In-cylinder pressure based model for exhaust temperature estimation in internal combustion engines

Abstract

Exhaust temperature is a valuable parameter for engine control. However, measurement conditions at the engine exhaust and the slow dynamic response of temperature sensors difficult the determination of the instantaneous exhaust temperature. The present paper proposes a methodology for estimating the exhaust temperature exclusively relying in-cylinder pressure signal, engine speed and exhaust lambda.The presented methodology can replace or actualize widespread look-up table models for correcting calibration offsets, due to ageing, sensor bias or disturbances associated with the engine operation. The method uses the existence of resonant modes in the in-cylinder pressure for inferring the trapped mass and the in-cylinder temperature. An isentropic expansion of the gasses through the valves is assumed for estimating the cylinder outlet temperature of the gases, and the gas temperature drop along the exhaust runner and manifold is modelled through a nodal thermal model. The method was compared with current models under steady and transient conditions in a four stroke CI engine. Variations of injection, EGR, intake pressure and rail pressure were performed under steady operation and the transient response of the method was validated under specific transient test and at the WLTP cycle. A time invariant first order model was used for comparing the estimated temperature with that provided by the experimental sensors.

Turbine and exhaust ports thermal insulation impact on the engine efficiency and aftertreatment inlet temperature

“…The need of an early aftertreatment light-off during warm-up periods drives thermal management research into different perspectives. Control techniques to estimate exhaust temperature have been proposed, as remarked in the work of Guardiola et al [18], who presented an in-cylinder pressure model to do so. Similarly, Gelso et al [19] used the model predictive control technique to control a diesel engine and estimate several EATS parameters, including exhaust temperature.…”

An analysis of the in-cylinder pressure resonance excitation in internal combustion engines

“…The method does not require any calibration for pent-roof combustion chambers while the acoustical response of piston-inbowl combustion chambers can be characterized with experimental data or by performing a numerical analysis of the combustion chamber by finite element method (FEM), as demonstrated in [38]. The measurement of trapped mass obtained from resonance has a cycle-to-cycle time response and does not rely in mass flow sensors, which might be used for improving the accuracy and the transient response of some models, such as proposed in [39] for NO x modelling , in [40] for exhaust temperature estimation , in [41] for residual gases modelling , or in [42] for knock prediction.…”

Implementation of fuel additive MAZ 100 for performance enhancement of compressed natural gas engine converted from in-used gasoline engine

“…Figure 6 shows the comparison of in-cylinder temperature profile that was calculated from the measured in-cylinder profile following the gas law as present in Equation ( 6) (Guardiola et al 2016):…”