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。Opposed Piston Engines (OPE's) are looking back to more than 100 years history and have been produced as Otto and Diesel engines, offering a promising challenge in specific output and thermal efficiency. Diesel-OPE's have been used regularly for commercial aircraft due to excellent power/weight ratio, but powering also merchant ships with big engines of several thousands of kW. Already 75 years ago a brake efficiency of more than 40% could be achieved. In recent decades these engines seems for-gotten while the research and development engineers put their main focus on emission improvement. Conventional OPE-technology is known for emission problems, especially caused by scraping lubrication oil into in-and outlet ports, as common OPE's scavenging is limited for use in 2-stroke engines only. Now some new developments in OPE-technology show their relevance to future power-train challenges. Better thermal efficiency is attracting the development engineers, as two pistons share only one combustion chamber, thus leading to beneficial volume/surface ratio of the combustion chamber. Nevertheless, also in most today's opposed-piston-engines the scavenging is con-trolled by pistons. Whereas the OPE presented is operated as 4-stroke-engine by arrangement of hydraulically shifted liners undisrupted by scavenging holes or gaps so that the pistons with their rings are shielded against crossing any in-or outlet-ports. Therefore all the modern engine-technology to increase mileage, reduce oil consumption, wear and emission can be implemented in this OPE-Technology presented. So this design combines the advantages of an opposed-piston-principle with the benefits of the classic engine technology for technical and economic progress. A first prototype has been tested successfully, demonstrating also the mechanical function of shift-liners without problems and showing very low friction losses for the shift liners. The wall thickness of these liners can be kept low-like conventional dry liners-as they are supported by the surrounding cylinder, leading to low oscillating liner masses during shifting. The in-and outlet ports are located near the pistons top dead center area and are opened and closed by the upper end of the shift liners like valves, which are closed by spring forces and opened by hydraulic actuation. Different to conventional OPE's there are no distinct exhaust or intake pistons and thermal load is nearly equally distributed on both pistons. The hydraulic system shares the lubrication oil with the engine, avoiding leakage problems and providing a simple oil circuit. The presented design offers also two different modes of combustion technologies: Injection from the outer combustion chamber edge towards the chamber center(from cold to hot), or injection from above the combustion chamber center towards the chamber walls(from hot to cold). For the first mode one or more injectors are positioned around the cylinder, providing the chance for multi-nozzle injection in different time and quantities. For the second mode the cylinder inner wall must be considered as a virtual cylinder head with all same geometric dimensions as for a classic combustion chamber, but including injection completely rotated by 90. It is providing state-of-the-art conditions like well developed common engines today in production, but requiring only one injector for 2 pistons. As no piston rings are crossing the in-and outlet ports, the presented engine is aiming for very big gas flow sections-not interrupted by window lands or port ribs so far much bigger than conventional multi-valve technique could allow for-with the result of better cylinder filling and less dynamic gas flow losses. As the shift liners are hydraulically actuated a variable valve timing can be easily achieved, as well as a complete cylinder cut-off in multi-cylinder engines.

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。This paper shows our approach and perspective to exhaust emission control of Mitsubishi UE low speed 2-stroke diesel engine for marine propulsion. Regulations for the emission from marine diesel engines are tightened still further. IMO Tier3 regulation requires nitrogen oxides to be reduced approx. 76% than Tier2 by 2016. Sulfur oxides are required the phased reduction of sulfur content in fuel. Carbon dioxide will also be introduced the new regulation. For IMO Tier3 regulation, we have developed SCR (Selected Catalytic Reduction) and EGR(Exhaust Gas Re-circulation) system. Both SCR and EGR are confirmed the performance of complying with IMO Tier3 regulation, especially SCR had experienced full-scale onboard test and a good result. EGR is a compact system and has a limited effect for engine room layout. For sulfur oxides, reduction of sulfur content in fuel might be well received and suitable for SCR and EGR system because of low sulfuric oxides. Because fuel oil price is rising very rapid recently, LNG is strongly concerned as fuel use for various types of commercial ship, so we are developing Dual-Fuel engine based UE Eco-engine. LNG fuel engine meets demand for carbon dioxide reduction. These above technologies should be validated and researched in detail performance, we have introduced state-of-the-art test engine in our Workshop.

