Contribution Ratio Study of Fuel Alcohol and Gasoline on the Alcohol and Hydrocarbon Emissions of a Gasohol Engine

The low vapor pressure of ethanol and the high latent heat of vaporization at low temperatures cause the difficulties of cold start in a flex fuel vehicle when it is fueled with pure ethanol. Preheating fuel is one of the effective methods to solve the above cold start problem. Thus, it is crucial to obtain the fuel temperature distribution in the heating system for fuel preheating process. For this purpose, the numerical analysis is adopted here to simulate the fuel preheating process at a cold start phase and explore the change of the fuel temperature field under different influence factors. The results indicate that the starting temperature has obvious impact on the temperature field distribution in the heating chamber and preheating time but has little effect on the volume of cold fuel in the connecting line at the end of heating. When the starting temperature is −5 °C, the preheating time is 8.3 s. When the starting temperature increases up to 15 °C, the preheating time will decrease as 4.9 s. Furthermore, the lower the starting temperature is, the higher the overall temperature of the heating chamber is. The installing angle of injectors has some influence on the temperature field distribution, and the cold fuel ratio reduces slightly when the angle increases from 30 deg to 60 deg. The calculation results indicate that the temperature of fuel at the injector inlet is above 20 °C, and the fuel injected during the first three cycles of the engine operation is hot fuel.

Numerical Study on Fuel Preheating at Cold Start Phase in an Ethanol Flex Fuel Engine

Wang

Liu

2018

Soot Formation With Light Extinction and Grayscale Extraction Methods Applied to Ethanol-Gasoline Blends Laminar Flame

Wei

Chen

Xu³

et al. 2020

In this paper, the two-dimensional (2D) parallel light extinction method (LEM) was carried out to study the soot formation in laminar diffusion flames of four different ethanol-gasoline blends, of which ethanol volume fractions ranging from 0% up to 100% (E0, E20, E80 and E100). The flame images were processed synthetically via MATLAB to accurately calculate the flame height. In addition, the flame structure was redefined as three zones to observe the soot formation. The results indicate that the flame height changes with the variation of gas volume flow rate and fuel mass flow rate during the experiment. In terms of soot formation, as the volume fraction of ethanol increases, the proportion of soot forming zone decreases, while the area of blue flame zone grows. Simultaneously, the transition zone accounts for about 21% of the total flame area, which has not significant change with the increase of ethanol volume fraction.

A Review on the Performance, Combustion, and Emission Characteristics of Spark-Ignition Engine Fueled With 2,5-Dimethylfuran Compared to Ethanol and Gasoline

Nguyen

Hoang

Trần

et al. 2020

Currently, the supply of diminishing fossil fuel reserves, and the rise in challenges in environmental, political and economic consequences have caused the great concerns in the development of modern society, these have been forced the policy makers and researchers to look for the renewable and green energy sources. Deemed as a promising renewable alternative to traditional fossil fuels, 2,5-dimethylfuran (DMF, chemical formula C6H8O) – a derivative of furan – has the potential to relieve the growing shortage of fossil fuels while satisfying the increase in global energy demand and minimizing the adverse effects of climate change. DMF can be used as a clean source of liquid transportation biofuel given the fact that it is directly obtained from biomass-derived carbohydrates. In reviewing current DMF production methods, this review paper analyzes and presents the comparison of catalytic performance in the conversion of biomass into DMF. In addition, the applicability of DMF in spark ignition (SI) engines is thoroughly analyzed based on the spray and flame, combustion, performance and emission characteristics of SI engines running on DMF compared with ethanol and gasoline. More interestingly, the knocking, lubrication, and wear characteristics in SI engines fueled with DMF are also evaluated and discussed. Nonetheless, further investigation on optimization strategies on DMF production process should be conducted prior to the initiation of large-scale commercialization as well as the application of DMF to real-world SI engines.