Comparison of Sensor Sets for Real-Time EGR Flow Estimation

Pachner, Daniel; Beran, Jaroslav

doi:10.4271/2016-01-1064

Cited by 3 publications

(3 citation statements)

References 5 publications

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“…In a first approximation to the model calibration, the heat transfer to the surroundings by convection is neglected in front of the heat exchange in the runner:Q amb <<Q gas1 (14) Consequently, while operating in steady conditions, the only temperature drop is caused by the liquid cooled section of the exhaust (T ti = T st ) and the steady state formulation is reduced to equation (9).…”

Section: Model Calibrationmentioning

confidence: 99%

“…However, current methods for the online estimation of the trapped mass have important errors: hot-film air mass flow sensors, which are widely employed in automotive applications, can have measurement errors typically in the 5% range [11] (and up to 20% [12,13]) because of ageing and other non-calibrated effects. EGR estimation is even more difficult: the EGR flow estimate based on mean value models is subject to significant errors due to the estimation of different exhaust parameters and semi-empirical corrections, resulting in typical errors of 10% [14]. Even when using research-grade gas analyzers at test benches, where EGR rate is determined by CO 2 balance, errors up to 36% can be found because of incomplete mixing when using high pressure EGR loops [15].…”

Section: Introductionmentioning

confidence: 99%

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

Guardiola

Olmeda

Plá

et al. 2017

Applied Thermal Engineering

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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.

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Section: Model Calibrationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

Guardiola

Olmeda

Plá

et al. 2017

Applied Thermal Engineering

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“…Within this context, the ability to continuously monitor the performance of cooling effectiveness represents an important advantage that would ensure better performance throughout the lifetime of the product, as well as overall benefits with respect to fuel consumption and emissions. Usually this task is performed based on a 'virtual sensor' approach [11][12][13][14], meaning that information on the recirculated gas is acquired indirectly (e.g. based on recorded air flow, intake manifold temperature, pressure etc.…”

Section: Introductionmentioning

confidence: 99%

Online Monitoring Solutions of Efficiency for Automotive EGR Heat Exchangers

et al. 2020

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Internal combustion engines are the dominating technology in the automotive transport sector. Within this context, even incremental improvements in efficiency are essential for reducing overall environmental impact. Maintaining rated specifications is also an important issue, with monitoring solutions being more and more the focus of development. Cooled exhaust gas recirculation (EGR) is a well established technology that allows improvements in efficiency and reduction of emissions. The present work looks at different solutions focused on the integration of a digital sensor directly into EGR valves, thus ensuring continuous monitoring and extensive diagnostics. As an initial stage, an evaluation of gas cooling efficiency was performed and different routes were identified to allow this parameter to be monitored online. Measurement of flow was discarded as a solution, mainly due to cost issues and complications of its application. Temperature based evaluation of efficiency was found to ensure the best compromise, with acceptable accuracy and practically no integration difficulties. This initial evaluation allowed the definition of basic principles of operation for the sensor, so as to ensure the final goal of more efficient and longerlasting EGR modules through continuous performance monitoring.

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