1. Dual-Fuel Compression Ignition Engine Fuelled with Methanol or LPG
TECHNICAL UNIVERSITY OF RADOM
Technical University of Radom, Poland
Sławomir LUFT
Dual-Fuel Compression Ignition Engine Fuelled with Methanol or LPG
Ecology and Safety as a Driving Force
in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

2. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 1. Scheme of fuel system of dual-fuel C.I. engine operating on LPG
Fig. 2. Scheme of fuel system of dual-fuel C.I. engine operating on methanol
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

3. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 3. Comparison of load characteristics of specific energy consumption
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

4. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 4. Comparison of maximal torque values M for the standard engine operating on diesel fuel (αi = 30o BTDC) and for dual fuelled engine operating on LPG (αi = 20o BTDC) and methanol (αi = 27o BTDC)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

5. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 5. Comparison of CO emissions during full‑load tests for standard engine operating on diesel fuel (αi = 30o BTDC) and for dual-fuel engine operating on LPG (αi = 20o BTDC) and methanol (αi = 27o BTDC) as main fuels
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

6. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 6. Comparison of NOx emissions during full‑load tests for standard engine operating on diesel fuel (αi = 30o BTDC) and for dual-fuel engine operating on LPG (αi = 20o BTDC) and methanol (αi = 27o BTDC) as main fuels
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

7. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 7. Comparison of HC emissions during full‑load tests for standard engine operating on diesel fuel (αi = 30o BTDC) and for dual-fuel engine operating on LPG (αi = 20o BTDC) and methanol (αi = 27o BTDC) as main fuels
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

8. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 8. Comparison of smoke emissions during full‑load tests for standard engine operating on standard diesel fuel (αi = 30o BTDC) and for dual-fuel engine operating on LPG (αi = 20o BTDC) and methanol (αi = 27o BTDC) as main fuels
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

9. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 9. Comparison of self-ignition delay τd changes versus load for the engine operating on diesel fuel and dual fuelled with LPG and methanol (pilot diesel fuel injection timing in all cases αi = 30o BTDC)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

10. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 10. Comparison of mean rate of pressure rise (dp/dα)av changes versus load for the engine operating on diesel fuel and dual fuelled with LPG and methanol (pilot diesel fuel injection timing in all cases αi = 30o BTDC)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

11. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig. 11. Comparison of maximal pressure Pmax changes versus load for the engine operating on diesel fuel and dual fuelled with LPG and methanol (pilot diesel fuel injection timing in all cases αi = 30o BTDC)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

12. Ecology and Safety as a Driving Force in the Development of Vehicles
0,7MPa
LPG+DF
αi=30 deg of CA BTDC
T =40Nm
T=25Nm
T =30Nm
T =35Nm
deg of CA p
[MPa]
Fig. 12. Indicator diagrams of single combustion runs for dual fuelled engine with standard injection timing for diesel fuel pilot dose αi = 30o BTDC
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

13. Ecology and Safety as a Driving Force in the Development of Vehicles
LPG+DF
αi=20 deg of CA BTDC
T =35Nm
T =55Nm
T =50Nm
T =45Nm
T =40Nm p
[MPa]
deg of CA
Fig. 13. Indicator diagrams of single combustion runs for dual fuelled engine with retarded injection timing for diesel fuel pilot dose αi = 20o of BTDC
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

14. Ecology and Safety as a Driving Force in the Development of Vehicles
Fig 14. Dependence of maximal pressure Pmax and mean rate of pressure rise (dp/dα)av versus load for standard fuelled engine with standard injection timing αi = 30o BTDC and for dual fuelled engine with standard injection timing for diesel fuel pilot dose αi = 30o BTDC and for dual fuelled engine with retarded injection timing
for diesel fuel pilot dose αi = 20o BTDC (engine speed n = 1800 rpm)
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

15. CONCLUSIONS REGARDING ENGINE PERFORMANCE
The dual-fuel C.I. engine, for both main fuels discussed in this paper, can achieve torque values comparable with standard fuelled engine, or even higher, showing at the same time higher overall efficiency in the range of maximal loads. This latest feature results from increase of thermal efficiency of dual-fuel engine cycle.
Decrease of dual-fuel engine overall efficiency in the range of partial loads results from incomplete combustion of the mixture air-main fuel vapour. This is confirmed by higher CO and HC emissions in this load range. It should be stressed here that at partial loads of dual-fuel engine the mixture air-main fuel is very lean. According to the author, this mixture cannot ignite out of the burning diesel fuel stream. This effect is favoured by adverse combustion chamber design, especially between the piston head and flat part of cylinder head behind toroidal part of combustion chamber located in the piston.
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

16. CONCLUSIONS REGARDING EXHAUST EMISSIONS
Decrease of CO emission observed at maximal loads of dual-fuel engine results from advantageous physico-chemical properties of gaseous fuels from the point of view their combustion at values of coefficient of excess air that are characteristic for these conditions. The reasons of CO emission increase at partial loads were partly given in the conclusion 5.1.
According to the author, decrease of NOx emission (especially at partial loads) from dual-fuel engine results from the discussed above – in the conclusion 5.1 – incomplete combustion of the air - main fuel mixture. It leads to temperature decrease in the combustion chamber in comparison with values appearing in standard fuelled engine and in consequence – to lower NOx emission.
Increase of HC emission in the range of partial loads results from incomplete combustion of the air-main fuel mixture in this range and while at loads close to maximal it may results from incomplete combustion of diesel fuel dose in the more and more reach air - main fuel mixture.
Decrease of smoke emission for dual-fuel engine is distinctive for combustion of gaseous fuels and alcohol vapour.
Ecology and Safety as a Driving Force in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008

17. Ecology and Safety as a Driving Force in the Development of Vehicles
TECHNICAL UNIVERSITY OF RADOM
Thank you for attention
Ecology and Safety as a Driving Force
in the Development of Vehicles
IP Radom, 02 March – 15 March, 2008