The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Closed-Loop Combustion Control for a 6-Cylinder Port-Injected Natural-gas Engine

På svenska

Author

Summary, in English

High EGR rates combined with turbocharging has been identified as a promising way to increase the maximum load and efficiency of heavy-duty spark ignition engines. With stoichiometric conditions a three-way catalyst can be used which means that regulated emissions can be kept at very low levels. Obtaining reliable spark ignition is difficult however with high pressure and dilution. There will be a limit to the amount of EGR that can be tolerated for each operating point. Open-loop operation based on steady state maps is difficult since there is substantial dynamics both from the turbocharger and from the wall heat interaction. The proposed approach applies standard closed-loop lambda control for controlling the overall air/fuel ratio for a heavy-duty, 6-cylinder, port-injected natural gas engine. A closed-loop load control is also applied for keeping the load at a constant level when using EGR. Furthermore, cylinder pressure-based dilution limit control is applied on the EGR in order to keep the coefficient of variation at the desired level of 5%. This way confirms that the EGR ratio is kept at its maximum stable level all times. Pumping losses decrease due to the further opening of the throttle, thereby the gas exchange efficiency improves and since the regulator keeps track of the changes the engine all the time operates in a stable region. Our findings show that excellent steady-state performance can be achieved using closed-loop combustion control for keeping the EGR level at the highest level while the stability level is still good enough.

Department/s

Publishing year

2009

Language

English

Pages

1232-1241

Publication/Series

SAE International Journal of Fuels and Lubricants

Volume

1

Issue

1

Document type

Journal article

Publisher

SAE

Topic

  • Energy Engineering

Keywords

  • Internal Combustion Engine
  • Natural Gas
  • Control

Conference name

SAE International Powertrains, Fuels and Lubricants Congress

Conference date

2008-06-23

Conference place

Shanghai, China

Status

Published

Project

  • Competence Centre for Combustion Processes

ISBN/ISSN/Other

  • ISSN: 1946-3952
  • SAE Technical Paper 2008-01-1722