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 recent trend toward higher output and compactness in marine and power generator engines, the solid type crankshaft used for the 4cycle diesel engine is demanded to have higher fatigue strength. It is well known that fatigue strength is influenced by non-metallic inclusions responsible for the fatigue crack initiation, fatigue strength can be improved by reducing the amount and size of nonmetallic inclusions. The non-metallic inclusions are mainly sulfide and oxide. Therefore, ’super clean steel making process’ that is the way to reduce sulfur and oxygen by vacuum ladle refining furnace has been developed. In order to confirm the material qualities of the steel manufactured by ’super clean steel making process’, the fatigue test on RR-forged crankshaft was carried out. As a result, it is confirmed that fatigue strength of super clean steel has been improved at least 10% higher than that of conventional steel. In the conventional steel, as for K factor in the fatigue strength calculation formula specified in IACS UR M53, K=1.05 is given for CGF (Continuous Grain Flow) forging crankshaft. By reducing the amount and size of non-metallic inclusions, fatigue strength has been improved 10% or more to conventional steel. This result shows that safety margin would be maintained at the same level with present state after K-factor raises up to 1.15 for super clean steel. Therefore, designed fatigue strength may be improved about 10%. On the other hand, in the fatigue of high strength steel, some cases in very high cycle (more than 10,000,000 cycles) fatigue region are reported in recent literatures. Nevertheless study for very high cycle fatigue behavior of low alloy steel used for solid type crankshaft is not enough. Therefore, the investigation for very high cycle fatigue property of super clean and conventional steel has been carried out. In very high cycle fatigue test up to 1,000,000,000 cycles, fatigue fracture did not occur in both steels. It was confirmed that the difference of fatigue strength between super clean steel and conventional steel is maintained in very high cycle region. From this result,it became clear that super clean steel has high fatigue strength and high reliability in both conventional (less than 10,000,000 cycles) fatigue region and very high cycle (more than 10,000,000 cycles) fatigue region.

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。Against a background of recent energy issues, demand of more efficient operation for power plants typified by the distribution of power plants involving the smart-grid concept are growing, meanwhile the use of shale gas as well as the extension for gas pipeline has been steadily progressing. Therefore, gas engine market is, definitely, expected to grow at a steady pace. Gas engine power generation has a lot of characteristics : High environmental performance, high thermal efficiency, high quick-start and load following capability, high exhaust heat recovery.KU30GSI gas engine has already realize the superior utilization for exhaust energy and cooling energy,like as steam, hot and cold water, and, thus, fulfill the higher efficiency as a cogeneration unit. In addition, its excellent performance for rapid starting potential makes it possible to apply to the backup for renewable energy powers. Mitsubishi Heavy Industries,Ltd.(MHI) has already receive an order of KU30GSI over 30 sets from its release, and requests from many clients regarding the consideration for the introduction of KU30GSI with the favorable feedback about its reliability based on the abundant track record. To cater to the recent demand from the customer more focusing on the power generation, MHI has complete the work for its efficiency increase, and achieve the excellent efficiency of 48.8% (ISO 3 046). The thermal efficiency improvement is an important item which not only lowers the operation cost, but also leads to environmental load reduction and energy saving. Enhancement for Miller cycle, high efficiency turbo charger MET-MB and optimization for combustion chamber aiming fast burn concept contribute to fulfill this efficiency improvement, which was thoroughly evaluated through the test engine verification. Three engines applied to this high efficiency specification were already delivered and have been in successful operation. This paper describes the features and technologies, including the latest development for this efficiency improvement,of KU30GSI gas engine as well as the operation result on actual site.

