Alcohol combustion chemistry

Fundamental phenomena affecting low temperature combustion and HCCI engines, high load limits and strategies for extending these limits

Fuel design and management for the control of advanced compression-ignition combustion modes

Evolution, challenges and path forward for low temperature combustion engines

Impacts of additives on performance and emission characteristics of diesel engines during steady state operation

In the present study, the combustion characteristics and emissions of biodiesel fueled direct injection engines with premixed dimethoxymethane (DMM) by port injection were investigated on a single-cylinder diesel engine. The experimental results show that, for a fixed equivalence ratio of biodiesel, the ignition timing and the center point of heat release advance, while the end point of heat release delays with the introduction of premixed DMM. For a constant equivalence ratio of premixed DMM, the ignition timing delays and the end point of heat release advances with the decrease of biodiesel quantity. Furthermore, the maximum gas pressure, the mean gas temperature, and the maximum pressure rise rate increase smoothly with the increase of premixed ratio. Meanwhile, when the premixed ratio reaches to a certain value, the maximum gas pressure and pressure rising rate increase remarkably. Regarding to the regulated emissions, CO and HC emissions are much higher than that of neat biodiesel fuel and increase u...

Experimental Study on the Combustion Characteristics and Emissions of Biodiesel Fueled Compression Ignition Engines with Premixed Dimethoxymethane

This paper focuses on a novel combustion mode that is developed from the original concept of homogeneous charge compression ignition (HCCI) combustion. Experiments on iso-octane thermo-atmosphere combustion were carried out on a modified single-cylinder engine. n-Heptane was induced from the intake manifold to promote the ignition of iso-octane spray that was directly injected into the cylinder, through HCCI combustion of n-heptane. The combustion and emission characteristics of this novel combustion strategy were analyzed, and the effects of the iso-octane supply advance angle and n-heptane premixed ratio were investigated. The results show that the influence of the thermal effect and active radical produced by n-heptane HCCI combustion on the iso-octane ignition and emission is varied, depending upon the iso-octane supply advance angle. With the advancing of this fuel supply angle, the ignition of iso-octane is enhanced at first but then suppressed. At an iso-octane supply advance angle of 25 °CA BTDC, ...

Experimental Study on Influencing Factors of iso-Octane Thermo-atmosphere Combustion in a Dual-Fuel Stratified Charge Compression Ignition (SCCI) Engine

Inhibition effect of doping methyl tert-butyl ether compounds to n-heptane on homogenous charge compression ignition combustion

Stratified charge compression ignition (SCCI) combustion was investigated on a single-cylinder, four-stroke diesel engine with n-heptane. A premixed atmosphere was realized by the early injection at the intake port, while the rest of fuel was directly injected into the cylinder. Premixed ratio (defined as the ratio of fuel amount in port injection divided by the total fuel amount in the charge) and fuel supply timing of direct injection were altered to explore their influences on SCCI combustion, emission, and engine performance characteristics. The results show that increased premixed ratio and earlier fuel supply timing can remarkably enhance the peak cylinder temperature and pressure while shortening the main combustion duration. NOx is strongly dependent on fuel supply timing, whereas premixed ratio and equivalence ratio play a secondary role. CO can be effectively reduced by increasing premixed ratio and advancing fuel supply timing. HC rises with increasing premixed ratio but is insensitive to the c...

Influence of Fuel Supply Timing and Mixture Preparation on the Characteristics of Stratified Charge Compression Ignition Combustion with N-Heptane Fuel

In this paper, an investigation of the n-heptane stratified-charge compression ignition (SCCI) combustion on a single-cylinder engine using port fuel injection combined with in-cylinder direct injection is reported. The effects of mixture homogeneity, overall equivalence ratio, and fuel delivery advance angle of directly injected fuel on the SCCI combustion characteristics and emissions were evaluated. The experimental results revealed that the heat release curve of SCCI combustion exhibited a three-stage combustion mode, which includes low-temperature reaction (LTR), high-temperature reaction (HTR), and diffusion burn. The operating ranges can be significantly broadened by mixture stratification, owing to the smooth heat release. As the mixture homogeneity increases, the peak value of the heat release in the HTR increased but the maximum heat release in the third stage decreased. For a fixed overall equivalence ratio, with an increase in the mixture homogeneity, the nitrogen oxide (NOx) emissions...

Libin Ji

Papers

Experimental Study on the Combustion Characteristics and Emissions of Biodiesel Fueled Compression Ignition Engines with Premixed Dimethoxymethane

Experimental Study on Influencing Factors of iso-Octane Thermo-atmosphere Combustion in a Dual-Fuel Stratified Charge Compression Ignition (SCCI) Engine

Inhibition effect of doping methyl tert-butyl ether compounds to n-heptane on homogenous charge compression ignition combustion

Influence of Fuel Supply Timing and Mixture Preparation on the Characteristics of Stratified Charge Compression Ignition Combustion with N-Heptane Fuel

Experimental study on the effects of mixture homogeneity on stratified-charge compression ignition combustion