【作者】

Lars Ryberg Juliussen,Stefan Mayer

【摘要】

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 ME-GI concept is based on a diesel-type combustion process of a gas jet that is injected into the combustion chamber with high pressure between 150 and 315 bar depending on engine load. The ignition of the gas is ensured by injection of a small amount of diesel oil prior to gas injection the so-called pilot injection. This paper describes the ME-GI concept and its implementation on a dedicated test engine as well as on a production type engine. Furthermore, it also presents performance and emission results from a subsequent optimisation effort. Successful development of the ME-GI concept required a suitable research facility platform for thorough investigations and engine tests. Therefore, it was decided to retrofit an electronically controlled two-stroke low speed marine diesel research engine, 4T50ME-X, to gas operation. Retrofitting the research engine to gas operation required development and installation of gas engine components as well as development of a new control and safety system, which is added to the standard electronic control system. Before adopting all new components and software to the research engine, preliminary tests were carried out on a one cylinder gas test rig in order to verify the functionality and reliability of the ME-GI concept. The establishment of the gas research platform also required considerable preparations in order to achieve authority approval of the gas supply installation, which was established according to EU’s ATEX regulations (e.g.Directive 94/9/EC, concerning equipment and protective systems intended for use in potentially explosive atmospheres). The ATEX regulations required for example risk analysis, zone classification plans and education of engineering staff. The engine tests performed can be divided into a two groups. Firstly, the ME-GI engine is benchmarked directly against operation on liquid diesel oil. This benchmark confirms a significant reduction in NOx emission. The NOx reduction exceeds 25% on average, which is consistent with simple theoretical estimates based on adiabatic flame temperature equilibrium NOx predictions, where the main driving force is a lower flame temperature due to a higher stoichiometric air amount for methane compared to diesel. Secondly, in order to explore the possibility of even further optimisation of the ME-GI concept a more elaborate study, applying theory from Design of Experiment (DoE) as well as Response Surface Methodology (RSM), is conducted, in which parameters related to the gas injection system are included as well. It is demonstrated that the ME-GI concept offers potential SFOC savings of 3-6 g/kWh in the part load range (below 85% engine load). The engine test data are furthermore supplemented with results from optical diagnostics.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

5

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