Performance, combustion and emission characteristics of a spark-ignition engine with simultaneous injection of n-butanol and gasoline in comparison to blended butanol and gasoline

Abstract

SUMMARYSimultaneous injection of n-butanol and gasoline through a new system of two injectors directing the sprays towards the back of the intake valve in a spark-ignition engine was tried in lieu of injecting a blend of these fuels through a single injector. This system avoids the problem of phase separation, which is generally faced during the use of alcohol-gasoline blends. Experiments were conducted on a spark-ignition engine with this dual injection system using a fuel ratio of 1:1 (B50S) on the mass basis. High-speed photographs indicated that the sprays from the injectors did not interfere till they reached the intake valve. Comparisons were made with pre-blended butanol-gasoline (B50) and neat (100%) gasoline at the best spark timing. All injection and spark parameters were controlled using a real time engine controller.Neat n-butanol (B100) was superior only near full throttle with improved efficiency of the engine of about 1.2% (absolute). Heat release rates were observed to be higher and more advanced with B100 at wide open throttle. However, a reverse of this trend was observed at the throttle position of 15%. NO emission was also lower by 30% with B100 at wide open throttle as compared with gasoline. However, a small increase in carbon monoxide (CO) levels was observed because of lower post combustion temperatures as compared with gasoline and B50S. Simultaneous injection reduced hydrocarbon (HC) emissions by 13% to 50% as compared with B50 (blended fuel). HC emissions with gasoline and B50S were similar. Nitric oxide (NO) emission was lower with B50S as compared with gasoline; however it was higher than B50 because of better combustion. On the whole, the developed dual injection system was superior to the conventional method of blending in terms of performance, emissions and ability to change the fuel ratio as needed. B50S is suitable at all throttle positions, whereas B100 shows benefits at full throttle conditions.

Evolution of liquid and gas phases in multi-plume spray injection

“…For convenience, all the plumes are numbered, and the transverse lines where the velocity profiles are extracted are shown. A similar symmetry in velocity profiles is observed for the plume pairs (3,4), (2,5), and (1, 6) through Z/D lines as shown in Figure 8c. For each individual plume, the velocity magnitude is reduced when moving from the center of the plume toward the edges where the jet is decelerated and entrainment occurs.…”

“…Locations Y/ D = À89 and 89 show a symmetry for the velocity profiles associated with plume pairs (1,3) and (4,6). A similar symmetry in velocity profiles is observed for the plume pairs (3,4), (2,5), and (1, 6) through Z/D lines as shown in Figure 8c. Except for the (2, 5) pairs located on the Y/D = 0 Figure 8.…”

“…Multiphase jets and sprays are widely used in industry, such as for mixing, heating/cooling, and combustion purposes [1]. Mixture formation process highly influences the ignition and combustion processes as well as the pollutant formation in mixing-controlled combustion systems [2]. Based on the type of information demanded as well as available computational resources, a variety of numerical methods have been used in the study of sprays [3][4][5][6].…”

Impact of higher n-butanol addition on combustion and performance of GDI engine in stoichiometric combustion

“…Pechout et al [21] studied the effects of 30% and 50% of n-butanol blends with gasoline on combustion and emissions of a naturally aspirated PFI spark ignition engine on stoichiometric operation and found that flame propagation was faster with higher butanol content, as well as with lower HC, comparable CO, and higher NOx. Venugopal and Ramesh [22] compared the effects of 50% n-butanol-gasoline adopting simultaneous port injection of two injector and pre-blended on performance, combustion and emission characteristics of a spark-ignition engine.…”

Improved SI engine efficiency using Acetone–Butanol–Ethanol (ABE)

“…The results also indicated a slight increase in brake specific fuel consumption (BSFC) with the butanol addition. Venugopal et al [30] studied engine performance with simultaneous injection of butanol and gasoline, as well as blended fuels. On the whole, at all operating conditions, simultaneous injection results in reduced HC levels and improved or similar performance as compared with B50 (injection of fixed blend).…”