278
Alternative Fuels for Transportation
Efficiency 2000 rpm
40
1.56
1.51
Lambda
38
36
34
32
30
1.61
Efficiency (%)
NG map-ign
H 2 map-ign
35%
31.2%
Figure 9.16
Efficiency and emissions of an ICE fueled with a HCNG8 blend.
6
5
4
3
2
1
0
1.61
Emissions 2000 rpm map ignition
Emissions [g/kWh]
5.9
4.2
3.5
2.9
HC NG
No x NG
No x H 2
CO NG
CO H 2
HC H 2
1.56
1.51
Lambda
Funzionamento non stabile
Figure 9.17
Emissions of an ICE fueled with a HCNG8 blend.
9.12.1 HCNg e ngine Tests at eNeA
In an application of 15% of HCNG at an ENEA research center on a naturally aspirated light duty vehicle (Figure 9.18), two configurations have been
tested: stoichiometric combustion and lean burn. In stoichiometric configuration, without any modification of the injection control map, the NO x
emissions increase as a consequence of the increasing combustion speed. A
spark advance reduction (which means a little retard compared to the case
Alternative Fuels for Transportation
Efficiency 2000 rpm
40
1.56
1.51
Lambda
38
36
34
32
30
1.61
Efficiency (%)
NG map-ign
H 2 map-ign
35%
31.2%
Figure 9.16
Efficiency and emissions of an ICE fueled with a HCNG8 blend.
6
5
4
3
2
1
0
1.61
Emissions 2000 rpm map ignition
Emissions [g/kWh]
5.9
4.2
3.5
2.9
HC NG
No x NG
No x H 2
CO NG
CO H 2
HC H 2
1.56
1.51
Lambda
Funzionamento non stabile
Figure 9.17
Emissions of an ICE fueled with a HCNG8 blend.
9.12.1 HCNg e ngine Tests at eNeA
In an application of 15% of HCNG at an ENEA research center on a naturally aspirated light duty vehicle (Figure 9.18), two configurations have been
tested: stoichiometric combustion and lean burn. In stoichiometric configuration, without any modification of the injection control map, the NO x
emissions increase as a consequence of the increasing combustion speed. A
spark advance reduction (which means a little retard compared to the case