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 vibration level of medium-speed engines is critical to quality measures like durability and noise. In combination with engine mounted after treatment systems used to meet the EPA T4 emission standard it becomes more and more important and challenging to control the global and local vibrations. The durability of the power train components is not only dictated by the crank train excitation forces but can also be influenced by the struc]tural component vibration behaviour. The objective of the global engine vibration analysis method presented in this paper is not to consider the dynamic loads as discrete static loads but to calculate the component durability under realistic time-dependent operating conditions including the dynamic structural behaviour. The hybrid analysis procedure uses the synergy of two widespread analysis types: Multi-Body-Analysis (MBA) and the Finite-Element-Analysis (FEA), to simulate the dynamic component loading but also the assembly, thermomechanical loads and local contact slipping/gapping effects. The simulation procedure has been verified in the past based on acceleration and strain gauge measurements at numerous engine components. The comparison between measurements and simulation results has shown that a good correlation of both the global deformation as well as the local strains can be achieved.

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 development of the 51/60DF engine started in 2005. The design of the engine considers the market requirements for marine and stationary applications. Driven by those market requirements the focus of the development was pointed on efficiency,emissions, fuel flexibility and a wide range of application possibilities. The first prototype engine started its test run in 2006. Since then a process of continues development has been started to optimize engine components and engine parameters to fulfill the costumers demands. In addition, new technologies like a turbocharger with variable turbine area were introduced and tested. The first type approval for constant speed application has been passed successful in 2007 followed by the order of inline engines for a 174.000m 3 LNG carrier delivered in December 2008 to the costumer. Up to now more then 50 V-type new build and retrofit engines for stationary power plants and 20 inline engines for marine applications has been placed to the market. As a result of continues development MAN Diesel &Turbo SE has opened up the application range of the 51/60 DF engine and passed successful the type approval for variable speed application in 2012. This gives MAN Diesel &Turbo SE now the possibility to offer the 51/60DF for mechanical propulsion with Control Pitch Propeller (CPP). One further step to fulfill the requirements for stationary application is the development of a pure gas engine the 51/60G in addition to the 51/60DF. The first prototype engine will be tested end of 2012. The paper will give an overview about the achieved results of the prototype and serial engines operating on liquid and gaseous fuels, the improvements and the new applications of the Dual Fuel and pure gas version of the MAN 51/60 engine.

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。 Noise and vibration attributes play an important role in the development of any rotating components, such as engines, drivelines, transmission systems, compressors and pumps. The presence of torsional vibrations and other specific speed-related phenomena require the dynamic behavior of systems and components to be designed accurately. Not taking into account torsional vibrations during the early design stages can lead to critical issues like comfort problems, performance decrease and durability related problems. Torsional vibrations are angular vibrations of an object, typically a shaft along its axis of rotation. As mainly rotational speeds are measured,torsional vibrations are assessed as the variation of rotational speed within a rotation cycle. These RPM variations are typically induced by a nonsmooth driving torque or a varying load. Structural sensitive frequencies along a driveline may then amplify and transfer these phenomena leading to comfort, durability or efficiency problems. The level of torsional vibration is influenced by a number of parameters, such as material properties, operating conditions like temperature,load, rpm... and will need to be taken into account. In the (very) early design stages, simulation techniques can be used, but despite tremendous progress in modeling accuracy, overall system complexity still necessitates accurate qualification and quantification of these torsional vibrations by means of experimental testing under controlled or real-life operating conditions. This paper provides an overview of the instrumentation and challenges related to torsional vibration testing. The accuracy and performance of five measurement techniques (high-speed incremental encoder, dual beam laser interferometer, zebra tape, zebra disc and direct pulse measurements with magnetic probe) are investigated and compared. The potential sources of error and possible corrections are discussed for each technique. Once accurate measurement data is available,specific processing techniques are used to quantify the torsional vibration phenomena or to correlate them with other acoustic or vibration responses of the structure. The interpretation of the measurement can be simplified with a good visualization of the deformation on a 3D geometry of the test object. Animating the deformation at a fixed frequency or according to measured torsional orders allows to better qualify the importance of the phase relation between the different shafts or sections of shaft and vibration or acoustic responses. Specific industry examples are discussed in which torsional vibration analysis plays an important role to improve the design and overall performance.

