Affiliation:
1. Technical University Munich, Institute of Sustainable Mobile
Powertrains, Germany
Abstract
<div>In today’s landscape, environmental protection and nature conservation have
become paramount across industries, spurring the ever-increasing aspect of
decarbonization. Regulatory measures in transportation have shifted focus away
from combustion engines, making way for electric mobility, particularly in
smaller engines. However, larger applications like ships and stationary power
generation face limitations, not enabling an analogous shift to electrification.
Instead, the emphasis shifted to zero-carbon fuel alternatives such as hydrogen
and ammonia. In addition to minimal carbon-containing emissions due to
incineration of lubricating oil, hydrogen combustion with air results in
nitrogen oxide emissions, still necessitating quantification for engine
operation compliance with legal regulations. A commonly used multicomponent
exhaust gas analyzer on FTIR principle can suffer from higher volumetric water
shares in the exhaust gas of the hydrogen engine, influencing the emission
analysis. This concern prompted the development of a new evaluation approach for
hydrogen operation, analyzing unique wavelength bands for hydrogen operation
while considering the higher volumetric water shares in the exhaust gas of a
hydrogen engine and its missing carbonaceous emissions. The method’s capability
of providing more credible results for hydrogen-powered engines is demonstrated
by assessing the newly introduced hydrogen method through variations of the
indicated mean effective pressure, the air–fuel equivalence ratio, and the
intake air humidity. Presuming minimal CO<sub>2</sub> emissions, the method
allows a more realistic allocation of absorption spectra to other emissions. In
addition to investigations on the new hydrogen evaluation method, a model for
calculating the volumetric water share in the hydrogen engine’s exhaust gas is
presented. By comparing the theoretical to the measured water share, the
hydrogen emissions of the engine can be calculated without the need for
additional hydrogen slip measurement.</div>