Effects of hydrogen addition and cylinder cutoff on combustion and emissions performance of a spark-ignited gasoline engine under a low operating condition

Development and Performance of a Plug-in Hybrid Hydrogen Vehicle

“…Since the addition of hydrogen could potentially decrease the engine power output at high loads considering its low volumetric energy density, it is reasonable to adjust the hydrogen addition fraction according to the engine operating condition to realize the coordinative control of fuel and engine conditions [7]. In the PHHV, the hydrogen blending is enabled only when the engine load is lower than 75%.…”

“…Although NOx emissions were increased after the hydrogen blending, HC and CO emissions were decreased obviously for the hydrogenenriched engines. Ji and Wang et al [7][8][9] conducted detailed investigations on performance of hydrogenenriched gasoline engine under the cold start, idle, part load and full load conditions. They found that the engine would run with high efficiency and low emissions for all tested conditions if the hydrogen-to-gasoline fraction were properly controlled.…”

“…Ji and Wang et al [7] also tested the performance of a vehicle powered by the HHGE based on NEDC procedure. They found that HC and CO could be reduced obviously through adopting the coordinative control of fuel and operating conditions strategy.…”

Controlling spark timing for consecutive cycles to reduce the cyclic variations of SI engines

“…Several sources of the cyclic variations in a spark ignition engine have been identified. They include (a) turbulence intensity of the flow field in the cylinder, (b) variations in the fuel-air ratio, (c) stochastic structure arising from the effects of residual gases from previous cycles or recirculated exhaust gases in the cylinder [19,20], (d) spatial inhomogeneity of the mixture composition especially near the spark plug, and (e) spark discharge characteristics and flame kernel development. It has been estimated that elimination of the cyclic variations may lead to about 10% increase in power output for the same fuel consumption in a gasoline engine [21].…”

Reducing Emissions of Polycyclic Aromatic Hydrocarbons and Greenhouse Gases from Engines Using a Novel Plasma-Enhanced Combustion System

“…PAHs, especially benzo(a)pyrene, not only injure the respiratory and immune system but also cause cell mutation and cancers such as lung and skin (Grevenynghe et al, 2003;Ji et al, 2009;Verhelst et al, 2009). Recently, much progress has been made in the control of combustion processes to limit the formation of environmentally harmful species such as hydrogen addition (Ji et al, 2010a, b;Wang et al, 2010;Zhao et al, 2010;Wang et al, 2011), biodiesel addition (Bueno et al, 2011;Valentino et al, 2011), methanol/ethanol addition (Berta et al, 2006;Graham et al, 2008;Abrantes et al, 2009;Najafi et al, 2009;Westphal et al, 2010;Lee et al, 2011;Ozsezen et al, 2011), ether oxygenate additives (Alex et al, 2007), premixed n-heptane flames (Li et al, 2007), and engine modification (Alkidas, 2007;Wel et al, 2007;Canakci, 2008).…”