Direct injection and variable valve train are becoming standard as OEM's strive to develop more efficient and eco friendly gasoline engines. They are also being downsized and boosted to shift key operating points to areas of higher efficiency in order to significantly improve fuel economy. Such trends challenge sub systems designers in new ways in order to improve or at least maintain the drivability of the vehicle. Key requirements are to enable the powertrain to reach high torque at low engine speeds while still increasing rated power and to provide spontaneous response that the modern drivers' and traffic situations demand. Honeywell has already presented a new turbocharger technology called DualBoost. This concept has been developed to address the above requirements by improving the overall turbocharger efficiency at the critical operating points and significantly reducing the relative inertia of the rotor. In addition to all of this though, there is a strong trend to introduce divided exhaust flow for certain engine architectures such as In-line 4 Cylinder ones. This configuration minimizes the undesirable interference between cylinders during the gas exchange process. The full potential of GDI and Variable Valve timing can be achieved while still fulfilling emission standards. This paper documents the effect of applying several types of flow division to DualBoost. The work is based on an industry benchmark 1,6L GDI engine and compares the potential performance of a DualBoost Twin-Flow to the performance of several conventional turbochargers (including the production units). Both axial turbine and double-sided compressor wheels have significantly reduced moments of inertia compared to standard larger diameter radial wheels of equivalent flow capacity. As a result, approximately 50-60% reduction of the moment of inertia of the complete rotating assembly has been achieved still using conventional materials. All these features combined lead to substantial improvement in turbocharger and inherently engine transient response. As already presented in literature over 30% of improvement can be achieved compare to best radial turbocharger already in the early stage of development. As a part of continuous improvement of the technology it has been decided to evaluate the performance and compatibility of this unique technology with exhaust manifold separation. The modern high power density engines are more and more using pulse separation to keep good low end torque and transient.
DualBoost Twin-Flow: An ultra-low inertia turbocharger compatible with exhaust pulse separation
2013
22 Seiten, 29 Bilder, 4 Quellen
Aufsatz (Konferenz)
Englisch
Exhaust gas turbocharger assembly having an exhaust gas turbocharger and an actuator
Europäisches Patentamt | 2022
|Engineering Index Backfile | 1956
Exhaust Gas Pulsation and Turbocharger Interaction
Springer Verlag | 2022
|Divided-Exhaust Turbocharger System with Boost-Valve
SAE Technical Papers | 2018
|