Air-Hybrid -
Quote:
Originally Posted by Air-Hybrid
I was under the impression that adding syngas, in a similar way to adding H2 could extend the lean-burn limit (to beyond the 22:1 ratio) without the burn becoming unstable. That is, no more fuel overall is used compared with normal lean-burn operation, so there is still an excess of O2 at the end of the burn.
There is also evidence that having one of these gaseous fuels (H2, syngas, NG) in the burn will speed up the flame speed - so ensuring that a better portion of the mechanical work can be extracted by the piston, as well as keeping the exhaust valve cooler.
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Yes, this has been done in the lab :
Fuzzy Pareto Frontiers in Multidisciplinary System - Architecture Analysis - Page 3
http://web.mit.edu/deweck/www/PDF_ar...-2004-4553.pdf
Quote:
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Hydrogen addition affects combustion in an internal combustion engine in several ways. First of all, hydrogen addition can significantly increase flame speed. Flame speed is a primary factor in defining the lean limit - excess air slows down the combustion process to the point of not completing combustion in the time given during the power stroke. Effectively, hydrogen can extend the lean limit by off-setting the reduction in flame speed due to excess air. Secondly, recent work has shown that a hydrogen rich gas can enhance the octane rating of the overall cylinder mixture. This finding has the potential for increasing compression ratio, leading to direct gains in engine efficiency. Figure 1 and 2 illustrate the effect of hydrogen addition and how new system architectures emerge by the shifting of constraints.
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Back in 2004 this was being researched at MIT :
Green Car Congress: ArvinMeritor / MIT Plasma Fuel Reformer
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Of particular long-term significance is the official release of the Plasma Fuel Reformer. The Plasma Fuel Reformer uses an electrical plasma (a strong, continuous “spark”) to combust partially a mixture of air and the vechicle’s hydrocarbon fuel -- diesel or gasoline.
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ArvinMeritor expects the Plasma Fuel Reformer to be in production in 2010. Currently the device is undergoing in-vehicle testing on heavy and light trucks and buses. ArvinMeritor is also exploring using the device in gasoline engines to support ultralean turbocharging, with resulting emissions reduction and fuel efficiency. To that end, it is partnering with Ingenieurgesellschaft Auto und Verkehr (IAV), a German automotive research and development provider.
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However, in the years since, Arvin-Meritor sold this R&D off with it's other emissions products and I lost of track of it, so I think it became a dead-end.
This is a search at the Arvin-Meritor site :
Search Arvin-Meritor - Plasma Fuel Reformer
CarloSW2