该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。There is currently strong interest in exploring alternative fuels for shipping, as one of the solutions for complying with Emission Control Area (ECA) requirements. At present, LNG represents the first and most likely alternative fuel to be widely adopted in shipping. A number of other fuels, such as LPG, methanol and various types of biofuels are also being considered and tested. The adoption of any new fuel will be driven by fuel price developments, technology, regulation, availability and the development of the appropriate infrastructure. In this paper a cost-benefit comparison between HFO/MGO and LNG, LPG, Methanol, and Hydrogevated Vegetable Oil (VGO) will be presented. A product tanker will be used as the test vessel, to enable the comparison between various fuels. A route including operations in ECAs is defined. Economical comparison of the equipment and installation cost for each fuel will be performed. A number of fuel price scenarios will be considered, to evaluate the operational costs of the vessel for each fuel option. The environmental implications of using each one of the alternative fuels will also be considered, by performing lifecycle assessment of the environmental footprint of each fuel. This will be mainly based on greenhouse gas equivalent emissions, but NOx and SOx emissions will also be included.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。Ural Diesel Motor Works LLC. (UDMZ) is developing a completely new engine family to be introduced into the market in 2016. The engine family is specifically designed to cover a wide power range to be used in mining vehicles, railway, marine and generator applications. In total, sixteen engines with a capacity from 840 to 3,800 kilowatts (protected up to 6,000 kW) are members of the DM-185 engine family. With the number of cylinders varying from six to twenty, the main characteristics of this new engine family are a high specific performance (up to 234 kW/cyl.) and low fuel consumption while at the same time complying with EU IIIA / IMO2 emission legislations, without use of external gas recirculation or exhaust gas aftertreatment systems. Key parameters of the new engine family will be introduced. From the development work, results will be presented from the engines combustion simulations as well as from the single-cylinder combustion development, which was successfully applied to define engine hardware and injection parameters. With the first prototype engines built and currently under operation at UDMZ's facilities in Yeakterinburg, Russia, furthermore first results of the complete engines will be shown to demonstrate feasibility of the engine family's concept.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。The proper layout of the accumulator function in a common rail system (CRS) is crucial for the competitiveness of the CRS in terms of costs and benefit. The accumulator function can be realized in various ways. It can be built up by a modular system that allows using the same accumulators and connecting parts in engines with different numbers of cylinders or by the integration of a manifold (common rail) that feeds several injectors. Accumulators can be integrated into the injectors. The accumulator function can alternatively be integrated into the fuel pipe line system between the high pressure pump and the injectors. A systematic approach is presented for the identification of an optimal layout of the accumulator function in diesel engines with a power output in the range between 1 and 5MW by taking into consideration of the engine layout conditions, hydraulic and lifetime requirements, manufacturability and manufacturing economies as well as assembly and maintenance requirements. The effects of various design layouts of the accumulator on the hydraulic performance and fatigue life has been studied by means of hydraulic simulations and fatigue calculations using an inline six cylinder model engine with 1750kW power output and a nominal operation pressure of 2000bars. Two fundamentally different approaches for the accumulator function have been studied in detail. In one approach the system is built-up in a modular way, whereas an accumulator of 500 or of 80cm3 volume content is integrated into the injectors. In a second approach the CRS was built-up using a one piece accumulator (rail) with 500cm3 volume content. In both approaches the damping effect of orifices on pressure fluctuations was studied. For the rail variant the damping effect of additional, small sized 40cm3 single accumulators, which can be integrated into the injector or in front of the injector, was additionally studied. Hydraulic performance is discussed in terms of the pressure drop within the injector, injected discharge rate development over one cycle, amount of injected fuel per cycle as well as their reproducibility from one cylinder to the other. It was shown that the best combination with respect to a minimum drop of the injection discharge rate and to a reproducible injection discharge rate function can be achieved with two fundamentally different approaches: (1) by a modular system with 500cm3 accumulator integrated injectors in which pressure pulsations within the jumper lines are dampened by orifices and (2) by a non-modular common rail system with a 500cm3 one piece accumulator, which is stabilized against pressure pulsations within the injector by means of additional 40cm3 single accumulators that are placed in front of the injector or integrated into the injectors. Under given design boundary