Control of the low-load region in partially premixed combustion

13th International Conference on Motion and Vibration Control; 12th International Conference on Recent Advances in Structural Dynamics

Ingesson, Gabriel^1 ; Yin, Lianhao^2 ; Johansson, Rolf^1 ; Tunestal, Per^2

Department of Automatic Control, Lund University, Lund, Sweden^1

Department of Energy Sciences, Lund University, Lund, Sweden^2

关键词: Combustion efficiencies;    Combustion stability;    Cylinder temperatures;    Direct-injection combustion;    Experimental performance evaluations;    Global equivalence ratio;    Partially premixed combustion;    Start of combustion;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/744/1/012106/pdf
DOI  :  10.1088/1742-6596/744/1/012106

来源: IOP

【 摘 要 】

Partially premixed combustion (PPC) is a low temperature, direct-injection combustion concept that has shown to give promising emission levels and efficiencies over a wide operating range. In this concept, high EGR ratios, high octane-number fuels and early injection timings are used to slow down the auto-ignition reactions and to enhance the fuel and are mixing before the start of combustion. A drawback with this concept is the combustion stability in the low-load region where a high octane-number fuel might cause misfire and low combustion efficiency. This paper investigates the problem of low-load PPC controller design for increased engine efficiency. First, low-load PPC data, obtained from a multi-cylinder heavy- duty engine is presented. The data shows that combustion efficiency could be increased by using a pilot injection and that there is a non-linearity in the relation between injection and combustion timing. Furthermore, intake conditions should be set in order to avoid operating points with unfavourable global equivalence ratio and in-cylinder temperature combinations. Model predictive control simulations were used together with a calibrated engine model to find a gas-system controller that fulfilled this task. The findings are then summarized in a suggested engine controller design. Finally, an experimental performance evaluation of the suggested controller is presented.