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Old 02-26-2014, 11:35 AM   #4 (permalink)
Daox
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I can't view the videos at work but, the reason for adding hydrogen to the air/fuel mix is that it speeds up the flame propagation. Adding high amounts of EGR to the air/fuel mixture slows down the flame speed. The same thing happens in a lean burn engine. The hydrogen speeds it back up and prevents misfiring as one of the linked articles state.

Green Car Congress: PSA to commercialize SwRI-developed Dedicated-EGR technology in high-efficiency gasoline engines by 2018

Quote:
Despite the benefits of EGR—e.g., improved cycle efficiencies through knock reduction, charge properties and pumping work; cooler combustion leading to lower emissions—there are challenges. These include misfire and stability; control; boosting; and design and materials.

Dilution reduces laminar burning velocities, decreasing volumetric heat release and slowing reaction rates. In an engine, slower burn rates can lead to unstable operation and full misfire.

High EGR rates (and low pre-turbine temperatures) can lead to low turbine efficiency.

Transient control of EGR is vital.

The design of the EGR system design will be key to control and packaging.

...

The D-EGR concept also combines the high efficiency potential of in-cylinder gasoline reformation. Under D-EGR, excess fuel is sent to the cylinder dedicated to producing the recirculated gases, the hydrogen (H2) content of which then increases. The reformate along with the EGR is distributed to the other cylinders. The resulting H2 levels increases EGR tolerance; increases knock resistance (i.e., higher compression ratios); reduces emissions; and improves fuel consumption.

Just because it is hydrogen doesn't mean its unicorn poo. There is a partial truth that hydrogen is beneficial, you just have to apply it correctly. You also have to produce it efficiently if you're doing so onboard.
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