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。Engine development is being driven by environmental considerations, tightening emission regulations, fuel economy and availability in combination with economical boundary conditions. It is within this framework that new approaches in bearing material, design and production are needed. New engine families with increased firing pressures are designed to fulfil these boundary conditions. The change in bearing loading and rough running conditions can be met by tailor-made bearings with special performance characteristics. The high firing pressure in combination with a much wider pressure range for gaseous fuels in combination with misfiring will on one hand change bearing hydrodynamic loading and on the other hand increase cyclic deformation of the bearing structure. Additional features like robustness of bearing types against disturbances as dirt contamination, oil starvation and corrosion are required in combination with extended oil drain intervals and bearing life. Within 2-stroke applications dimensional growth leads to exceptional high dry turn loads in assembly and to cross production limits of bearing production with standardized and robust production processes. In smaller bearings a concept to combine different bearing layers is used. The whole multi-layer composite with the bearing back for improvement of the assembly situation, the lining material to gain higher fatigue strength without losing all the tribological properties and overlays for short term emergency conditions and to compensate for the loss of tribological performance in other layers was rdesigned. This approach of combining difference performance criteria in different layers or areas is also applied in the Patch-Work bearing for 2-stroke engines. Not only to fulfil the demand for large bearings with standard material production processes, but also to combine different performance characteristics in different bearing areas segments can be combined to larger and more robust bearings. For the beforehand mentioned bearing concepts the working principles are described, internal validation and base production principles are shown.According to the internal test results and the first engine results the development targets have been met.Based on engineering and simulation, the bearings can be adapted to the special conditions in specific engine applications. Development and internal test results as well as engine experience are given together with possible bearing configuration in the publication.

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。 General Electric Gas Engines division has established a product line centered on very high efficiency and specific output due to industry leading two-stage turbocharging, lean burn combustion strategy and Miller valve timing in combination. This on-going strategy to continually increase engine efficiency has pushed engine development to higher peak firing pressures and thermal loads on key components. This continuous efficiency increase is demanded with the proviso of maintaining or improving product reliability, robustness, availability, unit price and the associated life cycle costs. To meet these demands, the engineering team at GE Jenbacher, has been continuously developing new technologies and new design & analysis methodologies in conjunction with Ricardo Consulting Engineers. This paper provides an overview of the methodologies applied to the design, analysis and development of a new cylinder head as part of the overall development program for the recently released two-stage 624 engine into the GE Jenbacher gas engine portfolio. The design methodologies developed and applied over the course of the cylinder head development have at their foundations the core tools and methodologies used throughout all General Electric engineering departments, namely DFSS DFR etc. Experience gathered within the existing GE Jenbacher customer fleet over hundreds of thousands of engine operating hours combined with the broad variety of customer operating conditions have been at the core of developing accurate reliability models down to the component level.This data has been further analysed through the use of Design for Reliability (DFR) tools and processes to allow clear failure mode identification and determination of key failure mode accelerating factors. This is key in predicting the response of current components placed under new boundary conditions, ie higher pressures and temperatures. Single cylinder testing has been used to gather the detailed component operational data to allow this correlation to occur. These factors have then been used as assessment criteria within the design and analysis of the new cylinder head. The new cylinder head assembly is a design that incorporates both a different material, a new head structure and with a new water jacket design that includes cooled exhaust valve seats. The new cylinder head assembly has been subjected to an extensive design and analysis optimisation process involving multiple iterative FEA and CFD loops, full conjugate heat transfer analysis and a number of breakout studies to examine the detail of certain components within the assembly Confidence in the analysis methodologies has been further increased by extensive single cylinder testing of the current production cylinder head. This allowed a closed loop correlation process to be established in order to increase accuracy of the analytical approach and thereby allow the design of the new cylinder head to progress with high confidence. Specific accelerated tests were developed for the full sized development engines in order to confirm reliability predictions on both the baseline and newly developed cylinder head.These tests incorporated the key accelerating factors identified from the previous SCE work, and were successful in initiating predicted failures on the original head. The same tests were then used to demonstrate the robustness of the new cylinder head when placed under the same test conditions.

