【作者】

Minoru Tsuda,Dai Yamanishi,Kazuyuki Maeda

【摘要】

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。 PM emitted from diesel engines has harmful effects on human respiratory organs. Consequently, a severe restriction on its emission amount has been implemented and various PM reduction de-vices have been developed for cars. However, these PM reduction devices which utilize a catalyst are not applicable to ships. This is because heavy fuel oil (HFO) used for ships contains a large amount of sulfur. PM from marine diesel engines is composed of dry soot, soluble organic fraction (SOF), and sulfate. Regulations for decreasing the sulfur content in the fuel have been proposed by IMO. Implementation of these regulations will reduce the amount of sulfur in fuelfrom3.5% to 0.5% globally by 2020 or 2025, and from 1.0%to 0.1% in the Emission Control Area(ECA) by 2015.Reducing the sulfate content will decrease the total amount of PM emission from ships significantly, but the amount of dry soot and SOF emissions will remain the same. In this study, a basic experiment to investigate the effects and reproductions of a PM reduction filter for marine diesel engines was conducted. And then, a newly developed diesel particulate filter (DPF)with a regenerator was connected to the exhaust line of a high-speed marine diesel engine, and the effects of PM reduction and engine performances were investigated. The outlines of the experiments are as follows. (1) Effect of DPF on PM reduction: To clarify the effect of PM reduction by DPF, the filter material used for DPF was installed between the PM sampling probe set in the exhaust line of the test engine and the dilution tunnel. The components of PM were compared for the cases with and without the filter material. The engines used for the experiments are the low-speed marine diesel engine (7,722 kW) of the training ship Seiun Maru' which uses HFO and the high-speed marine diesel engine (103 kW) of the laboratory of National Fisheries University which uses gas oil and Marine Diesel Oil (MDO). (2) Effective temperature and time for filter regeneration: Various temperatures were investigated for a given time in order to determine the appropriate temperature for filter regeneration in DPF.The collected elements on the filter were place into a furnace at a given temperature and the time required for regeneration was recorded.(3) Effect of the newly developed DPF on PM reduction: DPF with a regenerator was connected to the exhaust line of a high-speed marine diesel engine, and the effect of the device on PM emission and engine performance was investigated.(4) Regeneration of DPF: To remove PM on the filter, DPF equipped with a heating apparatus and the filter was developed. DPF was installed in the exhaust line of the engine, and an experiment on the regeneration of DPF was conducted. As a result, for practical applications of DPF for marine diesel engines, the following must be satisfied. (1)A comparison of the experimental data demonstrates that most of the dry soot can be removed by DPF, but SOF and sulfate remain. This is because the required high temperature for passage of the exhaust gas through DPF causes SOF and sulfate to become like gases. (2) The optimum temperature for assuring complete regeneration within the first few minutes at a minimum electric power is determined to be 650℃. Temperatures lower than 650℃ result in longer regeneration times, which is insufficient. Temperatures higher than 650℃ may lead to shorter regeneration times, but the cost for the required electric power increases.(3) Though most of the dry soot and some of the SOF and sulfate in PM can be removed by DPF, it has been known that specific fuel consumption(SFC) deteriorates by 3% when the exhaust gas pressure increases by a1 0-kPa inter-val.(4) PM can be removed by heating the filter to650℃ or more. As a result, a continuous regeneration of DPF becomes possible without the need to change the filter.

【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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