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Cimac Congress | Shanghai 2013 injection strategy, etc. With increasing engine power, the two-stage turbocharger can obviously improve EGR recyclability and the trade off between NOx, soot and BSFC compared with single-stage turbocharger at full load conditions under medium and low speed, which showed obvious advantages and potentials in the case of meeting Euro IV and Euro V regulations without any aftertreatment. At low load conditions, the NOx, soot emissions and the maximum pressure rise rate (MARR) can been efficiently reduced by lowering the injection pressure and postponing injection timing under a single-injection strategy. At high load conditions under low speed, soot and BSFC can been improved by the same control strategy used at low load. At high speed conditions, it is necessary to employ post injection and higher injection pressure to reduce engine emissions and BSFC. Tuesday May 14th / 10:30 – 12:00 Turbochargers – New Products 1 Room D New turbochargers for modern large engines with low emissions and high performance Silvio Risse, Kompressorenbau Bannewitz GmbH, Germany Klaus Buchmann, Kompressorenbau Bannewitz GmbH, Germany KBB faces up to the challenges of IMO Tier II with the ST27 range of radial turbine type turbochargers. Since their launch, the ST27 turbochargers have been well accepted on the market. This paper includes a brief report on field experience. Marine and large genset engines will not be able to meet the consistently increasing performance requirements with due consideration of the worldwide emission regulations in future through internal engine measures alone (moderate Miller cycle timing, for example). Apart from exhaust gas recirculation (EGR) and exhaust gas aftertreatment by selective catalytic reduction (SCR), two-stage turbocharging with intermediate cooling is regarded as a particularly promising way to reduce both consumption and emissions (in particular of NOx). The target in terms of the charging pressures is presently between 6 and 10 bar. KBB is developing new low-pressure and high-pressure turbochargers to meet this emerging challenge. The paper describes the concept behind the new turbocharger series. Apart from the performance targets, it addresses in particular the high demands in terms of sealing, minimising blowby and dimensioning the highpressure stage. In 2012, KBB built the first prototypes of the new generation of turbochargers, which are presently undergoing tests. The paper also reports on the test results achieved on a hotgas test stand and in initial engine tests. Furthermore, the paper covers the increasing requirements in terms of designing (CAE) and matching (1D engine simulation with GTpower) the high-pressure and low-pressure stages. It takes into account the multitude of potential two-stage boost and control concepts for modern large engines operated with gas, diesel and heavy fuel oil and provides corresponding examples. Specially designed EGR turbochargers are required for high-pressure exhaust gas recirculation. The paper addresses the distinctive features of such turbomachines and presents an approach to the design of prototypes ready for series production. Second generation of two-stage turbocharging Power2 systems for medium-speed gas and diesel engines Thomas Behr, ABB Turbocharging, Switzerland Markus Kahi, ABB Turbocharging, Switzerland Armin Reichl, ABB Turbocharging, Switzerland Melanie Hubacher, ABB Turbocharging, Switzerland The most important technology drivers in the development of modern four-stroke medium-speed engines are high total engine efficiencies, low operating costs and high power density while complying with ever more stringent emission legislation. In addition, optimisation of initial costs has been considered during the development to allow for short payback time and thus for a competitive advantage in the area of power generation where reciprocating engines compete with gas turbines. Improvement in all areas mentioned above can be achieved with the application of the latest turbocharging technologies. ABB Turbocharging is currently developing the second generation two-stage turbocharging system for medium-speed gas and diesel engines. The work comprises a complete portfolio with four sizes covering the entire power range of large medium-speed engines. All components of this new system will be fully optimised for combined use in the two-stage system. Completely new designs are being developed for the thermodynamic components. The focus is on high efficiencies for fuel savings, system compactness and flexible operation. Axial turbines will be applied for both low and high pressure stage. The turbine stage designs take into account the diverging needs between high- and low-pressure sides. These result from different temperature levels and flow area requirements. And, as contamination build-up is not comparable, this results in different turbine cleaning concepts. Compressor stage designs are specifically optimised for two-stage requirements. Consequently dedicated designs, highly efficient and compact turbochargers are being realised. Low and high pressure turbochargers will be based on the new concept of an extended cartridge which will facilitate service down times even shorter than those on existing single stage applications. The second generation system is the result of a step change development process motivated by field experience gathered from first generation serial systems. Studies presented at the CIMAC conference in 2007 revealed that two-stage turbocharging systems would soon become a commercially attractive alternative to state-of-the-art single-stage turbochargers. Three years later, the first two-stage turbocharger designs for medium- and high-speed gas and diesel engines were presented. The first serial engine applications were introduced to the market with claimed benefits proven. With the development of the second-generation Power2 turbocharging system, ABB Turbocharging provides an optimised technology enabling full exploitation of the advantages of two-stage turbocharging for large medium-speed engines. TCX – the new high-pressure turbocharger for twostage turbocharging Jiri Klima, PBS Turbo, Czech Republic Vladimir Hort, PBS Turbo, Czech Republic Markus Haidn, MAN Diesel & Turbo SE, Germany New, stricter emission limits and engine development are continuously increasing the requirement to boost pressure level. Turbocharger manufacturers have been trying to fulfil this requirement by increasing the maximum pressure ratio of single-stage compressors, until material limits were achieved. The situation changed when engines with Miller timing were put into operation and showed their potential for additional emission reductions. As a consequence, a pressure ratio well above six was required. This was the impulse to start thinking about multi-stage compression with intercooling. From the start, the requirements of potential customers were included into the design. Based on application investigations, it was decided to keep the low-pressure unit inside the standard product portfolio and develop a new high-pressure turbocharger according to the special requirements. In reference to 30 SPECIAL Schiff&Hafen | Ship&Offshore | May 2013
