An experimental study with renewable fuels using ECN Spray A and D nozzles

Abstract

The decarbonization process of the automotive industry and the road transport sector has raised the interest on the development of cleaner fuels. A proper characterization of their properties and behavior under different operating conditions is mandatory to achieve an effective implementation in commercial engines. With this objective, the current work presents a comparison of two injectors from the Engine Combustion Network (ECN), namely Spray A and Spray D injectors, in terms of spray characteristics and combustion behavior for different fuels: diesel, dodecane, Hydrotreated Vegetable Oil (HVO), and two types of oxymethylene ethers (OME1 and OME x). The aim is to analyze how differences in nozzle geometry affect the behavior of different types of fuels. The experiments were carried out in a High Temperature and High Pressure test rig and operating conditions were chosen following ECN guidelines. Visualization techniques such as high speed schlieren imaging, OH* chemiluminescence and diffused back illumination were implemented to analyze the differences in liquid length, vapor penetration, auto ignition, flame lift-off length, and soot formation for both nozzles. In general, results showed the same trend for all the fuels tested: longer liquid length and faster vapor penetration for Spray D, as well as higher ignition delay and longer lift-off length. However, it was found that these parameters were less sensitive to the nozzle diameter for the oxygenated fuels tested. Furthermore, a different trend was observed for OME1, in terms of ignition behavior, in comparison to the other fuels. In terms of soot production, the Spray D nozzle increases its formation with the non-oxygenated fuels. In contrast, no soot was observed with the oxygenated ones under any operating conditions.

Numerical analysis of the combustion process of oxymethylene ethers as low-carbon fuels for compression ignition engines

“…15 Different works have reported an important reduction of in-cylinder soot formation emissions either using neat OME X or blending it with other fuels. [16][17][18][19] Additionally, several authors reported the possibility of using of EGR to reduce nitrogen oxides (NO X ) emissions without affecting soot emissions, 14,20 overcoming the well-known Soot-NO X trade off. As a drawback, OME X has a lower heating value (LHV) lower than fossil Diesel.…”

Parametric assessment of the effect of oxygenated low carbon fuels in a light-duty compression ignition engine

“…Thus, there might be some potential for further optimization of fuel efficiency by changing the injectors for ones with a higher flowrate (where shorter injections are possible with reduced injection pressures) and performing an optimization with similar emission reduction targets. Conversely, OMEx has a higher vapor pressure and thus a lower liquid penetration length [46], and it has been previously shown that injectors with bigger diameter can increase the spray penetration of OMEx and cause a longer ignition delay [47], these characteristics could contribute in achieving lean-burn conditions for OMEx that improve fuel consumption, similarly to the lambda variations performed in [17]. Nonetheless, further research is needed to verify this hypothesis.…”

Analysis of Fuel Effects on the Diffusive Flame Structure Using Advanced Optical Techniques in a Single Cylinder Optical Engine

“… Comparison of the effect of nozzle diameter for HVO (left) and OME1 (right) on the characteristic spray parameters. Source:[103] …”