conditions a slight but visible advantage of variant (1) over variant (2) in terms of the reproducibility of the injection discharge rate function from one cylinder to the other is found. Damping of pressure pulsations is found to be crucial for the high pressure capability (fatigue life) under nominal operation conditions at the working pressure of 2000bar. The relevance of the hydraulic characteristics diminishes when fatigue lifetime is governed by a high number of start-up/shut-down cycles. As long as advanced requirements in regard to hydraulic performance and fatigue life can be realized with a modular set-up with large accumulator integrated injectors as well as with an optimized CRS based on an external accumulator system, the decision for either of these approaches must be made dependent upon given engine layout conditions, cost targets, manufacturing opportunities and preferences with respect to assembly and maintenance works. The relative strengths and weaknesses of studied variants are briefly discussed in relation to the above mentioned decision criteria.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。Hudong Heavy Machinery (HHM), a company within China State Shipbuilding Corporation (CSSC), is well known for manufacturing of large bore 2-stroke and 4-stroke engines. For many years E390VA serial engines and different types of Pielstick engines have been produced as a major part of Hudong's medium speed engine portfolio. In 2011, HHM decided to update the former E390VA medium speed engine family together with support from FEV. The focus for the development program of this new generation engine family was on market requirements, advanced performance, fulfillment of latest and future emission legislations and high reliability. The family with a bore of 390 mm and a stroke of 550 mm covers a power range from approximately 5 MW with an inline 6 engine and up to approximately 17 MW with a V20 version. The engine’s target applications are marine propulsion (river and coastal shipping) as well as genset use, meeting IMO Tier 2 NOx emission targets, and also IMO Tier 3 standards with an additional exhaust gas aftertreatment system. This paper describes the major advanced design features of the V12 version as the first member of the engine family as well as the development process including utilization of intensive CAE analyses and combustion development on a single cylinder engine, followed by information about corresponding test results.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。Stringent emission legislation and demands on low fuel consumption set some of the main trends for medium- and low-speed combustion engine development. To bring the engine performance to the next level, many aspects are to be taken into account. One area, which is getting more and more in focus, is the engine controls. High performing engines require high performance controls. By utilizing the foundation of the Wärtsilä UNIC engine control system platform, the next generation UNIC has been developed with a focus on engine performance, reliability, and safety as key cornerstones. The starting point of the next generation UNIC systems is the well-established UNIC system that is currently running on thousands of Wärtsilä engines in the field. Essentially, the UNIC is a scalable and modular system in terms of both the software and hardware architecture. The software is moreover developed according to model-based design principles, and the flying-lead concept is used for connecting all sensors to the on-engine modules to secure highest reliability. Along with new engine technologies, such as variable valve timing, there is an increased demand of controls and monitoring features. Furthermore, with different engine applications and configurations, there is an increased need for flexibility from the engine control system. In this paper, the development of the next generation UNIC system will be presented, including the design choices that have been made to comply with future requirements of marine and power plant engines. By creating a state-ofthe-art engine control system, future needs for controls and fault diagnostics have been secured. Advanced control methods aim at retaining highest engine performance throughout its lifetime and transient and fluctuating operation points. Reliability and minimized engine down-time are taken into account by new fault-diagnostic features as well as a clear emphasis on usability. In the new local display module design, the demands on usability have been put in front. To take quality to the next level, state-of-the-art engine software application testing and continuous integration methods have been taken into use. By building on the UNIC platform and by taking a leap in key areas to enable new engine performance, the foundation is built to enable engine performance, reliability, and safety today and in the future.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。