Continental | Leading Changes In Combustion Strategies Of The Future

Amid all the talk about hybridisation and electromobility gaining ground worldwide, diversified supplier Continental believes that by 2025, 95 % of the vehicles – spanning commercial, light commercial and passenger vehicles – will continue to have one or the other kind of combustion engine, while the remaining would be contributed by pure electric vehicles. Having said that, in a decade from now, all internal combustion (IC) engines would be quite different from what we have currently in the market.

In a recent interaction with Auto Tech Review, Wolfgang Breuer, Executive Vice President, Engine Systems, Continental said the company sees a lot of potential for both fuel consumption reduction and emission reduction in the near to long term. Every product designed and developed in his business unit, and the powertrain division in general, is geared towards making mobility based on the combustion engine cleaner, and sustainable.

With stricter legislations being enforced across markets – Euro VI-c in Europe that will kick in by 2014, and similar other legislations in markets like the United States and Japan – Continental, like all other suppliers, is engaged in design and development of components that would help their customers meet these legislations. The key challenge, Breuer said, “is the need to be cost-efficient, so as to ensure affordability of mobility.” Most of the growth in the industry would come from countries like India and China, where cost plays a defining role, he noted.

FUTURE COMBUSTION ENGINES

With IC engines slated to dominate vehicles of the near future, we asked Breuer what specific changes could be expected from a technology perspective. The primary change would be in the area of fuel injection systems, he said. While majority of the gasoline engines today are either manifold or port injection systems, the industry is gradually moving to direct injection systems. DI systems would allow companies to get into higher fuel injection pressure, say from the current 100-150 bar levels to 350 bar pressures in the future. “Higher pressures will help cut down on particulate emissions, but at the same time, we’ll also need to keep fuel consumption under control,” he said.

In mid-2013, Continental launched a new multi-hole gasoline injector – the XL3 high-performance solenoid injector for gasoline direct injection systems – that supports Euro 6c requirements. The XL3, which is currently in volume production for a four-cylinder, 1.5 l GDI engine, provides enhanced linearity due to very fast opening and closing times. Depending on the geometry of the combustion chamber, the injector would have seven to nine holes. This multi-stream spray geometry enables optimal adaptation to all engine-specific requirements.

The objective is to take the pressure up to 350 bar. “The standard pressure today is 150 bar, and we will take it to 250 bar over the next two years, and then to 350 bar,” Breuer said. It is important to avoid the formation of soot particles, which is influenced by opening and closing and also by the design of the nozzle or the spray holes, he explained.

On the diesel side, Continental would bring to the market a new generation diesel system with piezo injectors. Breuer is a firm believer in the advantage that piezo actuation will have on spray formation, and with this on combustion and emission. In this new generation direct-driven piezo injector, the piezo is linked directly to the needle and controls its movement – the opening and the closing – in a very precise manner. A very precise injection pattern is generated that allows for real benefit in terms of fuel consumption. Continental is in the final stage of preparing the direct-driven piezo injector for serial production, and will be launched next year.

“Higher pressure on the diesel side means less fuel consumption, better spray formation, and therefore utilising the energy of the fuel in a much better manner for propulsion. Interestingly, if we go to pressure above 2,500 bar, we see lower combustion pressure, which would also allow to think about lightweight concepts for the engine, and weight reduction overall,” Breuer said.

Also on the horizon is the next generation servo injector that helps improve performance, both with regards to needle control as well as leakage. With the next generation servo injector, leakage will be significantly reduced and therefore the efficiency in the hydraulic system will be much higher. “If you have a higher efficiency in the hydraulic system, you pump less fuel in order to generate the pressure and supply the injection quantity. As a result, it helps you save more fuel,” explained Breuer. Just based on the injector, one could achieve significant fuel saving to the tune of 2 %.

The other critical aspect in improving combustion is related to downsizing of engines. We have seen the gradual shift from six to four, and now from four to three cylinders. At the same time, we are witnessing a movement from naturally-aspirated engines to turbocharged engines. Globally, there is a clear trend even with premium manufacturers looking at downsized engines with turbocharging. Ford has taken the lead in this respect with the introduction of the 1 l EcoBoost engine. Continental has supplied the turbochargers for the EcoBoost engine.

OUTLOOK

Breuer and his team at Continental work around the objective of securing our future with clean mobility that is based on a combustion engine. There would be gradual shift towards hybridisation, but the numbers would continue to be small for a long time to come. On that count, Continental is harping on the potential of implementing a 48 V system that would offer an ideal compromise between the current 12 V micro hybrid start-stop systems, with very little possibilities for energy recuperation, and the costly 120 V or 200 V systems.

In the Indian context, though, there isn’t much demand for the latest hi-tech requirements. The company continues to work on conventional gasoline systems for all its customers in India. But there is excitement building up, and that is the confidence Continental drives home in.

Text: Deepangshu Dev Sarmah