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。: Due to future emission legislation for harbor as well as the upcoming IMO Tier III emission regulation for marine application and the promising development of the price for natural gas, a switch to gaseous fuels in the marine sector is a new line of conduct from customer side. Additionally ship owners develop more and more environmental awareness. With the latest development of its new mediumspeed four stroke 35/44 DF engine MAN Diesel & Turbo is continuing the expansion of its product program with a dual fuel engine based on common rail technology. The paper will give an overview about the engineering of the 35/44 DF as well as the new technologies employed to fulfill the future market requirements. In addition a short overview will be given on the thermodynamical properties and expected performances for a given range of application. This new high end four stroke engine with high flexibility was developed within a very short time frame of 18 month. The development objective was a high efficiency and a high specific power output in accordance with emission limits IMO Tier II in diesel mode and IMO Tier III in gas operation with high degree of fuel flexibility (HFO, MDO, MGO and natural gas). With an output of 530kW/cyl the engine is covering a power output range from 3,2MW to 10,6MW.The 35/44 DF has the highest power output in the segment and is complementary to the power output range from current serial engine 51/60 DF from MAN Diesel & Turbo SE. This engine is based on the 32/44 CR-T2 engine, using a high level of component synergies. Therefore MAN Diesel & Turbo can also offer a retrofit solution from 32/44 CR-T2 to 35/44 DF. The prototype engine is currently running and being validated at MAN Diesel & Turbo in Augsburg, Germany and will end with a classification approval.

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。: For years gas engines have been gaining importance within the global energy mix. One reason for that is the comparatively good, long term availability of natural gas, combined with highest efficiency potentials while meeting the most stringent worldwide emission standards. This makes large gas engines a clean technology for supplying electricity and heat around the globe as part of a decentralized energy concept. GE’s all new 10 MW range J920 Jenbacher gas engine is top of its class for electrical efficiency and designed for durability, simple installation, and maintainability. The engine consists of three modules,including a generator, engine, and turbocharger auxiliary module, that provide a high-quality, pre-fabricated,standardized generator-set module. Each module is factory-tested, then shipped separately and assembled on site, offering reduced installation time. In addition, the modules have highly standardized interfaces that work well with the balance of plant (BoP) systems, and ultimately simplify BoP installations and total plant erection time. Based on the extensive experience of GE’s type 6 gas engine combustion system,the J920 Jenbacher unit is equipped with an advanced pre-chamber combustion system with spark ignition and optimal conditions for longer part life. In addition, the individual gas mixing achieved by port injection in combination with cylinderspecific sensors allows each cylinder to be controlled to operate at optimal performance. The J920 mechanical structure is designed to allow high-peak firing pressure well above 200 bar. In combination with the latest early valve closing technology and the Jenbacher 2-stage turbocharging,the J920 Jenbacher gas engine achieves an electrical efficiency of up to 48.7%. GE’s 2-stage turbocharging concept for gas engines enables optimized miller technology high-power density and a large potential for high mixture temperatures allowing higher cooling water temperatures and with that making it an ideal fit for independent power production projects in hot ambient conditions. Combined heat and power (CHP) applications benefit from the use of mixture cooling heat at high temperatures to gain up to 90 % of overall efficiency. The J920 is equipped with the next generation of GE’s well-proven comprehensive Jenbacher gas engine management system with cutting edge cylinder individual balancing and optimization, adaptive condition-based controls, smart protection of core components and an intelligent limp home mode. This paper highlights the technology concept of the J 920 with special focus on combustion concepts and controls as well as the development strategy and validation result.

