Impact and observations of cylinder deactivation and reactivation in a downsized gasoline turbocharged direct injection engine

Abstract

Cylinder deactivation, sometimes referred to as variable displacement engine technology, is a method being employed in state-of-the-art reciprocating engines to improve fuel economy. The approach involves disabling the valve actuation of one or more cylinders to deactivate them, thus forcing the engine to operate at a higher specific load across the remaining cylinders to produce the torque demanded. Operating at such a point with an increased throttle opening reduces the engine’s pumping losses and hence reduces fuel consumption. In this work, the spray morphology, combustion and emissions of a three-cylinder downsized gasoline turbocharged direct injection engine with variable displacement engine capability on one cylinder were studied. This investigation allowed the interaction between the fuel spray, engine performance and emissions immediately following the reactivation of the deactivated cylinder to be better understood. Three operation modes were examined which included running the engine at full displacement, at the reduced displacement and at full displacement with increased indicated mean effective pressure, matching that of the reduced displacement mode. The study showed that cylinder deactivation significantly reduced specific fuel consumption at the conditions tested in comparison to full displacement operation. It was also found that when running the engine at full displacement but with the reduced displacement–level indicated mean effective pressure, the specific fuel consumption was greater than for reduced displacement operation. In addition, it was observed that particulate number emissions increase transiently during the deactivation period due to the disturbances to the fuelling control caused by displacement transitions. Improved fuelling control, refinement of the engine calibration during reduced displacement operation or a gasoline particulate filter could be used to manage this particulate number level.

Modelling liquid film in modern GDI engines and the impact on particulate matter emissions – Part 1

“…A schematic diagram of the engine test facility is given in Figure 4. A brief description of this is given below, and further details may be obtained from Parker et al 67 As shown in Figure 4, the engine is connected to a dynamometer to allow the engine speed to be controlled and maintained within 61 rpm. The fuel flow rate of this engine is measured using an AVL PD733S fuel balance at a frequency of 50 Hz.…”

Compressor Surge Mitigation in Turbocharged Spark-Ignition Engines without an Anti-Surge Control System during Load-Decrease Operation

“…Lumsden et al [4] and Shaded et al [5] demonstrated that downsizing with direct injection allows decreasing the pumping losses and increasing the compression ratio, thus reducing fuel consumption by around 25%. Besides, other interesting strategies are being applied to gasoline engines to improve fuel economy, such as exhaust gas recirculation (EGR), variable valve timing [6], deactivation of cylinders [7], and water injection in the intake ports [8].…”

Cylinder deactivation technique in multi-cylinder engines for fuel consumption reduction

“… General Motors debuted this system in 1981.  It continues to evolve as automobile manufacturers introduce new technologies [8]. Cylinder deactivation, which is utilized by automakers to progress fuel efficiency and diminish emissions, is based on this.…”