As a response to emission regulations, efficient SCR systems for NOx emission reduction of diesel engines have been developed and successfully introduced on the market. Tightening emission legislation can often be met also by introducing gas-operated engines. Despite of the low NOx, SOx, PM and CO2 emissions of gas engines, hydrocarbon emissions are getting more focus by the regulators and, consequently, also in product development. The operating temperature window of a SCR system for NOx control with high-sulphur fuels is mainly determined by ammonium bisulphate condensation at low temperature and increased SO3 formation under high temperature. The exhaust gas temperature of a single-stage turbocharged engine can be tuned for SCR operation with reasonable efforts, e.g. by controlled exhaust waste-gate and air by-pass valve operation. In 2-stage turbocharged engines, the exhaust gas temperature is further decreased creating more challenges for temperature control. Installation of SCR between the turbochargers (inter-turbine SCR) provides higher operating temperatures and compressed exhaust gas with lower volumetric flow rate. These conditions enable higher catalytic activity and a more compact SCR design compared to a post-turbine installation. An installation of reactor under pressurized conditions require detailed CFD simulation to optimize the pressure drop, flow behaviour and ammonia mixing in exhaust gas to reach high catalytic performance. The operating window for hydrocarbon oxidation catalyst in lean-burn gas engines is mainly determined by the low activity at low temperatures and non-reversible deactivation at high temperatures. Depending on the catalyst chemistry and reactivity of the targeted hydrocarbon compounds, the oxidation catalyst can be located for optimum exhaust gas temperature in a pre- or post-turbine location. While commercial solutions are available for volatile organic compound reduction, more stable methane requires more efficient catalyst. Fast deactivation of the catalyst by sulphur is the main challenge for the practical application of the methane oxidation. This paper gives an overview of the emission legislative development and the aspects of developing exhaust gas aftertreatment systems for NOx and hydrocarbons for high efficiency four-stroke medium-speed engines. Aspects of exhaust gas temperatures, pressure drop, design parameters, performance, and regeneration possibilities are discussed for the application on both 1-and 2-stage turbocharged engines. Results of simulation and engine tests with part-flow and full scale catalyst systems are presented.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。The continuously increasing mechanical and thermal load of modern engines causes the need to optimize the designs over a wide range of different aspects. The development process of many engine components supported by various computer simulations is currently advanced and well defined, leading to creation of highly optimized products. However, the optimization of such design variables like the firing order, which influences engine operation in several disciplines, is still challenging. In the time of application of high combustion pressures, the layout of the firing order in multi-cylinder commercial engines is an efficient way to reduce cranktrain/overall engine vibration and main bearing loads, whilst controlling engine balancing and preserving adequate gas flow dynamics through the engine intake and exhaust systems. The proposed general firing order selection process of the four-stroke engine and in particular its first part being the optimization of the firing order based on crank train torsional vibration is the main topic of this paper. A central role in this process plays a dedicated algorithm as developed at FEV GmbH, that generates series of firing orders for predefined crankshaft layouts, for which then engine simulations are to be performed. Such approach reduces the number of theoretically possible alternative firing orders only to those that are consistent with the boundary conditions of specific engine design and are technically feasible. The influence of each firing order is finally analyzed and rated by use of multi-criteria optimization techniques such as the proposed desirability index method. Considerations regarding the number of technically feasible alternative firing orders for typical engine configurations and crankshaft layouts being a result of development of above-mentioned algorithm and the study about the influence of the firing order on cranktrain torsional vibration of exemplary V16 commercial diesel engine is presented in this paper as well.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。The regulations as well as expectations on shipping concerning the environmental impact have been growing in recent years. At present, regulations on sulphur content in marine fuels are implemented in certain regions and a global decrease will be applied in the years to come. This has led to a search for very low sulphur (<0.1%) or sulphurfree alternative fuels. The maritime fuel of today being heavy fuel oil has often up to 4% sulphur, which requires exhaust gas cleaning systems to avoid excessive sulphur emissions. Consequently and on request from Stena Line, Wärtsilä initiated a project to select a sulphur-free fuel to be used initially on Stena ships in 2015. The fuel chosen is a liquid state methanol. The capability of methanol to replace fuels based on mineral oil has been known for a long time. In this context, methanol has been forwarded as a strong alternative that can be used in converted diesel engines. Besides the total sulphur reduction, methanol is also contributing to emission reduction, in terms of nitrogen oxides and particulates, and provides a fuel that is biodegradable, decreasing environmental impact from accidental spills. There are also demands that shipping should contribute to reducing carbon dioxide emissions radically in the future. Also here, methanol could play an important role if produced from non-fossil feedstock like CO2 capture or wooden mass. The physical and chemical properties of methanol make it very well suited for use in spark-ignited