In the current debate on environment and sustainability, Power to X presents a promising sustainable approach to solve future power supply issues. Regenerative e-fuels like hydrogen and methane are being produced with electrical power from solar or wind for long term energy storage or retro grid conversion purposes. The deployed unit-type power plants to intercept residual loads resulting from seasonal and regional energy availability fluctuations necessitate further improvement of internal combustion engines to push them beyond existing limits concerning reliability, effectiveness and environmental friendliness. To address one of the main environmental concerns and reduce the engine out emissions, an enhanced understanding of the combustion process itself is fundamental. Recent optical and laser optical measurement techniques provide a promising approach to investigate the combustion process from the in cylinder air-fuel distribution and charge motion to the combustion itself, allowing to observe the combustion flame’s chemiluminescence or the species radicals in the flame that define the emission formation and enable to deduce reaction kinetics. These measurement techniques are already quite common for passenger car and truck sized engines and significantly contribute to the understanding of combustion behavior. Transferring these measurement techniques to large bore engines from low to high speed is quite exceptional especially due to the bigger challenges for optical accessibility caused by the engine size and thus much higher stability requirements. The chosen optical design approach is analyzed giving a short overview of optical accessibility approaches to large bore engines summarizing advantages and disadvantages of the concepts. Based on those concepts a new approach using a so called fisheye lense is presented. The lens is integrated in the engine’s cylinder head directly facing the combustion chamber in addition to an already existing lateral access allowing a vertical as well as a lateral view into the combustion chamber. The design of the first prototype fits a medium speed dual fuel single cylinder research engine with a bore of 350mm and a stroke of 440mm producing 500kW at 750rpm. Using this type of dual fuel engine quite commonly chosen for marine applications offers the advantage of full fuel flexibility. This means in lack of a sufficient diesel or gas supply the engine could be changed from running in a full diesel mode into the gas engine mode using natural or e-fuel gas for a premixed combustion ignited by a small diesel pilot injection. First measurements through the fisheye optic observing the flame chemiluminescence of the dual fuel combustion using natural gas and a pilot injection of Diesel prove the successful implementation of the new concept for a full optical accessible medium speed large bore engine that withstands up to 85% nominal load in skipped fire operation mode. These measurements serve as a proof of realization and feasibility for this new approach, which facilitates and improves optical investigations at large bore engines.


Realization of a Fully Optically Accessible Medium Speed Large Bore Engine Using a Fisheye Optic

Division / Sponsors: 
Power Division & Nuclear Engineering Division (NED)

Power Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/POWER/POWER2020/volume/83747

International Conference on Nuclear Engineering
Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE2020/volume/83761

POWER-ICONE - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.