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。Recently, a diesel engine which has more specific power output and compact feature is developed to cope with customer's needs. From a vibration point of view, high power output results in increasing the excitation force and compact design reduces the structural rigidity. Anti-vibration design of a diesel engine is necessary to prevent high vibration and durability problem. Since the beginning of HiMSEN engine's production in

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。 In 2015/2016 stricter limits for marine engines concerning sulfur and nitrogen oxide emissions will come into force with IMO TIER ll.A NOx re-duction of approximately 75% compared with today is demanded as well as a desulfurization of over 85% in designated so-called emission controlled areas(ECA).In order to meet the upcoming emission limits, robust, reliable and efficient solutions must be developed. Be-sides the intensive development and test of selective catalytic reduction (SCR) technology to minimize NOx emissions, other emission reduction methods as desulfurisation are analysed and optimized in Augsburg. Focus of development activities hereby is besides the optimization of the single technologies to find the best possible combination of the solutions. A core competence is the proven MDT safety and control system SaCoSone, enlarged by aftertreatment modules of SaCoSone Up to now a wide experience is available on the various aftertreatment technology demonstrators. The most effort is placed in the field of SCR technology, which is the basic solution for reaching IMO TIER lII emission limits. With the valuable measuring results theoretical models have been adopted and validated, so that the prediction of relevant characteristic parameters is possible with a good accordance to the test results for the MDT engine family. With these models an optimization of the chosen technologies has been executed. Compared with the initial configuration, significant improvements have been achieved in the fields of catalyst type and size, reductive injection and mixing unit. A uniform distribution of the exhaust gas, mainly in velocity and composition as well as an improved thermolysis of the reductive to ammonia led to series modules with less installation space. Further potential is seen in the development of innovative concepts for ammonia generation. To be able to operate the aftertreatment technologies with minimized consumption of energy and reductive, the system control is executed with SaCoS, including the safety strategy of the complete system. An intelligent control unit which controls all relevant parameters as a function of the engine is furthermore important when switching between ECA and non-ECA mode. Besides the efforts to develop a high performance SCR system, some predefinitions from engine side have to be fulfilled. The composition of the raw emissions has a great influence on type of catalyst to be used, and boundary conditions concerning optimal temperatures have to be met. For a further reduction of particulate matter(PM) emissions and to eliminate the sulfur oxides, dry and wet scrubber technique is tested in-house as well as on field tests. The first step towards IMO TIER IlI compliant systems is the development of the single techniques. More benefits concerning in-vest and operation cost as well as reliability and performance are generated by smart combination of the subsystems. As example, when the desulfurization is placed in front of the SCR catalyst, a much better quality of the exhaust gas is entering the catalyst, with a lower risk of blocking, fouling or poisoning. Therefore the complete system can be further optimized regarding volume and weight. The paper summarizes the test results and challenges and concludes with an out-look to future developments.

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。 The increasing global demand for power generation and transportation presents a significant opportunity to the world's large engine producers, but presents a key question regarding the protection of our environment and preservation of our natural resources. To meet this challenge requires the introduction of higher efficiency and cleaner engines to the market that extend the known boundaries of performance whilst ensuring product reliability. The successful delivery of these new engines with competitive time to market demands a leap in development philosophy and method. This paper presents the design approach for a single cylinder engine that in close combination with a powerful analysis process enables the significant reduction of development cost and duration, whilst substantially enhancing the fundamental reliability achieved in new product development. Traditionally single cylinder engines have been applied to the early life evaluation of combustion processes. As such the flexibility in configuration, greater refinement in test control and measurement, reduced costs of prototype parts and operation, and reduced test facility demands have accelerated the development of ever cleaner and more efficient combustion systems. Coupled with assessment of the combustion process there has existed the opportunity for the preliminary durability assessment of certain performance related components. This has offered promise in particular due to the much-reduced overhead in operation. However, there remains a substantial and unrealised opportunity in the application of single cylinder engines to the accelerated validation of multi-cylinder engine function and reliability. In this paper the authors lay out this opportunity and the approach to deliver to market both class leading functionality and reliability. At first the boundary conditions for operation representative of a multi-cylinder engine maybe established through the coupled use of multi-cylinder and single cylinder engine simulations. The gas exchange processes that influence cylinder filling and trapping of residual fractions, charge motion, and transport of emissions maybe determined such that early stage confirmation of the boosting strategy can be given. Simulation of whole engine cooling and lubrication flows coupled with detailed analysis of individual cylinder operation gives confirmation of operating boundary conditions and enables the single cylinder replication of heat exchange processes and component thermal loading, lubrication and friction. Secondly, the architecture of the single cylinder engine is created such that the maximum commonality with engine hardware maybe achieved. Evidently this would include the replication of bore and stroke, but also deck height, connecting rod length and cylinder bore offset. Ensuring the use of common big end bearings and entire valvetrain geometry will then enable not only the use of common cylinder head and piston assemblies, but also connecting rod, liner and all valve gear. The development of rapid prototyping methods which align with production design, materials and manufacturing processes ensures the seamless transfer of designs to the production supply chain. Thirdly, and with the foundation of representative components operating under representative conditions, it becomes possible to significantly extend the validation of both function and reliability. With precise measurement of temperature, pressure and strain the thermal and mechanical performance of components may be confirmed. Further, with representative thermal and mechanical loading, and component deformation and dynamics, the performance of the piston and cylinder liner systems, valvetrain kinetics, and rotating and reciprocating friction may be confirmed.