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。 Diesel Engine has been the most powerful and relevant source of power in the automobile industries from decades due to their excellent performance, efficiency and power. On contrary, there are numerous environmental issues of the diesel engines hampering the environment for which it has been a great challenge for the researchers and scientists. In the recent years, numerous strategies have been introduced to eradicate the emission of the diesel engines.Among them, Partially Premixed Combustion (PPC) is one of the most emerging and reliable strategy. PPC is a compression ignited combustion process in which ignition delay is controlled to enhance better homogeneity of air-fuel mixture. PPC is intended to endow with better combustion with low soot and NO x emission. The paper presents the validation of the measurement data with the simulated cases followed by the study of the spray impingement and fuel vapor mixing in PPC mode for different injection timing.The study of the correlation of early injection with the fuel vapor distribution and wall impingement has been made in details. The engine is a single-cylinder engine EVE, installed in Aalto University Internal Combustion Engine Laboratory with the bore diameter of 200 mm. This implies the use of PPC strategy in large engine environment. The simulation is carried out with the commercial CDF code software STAR CD. Different injection parameters have been consider to lower the wall impingement and to produce better air-fuel mixing with the purpose good combustion and reduction of the emissions. The result of the penetration length of the spray and the fuel vapor distribution for different early injection cases have been illustrated in the study. Comparisons of different thermodynamic properties for different injection timing such as average density, average temperature, droplets evaporation percentage rate and liquid penetration length have been very clearly illustrated to get the insight of effect of early injection. The parameters like injection timing,injection period, injection pressure, inclusion angle of the spray have been taken as a major parameter that influence the combustion process in PPC mode. Extensive study has been made for each of these parameters to better understand their effects in the combustion process. Different split injection profiles have been implemented for the study of better fuel vapor distribution in the combustion chamber. The final part of the paper includes the study of the combustion and implementation of EGR to control the temperature so as to get more prolonged ignition delay to accompany the PPC 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。A double Ω -combustion chamber matching double-row nozzle injector combustion system was proposed.The in cylinder spray and combustion process of diesel engine was simulated by using AVL FIRE software. The influence of different nozzle hole cone angles and fuel injection advance angles were analyzed on the concentration field, temperature field as well as combustion and emission characteristics. The results show that new combustion system can improve the quality of mixture, meanwhile, the emission performance is enhanced, and the maximum mass fraction of soot was reduced by 53.4% than the single-row nozzle injector. The combustion mean temperature and pressure decreased with retarded injection timing, moreover, the rate of heat release and the accumulated heat release curves went back, and the both maximums were decreasing. When it was 4°CA BTDC, NO and soot emissions were all low.

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 this paper, two kinds of microemulsified biodiesel containing 5.6% and10% water are prepared. The effects of microemulsified biodiesel on engine’s power, combustion and emission characteristics are investigated in a DI diesel engine. The results show that under the rated speed and full load operating conditions, the maximum pressure rise rate and peak heat release rate for micro-emulsified biodiesel increase dramatically, while the ignition delay is prolonged and the combustion duration becomes shorter. Compared to base diesel, the HC, CO and smoke emissions from the engine fueled with biodiesel decrease sharply, except for a 9% increased NOx at large loads. However, micro-biodiesel could significantly reduce the NOx and smoke emissions, except for the higher HC and CO emissions at low and medium loads. When fuelled with 10%MB, the NOx and smoke emissions are 9% and 90% lower than that of diesel, respectively. Results reported here suggest that the application of micro-emulsified biodiesel in diesel engines has a potential to improve combustion process and reduce NOx , PM emissions simultaneously. Keywords: Micro-emulsified biodiesel; Emission; Combustion; Diesel engine

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 engine heat balance system model,waste heat boiler heat balance system model and power sets operations lumped parameter model of heat transfer were established to study the energy balance of supply and demand situation for cogeneration large internal combustion gas engine generator sets,and the calculation and experiment study of steady operation total energy were done using these models, the research results include the percentage of combustion exothermic heat in the different systems of the engine and the heat utilized efficiencies of exhaust and cooling circulating water. The results could provide theoretical and experimental study basis on improving the utilized efficiency of total energy and the matching study of internal combustion engine with residual heat utilization system.

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。Number concentration and size distribution of exhaust particles from diesel engine and abnormal particle emission with particulate oxidation catalyst(POC)were investigated on the engine test bench through a two-stage dilution system and engine exhaust particle sizer(EEPS). EEPS was used to study the abnormal particle emission after POC on a steady state for 6.5h. The results indicate that, the average particle conversion efficiency of POC was 61%, POC has higher conversion efficiency for nucleation mode particle. In the long time observation, abnormal particle emission after POC happens seven times in the first hour, and the number concentration of these abnormal peaks is higher than normal state by up to two orders of magnitude, the accumulated number and mass concentration of 1 ∼ 5peaks are higher than the filtered particles by POC between every peaks, most of these particles of these peaks are from substrate surface before this test, particle number concentration after POC increases over time from second to sixth hour.