engines. It has excellent ignition properties with an Octane number of 106. But its ability to combust without forming soot (due to the lack of carbon-to-carbon bonds) has attracted diesel engine designers to find ways of using it as well. The challenges for the design of the fuel injection system are connected to the properties of methanol, in particular the combination of high viscosity of 0.57cSt at 40°C and a low boiling point of 65°C in atmospheric pressure. Then the fuel system has to be resized to accommodate the lower energy values around 19.8 MJ/kg. Eventually, the cost of methanol should be lower than that of marine gas oil, making it a competitive commercial alternative. This paper describes the patented injection system working principles and its key design challenges, the first laboratory engine results, as well as the results from the application on the first ever ship operated on methanol, the passenger ferry Stena Germanica, leading the technology development and leaving a positive trace on the society.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。”To measure is to know” says an old quote presumably from Lord Kelvin. This holds true more than ever also for exhaust gas emissions – we must measure to gain knowledge. There is an ever increasing demand to measure. The scope and range of the measured emission components are wide and expanding: stricter emission legislation, fuel flexibility, aftertreatment systems, customers’ needs, etc. This paper concentrates on two areas: particulate measurements and special gaseous emission measurements. The focus is on medium-speed diesel and gas engines used for power generation in power plants or in marine applications. Emission limits can vary depending on application, location, engine size, and power output. The emission level for a specific engine depends, for example, on the fuel type and quality. This means that one must be able to measure a wide variety of different emission components over a wide range – both gaseous and particulate. In the first part of this paper, particle emissions from engines operated with different fuels and fuel qualities are studied, using novel particle analysers (e.g. Dekati ELPI+ and AVL Micro Soot Sensor). One interesting result is that Black Carbon (BC) exhaust concentration is on the same level when running on LFO as on HFO fuels. When running on gas, the BC level drops by over 90%. Traditional gravimetric particle measurement method (ISO 8178&9096) results are incorporated into the study. The second part presents how sophisticated gas emission analysers are used in engine development, allowing more detailed and faster testing compared to traditional methods. Results on fast measurement of NOx and THC are presented as well. This method is used in the study to optimise combustion quality, leading to lower emissions. Based on findings presented in this paper, future prospects regarding requirements and needs for emission measurements are discussed. Lower emissions are harder to measure, pushing the performance limits of the current measurement methods and equipment. On the other hand, more advanced measurement equipment enable a more versatile use of the equipment. Novel particle and gas analysers are not just emission measurement devices but an important part of the engine development process.

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。Since January this year, new requirements are in place regulating the NOx emissions from ship’s engine exhausts. For decades Selective Catalytic Reduction (SCR) has been an established method for NOx abatement on board seagoing vessels and SCR equipment has been installed on a large number of four-stroke diesel engines. So far, only a few large marine two-stroke diesel engines have been equipped with SCR. The exhaust gas temperatures of such two-stroke diesel engines are in general lower compared to four-stroke engines so, in order to obtain sufficient operating temperatures, the SCR can be placed upstream of the turbine (turbocharger). As a consequence, the catalyst is operating at elevated pressures and high temperatures during high loads of the engine. On the other hand, at part loads the exhaust gas is close to ambient pressure and the temperature is at the lower operating limit of the SCR. In 2015 Winterthur Gas & Diesel conducted a series of tests on a full scale pre-turbocharger SCR to establish engine test-bed procedures, map the performance of the engine/SCR, and to demonstrate compliance with Tier III limits. Moreover, a series of laboratory and bench scale experiments were conducted in order to test the catalyst operation and, explicitly, to be able to assess the effects of temperature and pressure on the catalyst performance. Our tests show that a modern two–stroke engine, in combination with an SCR upstream the turbocharger, presents a fuel-flexible NOx compliant solution for sea-going vessels. This paper confirms methods for predicting the operating temperature of the catalyst when using residual fuels and when operating at elevated as well as atmospheric pressures. We show that the absolute minimum temperature for long-term operation is limited by the condensation of ammonium- and sulphate-containing salts in the bulk phase and that the SCR must not run for long periods at temperatures where significant amounts of the salt can condense in the catalyst pores. In summary, careful control of the exhaust gas temperature of the two-stroke engine enables successful SCR operation with low sulphur fuels as well as with residual fuels containing high amounts of sulphur.