【作者】

Constantin Kiesling

【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。Dual fuel engines have become increasingly important in recent years thanks to their lower emissions compared to diesel engines, the possibility to easily switch between different fuels and the increasing availability of gaseous fuels at comparatively low prices. State-of-the-art diesel-gas engine concepts have the disadvantage of high system complexity because they are equipped with either two diesel injectors (one main injector for diesel operation and one pilot injector for dual fuel operation) or a double nozzle injector. In addition, the double injector concept suffers from the decentralized position of the pilot injector. Therefore, concepts with only one centrally located diesel injector that allows engine operation over the whole diesel range are the preferred solution. However, it is a challenge for injection system design to achieve the required injection accuracy especially at very small energetic diesel fractions of approximately 1%. The adjustment of nozzle geometry to obtain adequate spray behavior over the whole operating range with up to 100 % diesel also remains an important issue. This paper will provide a comparison of the injection behavior of an advanced L’Orange wide range diesel injector with that of a state-of-the-art pilot diesel injector. Their injection characteristics will be evaluated on the basis of rate of injection measurements and optical investigations in a spray box. Spray vapor phase and spray liquid phase will be characterized using high speed Schlieren and high speed Mie scattering visualization techniques. The focus of the investigations will be on small diesel fractions (1 - 10% of full load diesel operation) as applied to high speed dual fuel engines. Selected results of single cylinder engine measurements will be discussed once again by comparing the two different injectors. In order to avoid any influence of injector position on the evaluation, both injectors are mounted at the center of the cylinder head. The measurements will provide the limits with regard to very low diesel fractions which still result in stable combustion. In addition, the overall engine performance with the new injector design will be compared to that of the state-of-the-art pilot diesel injector at different engine operating conditions.

【会议名称】

第28届CIMAC会议

【会议地点】

芬兰 赫尔辛基

【下载次数】

3

返回