Cycle by cycle NOx model for diesel engine control. (5th January 2017)

• Record Type: Journal Article
• Authors: Guardiola, C.; Martín, J.; Pla, B.; Bares, P.
• Is Part Of: Applied thermal engineering. Volume 110(2017:Jan.)
• Page Start: 1011
• Page End: 1020
• Publication Date: 2017-01-05
• Subjects: Reciprocrating engines -- NOx -- Trapped mass -- Adiabatic flame temperature -- Resonance; BMEP Break Mean Effective Pressure -- CAD Crank Angle Degree -- CI Compression Ignited -- ECU Electronic Control Unit -- EGR Exhaust Gases Recirculated -- HCCI Homogeneous Charge Compression Ignited -- HRL Heat Release Law -- HRR Heat Released Rate -- LNT Lean NOx Trap -- LTC Low Temperature Combustion -- MAE Mean Absolute Error -- MAF Mass Air Flow -- MRE Mean Relative Error -- NO Nitrogen Oxides -- OP Operating Point -- PEMS Portable Emission Measurement System -- SOI Start Of Injection -- SCR Selective Catalytic Reduction -- TDC Top Dead Center; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2016.08.170
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: A method for inferring NOx emissions from in-cylinder pressure signal is presented. Sensor errors (aging or malfunctions) are avoided by relying only on in-cylinder pressure data. The method has one cycle resolution, allowing good transient NOx estimation. The presented method improves precision of current algorithms in 25%. The model can be used for replace or improve Smart NOx sensor information. Abstract: This paper presents a model for on-line NOx estimation. The method uses both, low frequency components and high frequency components of in-cylinder pressure signal: it harnesses in-cylinder pressure resonance to estimate the trapped mass, and based on this measurement, a NOx model is adapted to estimate NOx emissions cycle by cycle. In addition of the in-cylinder pressure signal, the procedure only requires from lambda and air mass flow to estimate NOx, so it can give a direct estimation of NOx or improve transient response and aging of current NOx sensors. The method was validated on a CI engine with high pressure EGR loop under steady and transient conditions showing errors below 10% and cycle by cycle time response.