet temperature and has delivered these units worldwide accumulating successful commercial operations. Since 2004, MHI has been participating in a Japanese Government funded project called the Japanese National Project. This project is still ongoing and targets combined cycle efficiencies in the 62 to 65% range through the development of innovative technology. The gas turbine for this National Project is expected to operate at a Turbine Inlet Temperature of 1,700℃. MHI recently developed a 1600℃ turbine inlet temperature J-series gas turbine (M501Jand M701J for 60Hz and 50Hz respectively), utilizing some of the advanced technologies developed in the Japanese National Project. This new frame is expected to achieve higher combined cycle efficiency and will contribute to reduce CO2 emissions. The target combined cycle efficiency of the J series gas turbine will be above 61.5%(gross, ISO standard condition, LHV) and the lon1 combined cycle output will reach 470MW for 60Hz engine and 680MW for 50Hz engine. This new engine incorporates:1) A high pressure ratio compressor based on the advanced M501H compressor, which was verified during the M501H development in 1999 and 2001.2) Steam cooled combustor, which has accumulated extensive experience in the MHI G engine (>1,356,000 actual operating hours).3) State-of-art turbine designs developed through the 1700℃ gas turbine component technology development program in the Japanese National Project for high temperature components. The M501J started commissioning in February 2011 at the MHI demonstration plant, T-Point, in Takasago, Japan. Upon completion of numerous commissioning tests including measurement of more than 2,300 temporary data points, and a thorough inspection of the hard-ware, the unit went commercial on July 1,2011. As of March 2012, M501Jat T-point had accumulated more than 5300 actual operating hours and 62 starts. The first of six M501J for a Japanese project was already shipped in Dec.2011, and scheduled to go commercial operation in 2013. An additional ten M501J have been sold in Korea.M701J is a 50Hz version of J series gas turbine. It was designed as a full scale of M501J with useful feedback from M501Joperation and test result at T-point.M701J will be ready for de-livery in 2014. This paper discusses the technical features and the updated status of the J series gas turbine, especially the operating condition of the M501J gas turbine in the MHI demonstration plant, T-Point.