How to create a self-charging electric car?

Research results of scientists from the Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences, obtained under the RFBR project, can be used to create new prototypes of electric cars with increased driving range. These results were reported by the British scientific journal Energy Conversion and Management (Q1), which published an article by Sergey Zambalov, Igor Yakovlev and Anatoly Maznoy devoted to the development an auxiliary power unit (range extender) for modern electric cars.

One of the co-authors of the article Effect of multiple fuel injection strategies on mixture formation and combustion in a hydrogen-fueled rotary range extender for battery electric vehicles (Vol. 220, September 15, 2020) Sergey Zambalov, Senior Researcher (Department for Structural Macrokinetics of TSC SB RAS), explains that an increasing number of global automakers are starting to develop fully electrified personal vehicles. This is affected by both the constant tightening of environmental standards for the toxicity of vehicle exhaust gases and state subsidies aimed at developing the electric transport market. In addition, the conventional engine has almost exhausted its development potential as the main power unit.

In turn, the mass proliferation of electric vehicles is hampered by a number of shortcomings of existing models. One of the main problems that frighten potential car owners is the limited autonomous driving efficiency with a single charge of electric car batteries: a driver has to think over the travel plan, taking into account the presence of charging stations on the way and look for a place where he can charge his electric car. If in countries with a warm climate and developed road infrastructure it can be done quite comfortably, then in sparsely populated and hard-to-reach regions with cold winters it will be extremely difficult.

“One of the possible effective ways to solve this problem is to develop and use the so-called range extender in the design of the electric car”, says Sergei Dorzhievich. “The range extender is a combination of an internal combustion engine and an electric generator. Batteries are recharged both while moving and during parking: the device switches on when the battery charge drops below a certain level.

The concept of the range expander from Tomsk scientists assumes at least three basic components: type of engine, type of fuel and the way it is fed into the combustion chamber.

First, the scientists from the TSC SB RAS propose using a rotary engine in the range extender. In contrast to the conventional engine, it has a higher power density at high rpm, lightweight and compact design with fewer parts, low noise level and excellent balance.

Secondly, the fuel of the future - hydrogen - is supposed to be used as fuel for the range extender. This will not only eliminate harmful carbon-containing emissions generated during the combustion of gasoline, diesel fuel or gas, but also increase the efficiency of the engine, as it is known that more energy is released during combustion of hydrogen.

Thirdly and finally, by means of numerical simulation methods it was shown that application of the system of multiple direct fuel injection will reduce twice the emission of nitrogen oxides, the main atmospheric pollutant in hydrogen engines without any losses in engine efficiency and performance, compared to the traditional scheme of fuel supply.

It is important to note that the developed methods and models can be used not only for vehicles, but also in other areas, in particular, for the development of unmanned aerial vehicles or the design of autonomous power sources for remote regions. At present, the scientists are contacting with innovative companies engaged in the development of auxiliary equipment for electric vehicles.