Effect of Natural Gas/Hydrogen Blends on Spark Ignition Stoichiometric Engine Efficiency Istituto Motori CNR

Format:

Conference/Event

Author/Creator:

De Simio, De Simio, author.

Contributor:

Gambino, Michele

Iannaccone, Sabato

Conference Name:

10th International Conference on Engines & Vehicles (2011-09-11 : Naples, Italy)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

Hydrogen (H₂) added to natural gas (NG), improves the combustionprocess of the air-fuel mixture. This gives the potentiality todevelop engines with better performance and lower environmentalimpact. In any case how hydrogen is produced represents a crucialaspect. In general, if H₂ is produced utilizing fossil fuels andnot renewable or nuclear sources, the environmental benefit of CO₂reduction could be reduced.In this paper two engines, a light-duty (LD) and a heavy-duty(HD), were tested in stoichiometric conditions. The engines werefuelled with NG and with two blends of NG with a 20% and a 40% byvolume of H₂, respectively named NG/H₂ 20% and NG/H₂ 40%. Thelight-duty engine was tested at different loads and speeds, withspark advance set by the electronic control unit (ECU). The ECUactuated a retarded ignition, especially at low load.With the heavy-duty engine, the tests were carried out only athigh load. Spark advance was tuned to obtain burning gravity centerat the same angular position with NG and the two NG/H₂ blends.Hydrogen positive effect on combustion development has beenobserved, even if global efficiency was only marginally affectedfor both the light- and the heavy-duty engine. Moreover, only withthe heavy-duty engine and NG/H₂ 40% blend, knocking phenomena havebeen observed, requiring great attention in spark advance, boostpressure and EGR rate optimization. For best performance with highH₂ content, a specific combustion system design would be necessaryto fully exploit H₂ characteristics

Notes:

Vendor supplied data

Publisher Number:

2011-24-0121

Access Restriction:

Restricted for use by site license