Idle Operation with Low Intake Valve Lift in a Port Fuel Injected Engine

Adrian Clenci,Georges Descombes,Michael Deligant,Rodica Niculescu,Pierre Podevin,Adrian Bîzîiac

doi:10.3390/en6062874

Adrian Clenci, Georges Descombes + Show 4 more

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https://doi.org/10.3390/en6062874

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Abstract

Reducing fuel consumption is a prime objective in the automotive industry in order to meet regulatory and customer demands. Variable valve actuation offers many opportunities for improving the spark ignition engine’s performance in areas such as fuel economy and pollutant emissions. Our studies revealed that the ability to control maximum intake valve lift does indeed offer the ability to control intake air mass, but also has the added benefit that it improves the fuel-air mixing process thanks to an increased turbulence, caused by the increased intake flow velocity. This is particularly important at idle and low part loads when low maximum lifts are to be used for improving the fuel economy or for achieving the required power. The paper focuses on the experimental results obtained when approaching idle operation with different intake valve laws. Results indicating the potential of using low intake valve lift for fuel economy and cyclic dispersion improvement are presented in this paper.

Highlights

In spite of the development of electrical vehicles, the internal combustion engine still remains today an appropriate and attractive solution for ensuring mobility
While the compression ignition (CI) engine has made enormous progress in recent years concerning fuel economy, the spark ignition (SI) engine still lags behind from this point of view. This gap can be reduced by the use of different technical solutions: lean burn and stratified-charge gasoline direct injection—GDI, variable valve actuation—VVA, variable compression ratio—VCR, Downsizing, Atkinson-Miller cycle, some of them already applied in mass production [1,2,3,4,5,6,7,8,9,10,11]
In both cases (Hmin and Hmax), it can be seen that when ignition/spark advance (IA) goes from the positive to negative values, this induces the opening of the throttle plate in order to attain the idle speed target

Summary

Introduction

In spite of the development of electrical vehicles, the internal combustion engine still remains today an appropriate and attractive solution for ensuring mobility. While the compression ignition (CI) engine has made enormous progress in recent years concerning fuel economy, the spark ignition (SI) engine still lags behind from this point of view This gap can be reduced by the use of different technical solutions: lean burn and stratified-charge gasoline direct injection—GDI, variable valve actuation—VVA, variable compression ratio—VCR, Downsizing, Atkinson-Miller cycle, some of them already applied in mass production [1,2,3,4,5,6,7,8,9,10,11]. During most of its life, a passenger car engine is run under low loads and speeds. At these operating points, the overall engine efficiency decreases from the peak values (about 35%) to dramatically lower values (sometimes even below 10%), so technical solutions capable of offering better efficiency in this operating area are required

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