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An Integrated Simulation Methodology of Thermal Management Systems for the CO2 Reduction after Engine Cold Start
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 14, 2015 by SAE International in United States
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The emissions limits of CO2 for vehicles are becoming more stringent with the aim of reducing greenhouse gas emissions and improve fuel economy. The New European Driving Cycle (NEDC) is adopted to measure emissions for all new internal combustion engines in the European Union, and it is performed on cold vehicle, starting at a temperature of 22°C ± 2°C. Consequently, the cold-start efficiency of internal combustion engine is becoming of predominant interest.
Since at cold start the lubricant oil viscosity is higher than at the target operating temperature, the consequently higher energy losses due to increased frictions can substantially affect the emission cycle results in terms of fuel consumption and CO2 emissions.
A suitable thermal management system, such as an exhaust-to-oil heat exchanger, could help to raise the oil temperature more quickly. To evaluate CO2 emissions and the benefits deriving from thermal management devices, an integrated model of the engine under consideration has been developed in GT-SUITE. The model is characterized by the integration of engine performance, vehicle, cooling system, lubricant system and friction sub-models.
In particular, a friction sub-model has been developed in this work, by extending the Chen-Flynn engine friction model to take into account the actual oil temperature. The calibration of the thermal and friction sub-models has been done by defining a methodology based on few simple engine tests on a dynamometric bench. The tool, once calibrated and verified, can be used to predict the efficiency of different thermal management devices and strategies during engine warm-up and in different driving cycles.
CitationGrimaldi, C., Poggiani, C., Cimarello, A., De Cesare, M. et al., "An Integrated Simulation Methodology of Thermal Management Systems for the CO2 Reduction after Engine Cold Start," SAE Technical Paper 2015-01-0343, 2015, https://doi.org/10.4271/2015-01-0343.
- Roberts, A., Brooks, R., Shipway, P., “Internal combustion engine cold-start efficiency: A review of the problem, causes and potential solutions,” Energy Conversion and Management 82 (2014) 327-350, doi:10.1016/j.enconman.2014.03.002.
- Will, F. and Boretti, A., “A New Method to Warm Up Lubricating Oil to Improve the Fuel Efficiency During Cold Start,” SAE Int. J. Engines 4(1):175-187, 2011, doi:10.4271/2011-01-0318.
- Janowski, P., Shayler, P. J., Robinson, S., Goodman, M., “The effectiveness of heating parts of the powertrain to improve vehicle fuel economy during warm-up,” Vehicle Thermal Management Systems Conference and Exhibition (VTMS10), Institution of Mechanical Engineers (IMechE), ISBN: 978-0-85709-172-7.
- Seider, G., Mehring, J., Weber, C., “A High-Resolution Warm-Up Simulation Model for a Gasoline Engine with Advanced Thermal Control,” Vehicle Thermal Management Systems Conference and Exhibition (VTMS10), Institution of Mechanical Engineers (IMechE), ISBN: 978-0-85709-172-7.
- Farrant, P., Robertson, A., Hartland, J., and Joyce, S., “The Application of Thermal Modelling to an Engine and Transmission to Improve Fuel Consumption Following a Cold Start,” SAE Technical Paper 2005-01-2038, 2005, doi:10.4271/2005-01-2038.
- Patton, K., Nitschke, R., and Heywood, J., “Development and Evaluation of a Friction Model for Spark-Ignition Engines,” SAE Technical Paper 890836, 1989, doi:10.4271/890836.
- Sandoval, D. and Heywood, J., “An Improved Friction Model for Spark-Ignition Engines,” SAE Technical Paper 2003-01-0725, 2003, doi:10.4271/2003-01-0725.
- Shayler, P., Leong, D., and Murphy, M., “Contributions to Engine Friction During Cold, Low Speed Running and the Dependence on Oil Viscosity,” SAE Technical Paper 2005-01-1654, 2005, doi:10.4271/2005-01-1654.
- Shayler, P., Christian, S., and Ma, T., “A Model for the Investigation of Temperature, Heat Flow and Friction Characteristics During Engine Warm-Up,” SAE Technical Paper 931153, 1993, doi:10.4271/931153.
- Leong, D. K. W., Shayler, P. J., Pegg, I. G., and Murphy, M., “Characterizing the effect of viscosity on friction in the piston assembly of internal combustion engines,” Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 2007 221: 469, doi:10.1243/13506501JET261.
- Macek, J., Fuente, D., and Emrich, M., “A Simple Physical Model of ICE Mechanical Losses,” SAE Technical Paper 2011-01-0610, 2011, doi:10.4271/2011-01-0610.
- Chen, S. and Flynn, P., “Development of a Single Cylinder Compression Ignition Research Engine,” SAE Technical Paper 650733, 1965, doi:10.4271/650733.
- Woschni, G., “A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine,” SAE Technical Paper 670931, 1967, doi:10.4271/670931.