With the objective to get comparative technical information about performance and emissions of dual fuel trucks available in the market in 2013, it was tested with a Mercedes Benz Actros (with HARDSTAFF system) and a VOLVO methane diesel truck (VOLVO and Clean Air Power cooperation), on a IDIADA’s proving ground and real life route testing.
It has been considered interesting to gather information of the performances and emissions of dual-fuel trucks available in the market in 2013, to allow an objective comparative of the future dual-fuel LPI prototype MAN truck to be developed in HDGAS.
A Mercedes Benz Actros, using a system from HARDSTAFF and a VOLVO methane diesel truck (developed by VOLVO in cooperation with Clean Air Power) were tested on IDIADA’s proving ground and real life route testing. Both trucks, sold in Europe in 2013, were Euro V emissions certified since this Directive 2005/55/EC was in place at that time.
These two trucks are used on daily basis by a Spanish fleet operator, Transportes Monfort , one of the most renowned and experienced fleet operators in Europe. Transportes Monfort is related to the commitment with LNG as part of the European Commission 7th Framework Program LNG Blue Corridors project, which is coordinating by IDIADA. This project is in its third year and has already constructed 10 LNG stations around Europe of the 13 planned, and more than 100 trucks are in demonstration using LNG.
These trucks are the only dual-fuel vehicles developed with OEM support. Trucks retrofitted with other systems are considered out of the scope of the study, since it was not considered to be equivalent to the high technological level of this Mercedes Benz and specially the VOLVO truck. None of them was featuring HPDI technology, which was available only in United States and limited to Class 8 trucks.
To achieve objective and comparable data, it was performed a comprehensive instrumentation to gather fuel consumption and emissions in pure diesel engine and on dual-fuel operation modes, with the same fuel for both (Methane number higher than 90) to avoid any impact due to the fuel quality.
The main tests performed from 50 km/h to 90 km/h (maximum allowed vehicle speed in Europe) at constant speed and with realistic loadings demonstrate dual-fuels from 2013 substitute high percentages of diesel at stationary conditions and low engine loads (typical for BeNeLux countries), while real substitution decreases when high loads are demanded. Moreover the figures of constant speed testing in test truck rarely match the figures observed during the real life route testing.
VOLVO FH and MERCEDES BENZ ACTROS trucks, both DUAL-FUELS, demonstrated good similar performance during the tests at IDIADA’s proving ground (Figure 3) and in real driving route (Figure 4+5). Considering both trucks are from the same class, similar power and torque (slightly higher for the VOLVO) no significant differences are observed in real operation in terms of performance.
Figure 3: IDIADA’s proving ground located in Spain
Figure 4: Route used for the trucks testing (Google Earth)
Figure 5: Route elevation profile (Google Earth Tools)
It is well known from the LNG Blue Corridors project and IDIADA’s experience a substitution ratio typically used by the fleet operators is “50%” as average, which has been validated in the tests.
As conclusions, 2013 dual-fuels do have significant potential to reduce CO2 emissions while keeping a still necessary Diesel mode, thus allowing fleet operators use their trucks without the limitations of 100% gas trucks (low power, limited routes due to lack of LNG stations, low range). Measured data will be used for future comparatives with the new technology under development by MAN and IDIADA, to demonstrate the higher performances in terms of emissions and CO2 reduction potential.
View the report: MPI low pressure dual-fuel functional operation by Idiada (Public summary)