The results of the first theoretical and experimental tests have convincingly proved – the new technology proposed by the researchers of the Polytechnic University of Valencia reduces the level of air pollution during engine operation. During operation of the new “green engine” emissions of nitrogen oxides and soot decreased by 92% and 88% respectively, while CO2 from the exhaust gases of the pipe decreased by 15% to 52 g/km (grams per ton and kilometer). The new development is ahead of the strict pollution control regulations approved by the Spanish government for 2025. By the way, the new configuration combines all the advantages of hybrid and dual-fuel internal combustion engines. The results of the study are published in the journal Energy Conversion and Management.
Maximum efficiency, less pollution
Combining the two technologies, dual-fuel combustion and hybrid design, makes it possible to maximize the benefits of the two technologies at once, the researchers explain. “Electrical equipment prevents the use of a heat engine in low efficiency conditions. At the same time, adding a heat engine to the system makes it possible to obtain cost-effective cars compared to electric and relatively clean ones,” stresses Antonio Garcia, Professor at the Polytechnic University of Valencia (UPV).
The professor stresses that the technology of dual-fuel parallel hybrid combustion allows reducing nitrogen oxide emissions by more than 90% compared to a diesel engine. There is practically no soot in the process. In addition, the optimization of electrical components allows the thermal engine to operate at maximum efficiency with lower fuel consumption. Namely, by 13% compared to an ordinary diesel vehicle.
The new configuration combines all the advantages of hybrid and dual combustion engines.
Why mathematical models are important
Santiago Martinez, researcher at CMT-Thermal Engines UPV, spoke about the progress of the study.
“For this research, a virtual model of the original vehicle with an ordinary diesel engine was created. It was confirmed by using experimental data obtained from the truck by Volvo. After that we carried out optimization of various electrical components – engine, generator and battery. The real driving cycles of the truck with the new engine were taken into account. This methodology allows us to significantly reduce the number of experimental tests, and therefore the development cost of any given technology,” emphasizes Martinez.
Which battery will be the most efficient?
Javier Monsalvet, another member of the CMT-Thermal Engines team, explains that in order to determine the potential of a new technology compared to an existing one, it is necessary to estimate its cost taking into account two main factors. On the one hand, the price of the batteries, and on the other hand, possible savings in the form of penalties for exceeding CO2 emissions in Spain.
In their analysis, the researchers took into account the current price of batteries (about 176 euros/kWh) and their estimated cost in 2025 (about 100 euros/kWh). They also took into account the financial penalty that truck manufacturers face if they do not meet the 2025 CO2 limit of 4,250 euros per year/kWh.
“Taking into account the current price of batteries and the penalties proposed by the European Union for 2025, dual-fuel technology for trucks from 18 to 25 tons gives the best advantages when using low capacity batteries (up to 10 kWh). And the use of bags with larger batteries will significantly increase the final cost of the vehicle. Yes, it will fall due to the predictable drop in prices for lithium-ion technology in the coming years. But until then, it is unlikely to see the production of purely electric trucks on a large scale,” concludes Monsalve.