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。 By 2016, under the IMO Tier III rules,NO x emission from ships sailing in the Emission Control Area (ECA) should be reduced by more than 80% relative to the IMO Tier I levels. A selective catalytic reduction (SCR) system, a water treatment (such as emulsification fuel) system and an exhaust gas recirculation (EGR) system are proposed as concrete methods. Recently, the Nitrogen-enrichment Humidification Membrane (NHM) system developed by Asahi Kasei Chemicals Corporation (Japan) has received much attention. This device reduces NOx emission by decreasing the oxygen density in the suction air using a special membrane while increasing the moisture content in the suction air. Because this device is installed on the suction air side, it will not be affected by trends on marine fuel sulfur content regulations or supply trends of marine fuel in the future. Moreover,because the operation materials are water and air,this system is environmentally friendly. In this study, in order to reduce NO x emission from marine diesel engines, the following experiments were carried out. At the first, to explore the spray combustion characteristics of diesel fuel under very low oxygen density ambient condition, high temperature and high pressure combustion vessel with two observation windows was observed. And the second, the NHM system was connected to the suction line of a high-speed marine diesel engine and a low-speed two-stroke single cylinder engine, and the effects of the oxygen density and the moisture content in the suction air on NO x emission were investigated. The NHM system with a polymer membrane that has selective permeability with respect to oxygen and water vapor is composed of an ’oxygen reduction system’ that can freely establish the oxygen density and a ’humidifying system’ that can freely establish the moisture content in the suction air.The following experiments were carried out. (1) Visualization of combustion: high temperature and high pressure combustion vessel with two observation windows was photographed by a high speed color video camera through one of the windows. (2) Effect of the oxygen density: Humidity of the suction air was adjusted to 0 % using a dryer. The oxygen density of the suction air was then reduced from 21 to 16.2 % using the ’oxygen reduction system’. (3) Effect of the moisture content: The moisture content in the suction air was increased from 0 to 16 % using the ’humidifying system’. (4) Combination effect of the oxygen density and the moisture content: The density of oxygen was set to 21, 20, 19 and 18 % using the ’oxygen reduction system’ and the moisture content was then increased for each density. Results clarified that the IMO standards can be satisfied based on the following conditions. (1) The flame temperature becomes lower as the decrease of oxygen density mainly due to the dilution effect and as the increase of CO2 mixing due to the increase of specific heat, and results in the low NOx emission. (2) NOx emission decreased as the oxygen density decreased for each load factor, and thus the restriction on NOx emission set by the IMO standards can be satisfied simply by setting the oxygen density at less than 17%. (3) NOx emission decreased because the oxygen density decreased for increases in the moisture content, and thus the IMO standards can be satisfied simply by adjusting the humidity of the suction air at more than 16 mol.%. (4) Taking into account the operating conditions of the engine, NOx emission can be effectively reduced by decreasing the oxygen density as well as increasing the humidity of the suction simultaneously.