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 studies the influence of dimethyl ether and non-standard diesel blended fuels on engine performance, first using the software FIRE to simulate engine emissions of D50 mixed fuels(mass ratio of dimethyl ether 50%, nons tandard diesel 50%).And then doing experiments on 4100QBZL cooled diesel engine to study the impact to emissions with EGR technology. The results show that the appropriate EGR rate can effectively reduce engine emissions and get the optimum EGR rate under various load conditions at 2200r/min.

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 coupling model of body-head-liner was established according to elastic mechanics theory and nonlinear contact theory. Then static analysis of the assembly was carried out in the preload conditions, and deformation characteristics of cylinder liner were researched, in addition the influence of structure factors on deformation of liner was also studied by using orthogonal design method, meanwhile, the structure of liner was optimized. The results indicate that each cylinder liner presents shrinkage deformation in the upper cross-section, expansion deformation in the middle and lower cross-section, and the maximum deformation is located the top of cylinder liner; because of the effect of the structure rigidity of body, the deformation of four cylinder liners is uneven, and the deformation of the first and fourth liner in the free end is relatively larger; the depth of counter bore and thickness of cylinder liner have the greater influence on the deformation of cylinder liner; as the depth of counter bore increases, the deformation of the top surface of body becomes smaller, while the biggest expansion deformation of liner can be increased in the same preload conditions, and the cross-section shrinkage deformation increases and cross-section expansion deformation decreases with the deceasing of the thickness of liner.

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 current Wärtsilä two-stroke portfolio consists of engine-types; RT96C, RT84T-D, RT82C,RT82T, W-X82, RT68-D, RT58T-E, RT60C-B, RT50D and RT48T-D as well as the newly-developed W-X35, W-X40, W-X62, W-X72 and W-X92 engines. TheRT-flex82T engine has been upgraded for modern requirements and is presented in the portfolio as the new Wärtsilä W-X82 engine for VLCC/VLOC (Very LargeCrude/Ore Carriers) and Panamax container vessels.Introduction of the new engine-types W-X35 to W-X92 will be described in a separate paper. By the end of 2012 more than one thousand electronically controlled Wärtsilä 2-stroke engines had been ordered. As these flex-engines now account for 100% orders placed and RTA engines are no longer popular, this confirms that the common rail technology is highly attractive and well established. The trend of reduced ship’s service speeds in combination with lower shaft speeds and lower engine powers for engine new buildings requires a continuous upgrading of the existing engines in the portfolio. To cope with this trend, engines are configured at lower ratings to gain the lowest possible specific fuel consumptions and to achieve low EEDI (Energy Efficiency Design Index) numbers. Therefore,for example, the rating field of the W-X82 engine was enlarged and the power of the RT-flex58T-E engine has been increased by 4% in order to fulfil specific market requirements. Additionally, an ’RT-flex’ version of the RTA48T-D engine has been designed and released to meet the requests mainly of the Chinese market. Also, on the RT-flex50, an engine arrangement with the turbocharger at the aft end of the engine has been introduced. This paper also reports on the development of Wärtsilä’s RT-flex engines focusing on design improvements to increase their reliability and serviceability, and to reduce maintenance costs. Pulse Jet cylinder lubrication and FAST (Fuel Actuated Sac-less Technology) fuel valves have been introd uced to gain lower cylinder oil feed rates, lower fuel oil consumptions and reduced emissions respectively. The first measurements with FAST fuel valves during shop tests on different bore sizes confirmed the potential of reduced fuel oil consumption over the whole engine load range. The first engine with this new technology entered service at the beginning of 2012. The above-mentioned major improvements will be introduced on all portfolio engine types step-by-step. Wärtsilä two-stroke engines can be equipped with the Intelligent Combustion Control (ICC) system which adjusts the peak firing pressure of the engine according to the given design criteria and automatically balances compression and firing pressures in all cylinders by selecting the injection timing and exhaust valve closing within the allowed operating range. The Waste Heat Recovery (WHR) system which has now been installed on many projects will also be described in the paper and the operational benefits will be reported. The second part of the paper will highlight the wide range of service experience gained with the different engines. From this service experience, the good engine performance and reliability as well as the attractiveness of the common rail engines can be confirmed. The first RT82C and RT82T engines have exceeded four and three years of successful operation respectively. The total accumulated run ning time of one hundred engines at sea has reached more than 1,000,000 hours. Further, the first RT-flex 48T-D engine passed its’ shoptest and was commissioned in May 2012. A thorough insight into the behaviour of RTA and RT-flex components will be given including information on fuel and servo oil pumps, as well as injection control units and a review of Piston-running results. Additionally, the excellent performance of crank train bearings will be mentioned. Broader service experience of FAST injectors will be available after the validation test at the beginning of 2013 and will be during the CIMA

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 effects of biodiesel blending fuels with different biodiesel fractions on power performance, fuel economy and emission characteristics were investigated on a high pressure common rail diesel engine, according to ESC steady state 13-mode test cycle without modifications of engine construction and parameters adjustment. The test results showed that the engine power decreases slightly, fuel consumption increases, while energy consumption decreases. With the increase of biodiesel fuel proportion in blends fuel, the brake specific emissions(BSE),weighted BSE, and 13-mode weighted average BSE of CO, PM and HC decrease, but ones of NOx appears as opposite trend. On higher load, contribution rate of CO, PM and NOx are greater, while one of HC is smaller.

