【作者】

Arman Garshasebi

【摘要】

该论文已在赫尔辛基举行的第28届CIMAC大会上发表，论文的版权归CIMAC所有。For marine engines, IMO Tier III regulations require a significant reduction in NOx emissions of up to 80%, compared to Tier I, for ships operating within NOx Emission Controlled Areas (ECAs). Ships whose keels were laid after January 1st, 2016 have to comply with Tier III limits when sailing inside a NOx ECA. Thus, manufacturers of marine engines have focused on two approaches in order to fulfil the new requirements for low emission levels, namely Selective Catalytic Reduction (SCR) and Exhaust Gas Recirculation (EGR) - both well-known technologies within this field. SCR addresses emission reduction by using a catalyst, which has been identified as a promising approach for smallbore engines – as well as stationary plants – where space and logistic requirements are manageable. As a second approach to reducing NOx emissions in marine diesel-engines, EGR is characterized by a compact design and its ease of integration into large-bore engines. It limits NOx formation during combustion, making catalytic converters obsolete. One of the challenges for this technology is the positive scavenging differential pressure. For this reason, an EGR blower is necessary to realize exhaust-gas recirculation. The purpose of the blower is to raise the pressure of the cooled and cleaned exhaust gases so that recirculation to the engine inlet is possible. In this way, a reduction of combustion-temperature peaks – and an according reduction in NOx formation – can be achieved. The required EGR flow varies, depending on load and ambient conditions. MAN Diesel & Turbo’s (MDT) Electrical Turbo Blower (ETB) plays an important role in the operation of the EGR system by providing active control. Its materials are designed to withstand corrosive agents and its tailor-made compressor wheel is robust and designed for high performances, derived as it is from the MDT turbocharger portfolio. The desired EGR operating condition is achieved by using an electrical high speed motor directly coupled to the compressor wheel and driven via a frequency converter. A casing unit holds the stator of the motor and provides a supply for cooling water and lube oil for the journal bearings. The interface between the ETB, frequency drive, instruments and control panel in the engine control room is hardwired. This paper describes the EGR blower’s central role in the operation of the EGR system and presents important development steps of this common development project between MAN Diesel & Turbo SE and PBS Turbo s.r.o. from preliminary sketches to concept, design and simulation, testing and field experience.

【会议名称】

第28届CIMAC会议

【会议地点】

芬兰 赫尔辛基

【下载次数】

2

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