The Senkin code of package is used to simulate the the Chemkin chemical kinetics combustion process of a porous medium（PM） engine fueled by n-heptane. The code is modified to incorporate the Woschni heat transfer co...The Senkin code of package is used to simulate the the Chemkin chemical kinetics combustion process of a porous medium（PM） engine fueled by n-heptane. The code is modified to incorporate the Woschni heat transfer correlation and heat transfer model within a porous medium. A detailed chemistry mechanism of NOx formation is coupled with the detailed chemical kinetics mechanism of n-heptane. The code is applied to a zero- dimensional single-zone model of engine combustion. Influences of operating parameters on the performance of the PM engine are discussed. With the increase in the intake temperature and compression ratio, or with the decrease of the excess air ratio, the ignition timing of the PM engine obviously advances. It is found that the porous medium acting as a heat recuperator can considerably preheat the fuel-air mixture, which promotes the ignition and combustion in the cylinder. And the initial PM temperature is a critical factor controlling the compression ignition of the mixture.展开更多
The combustion processes of homogeneous charge compression ignition （HCCI） engines whose piston surfaces have been coated with catalyst （rhodium or platinum） were numerically investigated. A singlezone model and a...The combustion processes of homogeneous charge compression ignition （HCCI） engines whose piston surfaces have been coated with catalyst （rhodium or platinum） were numerically investigated. A singlezone model and a multi-zone model were developed. The effects of catalytic combustion on the ignition timing of the HCCI engine were analyzed through the single-zone model. The results showed that the ignition timing of the HCCI engine was advanced by the catalysis. The effects of catalytic combustion on HC, CO and NOx emissions of the HCCI engine were analyzed through the multi-zone model. The results showed that the emissions of HC and CO （using platinum （Pt） as catalyst） were decreased, while the emissions of NOx were elevated by catalytic combustion. Compared with catalyst Pt, the HC emissions were lower with catalyst rhodium （Rh） on the piston surface, but the emissions of NOx and CO were higher.展开更多
基金The National Natural Science Foundation of China(No.50476073)
文摘The Senkin code of package is used to simulate the the Chemkin chemical kinetics combustion process of a porous medium（PM） engine fueled by n-heptane. The code is modified to incorporate the Woschni heat transfer correlation and heat transfer model within a porous medium. A detailed chemistry mechanism of NOx formation is coupled with the detailed chemical kinetics mechanism of n-heptane. The code is applied to a zero- dimensional single-zone model of engine combustion. Influences of operating parameters on the performance of the PM engine are discussed. With the increase in the intake temperature and compression ratio, or with the decrease of the excess air ratio, the ignition timing of the PM engine obviously advances. It is found that the porous medium acting as a heat recuperator can considerably preheat the fuel-air mixture, which promotes the ignition and combustion in the cylinder. And the initial PM temperature is a critical factor controlling the compression ignition of the mixture.
基金the National Key Basic Research Development Project of China (2001CB209201)
文摘The combustion processes of homogeneous charge compression ignition （HCCI） engines whose piston surfaces have been coated with catalyst （rhodium or platinum） were numerically investigated. A singlezone model and a multi-zone model were developed. The effects of catalytic combustion on the ignition timing of the HCCI engine were analyzed through the single-zone model. The results showed that the ignition timing of the HCCI engine was advanced by the catalysis. The effects of catalytic combustion on HC, CO and NOx emissions of the HCCI engine were analyzed through the multi-zone model. The results showed that the emissions of HC and CO （using platinum （Pt） as catalyst） were decreased, while the emissions of NOx were elevated by catalytic combustion. Compared with catalyst Pt, the HC emissions were lower with catalyst rhodium （Rh） on the piston surface, but the emissions of NOx and CO were higher.