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。Nowadays, asphaltene contamination called ’Black Sludge’ in marine trunk piston engine oils (TPEOs) continues to be a common issue. ’Black Sludge’ can occur through leaky fuel pumps or poor combustion which is usually detrimental to lube oil properties such as increasing viscosity and volatility, weakening the function of the additives. Meanwhile ’Black Sludge’ can deposit on a piston surface and act as an inulating layer to influence engine efficacy and heat transfer, sometimes may even cause crankcase explosion, therefore selecting proper TPEOs plays a significant role in controlling ’Black Sludge’. A key design feature for preventing asphaltene precipitation is choosing the proper additives, especially detergent additives in reducing ’Black Sludge’. In this paper, asphaltene dispersancy effectiveness was investigated through making the simulated solutions according to the hydrocarbon types of typical Group I and Group II base oils. Utilizing different facilities including Malvern Mastersizer 2000 particle size analyzer,LaserNet Fines®-C particle counter, Focused Beam Reflectance Measurement to interpret the effectiveness of calcium alkyl sulfonate and calcium alkyl salicylate with combining traditional spot dispersancy test.All tests have a good correlation with real asphaltene dispersancy effectiveness. Test results show that salicylate package has a more outstanding performance than sulfonate one.

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 estab- lished mathematical model of the electro-hydraulic speed governing system of diesel engine. By means of simulink simulation,analyzed the main factors which affect dynamic characteristics of hydraulic actuator, emphatically analyzed influence of damping ratio natural frequency and flow gain of servo valve on dynamic characteristics of hydraulic system,and analyzed the dynamic characteristics of the speed governing system of diesel engine and obtained coincide with experimental results. The research provides theoretic basis for design of electro-hydraulic governor.

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, the uniform pressure method, the contact model method and the temperature method are used to simulate the shrink fit of the valve seat ring. Based on theories and calculation results, it is concluded that the contact model method can reflect the real contact condition. In order to investigate the influence of the valve seat ring on the fire deck stresses, the contact model is used. The mechanical stress,thermal stress and thermomechanical stress are calculated. With the valve seat ring, the mechanical stresses increase while the thermal stresses and thermomechanical stresses decrease in the valve bridge areas. Therefore, the influence of the valve seat ring can not be ignored when calculating the stresses of the cylinder head.

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。: An active vibration isolation system is developed for a diesel engine generator in a floating tug boat. This system consists of six inertial actuators and a DSP processor. A six-input and six-output adaptive control strategy is applied and the reference input signal comes from a laser tachometer on the shaft of the diesel. Six accelerometers are located on the top of isolators to act as error sensors. A hydrophone is dropped in the sea water to measure the underwater radiation from the diesel generator. The active vibration isolation experiment is conducted in the tug boat when only the diesel engine generator is working. The experimental results demonstrate that good reductions are obtained not only for vibrations of error sensor’s locations but also outputs of the hydrophone which is dropped in the water under the hull. Some discussion and conclusions are given at last.

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。 To explore the potential of combinational combustion of diesel and methanol for the improvement of integrated fuel economy, experiments were carried out on a certain high pressure common rail heavy duty diesel engine on different modes (A B andC speed with the load ratio of 100% 75% and 50% was included) based on the specially designed methanol supply project, which injects methanol into the engine intake manifolds. Firstly, the brake thermal efficiency (BTE), which is calculated based on diesel saving and methanol burning on the premise of the same BMEP, is utilized as information to evaluate the economy of the tested engine. Secondly, the shortages for BTE to indicate the economy of MDCC engines are set forth. And then, fuels total cost is proposed to evaluate the economy of MDCC engines. The optimal replacement ratio of diesel (RRD) for the lowest fuel cost is formulized by structuring an objective function. In addition, the major factors hindering the economy promotion are discussed and the effective measure to relax the constraints when they evolve into limiting factors of better economy for the MDCC engine. Finally, some valuable conclusions are arrived at the end of this paper. The research presents important references for the determination of optimal methanol ratio for MDCC 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。 It is commonly known that the fuel injection system is the most significant sub-system within a Diesel engine and that it requires parts of the highest manufacturing precision. In order to meet the extensive applications of Diesel engines, the highperformance fuel injection systems must be developed and made available. This paper introduces the development of the conventional fuel injection system and the modern fuel injection systems (such as electronic control unit injector system and common rail injection system) and discusses their characteristics and application prospects. It is indicated that although electronic control common rail and control unit injector systems have been flourishing, the accumulated experiences of manufacturing and matching for conventional pump-line-nozzle fuel systems are available conveniently and economically, which will coexist with the modern fuel injection systems in the near future. So the conventional fuel injection systems should be paid more attention to while developing the new fuel injection systems.