Monday, May 13th Tuesday, May 14th Wednesday, May 15th Thursday, May 16th market potential, a medium-size unit was chosen to be designed and tested as a pilot version. Highest efficiencies at low-pressure ratios and increased mass flow capacities corresponding to high engine power density, together with higher mechanical load, were a considerable challenge in developing a new turbocharger. After the initial study, which defined operating conditions and ranges, the new compressor and turbine were designed using advanced CFD and FE tools. Some well-proven concepts from NR/S and TCR turbochargers were adopted for the project. The best versions were built by rapid prototyping methods and tested separately on compressor and turbine test benches. Simultaneously with production of prototypes, a new two-stage turbocharger test bench has been prepared capable of pressure levels up to 11 bar g, for which more sophisticated controls have been installed. The measuring system was upgraded for two-stage group measurements as well. The test of the main parameters confirmed the reliability of the design and thermodynamic expectations. Based on single-stage and two-stage configuration measurements, a significant increase in the efficiency of the turbocharging system compared with just one stage was recorded. Special component tests were performed as well. In recent years, the TCX 14 has been developed as the basis of a new series of high-pressure turbochargers for two-stage turbocharging, suitable for the upcoming generation of reciprocating engines. The turbocharger performance fully covered the planned range and confirmed the potential of two-stage turbocharging to achieve charging group efficiencies far above maximum single-stage figures. PBS Turbo, a member of the MAN group, is ready to provide the new technology – comprising TCX as high pressure and TCR/ TCA as low pressure turbochargers. In the paper the development steps are presented, with main focus on the TCX design features including comprehensive results of the component validation as well as test data in single-stage and two-stage configuration. Development of high-pressure ratio and highefficiency type turbocharger Keisuke Matsumoto, IHI Co, Ltd, Japan In recent years, various approaches to environmental problems were carried out. As for marine diesel engines, the IMO (International Maritime Organization) has phased in emission regulations mainly against NOx reduction in exhaust gas. To comply with this emission regulation, all marine diesel engine manufacturers are advancing the development of next-generation marine engines. Some typical technologies effective for reducing NOx in exhaust gas are the Miller cycle engine, EGR (exhaust gas recirculation), SCR (selective catalytic reduction), gas fuel engines, and the application of water emulsion fuel, etc. Among these technologies, the Miller cycle engine has already been put to practical use by many marine diesel engine manufacturers, because of the great advantage in development cost due to smaller change necessary in structural design compared with conventional designs. Additionally, the Miller cycle engine is known to be effective in combination with other NOx-reducing technologies and is expected to be applied continuously. Higher supercharging is necessary to realise the Miller cycle engine. Therefore, a higher pressure ratio is coming to be required for marine turbochargers in the next years. In addition, there are constant requirements for marine turbochargers such as higher efficiency, wider operational range and higher performance at low speed. To meet these demands, IHI has developed a radial type high-pressure ratio turbocharger, named high-pressure ratio AT14 (New AT14). The New AT14 has achieved a higher pressure ratio than usual by improving some design methods such as the increase of circumferential speed of compressor wheel and optimisation of compressor blades and recirculation devices aerodynamic geometry by using CFD etc. These technical efforts lead to the improvement of the pressure ratio from 3.8 up to 5.0 at the engine operation point. The New AT14 turbocharger has already been adopted as a standard model by some engine builders, and is expected to show its high performance in the global market. In this paper the development of the AT23 turbocharger will be shown with some of the obtained test results. The AT23 turbocharger is the turbocharger IHI has developed lately for smaller marine diesel engines than engines that apply AT14 turbochargers. Aerodynamic parts such as the compressor and turbine were redesigned and the shafting was also redesigned to reduce mechanical loss. The AT23 turbocharger has achieved a higher pressure ratio and efficiency compared with IHI’s conventional turbochargers. On the other hand, turbochargers are required not only to feature a high-pressure ratio and efficiency but also safety, durability, longer mechanical life and easier maintenances. The AT23 turbocharger has improved some of the structures to respond to these requirements. We are not afraid of seawater… …neither are our products. That is why KTR couplings, brakes and hydraulic components are available as seawater-resistant designs for maritime applications, too. Thus, various sub systems for windlasses, cranes, thrusters, rudders and many more are fi tted with KTR components. KTR is not afraid of water! www.ktr.com
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Page 3 and 4: CiMaC CongRess | SHAnGHAI 2013 Welc
Page 5 and 6: The Future is Clear ME-GI dual fuel
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