A Layout for the Hydrogen Engine

Authors

  • P. A. Lakshminarayanan Retired CTO, Simpson and Co. Ltd., Chennai

Keywords:

Hydrogen, Fuel Cell, H2 -ICE, Nitric Oxide, Ignition, Quenching Distance, Lean Burn, Engine Design

Abstract

Hydrogen combustion leaves no carbon footprint and holds high promise for energy production. It can be used in a fuel cell, H2-FC, or an internal combustion engine (ICE). The net lifetime cost of the H2-ICE is less than that of the H2-FC, making it attractive for off-road and heavy-duty on-road applications. Physical and chemical properties such as diffusivity, flame speed, ignition energy and ignition temperature are favourable for high-speed operation and high compression ratio. Low density makes storage and transport of the fuel cumbersome, and high flame temperature at stoichiometric composition results in excessive NOx compared to gasoline. The popular three-way catalyst used in gasoline engines is not applicable to quell NOx. The other option is to run the fuel very lean at an air excess ratio, λ = 2.2. To produce respectable power, the lean burn engine must be turbocharged and intercooled. Direct injection is preferred due to the high diffusivity of hydrogen. A prechamber with the spark plug and fuel injector mounted inside is beneficial in creating high turbulence in the main chamber by the high-velocity hot jets and providing a multitude of ignition points. It achieves leaning to λ=2.2. It could further help in reducing backfire as the raw fuel may not stay very close to the walls or small gaps of the main combustion chamber.

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Published

20-04-2023

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Section

Articles