【作者】

Dimitrios Hountalas，Nikolaos Sakellaridis

【摘要】

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。 The large scale 2-stroke Diesel engine is the primary mover for the majority of commercial vessels, due to its reliability and high thermal efficiency. Variable injection timing (VIT) is extensively used in two stroke diesel engines to adjust SOl in or-der to control firing pressure and to guarantee minimum BSFC while at a wide operating range keeping at the same time NOx emissions at acceptable levels. Use of experimental methods (trial and error, coupled with continuous measurements) to achieve this goal i.e. optimum SOI setting requires significant effort and time, which results into vessel downtime and significant cost. Towards this goal simulation and monitoring techniques can become an important tool that can be applied efficiently at sea with minimum effort. In the present paper are presented the first results from such an application, at sea, where SOI was adjusted through the VIT system. The method is based on the measurement and processing of cylinder's pressure from which results (beyond diagnosis and tuning) are generated for operating parameters, such as indicated power, specific fuel consumption, heat release rate, SOC etc. This is achieved with the use of minimum instrumentation and effort. Measurements where conducted at sea between two ports on a large marine 2-stroke engine at various operating conditions. Measurements were first conducted at various loads using existing settings and the results were analysed on-board providing the engine settings and in addition the VIT scale (the proportionality constant between VIT rack setting and SOI variation). Then VIT set-ting of all cylinders was then modified without peak firing pressure exceeding the specified limitation. Measurements of exhaust gas emissions were also made, ensuring that NOx would not exceed limiting values as imposed by Marpol Annex VI. The investigation also revealed small loading differences between cylinder loading, as well as improper operation of the VIT system on one engine cylinder. From the results it is clearly demonstrated the possibility for fuel saving which, considering the absolute consumption of the specific engine, is very important. Therefore, with this first attempt it is revealed the potential of the applied method to be used as a tuning optimization and diagnosis tool with minimum effort and equipment, without the disadvantages of purely experimental trial and error methods.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

1

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